Concepts of Fitness And Wellness

Table 7  The Basic Eight for Free Weights Table 7 5.  Wrist Curl 7.  Half Squat This exercise develops the muscles of the fingers, wrist, and This exercise develops the muscles of the thighs and but- tocks. Stand erect, feet shoulder-width apart and turned forearms. Sit astride a bench with the back of one forearm out 45 degrees. Rest bar behind neck on shoulders. Spread hands in a comfortable position. Begin squat by on the bench, wrist and hand hang- first moving hips backward, keeping back straight, eyes ahead. By moving first at the hips and then bending ing over the edge. Hold a dumbbell knees, shins will remain vertical. Bend knees to approxi- in the fingers of that hand with the mately 90 degrees. Pause; then stand. Repeat. Spotters are needed. Variations: palm facing forward. To develop the Substitute dumbbell in each hand at sides. flexors, lift the weight by curling the fingers then the wrist through a full range of motion. Slowly lower and repeat. To strengthen the exten- sors, start with the palm down. Lift the weight by extending the wrist through a full Gluteus maximus range of motion. Biceps femoris, Slowly lower and long head Rectus femoris repeat. Note: Vastus lateralis Both wrists may Wrist be exercised at flexors the same time by substituting a barbell in place of the Semi- membranosus dumbbell. 6.  Dumbbell Rowing 8.  Lunge This exercise develops the muscles of the upper back. It This exercise develops the thigh is best performed with the aid of a bench or chair for sup- port. Grab a dumbbell with one hand and place opposite and gluteal muscles. Place a hand on the bench to support the trunk. Slowly lift the weight up until the elbow is parallel with the back. Lower barbell (with or without weight) the weight and repeat to com- behind your head and support plete the set. Switch hands and repeat with the oppo- with hands placed slightly site arm. The exercise can also be performed wider than shoulder- with one leg kneeling on the bench. width apart. In a slow and controlled motion, take a step forward and allow the leading leg to drop so that it is nearly parallel with the ground. The lower part of Rhomboids the leg should be nearly ver- Rectus Gluteus tical and the back should be femoris maximus Teres maintained in an upright pos- Vastus major ture. Take stride with oppo- lateralis Latissimus site leg to return to standing dorsi 178 posture. Repeat with other leg, remaining stationary or moving slowly in a straight line with alternating steps.

The Basic Eight for Resistance Machine Exercises  Table 8 VIDEO 8 Table 8 1.  Chest Press Pectoralis 3.  Biceps Curl major This exercise Triceps This exercise develops develops the the elbow flexor mus- chest (pecto- cles on the front of ral) and tricep the arm, primarily the muscles. Position biceps. Adjust seat seat height so that height so that arms arm handles are are fully supported by directly in front pad when extended. of chest. Posi- Grasp handles palms tion backrest so up. While keeping the that hands are back straight, flex the at a comfort- elbow through the full able distance range of motion. away from the chest. Push handles forward to Biceps full extension and return to start- ing position in a slow and con- trolled manner. Repeat. Note: Machine may have a foot lever to help position, raise, and lower the weight. 2.  Overhead Press 4.  Triceps Press This exercise devel- This exercise develops the extensor muscles on the ops the muscles of back of the arm, primar- ily the triceps. Adjust the shoulders and seat height so that arm handles are slightly arms. Position seat so above shoulder height. Grasp handles with that arm handles are thumbs toward body. While keeping the slightly above shoulder back straight, extend arms fully until wrist con- height. Grasp handles tacts the support pad (arms straight). Return to starting posi- with palms fac- tion and repeat. ing away and Triceps push lever up until arms are fully extended. Return to start- ing position and repeat. Note: Some machines Deltoid may have an incline press. 179

Table 8  The Basic Eight for Resistance Machine Exercises Table 8 5.  Lat Pull-Down 7.  Knee Extension This exercise pri- This exercise develops the thigh (quadriceps) muscles. Sit marily develops the on end of bench with ankles hooked under padded bar. latissimus dorsi, but the Grasp edge of table. Extend knees. Return and repeat. biceps, chest, and other Alternative: Leg press (similar to half squat). Note: The back muscles may also be developed. Sit on knee extension exercise isolates the floor. Adjust seat the quadriceps but places greater height so that hands stress on the structures of the can just grasp bar when knee than the leg press or half arms are fully extended. squat. Grasp bar with palms facing away from you and hands Middle Rhomboid shoulder-width (or wider) trapezius minor apart. Pull bar down to chest and return. Repeat. Latissimus Teres dorsi major Quadriceps Pectoralis major 6.  Seated Rowing 8.  Hamstring Curl This exercise develops the This exercise develops the hamstrings (muscles on back muscles of the back and of thigh) and other knee flexors. Sit on bench with legs shoulder. Adjust the machine over padded bar, pads contracting lower leg or calf just so that arms are almost fully above the ankles. Grasp handles or edge of seat. Bend extended and parallel to the knees as far as possible. Return slowly and repeat. ground. Grasp handgrip with palms turned down and hands Hamstring shoulder-width apart. While keeping the back straight, pull levers straight back to chest. Slowly return to starting posi- tion and repeat. Rhomboid minor Trapezius Teres major Latissimus dorsi 180

The Basic Eight for Calisthenics  Table 9 1.  Push-Ups 3.  Dips VIDEO 9 Table 9 This exercise develops the muscles of the arms, shoulders, This exercise develops the deltoid, and chest. Lie on the floor, face down with hands under shoulders. Keep body straight from the knees to the top of latissimus, rhomboid, and tricep. Start in a fully extended the head. Push up until the arms are straight. Slowly lower chest to floor. Repeat. Variation: If this exercise is too dif- position with hands grasping the bar (palms facing in). ficult, modify by performing on bent knees. Slowly drop down until the upper part of the arm is horizontal or parallel with the floor. Extend the arms back up to the Variation: Start from the up starting position and repeat. position and lower until the arm is bent at 90 degrees; Pectoralis Note: Many gyms have a dip/ then push up until arms are minor extended. Caution: Do not Pectoralis pull-up machine with accom- major arch back. modating resistance that Triceps brachii provides a variable amount of assistance to help you complete the exercise. Rhomboid major Deltoid Triceps Latissimus dorsi 2.  Modified Pull-Ups 4.  Crunch (Curl-Up) This exercise develops This exercise develops the upper abdominal muscles. Lie the muscles of the arms on the floor with the knees bent and the arms extended and shoulders. Hang or crossed with hands on shoulders (palms forward and or palms on ears. If desired, legs shoulder-width apart) may rest on bench to increase from a low bar (may difficulty. For less resistance, be placed across two place hands at side of body chairs), heels on floor, (do not put hands behind with the body straight Internal head or neck). For more abdominal resistance, move hands from feet to head. Brac- oblique higher. Curl up until the ing the feet against a shoulder blades leave floor; then roll down to the partner or fixed object Trapezius External starting position. Repeat. is helpful. Pull up, keeping the Rhomboids abdominal Note: Twisting the trunk body straight; touch the chest oblique on the curl-up develops to the bar; then lower to the Deltoid Rectus starting position. Repeat. Note: Teres major abdominis This exercise becomes more Latissimus difficult as the angle of the dorsi the oblique abdominals. body approaches horizontal and easier as it approaches the vertical. Variations: Perform so that the feet do not touch the floor (full pull-up). Or, perform with palms turned up. When palms are turned away from the face, pull-ups tend to use all the elbow flexors. With palms facing the body, the biceps are emphasized more. 181

Table 9  The Basic Eight for Calisthenics Table 9 5.  Trunk Lift 7.  Step-Ups This exercise develops the muscles of the upper back This exercise devel- ops the muscles of and corrects round shoulders. Lie face down with hands the thighs and but- Gluteus tocks. Stand facing maximus clasped behind the neck. Pull the an 8-15” high box or stair. Step up, shoulder blades together, raising the straightening knee. Keep back straight. elbows off the floor. Slowly raise Slowly lower oppo- Quadriceps site foot back to the the head and chest off the floor floor by bending the knee. Repeat. by arching the upper back. Variation: Hold onto dumbbells for Return to the starting posi- greater resistance. tion; repeat. For less resis- Back tance, hands may be placed extensors under thighs. Caution: Do not arch the lower back. Lift only until the sternum (breast- bone) clears the floor. Variations: Arms down at sides (easiest), hands by head, arms extended (hardest). 6.  Side Leg Raises Pectineus 8.  Lunge Walk Adductor These exercises develop the brevis This exercise develops the muscles muscles of the outer and inner Adductor of the legs and hips. Stand tall, feet thigh. Lie on your side. With longus together. Take a step forward with the knee pointing forward, slowly Gracilis right foot, touching the left knee to raise and lower the top leg. Next, Adductor the floor. The knees should be bent bend the top leg and cross it in magnus only to a 90-degree angle. front of bottom leg for support. Rise and step forward with Raise and lower the bottom leg. Gluteus the opposite leg, repeating. Variation: Ankle weights may be medius Variation: Dumbbells may added for greater resistance. be held in the hands for Tensor greater resistance. 182 fasciae latae Gluteus maximus Rectus femoris Vastus lateralis Biceps femoris, long head Semimembranosus Biceps femoris, short head

Exercises for Abdominal Strength  Table 10 VIDEO 10 1.  Crunch 3.  Crunch with Twist (on Bench) Table 10 This exercise develops the This exercise strengthens the oblique abdominals and upper abdominal muscles. Lie on the floor with the helps prevent or correct lumbar lordosis, abdominal knees bent and the arms extended or crossed with hands Rectus ptosis, and backache. Lie on your back with your feet on shoulders or palms on ears. If abdominis desired, legs may rest on bench Transversus on a bench, knees bent at 90 degrees. Arms may be to increase difficulty. For less resis- abdominis tance, place hands at side of body extended or on shoulders or hand on ears (the most (do not put hands behind neck). External For more resis- oblique difficult). Same as crunch except twist the upper trunk tance, move (cut) hands higher. so the right shoulder Curl up until shoulder blades Internal is higher than the left. leave floor; then oblique roll down to the (cut) Reach toward the left starting posi- tion. Repeat. knee with the right Note: Twisting the trunk on the elbow. Hold. External curl-up devel- ops the oblique Return and Internal oblique abdominals. repeat to the oblique opposite side. 2.  Reverse Curl 4.  Sitting Tucks Rectus abdominis This exercise develops the lower abdominal muscles. This exercise strength- Lie on the floor. Bend the ens the lower abdomi- knees, place the feet flat nals, increases their on the floor, and place endurance, improves arms at sides. Lift the posture, and prevents knees to the chest, raising backache. (This is an the hips off the floor. Do advanced exercise and not let the knees go past is not recommended the shoulders. Return to the for people who have starting position. Repeat. back pain.) Sit on floor with feet raised, arms extended for balance. Alternately bend and extend legs without letting back or feet touch floor. Rectus abdominis 183

Table 11 Table 11  Exercises for Trunk Strength 1.  Dynamic Trunk Exercises (a) Forward Curl-up (b) Curl-up with Rotation Internal Rectus oblique abdominis (cut) Transversus abdominis External oblique (cut) Erector spinae Gluteals (c) Lateral Trunk Raise (d) Trunk Extension Raise These exercises strengthen the abdominal and back muscles by moving the trunk through a small arc of motion. (a) The Forward Curl-up targets the rectus abdominis. Sit on large ball with hands crossed over chest. Recline back- wards to the point where feet just begin to lose grip on floor. Curl forward. Repeat. (b) The Curl-up with Rotation targets the obligue abdominal muscles. Begin with fingertips by ears and trunk reclined ~45-degrees. Curl forward with rotation by drawing one shoulder towards opposite knee. Recline back. Curl forward again. rotating trunk in the opposite diago- nal. Repeat. (c) The Lateral Trunk Raise also targets the oblique muscles. Lie side-bent over ball with fingertips by ears. Straighten spine by raising head and shoulders upward. Repeat. (d) The Trunk Extension Raise targets the back extensor muscles. Lie flexed on stomach over ball with fingertips by ears. Straighten spine by raising head and chest upward, away from ball. Repeat. 184

Lab 10A  Evaluating Muscle Strength: 1RM and Grip Strength Name Section Date Lab 10A Purpose: To evaluate your muscle strength using 1RM and to determine the best amount of resistance to use for various strength exercises Procedures: 1RM is the maximum amount of resistance you can lift for a specific exercise. Testing yourself to determine Evaluating Muscle Strength: 1RM and Grip Strength how much you can lift only one time using traditional methods can be fatiguing and even dangerous. The procedure you will perform here allows you to estimate 1RM based on the number of times you can lift a weight that is less than 1RM. Evaluating Strength Using Estimated 1RM 1. Use a resistance machine for the leg press and arm or bench press for the evaluation part of this lab. 2. Estimate how much weight you can lift two or three times. Be conservative; it is better to start with too little weight than too much. If you lift a weight more than 10 times, the procedure should be done again on another day when you are rested. 3. Using correct form, perform a leg press with the weight you have chosen. Perform as many times as you can up to 10. 4. Use Chart 1 in Lab Resource Materials to determine your 1RM for the leg press. Find the weight used in the left-hand column and then find the number of repetitions you performed across the top of the chart. 5. Your 1RM score is the value where the weight row and the repetitions column intersect. 6. Repeat this procedure for the arm or bench press using the same technique. 7. Record your 1RM scores for the leg press and bench press in the Results section. 8. Next divide your 1RM scores by your body weight in pounds to get a “strength per pound of body weight” (1RM/body weight) score for each of the two exercises. 9. Determine your strength rating for your upper body strength (arm press) and lower body (leg press) using Chart 2 in Lab Resource Materials. Record in the Results section. If time allows, assess 1RM for other exercises you choose to perform (see Lab 10C). 10. If a grip dynamometer is available, determine your right-hand and left-hand grip strength using the procedures in Lab Resource Materials. Use Chart 3 in Lab Resource Materials to rate your grip (isometric) strength. Results Arm press: Wt. selected Reps Estimated 1RM (Chart 1, Lab Resource Materials, page 173) (or bench press) Rating Strength per lb body weight (Chart 2, Lab Resource Materials, page 174) (1RM ÷ body weight) Estimated 1RM Leg press: Wt. selected Reps (Chart 1, Lab Resource Materials, page 173) Rating (Chart 2, Lab Resource Materials, page 174) Strength per lb body weight (1RM ÷ body weight) Right grip rating Grip strength: Right grip score Left grip rating Left grip score Total rating (Chart 3, Lab Resource Materials, page 176) Total score 185

Lab 10A Seated Press (Arm Press) Leg Press This test can be performed using a seated press (see To perform this test, use a leg press machine. Typically, the Evaluating Muscle Strength: 1RM and Grip Strength below) or using a bench press machine. When using the beginning position is with the knees bent at right angles with seated press, position the seat height so that arm handles the feet placed on the press machine pedals or a foot plat- are directly in front of the chest. Position back- form. Extend the rest so that hands are legs and return at comfortable distance to beginning away from the chest. position. Do not Push handles forward to lock the knees full extension and return when the legs to starting position in are straightened. a slow and controlled Typically, handles manner. Repeat. Note: are provided. Machine may have a Grasp the handles foot lever to help posi- with the hands tion, raise, and lower the when performing weight. this test. Conclusions and Implications: In several sentences, discuss your current strength, whether you believe it is adequate for good health, and whether you think that your “strength per pound of body weight” scores are representative of your true strength. 186

Lab 10B  Evaluating Muscular Endurance and Power Name Section Date Lab 10B Purpose: To evaluate dynamic muscular endurance, static muscular endurance, and power Procedures Evaluating Muscular Endurance and Power 1. Perform the curl-up, push-up, flexed-arm support, vertical jump, and medicine ball throw tests described in Lab Resource Materials (pages 174–175). 2. Record your test scores in the Results section. Determine and record your rating in Chart 1 below, based on Charts 4, 5, and 6 in Lab Resource Materials (page 176). 2. Ninety-degree push-up (dynamic muscular endurance) 1. Curl-up (dynamic muscular endurance) 3. Flexed-arm support (static muscular endurance): women in knee position and men in full support position 4. Vertical jump (power) 5. Medicine ball throw (power) 187

Results Record your scores below. Lab 10B Curl-up Push-up Flexed-arm support (seconds) Vertical jump Medicine ball throw Check your ratings in Chart 1 below. Chart 1  Rating Scale Evaluating Muscular Endurance and Power Curl-Up Push-Up Flexed-Arm Support Vertical Jump Medicine Ball Throw High Good Marginal Poor Conclusions and Implications: In several sentences, discuss your current levels of muscular endurance and power. Indicate whether you think you are fit enough to meet your health, work, and leisure-time needs. 188

Lab 10C  Planning and Logging Muscle Fitness Exercises: Lab 10C Free Weights or Resistance Machines Name Section Date Purpose: To set lifestyle goals for muscle fitness exercise, to prepare a muscle fitness exercise plan, and to self-monitor progress for the 1- to 2-week plan Procedures Planning and Logging Muscle Fitness Exercises 1. Using Chart 1 below, provide some background information about your experience with resistance exercise, your goals, and your plans for incorporating these exercises into your normal exercise routine. 2. Using Chart 2 on next page, select at least eight muscle fitness exercises as directed. Perform the exercises for 3 days over a 1- to 2-week period. Be sure to plan your exercise program so that it fits with the goals you described in Chart 1. If you are just starting out, it is best to start with light weights and more repetitions (e.g., 12–15). For best results, take the log with you during your workout, so that you can remember the weights, reps, and sets you performed. 3. Complete the Results section and then answer the questions in the Conclusions and Implications section. Chart 1  Muscle Fitness Survey 1.  Determine your current stage for resistance exercise. Check only the stage that represents your current activity level.   Precontemplation. I do not meet resistance exercise guidelines and have not been thinking about starting.   Contemplation. I do not do resistance exercises but have been thinking about starting.   Preparation. I am planning to start doing regular resistance exercises to meet guidelines.   Action. I do resistance exercises, but am inconsisent or have only recently started being consistent (less than 6 months).   Maintenance. I regularly meet guidelines for resistance exercises and have been doing it for more than 6 months. 2.  What are your primary goals for resistance exercise? General conditioning Improved appearance Other________________ Sports training Avoidance of back pain 189

Chart 2  Muscle Fitness Exercise Log Lab 10C Check (√) the exercises you plan to perform in the first column. Choose eight exercises from free weight, machine, or a combination of the two types of exercises. Record the weight (resistance), number of reps, and number of sets you plan to perform. Perform the exercises for 3 days over a period of 1–2 weeks. Write the date (month/day) in the day column for the date you performed the exercise. You may do upper body and lower body exercises on different dates. Exercises Exercise Plan Day 1 _____ (date) Day 2 _____ (date) Day 3 _____ (date) Wt. Reps Sets Wt. Reps Sets Wt. Reps Sets Wt. Reps Sets Free Weight Exercises (Table 7, pages 177–178)  1. Bench press Planning and Logging Muscle Fitness Exercises  2. Overhead (military) press  3. Biceps curl  4. Triceps curl  5. Wrist curl  6. Dumbbell rowing  7. Half squat  8. Lunge Machine Exercises (Table 8, pages 179–180)  1. Chest press  2. Overhead press  3. Biceps curl  4. Triceps press  5. Lat pull-down  6. Seated rowing  7. Knee extension  8. Hamstring curl Results Yes No Were you able to do your basic eight exercises at least 2 days in the week? Conclusions and Implications: Do you feel that you will use muscle fitness exercises as part of your regular lifetime physical activity plan, either now or in the future? In the box below, indicate what modifications you would make in your program in the future. 190

Lab 10D  Planning and Logging Muscle Fitness Exercises: Lab 10D Calisthenics, Core Exercises, or Plyometrics Name Section Date Purpose:  To set lifestyle goals for muscle fitness exercises that can easily be performed at home, to prepare a muscle fit- ness exercise plan, and to self-monitor progress for a 1-week plan Procedures Planning and Logging Muscle Fitness Exercises 1. Using Chart 1 below, provide some background information about your experience with calisthenic, core exercise, or plyometrics, and your plans for incorporating these exercises into your normal exercise routine. 2. Using Chart 2 on next page, select at least eight calisthenics or core exercises by circling the name of the exercises or writ- ing in the name of the exercises. Perform the exercises for 2 or 3 days. Record the reps and sets performed on each day. 3. Complete the Results section and then answer the questions in the Conclusions and Implications section. Chart 1  Muscle Fitness Survey 1. What is your level of experience with calisthenic, core, and plyometric exercises? Check a box for each of the 3 types of exercise. Inexperienced Somewhat Experienced Very Experienced Calisthenic Exercises Core Exercises Plyometric Exercises 2.  What are your primary reasons for doing calisthenic or core exercise? General conditioning Improved appearance Sports training Avoidance of back pain 191

Chart 2  Muscle Fitness Exercise Log Lab 10D Check (√) the exercises you plan to perform in the first column. Choose eight exercises from calisthenic, core, or a combination of the two types of exercises. Record the number of reps and number of sets you plan to perform. Perform the exercises for 3 days over a period of 1–2 weeks. Write the date (month/day) in the day column for the date you performed the exercise. You may do upper body and lower body exercises on different dates. Exercise Plan Day 1 _____ (date) Day 2 _____ (date) Day 3 _____ (date) Exercises Reps Sets Reps Sets Reps Sets Reps Sets Calisthenic Exercises (Table 9, pages 181–182)  1. Push-ups Planning and Logging Muscle Fitness Exercises  2. Modified pull-ups  3. Dips  4. Crunch (curl-up)  5. Trunk lift  6. Side leg raises  7. Step-ups  8. Lunge walk Abdominal and Trunk Exercises (Tables 10 and 11) (Table 10, pages 183–184)  1. Crunch (curl-up)  2. Reverse curl  3. Crunch with twist (on bench)  4. Sitting tucks  5. Forward curl-up  6. Curl-up with rotation  7. Lateral trunk raise  8. Trunk extension raise Plyometric Exercises (Figure 6, page 163)  1. Rope jumping or hopping  2. Medicine Ball Exercise  3. Depth Jumps (advanced) Results Yes No Were you able to do your planned exercises at least 2 days in the week? Conclusions and Implications:  Do you feel that you will use these muscle fitness exercises as part of your regular life- time physical activity plan, either now or in the future? Discuss the exercises you feel benefited you and the ones that did not. What modifications would you make in your program for it to work better for you? 192

Flexibility Concept 11 LEARNING OBJECTIVES After completing the study of this Concept, you will be able to: c Identify and explain several misconceptions about flexibility. c List the health benefits of flexibility and stretching. c Describe the various methods of stretching and their advantages and disadvantages. c Determine the amount of exercise necessary to improve flexibility, explain the FIT formulas for the different types of stretching, and describe factors in the “do and don’t list for stretching.” c Describe a variety of flexibility-based activities for improving flexibility and some of the advantages and disadvantages of each. c Identify some of the guidelines for safe and effective stretching. c Describe several self- assessments for flexibility, select the self-assessments that help you identify personal needs, and plan (and self-monitor) a personal flexibility exercise program. Regular stretching exercises promote flexibility, a component of fitness that permits freedom of movement, contributes to ease and economy of muscular effort, allows for successful performance in certain activities, and provides less susceptibility to some types of injuries or musculoskeletal problems. 193

194 Section 3  c  The Physical Activity Pyramid Flexion Flexibility refers to the amount of motion that is possible Adduction Hip at a given joint or series of joints. A joint with limited Knee ability to bend or straighten is said to be tight or stiff, while Extension joints with a high degree of flexibility are said to be loose- jointed, or hypermobile. A reasonable amount of flexibility Abduction is needed to perform efficiently and effectively in daily life, Extension but excessive flexibility is not desirable. Flexion It is important to distinguish between stretching (the principal type of exercise used to build flexibility) and Dorsiflexion Ankle flexibility (a component of fitness resulting from stretch- Plantar flexion Eversion ing). It is also important to distinguish between stretching Inversion exercises for building flexibility as part of your workout and stretching as a warm-up. Figure 1  c  Ranges of joint motion. This Concept will further clarify the distinctions between and limits movement to primarily forward and backward flexibility and stretching. The initial sections explain the (flexion and extension). Motion at other joints, such as factors influencing flexibility and how flexibility impacts the ankle, involves the combined movements of numer- health and wellness. You will learn about the FIT formula ous bony surfaces. A hinge-type por- for building flexibility using various stretching methods as tion permits the up and down motion well as guidelines for incorporating stretching into your fit- of the foot (dorsiflexion and plantar ness program. Details about advanced flexibility for sports flexion), while a separate planar-type VIDEO 1 performance are provided in a later Concept. joint allows the side-to-side motion Factors Influencing Flexibility (inversion and eversion) of the foot. A basic understanding of this terminology is important in understanding principles The range of motion in a joint or joints is a of flexibility and stretching. reflection of the flexibility at that joint. Clinically, the range of motion (ROM) of a joint is the extent and direc- Flexibility is influenced by the extensibility of soft tion of movement that is possible. The extent of movement tissues such as muscles, tendons, and ligaments. Soft is described by the arc through which a joint moves and is tissues are made up of a number of substances, including typically measured in degrees using a tool called a goniom- fibers called collagen and elastin. These structural building eter. The direction of movement at a specific joint is deter- blocks influence the degree of extensibility of tissues such mined by the shapes of the bony surfaces that are in contact. as ligaments, tendons, and muscles. Tissues with a greater Certain types of joints allow for greater movement than oth- proportion of collagen fibers tend to be stiffer while those ers. In fact, flexibility is highly joint specific. An individual with more elastin tend to bend and stretch more readily. may demonstrate optimal flexibility in one region of the Ligaments contain a greater proportion of collagen and this body but not in others. For example, a person may have good enhances their function in providing rigidity and stability to flexibility of the spine, hips, and legs in order to reach down a joint and their role in restricting excessive joint motion. and touch the toes, but is unable to clasp both hands behind Damage to ligaments from repeated sprains can lead to the back due to stiffness of the shoulder joints. excessive joint laxity and increased risk for injuries. Ten- dons contain a greater proportion of elastin than ligaments, Medical professionals use a specific vocabulary to but muscles contain even more and this contributes to their describe the movement of joints. Figure 1 illustrates some relatively high degree of flexibility. Together, the muscles of these movement terms as they relate to hip, knee, or ankle motion. Similar terms are applied in describing movement of the spine and upper body. Note that the same terms (such as flexion/extension) can be applied to different joints, while other terms (such as dorsiflexion/plantar flexion) are unique to a specific joint such as the ankle. The shape, size, and orientation of a joint greatly influence the amount of motion available. The circular surface of the ball-and-socket joint of the hip, for example, allows for considerable mobility, including movement to the side (adduction and abduction), forward and backward (flexion and extension), and in and out (internal and exter- nal rotation). The hinge joint of the knee is more restrictive

Concept 11  c  Flexibility  195 and tendons are referred to as a muscle-tendon unit (MTU), working lives, adults typically lose 3 to 4 inches of lower and due to their connection, they are both stretched back flexibility as measured by the common “sit-and-reach” together. We will generally refer to muscles or tissues test. Research studies have confirmed that declines in flex- rather than the MTU. ibility are not as evident in individuals who maintain regular patterns of physical activity. The use of planned stretching The short-term gains in range of motion immediately programs has also been shown to help maintain flexibility following stretching are commonly attributed to changes in with age. the “viscoelastic” properties of muscle. Viscosity refers to a property that allows tissues to undergo slow changes in length Gender differences exist in flexibility. Girls tend to be over time (like taffy) while elasticity refers to a property that more flexible than boys at young ages, but the gender dif- allows tissues to return to normal shape after being stretched ference decreases for adults. Greater flexibility of females (like a rubber band). When a muscle is stretched, there are is generally attributed to anatomical differences (e.g., wider changes in muscle length as well as a decline in muscle hips) and hormonal influences. stiffness. However, due to the elastic nature of the MTU, these changes are short-lived. In fact, studies have shown that Genetic factors can explain some individual variability the beneficial effects of a 30- or 45-second static stretch can in flexibility. In some families, the trait for loose joints is disappear in less than 30 seconds. Thus, changes in viscoelas- passed from generation to generation. This hypermobility ticity contribute to small temporary changes in muscle length is sometimes referred to as joint looseness. Studies show and stiffness rather than long-term changes in flexibility. that people with this trait may be more prone to joint dis- Some regions of the body are more prone to tightness location. There is not much research evidence, but some than others. A number of muscles in the body have a experts believe that those with hypermobility may also be predictable tendency toward tightness. Clinicians refer to more susceptible to athletic or dance injuries, especially these muscles as “tonic” or “postural” muscles because to the knee, ankle, and shoulder, and may be more apt to of their tendency to tighten or shorten. A characteristic of develop premature osteoarthritis. these muscles is that they tend to cross more than one joint. Included in the list are the upper trapezius, the muscles at Lack of use or misuse can cause reductions in the base of the skull, the pectoralis, hip flexors, low back flexibility. Lack of physical activity is one of the major extensors, hamstrings, adductors, and calf muscles. These factors contributing to poor flexibility. When muscles are muscles typically benefit the most from stretching and there- moved as part of normal daily activities or during structured fore are often targeted by common stretching exercises. Spe- physical activity, the muscles and tendons get stretched. cific exercises for these muscle groups are provided at the Without this regular stimulation, flexibility will decrease. end of the Concept. Static flexibility is different from dynamic flexibility. Improper exercise can lead to muscle imbalances that may The flexibility of a joint differs under static versus dynamic negatively impact flexibility. The most common example is conditions. Static flexibility is the maximum range a joint when bodybuilders overdevelop their biceps in comparison can achieve under stationary conditions, and it is limited by to their triceps. This leads to a muscle-bound look character- the structural (viscous and elastic) properties of the mus- ized by a restricted range of motion in the elbow joint. To cles. Dynamic flexibility is the maximum range a joint can avoid this, it is important to exercise muscles through the achieve under active conditions, and it is influenced by both full range of motion. structural characteristics and neural factors. Although good static flexibility is necessary for good dynamic flexibility, it Range of Motion (ROM)  The full motion possible in a joint or does not ensure it. Techniques for both static and dynamic series of joints. stretching are discussed later in this Concept. Ligaments  Bands of tissue that connect bones. Unlike muscles Flexibility varies considerably across the lifespan. and tendons, overstretching ligaments is not desirable. Flexibility is generally high in children but declines dur- Tendons  Fibrous bands of tissue that connect muscles to bones ing adolescence because of the rapid changes in growth— and facilitate movement of a joint. essentially, the bones grow faster than the soft tissues. In Laxity  Motion in a joint outside the normal plane for that joint, early adulthood, the muscles and tendons catch up to the due to loose ligaments. skeletal system, causing flexibility to peak in the mid- to late Muscle-Tendon Unit (MTU)  The skeletal muscles and tendons 20s. With increasing age, range of motion tends to decline that connect them to bones. Stretching to improve flexibility is again. Reduced flexibility is due to a loss of elasticity in the associated with increased length of the MTU. MTU and cross-linkages within collagen fibers of the ten- Stiffness  Elasticity in the MTU; measured by force needed dons, ligaments, and joint capsules. Over the span of their to stretch. Hypermobility  Looseness or slackness in the joint and of the muscles and ligaments (soft tissue) surrounding the joint.

196 Section 3  c  The Physical Activity Pyramid Flexibility may reduce injuries. The ACSM notes that good flexibility may reduce risk of MTU injuries and TECHNOLOGY UPDATE delayed-onset muscle soreness. It also notes, however, that the evidence is far from definitive. Evidence does indicate Software Facilitates Stretching at Work that tests of functional fitness that include a combination of strength, balance, dynamic, and/or static flexibility test Millions of people have sedentary office jobs that require items are predictive of occupational injuries in football play- sitting at a desk all day, which isn’t good for the body. There ers, firefighters, and military personnel. The tests rate the are many downloadable programs, such as StretchClock. quality of motion during basic func- com and StretchWare.com, that can help by providing tional movement tasks and identify prompts and suggest exercises and stretches designed to functional limitations that may predis- reduce your risk for common maladies caused by sitting pose people to injury. VIDEO 2 (e.g., carpal tunnel syndrome, repetitive stress injury, back pain, shoulder pain). The user can control the frequency of Stretching is used to assist in rehabilitation from the stretch-break prompts. injuries and for prevention. Physical therapists and ath- Would this type of behavioral prompt help you remember letic trainers frequently prescribe stretching to help patients to get up and move periodically? Why or why not? regain normal range of motion or function or to reduce pain after injury. Typical injuries include muscle strains, liga- ACTIVITY mentous sprains, and open wounds. Joint stiffness is also a common problem following surgery to the shoulder, knee, Health Benefits of Flexibility and ankle or following immobilization of any fracture in and Stretching a cast or walking boot. In each case, gentle stretching and range of motion exercises are used to stimulate the heal- Adequate flexibility is necessary for achieving and ing process and add strength to the healing tissues. Prior to maintaining optimal posture. Good posture implies that stretching, tissues are warmed up through the use of active the body’s segments are well aligned for efficient function exercise, massage techniques, or modalities such as moist and the least amount of strain. Poor posture, by contrast, heat or ultrasound. Stretching is followed by exercises to places body segments at a biomechanical disadvantage, increase strength within the newly gained range of motion adding stress and strain to the body with eventual wear and and neuromuscular activities to restore functional movement tear on the joints and tendons. In many cases, poor posture patterns. Physical therapists and athletic trainers prescribe occurs over time due to poor habits. Sensory receptors in stretching to assist in rehabilitation and recovery, but it is the skin and joints appear to maintain poor posture through up to the patient to perform the recommended stretching feedback loops within the nervous system. The nervous sys- exercises. tem keeps some muscles overly active and “tight” and oth- ers overly quiet or “weak.” This feedback loop reinforces the Stretching can help with treatment of musculoskeletal muscle imbalance and the poor posture—(long/weak mus- pain. Stretching is often one component of a larger treatment cles on one side of the body are countered by muscles on plan for addressing low back and neck pain, muscle strains, the opposite side of the body that are too short/tight). Pos- and joint stiffness post surgery or following immobilization. tural correction begins by improving the flexibility of the Because it is rarely used as the sole treatment approach, it shortened muscles, followed by strengthening of the “weak” muscles, and finally use of improved body awareness. HELP Health is available to Everyone for a Lifetime, and it’s Personal Flexibility contributes to functional fitness. Functional The concept of functional fitness has generated consid- fitness refers to the ability to function effectively in daily erable interest among health and fitness professionals. living. Properly performed stretching exercise has been Many fitness centers offer group classes focused on shown to improve flexibility in people of all ages. Good improving functional fitness and these courses typically range of joint motion (flexibility) is necessary to participate involve flexibility and functional movement tasks. in some sports and recreational activities; however, it is also Do you believe that flexibility and functional fitness important for a variety of normal daily tasks (e.g., reaching provide important benefits to your health now, or do you and bending tasks). As we age, flexibility becomes increas- think the benefits may be more relevant as you age? ingly important for maintaining function and independence. Research suggests that flexibility is a key contributor to a ACTIVITY broader construct of functional fitness, which also incorpo- rates core strength, balance, and agility.

Concept 11  c  Flexibility  197 In the News Yoga as a Complementary Health Approach Yoga has been around for thousands of years, the strongest trends. Yoga was also identified as one of the but recently it has new advocates among most prominent trends in the 2015 ACSM fitness trend report. consumers as well as a national scientific committee. Because Experts attribute the wide appeal of yoga to the diversity of of its health benefits, the National Center for Complementary disciplines and applications. The positive impacts on health and Integrative Health (a division of the National Institutes of and mental well-being likely also keep people engaged once Health) has identified yoga as a top 10 complementary health they try it. approach. A survey conducted by the National Center for What factors do you think explain the increased popularity Health Statistics examined Americans’ use of alternative or of yoga? complementary medicine approaches, and yoga was among ACTIVITY is difficult to isolate its effectiveness from other treatments Trigger points can be caused by trauma, or occur after over- commonly provided. However, stretching has been shown to use or from prolonged spasm in the muscles. The applica- be as effective as strengthening or massage in the treatment tion of direct pressure on myofascial trigger points followed of chronic neck pain. Additionally, movement-based activi- by stretching has been shown to help relieve pain. However, ties such as tai chi have been shown to facilitate movement stretching has less effect on relieving nonspecific areas of and reduce low back pain. soft tissue tenderness in the body (often referred to as tender Stretching may help relieve muscle cramps and pain points). associated with myofascial trigger points. Many people experience some form of muscle cramping during exercise. Stretching Methods A muscle spasm or cramp may result for various reasons, including overexertion, dehydration, and heat stress. Stretch- Static stretching is the most commonly used method ing a cramped (but not a strained) muscle will often help of stretching. Static stretching is done slowly and held relieve the cramp. Myofascial trigger points are character- for a period of several seconds. The probability of tear- ized by taut bands within skeletal muscle that have a nodu- ing the soft tissue is low if performed properly. Static lar texture. They are sensitive to touch and can produce a stretches can be performed with active assistance or with radiating pain in specific regions of the body when touched. passive assistance. When active assistance is used, the opposing muscle group is contracted to produce a reflex relaxation (reciprocal inhibition) in the muscle being stretched. This enables the muscle to be more easily stretched. For example, when doing a calf stretch exercise (see Figure 2A), the muscles on the front of the shin are contracted to assist in the stretch of the muscles of the calf. However, active assistance to static stretching has one prob- lem. It is almost impossible to produce adequate overload by simply contracting the opposing muscles. Physical therapists and athletic trainers use carefully planned Myofascial Trigger Points  Tight bands or knots in a muscle or stretching exercise for treatment. fascia (a sheath of connective tissue that binds muscles and other tissues together). Trigger points often refer pain to another area of the body. Active Assistance  An assist to stretch from an active contrac- tion of the opposing (antagonist) muscle. Passive Assistance Stretch imposed on a muscle with the assistance of a force other than the opposing muscle. Reciprocal Inhibition Reflex relaxation in stretched muscle during contraction of the antagonist.

198 Section 3  c  The Physical Activity Pyramid Contrasting Three Methods of Stretching I. Static Stretch Active Passive Passive A. (Self-Assisted) (Gravity Assisted) B. C. II. Pre-Contraction Stretch (e.g., PNF Stretch) Step 1: From a Step 2: Relax calf Step 3: Continue active lengthened position, muscles and contract contraction while rope contract calf muscles dorsiflexors (shin provides passive assist. isometrically against muscles) in active resistance of rope stretch of calf. F. or partner. E. D. III. Dynamic Stretch Active Passive Passive G. (Partner Assisted) (Gravity Assisted) H. I. Figure 2  c  Examples of static, pre-contraction, and dynamic stretches of the calf muscles (gastronemius and soleus). Muscles shown in dark pink are the muscles being contracted. Muscles shown in light pink are those being stretched.

Concept 11  c  Flexibility  199 When passive assistance (see Figures 2B and 2C) is used, Dynamic flexibility an outside force, such as a partner, aids in the stretching. is important in For example, in the calf stretch, passive assistance can be many sports. provided by another person, another body part (Figure 2B), or gravity (Figure 2C). This type of stretch does not create more vigorous body motion, such as swinging a body part to the relaxation in the muscle associated with active assisted create a bouncing movement. The inherent problem with most stretch. An unrelaxed muscle cannot be stretched as far, ballistic stretching is lack of control over the force and range and injury may happen. Therefore, it is best to combine the of movement. The forceful movement in ballistic stretching active assistance with a passive assistance when performing may increase risks for injury. Ballistic stretching may be use- a static stretch. This gives the advantage of a relaxed muscle ful for some athletes who do sports that and a sufficient force to provide an overload to stretch it. involve ballistic movements; however, this form of stretching is not recom- A good way to begin static stretching exercises is to mended for most people. VIDEO 3 stretch until tension is first felt, back off slightly and hold the position several seconds, and then gradually stretch a little How Much Stretch Is Enough? farther, back off, and hold. Decrease the stretch slowly after the hold. The appropriate amount of flexibility for health is not known. Flexibility is joint specific, so the amount of flex- Pre-contraction stretching activities such as PNF ibility varies by joint. Norms are available for the amount of have proven to be effective at improving flexibility. flexibility for males and females of different ages, but it is Proprioceptive neuromuscular facilitation (PNF) stretch- not clear how much is needed for health. For example, there ing utilizes techniques to stimulate muscles to contract more is little scientific evidence to indicate that a person who can strongly (and relax more fully) in order to enhance the effec- reach 2 inches past his or her toes on a sit-and-reach test is tiveness of stretching. The contract-relax-antagonist-contract less fit (or healthy) than a person who can reach 8 inches (CRAC) technique is the most popular. CRAC PNF involves past the toes. The standards presented in the Lab Resource three specific steps: (1) Move the limb so the muscle to be Materials are based on the best available evidence. stretched is elongated initially; then contract it (agonist mus- cle) isometrically for several seconds (against an immovable Too much flexibility (hyperflexibility) in a joint may object or the resistance of a partner); (2) relax the muscle; increase susceptibility to injury. While an appropriate and (3) immediately statically stretch the  muscle with the amount of flexibility is beneficial, too much flexibility can active assistance of the antagonist muscle and an assist from compromise the integrity of the joint and make it less stable a partner, gravity, or another body part. Figures 2D, 2E, and 2F provide a detailed illustration of how this technique Proprioceptive Neuromuscular Facilitation (PNF)  A stretch- is applied to the calf stretch. Research shows that this and ing technique that incorporates muscle contraction prior to stretch. other types of PNF stretch are more effective than a simple Ballistic Stretch  Bouncing or swinging to facilitate lengthening static stretch. of the muscle-tendon unit. Dynamic stretching can be safe and effective if performed properly. Dynamic stretching uses gradual and controlled movement of body parts up to the limit of a joint’s range of motion. Stretches may involve arm or leg swings of increasing reach or increasing speed. The key is to perform the movement in a controlled manner through the normal range of motion. This approach allows dynamic stretching to be a safe and efficient means of using active stretching tech- niques. As with static stretching, the movement can be pro- vided either actively or passively. For example, in the calf stretch shown in Figures 2G, 2H, and 2I, the foot is actively bounced forward by the antagonist muscle force or pas- sively by an assist from another person or gravity. Dynamic stretching movements are common in many functional fit- ness programs and hybrid exercise classes. Ballistic stretching is a specific type of dynamic stretching, but it presents risks if not done properly. A ballistic stretch uses momentum to stretch the muscles up to (and beyond) their normal range of motion. Momentum is produced by a

200 Section 3  c  The Physical Activity Pyramid and prone to injury. Most muscles and tendons can lengthen and target zones for safe and effective stretching are provided (extensibility) and return to their normal length after appro- in Table 1. The threshold of training refers to the minimum priate stretching (elasticity). However, short, tight muscles amount of stretching required to make gains and/or maintain and tendons can be easily overstretched (strained). Even a level of flexibility. Target zone refers to the overload needed more likely to be injured are the ligaments that connect bone to make significant gains in flexibility or to progress one’s to bone. Ligaments and the joint capsule lack the elasticity level of flexibility following a plateau. and tensile strength of the muscles and tendons. When invol- Stretching should ideally be performed at least 2 to untarily overstretched, they may remain in a lengthened state 3 days a week (frequency). The ACSM guidelines suggest or become ruptured (sprained). If this occurs, the joint loses that 2 to 3 days are effective for increasing range of motion, but stability and is susceptible to chronic dislocation, repeated they point out that gains are greater if performed daily. How- sprains, and excessive wear and tear of the joint surface. ever, like other forms of exercise, 1 day a week is still better This is particularly true of weight-bearing joints, such as the than none. The ACSM guidelines emphasize that stretching is hip, knee, and ankle. Appropriate stretching techniques can most effective when the muscles are warm. Performing a light increase flexibility without leading to hyperflexibility. to moderate aerobic warm-up activity prior to stretching can Specific FIT guidelines are established for safe and increase internal muscle temperature and the extensibility of effective stretching. Lifestyle and cardiovascular activ- soft tissues, allowing for a more effective stretch. Since some ity do little to develop flexibility. To build this important people do not want to interrupt their workout in the middle, part of fitness, stretching exercises from step 5 of the pyra- they prefer to stretch at the end. Stretching at the end of the mid are essential (see Figure 3). The American College of workout serves a dual purpose—building flexibility and cool- Sports Medicine (ACSM) has authored guidelines for effec- ing down. It is, however, appropriate to stretch at any time in tive stretching. The guidelines indicate that stretching can be the workout after the muscles have been active and are warm. done using static stretches (active or passive), pre-contraction If you prefer to include it at the beginning of a workout, ease stretches, and dynamic stretches. The recommended threshold into the stretching gradually. Energy Balance Energy Out Energy In (Activity) (Diet) STEP 5 Flexibility • Yoga Exercises • Stretch STEP 4 Muscle • Calisthenics Fitness • Resistance Exercises exercise STEP 3 Vigorous Sports • Tennis and Recreation • Hike STEP 2 Vigorous • Jog Aerobics • Bike • Aerobic dance STEP 1 Moderate Physical Activity • Walk • Yard work • Golf Avoid Inactivity Figure 3  c  Flexibility or stretching exercises should be selected from step 5 of the physical activity pyramid. Source: C. B. Corbin

Concept 11  c  Flexibility  201 Table 1  c  FIT Formula for Stretching—Thresholds and Target Zones Static Ballistic PNF (CRAC) Threshold Target Threshold Target Threshold Target Frequency At least 2 to 3 2–7 days a week At least 2 to 3 2–7 days a week At least 2 to 3 2–7 days a week days a week days a week days a week (threshold) (threshold) (threshold) Intensity Stretch to the Add passive Stretch beyond Same as ballistic Use a 3- to Perform 4–5 reps with point of feeling assistance. normal length threshold. 6-second 6-second contractions, tightness or with gentle contraction each followed by a slight discomfort. Avoid overstretching bounce or at 20%–75% 10- to 30-second Holding a static or pain. swing. Do not maximum assisted stretch. Rest stretch for exceed 10% of voluntary 30 seconds between 10–30 seconds static range of contraction reps. is recommended motion. followed for most adults. by a 10- to In older persons, 30-second holding a stretch assisted stretch. for 30–60 seconds may give greater benefit. Time Perform 2 Perform 2–4 Perform 1 set Perform 1–3 sets Perform 2 Perform 2–4 repetitions. Hold repetitions. Hold involving 30 of 30 consecutive repetitions. Rest repetitions. Rest 30 each for 15 each for 15–60 continuous seconds of motion. 30 seconds seconds between seconds. Rest seconds. Rest 30 seconds. Rest 1 minute between reps. reps. Rest 1 minute 30 seconds seconds between between sets. between sets. between reps. reps. To increase the length of a muscle, stretch it more muscle decreases as the stretch is held over time, with most than its normal length but do not overstretch it of the decrease occurring during the first 15 to 30 seconds. (intensity). The best evidence suggests that muscles The multicolor curves in the figure illustrate that each suc- should be stretched to about 10 percent beyond their nor- cessive stretch further reduces tension in the muscle, allow- mal length to bring about an improvement in flexibility. ing greater stretch. For most people, four repetitions of 10 to More practical indicators of the intensity of stretching are to 30 seconds is adequate; however, for athletes, more repeti- stretch just to the point of tension or just before discomfort. tions of greater length may be used. Exercises that do not cause an overload will not increase Regular stretching exercise (based on the FIT flexibility. Once adequate flexibility has been achieved, guidelines) leads to improved range of motion, range of motion (ROM) exercises that do not require but the mechanisms of action are not completely stretch greater than normal can be performed to maintain understood. As previously described, the increases in mus- flexibility and joint range of motion. cle length and reductions in stiffness immediately following stretching are temporary. However, regular stretching does To increase flexibility, stretch and hold muscles lead to improvements in flexibility. Many scientists believe beyond normal length for an adequate amount of that the resulting gains in motion following stretching are time (intensity) and for 2 to 4 repetitions (time). Guide- due as much to sensory changes in the nervous system as lines suggest that to get the most benefit for the least effort, stretches should be maintained for 10 to 30 seconds and be Range of Motion (ROM) Exercises  Exercises used to maintain repeated 2 to 4 times. Holding the stretch for a sustained existing joint mobility (to prevent loss of ROM). period is important in overcoming the stretch reflex. When Stretch Reflex  A reflexive contraction (shortening) of a muscle the muscle is first stretched, neural factors resist the stretch that occurs when sensory neurons in the MTU perceive a stretch but the reflex contraction subsides, allowing the muscle to of a muscle. The reflex subsides gradually, allowing the muscle to be stretched more easily. Repeating the stretch several times be stretched beyond resting length. is important to gradually increase the overload and pro- mote adaptations. Figure 4 shows the typical responses to a stretched muscle during a series of stretches. Tension in a

202 Section 3  c  The Physical Activity Pyramid Muscle tension Stretch 1 Tai chi is a safe and established movement discipline. Tai chi (often translated as Chinese shadow boxing) is con- Stretch 2 sidered a martial art but involves the execution of slow, flow- ing movements called “forms.” Tai chi has been shown to be Stretch 3 useful for improving muscle fitness and balance, reducing risk of falls among elderly individuals, and reducing symp- Stretch 4 toms and pain of arthritis. For older adults, the improved muscle fitness translates into joint protection and stability Stretch 5 as well as improved functional fitness. Younger participants can benefit as well. 10 20 30 40 50 60 Yoga is a diverse mind-body movement discipline. Time in seconds Yoga is an umbrella term that refers to a number of yoga traditions. The foundation for most yoga traditions is hatha Figure 4  c  Typical responses to a stretched muscle yoga, which incorporates a variety of asanas (postures). during a series of stretches. Iyengar yoga is another popular variation. It uses similar asanas as hatha yoga but uses props and cushions to enhance to increased muscle length or reduced muscle stiffness. the movements. Emphasis is placed on balance through According to the theory, stretching leads to increases in coordinated breathing and precise body alignment. Most stretch tolerance, which causes people to perceive dis- forms of yoga are considered to be safe, but positions in comfort at greater ranges of motion. For example, an indi- some of the extreme yoga disciplines are controversial (and vidual who regularly performs stretches for tight hamstring potentially harmful) so care should be used when perform- muscles may see improvements in range of motion during ing some movements. Recent reviews document clear health a straight leg raise. The sensory theory explains that much benefits (including cardiovascular health) from yoga; how- of the improvement in range of motion is due to a change in ever, it is not clear what types of yoga have better effects sensation. In other words, the perceived onset of pain is now or how often people need to practice the discipline to see further toward the end of the range of motion. The sensory theory has also been used to explain individual differences in flexibility. People who are hypermobile or very flexible may have longer muscles and/or looser joints but they may also simply perceive the physical limits later in the arc of motion. Flexibility-Based Activities The popularity of flexibility-based activities has increased in recent years. A recent survey of Worldwide Fitness Trends indicates that of the 25 top trends, 6 relate to flexibility. Included are yoga, functional fitness training, special training for older adults, core training, and sport-specific training. The popularity of these activities sug- gests that people may be more inter- VIDEO 4 ested in flexibility-related activity when it is presented in an engaging and interactive format. Some of the growth may also be attributed to increased acceptance of these activities by medical professionals. The following provides distinctions among these activities. Yoga and other movement classes involving stretching are increasingly popular.

Concept 11  c  Flexibility  203 benefits. A factor contributing to the recent popularity of done to build flexibility, as described in this Concept, are yoga is that there are forms suitable to diverse ages and performed as a workout or as part of a workout. Similar interests. exercises can be used in both the stretch warm-up and the Pilates classes are a popular offering at many fitness flexibility workout but each has a different purpose. Both centers and health clubs. Pilates is a therapeutic exercise should be preceded by a general or dynamic warm-up. regimen that combines strength and flexibility movements. Stretching is specific to each muscle or muscle group. It was originally developed as more of a therapeutic form of No single exercise can produce total flexibility. For example, exercise, but it is increasingly being promoted as an overall stretching tight hamstrings can increase the length of these form of conditioning. Emphasis in Pilates exercise is on core muscles but will not lengthen the muscles in other areas of stabilization movements and enhanced body awareness, but the body. For total flexibility, it is important to stretch each classes typically include some stretching activities as well. of the major muscle groups and to use the major joints of the Check the qualifications of instructors conducting body through full range of normal motion. The guidelines flexibility-related classes. The popularity of flexibility in Table 2 will help you gain the most benefit from your exercise has led to an increasing array of classes, videos, stretching exercises. and on-demand links available for tai chi, yoga, and Pilates. A flexibility workout should be done when the body When reviewing these programs, keep in mind that not all of is warmed up and when adequate time is available the suggested positions or movements should be considered to perform stretching exercises. Regular stretching is wholesome or harmless. In fact, some may be contraindi- needed to see improvements in flexibility. The consensus cated exercises that could increase risk for injury. Each exer- is that stretching exercise is most effective when the body cise should always be performed within the safe limits of is already warmed up. For this reason, some people prefer the joints and muscles so as not to overstretch them. Always to perform their stretching routine at the end of a workout seek qualified instructors and progress gradually. when muscles are warm. Others prefer to perform their flexibility workout at a time when they can concentrate Guidelines for Safe and Effective specifically on building flexibility. In either case, sufficient Stretching Exercise time should be allowed to ensure that the exercises are done correctly. Do not confuse the flexibility exercise workout with a stretch warm-up. People who choose to do a stretch warm- Stretch Tolerance  Greater stretch for the same pain level. up do it to prepare for their workout. Stretching exercises Table 2  c  Do and Don’t List for Stretching Do Don’t Do warm muscles before you attempt to stretch them. Don’t stretch to the point of pain. Remember, you want to stretch Do stretch with care if you have osteoporosis or arthritis. muscles, not joints. Do use static or PNF stretching rather than ballistic stretching if you are a beginner. Don’t use ballistic stretches if you have osteoporosis or arthritis. Do stretch weak or recently injured muscles with care. Do use great care in applying passive assistance to a partner; go Don’t perform ballistic stretches with passive assistance unless you slowly and ask for feedback. are under the supervision of an expert. Do perform stretching exercises for each muscle group and at each joint where flexibility is desired. Don’t ballistically stretch weak or recently injured muscles. Do make certain the body is in good alignment when stretching. Don’t overstretch a muscle after it has been immobilized (such as in a Do stretch muscles of small joints in the extremities first; then sling or cast) for a long period. progress toward the trunk with muscles of larger joints. Don’t bounce muscles through excessive range of motion. Begin ballistic stretching with gentle movements and gradually increase intensity. Don’t stretch swollen joints without professional supervision. Don’t stretch several muscles at one time until you have stretched individual muscles. For example, stretch muscles at the ankle, then the knee, then the ankle and knee simultaneously.

204 Section 3  c  The Physical Activity Pyramid A CLOSER LOOK Potent Health Benefits from Tai Chi Tai chi can improve flexibility, improve balance, improve lower leg strength, improve immune capacity, build bone density, reduce fall risk, improve cardiovascular func- tion, reduce stress, and improve quality of life. The evi- dence for most health outcomes has been substantiated in well-controlled clinical trials. Interestingly, scientists really don’t have a good sense of how tai chi works to improve these outcomes. The movements are very slow and controlled, so it is likely that the effects are related in part to the concentration and focus required to exe- cute the various movements rather than the movements themselves. In what ways could you benefit from tai chi? ACTIVITY Specialized equipment may help improve the To get the most out of yoga, tai chi, and Pilates classes, find a effectiveness and ease of stretching exercise. One qualified instructor. advance in equipment technology for flexibility training is the development of “stretching ropes.” These ropes have multiple loops, which enable individuals to change the length of the rope and perform a variety of different exer- cises. This feature provides an easy way to vary the degree of stretch. Because you can apply resistance through the elastic straps, it is even possible to perform PNF stretching without the assistance of a partner. A variety of stretching ropes are available on the market, and they all provide simi- lar functionality. Strategies for Action An important step for developing and Scores on flexibility tests may be influenced by several maintaining flexibility is assessing your factors. Your range of motion at any one time may be current status. There are dozens of tests of flexibility. Four influenced by your motivation to exert maximum effort, warm- tests that assess range of motion in the major joints of the body, up preparation, muscular soreness, tolerance for pain, and that require little equipment, and that can be easily admin- ability to relax, as well as by room temperature. Recent stud- istered are presented in the Lab Resources Materials in this ies have found a relationship between leg or trunk length and Concept. In Lab 11A, you will get an opportunity to try these self- the scores made on the sit-and-reach test. The sit-and-reach assessments. Perform these assessments before you begin test used here is adapted to allow for differences in body your regular stretching program and use these assessments to build. reevaluate your flexibility periodically.

Concept 11  c  Flexibility  205 Select exercises that promote flexibility in all areas of the the pectoral stretch and back-saver hamstring stretch use PNF body. For total-body flexibility, 8 to 10 stretching exercises for techniques. the major muscle groups of the body are recommended. Table 3 describes some of the most effective exercises for a basic Keeping records of progress will help you adhere to a flexibility routine. Individual stretching needs may vary, but the stretching program. An activity logging sheet is provided in most common areas to target are the trunk, the legs, and the Lab 11B to help you keep records of your progress as you regu- arms. A variety of stretches for these areas are described in larly perform stretching exercises to build and maintain good Tables 3, 4, and 5. Most are designed for static stretching, but flexibility. ACTIVITY Suggested Resources ∙ Johnson, J. (2012). Therapeutic Stretching. Champaign, IL: and Readings Human Kinetics. The websites for the following sources can be accessed by searching online for the organization, program, or title listed. Specific scientific ∙ Kovacs, M. (2009). Dynamic Stretching: The Revolutionary New references are available at the end of this edition of Concepts of Fit- ness and Wellness. Warm-Up Method to Improve Power, Performance, and Range of Motion. Berkeley, CA: Ulysses Press. ∙ ACSM. (2014). ACSM’s Guidelines for Exercise Testing and Pre- scription (9th ed.). Philadelphia: Lippincott, Williams & Wilkins. ∙ McAttee, R., & Charland, J. (2011). Facilitated Stretching ∙ Garber, C. E., et al. (2011). Quantity and quality of exercise for (4th ed.). Champaign, IL: Human Kinetics. (iPad version with developing and maintaining cardiorespiratory, musculoskeletal, video.) and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Medicine and Science in Sports and Exercise, ∙ Monoem, H., et al. (2014). Static stretching can impair explosive 43(7): 1334–1359. ∙ Gray Institute Functional Therapy: Functional Flexibility (pdf). performance for at least 24 hours. Journal of Strength and Condi- tioning Research, 28(1): 140–146. ∙ National Center for Complementary and Integrative Health. Yoga for Health (pdf). ∙ Paradisis, G. P., et al. (2014). Effects of static and dynamic stretch- ing on sprint and jump performance in boys and girls. Journal of Strength and Conditioning Research, 28(1): 154–160.

Table 3  The Basic Eight for Trunk Stretching Exercises Table 3 1.  Upper Trapezius/Neck VIDEO 5 3.  Pectoral Stretch Stretch This exercise stretches the chest muscles (pectorals). This exercise stretches the muscles on the back and 1. Stand erect in doorway, with arms raised 45 degrees, sides of the neck. To stretch the right trapezius, place left hand on top of your head. Gently look down toward your elbows bent, hands grasping the doorjamb, and left underarm, tucking your chin toward your chest. Let feet in front-stride position. Press out on door frame, the weight of your arm gently draw your head forward. contracting your arm muscles maximally for 6 seconds. Hold. Repeat to the opposite side. Relax and shift weight forward on legs. Lean into doorway, so that the Variations: The stretch above may be modified to muscles on the front of your stretch the muscles on the front and sides of the neck. shoulder joint and chest are Start from the stretch position described above. Keep your stretched. Hold. 2. Repeat with your arms left ear near your left shoulder. Turn raised 90 degrees. your head slightly and look up 3. Repeat with your arms toward the ceiling, lifting your raised 135 degrees. This chin 2–3 inches. Hold. exercise is useful to prevent or correct round shoulders and sunken chest. Trapezius Pectoralis Pectoralis major minor 2.  Chin Tuck 4.  Lateral Trunk This exercise stretches the muscles at the base of the Stretch skull and reduces headache symptoms. Sit up straight, This exercise stretches the with chest lifted and shoulders back. trunk lateral flexors. Stand Gently tuck in the chin by making with feet shoulder width a slight motion of nodding apart. Stretch left arm “yes.” Imagine a string overhead to right. Bend attached to the back of your to right at waist, reaching head, which is pulling your as far to right as possible head upward, like a puppet. with left arm; reach as far As your chin draws inward, as possible to the left with attempt to lengthen the back right arm. Hold. Do not let of your neck. Hold. trunk rotate or lower back arch. Repeat on opposite Longissimus Semispinalis side. Note: This exercise Trunk capitis capitis is more effective if a weight is lateral Splenius Semispinalis held down at the side in the hand flexors capitis cervicis opposite the side being stretched. More stretch will occur if the hip on the stretched side is dropped and most of the weight is borne by the opposite foot. 206

The Basic Eight for Trunk Stretching Exercises  Table 3 5.  Leg Hug 7.  Trunk Twist Table 3 This exercise stretches the hip and back extensor This exercise stretches the trunk muscles and the muscles. Lie on your back. Bend one leg and grasp your muscles on the outside of the hip. Sit with your right leg thigh under the knee. Hug it to your chest. Keep the extended, left leg bent and crossed over the right knee. other leg straight and on the floor. Hold. Repeat with the Place your right arm on the left side of the left leg and opposite leg. push against that leg while turning the trunk as far as possible to the left. Place the left hand on the floor behind the buttocks. Stretch and hold. Reverse position and repeat on the opposite side. Erector Erector spinae spinae Gluteus Gluteals maximus 6.  Cobra and Child’s Pose 8.  Spine Twist Begin on stomach with legs extended behind you. Place This exercise stretches the trunk rotators and lateral hands on floor directly under shoulders and fingertips rotators of the thighs. Start in hook-lying position, arms pointed forward. Press tops of feet and thighs into extended at shoulder level. Cross your left knee over the floor. Gently raise head and chest from the ground, right. Push the right knee to the floor, using the pressure straightening the elbows. Hold 30 seconds. Relax. of the left knee and leg. Keep your arms and shoulders on Keeping hands on the ground, sit back toward heels, rounding out low back and lowering forehead toward the floor while touching your knees the floor. Hold for 30 seconds. to the floor on the left. Stretch and hold. Reverse leg position and lower your knees to right. Latissimus dorsi Erector spinae Gluteus maximus 207

Table 4  The Basic Eight for Leg Stretching Exercises 1.  Calf Stretch VIDEO 6 3.  Back-Saver Hamstring Stretch Table 4 This exercise stretches the calf This exercise stretches the hamstrings and calf muscles muscles and Achilles tendon. Face a wall with your feet and helps prevent or correct backache caused in part by 2 or 3 feet away. Step forward on your left foot to allow short hamstrings. Sit on the floor with the feet against the both hands to touch the wall. Keep the heel of your right wall or an immovable object. Bend left knee and bring foot on the ground, toe turned in slightly, knee straight, foot close to buttocks. Clasp hands behind back. Contract and buttocks tucked in. Lean forward by the muscles on the back of the upper leg (hamstrings) by bending your front knee and arms pressing the heel downward toward the floor; hold; relax. and allowing your head to move Bend forward from hips, keeping lower back as straight nearer the wall. Hold. Bend your as possible. Let bent knee rotate outward so trunk can right knee, keeping your heel move forward. Lean forward keeping back flat; hold and on floor. Stretch and hold. repeat on each leg. Repeat with the other leg. Gastrocnemius Hamstrings 2.  Shin Stretch 4.  Hip and Thigh Stretch This exercise relieves shin muscle soreness by stretching This exercise stretches the hip (iliopsoas) and thigh muscles the muscles on the front of the shin. Kneel on both knees, turn to the right, and press down and stretch your right (quadriceps) and is useful for ankle with your right hand. Move your people with lordosis and back Iliopsoas pelvis forward. Hold. Repeat on the problems. Place your right knee opposite side. Except when they are sore, most people need to directly above your right ankle and strengthen rather than stretch these muscles. stretch your left leg backward so your Shin knee touches the floor. If necessary, muscles place your hands on floor for balance. Quadriceps 1. Tilt the pelvis backward by tucking in the abdomen and flattening the back. 2. Then shift the weight forward until a stretch is felt on the front of the thigh; hold. 2 1 Repeat on the opposite side. Caution: Do not bend your front knee more than 90 degrees. 208

The Basic Eight for Leg Stretching Exercises  Table 4 5.  Groin Stretch 7.  Inner Thigh Stretch Table 4 This exercise stretches the muscles on the inside of the This exercise stretches the muscles of the inner thigh. thighs. Sit with the soles of your feet together; place your Stand with feet spread wider than shoulder-width apart. hands on your knees or ankles and lean your forearms Shift weight onto the right foot and bend the right knee against your knees; resist (contract) by attempting to raise slightly. Straighten left knee and raise toes of left foot off your knees. Hold. Relax and press the knees toward the the floor. Lean forward slightly from the waist, keeping floor as far as possible; hold. This exercise is useful for back straight/shoulders back. Shift weight back over the pregnant women and anyone right foot by moving hips diagonally whose thighs tend to rotate away from the left foot. Hold. inward, causing backache, Repeat in the opposite direction. knock-knees, and flat feet. Adductors Adductors 6.  Lateral Thigh and Hip Stretch 8.  Deep Buttock Stretch This exercise stretches the muscles and connective This exercise stretches the deep buttock muscles, such tissue on the outside of the legs (iliotibial band and tensor as the piriformis. Lie on your back with knees bent and fascia lata). Stand with your left side to the wall, left arm one ankle crossed over opposite knee. Hold thigh of extended and palm of your hand flat on bottom leg and pull gently toward your chest. Hold. the wall for support. Cross the left Repeat on the other side. leg behind the right leg and turn the toes of both feet Piriformis out slightly. Bend your Superior left knee slightly and gemellus shift your pelvis toward the wall (left) as your Obturator trunk bends toward the internus right. Adjust Inferior until tension is gemellus felt down the outside of the left hip and thigh. Stretch and hold. Repeat on the other side. Iliotibial band 209

Table 5  The Basic Four for Arm Stretching Exercises Table 5 1.  Forearm Stretch 3.  Overhead Arm Stretch This exercise stretches the muscles on the front and back This exercise stretches the triceps and latissimus dorsi sides of the lower arm. It is particularly useful in relieving muscles. Stretch your arms up stress from excessive keyboarding activity. Hold your overhead. Grasp your right right arm straight out in front, with your palm facing down. elbow with your left hand. Use your left hand to gently stretch the fingertips of your Pull your right elbow right hand toward the floor. Hold. Turn your right arm over back behind your with your palm facing up. Use your left hand to gently head. Hold. Repeat on opposite side. stretch the fingertips of your right hand toward the floor. Hold. Repeat on the opposite side. Forearm Triceps flexor Latissimus or dorsi extensors 2.  Back Scratcher 4.  Arm Hug Stretch Stand straight with back of left hand held flat against This exercise stretches the shoulder muscles (lateral back. With right hand, throw one end of a towel over right rotators and posterior deltoid). Hold onto arm above the shoulder from front to back. Grab end of towel with left elbow and gently pull arm across chest. hand. Pull down gently on the Posterior towel with right hand, raising cu arm in back as high as is comfortable. Hold. Repeat to opposite side. Pectoralis Deltoid 210

Lab Resource Materials:  Flexibility Tests Lab Resource Materials Flexibility Tests VIDEO 7 Directions: To test the flexibility of all joints is impractical. These tests are for joints used frequently. Follow the instructions carefully. Determine your flexibility using Chart 1. 1. Test: Modified Sit-and-Reach (Flexibility Test of Hamstrings) a. Remove shoes and sit on the floor. Place the sole of the foot of the extended leg flat against a box or bench. Bend opposite knee and place the head, back, and hips against a wall with a 90-degree angle at the hips. b. Place one hand over the other and slowly reach forward as far as you can with arms fully extended. Keep head and back in contact with the wall. A partner will slide the measuring stick on the bench until it touches the fingertips. c. With the measuring stick fixed in the new position, reach forward as far as possible, three times, holding the position on the third reach for at least 2 seconds while the partner records the distance on the ruler. Keep the knee of the extended leg straight (see illustration). d. Repeat the test a second time and average the scores of the two trials. 2. Test: Shoulder Flexibility (Zipper Test) a. Raise your arm, bend your elbow, and reach down across your back as far as possible. b. At the same time, extend your left arm down and behind your back, bend your elbow up across your back, and try to cross your fingers over those of your right hand as shown in the accompanying illustration. c. Measure the distance to the nearest half-inch. If your fingers overlap, score as a plus. If they fail to meet, score as a minus. Score as a zero if your fingertips just touch. d. Repeat with your arms crossed in the opposite direction (left arm up). Most people will find that they are more flexible on one side than the other. 211

Flexibility Tests Lab Resource Materials 3. Test: Hamstring and Hip Flexor Flexibility 15-inch mark a. Lie on your back on the floor beside a wall. b. Slowly lift one leg off the floor. Keep the other leg flat on the floor. c. Keep both legs straight. d. Continue to lift the leg until either leg begins to bend or the lower leg begins to lift off the floor. e. Place a yardstick against the wall and underneath the lifted leg. f. Hold the yardstick against the wall after the leg is lowered. g. Using a protractor, measure the angle created by the floor and the yardstick. The greater the angle, the better your score. h. Repeat with the other leg. Note: For ease of testing, you may want to draw angles on a piece of posterboard, as illustrated. If you have goniometers, you may be taught to use them instead. 4. Test: Trunk Rotation a. Tape two yardsticks to the wall at shoulder height, one right side up and the other upside down. b. Stand with your left shoulder an arm’s length (fist closed) from the wall. Toes should be on the line, which is perpendicular to the wall and even with the 15-inch mark on the yardstick. c. Drop the left arm and raise the right arm to the side, palm down, fist closed. d. Without moving your feet, rotate the trunk to the right as far as possible, reaching along the yardstick, and hold it 2 seconds. Do not move the feet or bend the trunk. Your knees may bend slightly. e. A partner will read the distance reached to the nearest half-inch. Record your score. Repeat two times and average your two scores. f. Next, perform the test facing the opposite direction. Rotate to the left. For this test, you will use the second yardstick (upside down) so that, the greater the rotation, the higher the score. If you have only one yardstick, turn it right side up for the first test and upside down for the second test. Chart 1  Flexibility Rating Scale for Tests 1–4 Men Women Classification Test 1 Test 2 Test 3 Test 4 Test 1 Test 2 Test 3 Test 4 High-performance zone* 161 Right Left 1111 201 20.51 171 Right Left Up Up 14–16 Up Up 11–13 51 41 ,10 61 51 1111 Good fitness zone 13–15 1–4 1–3 80–110 16–19.5 2–5 2–4 80–110 17–20 Marginal zone 10–12 0 0 60–79 13.5–15.5 1 1 60–79 14.5–16.5 Low zone ,9 ,0 ,0 ,60 ,13.5 ,1 ,1 ,60 ,14.5 *Though performers need good flexibility, hypermobility may increase injury risk. 212

Lab 11A  Evaluating Flexibility Name Section Date Lab 11A Purpose: To evaluate your flexibility in several joints Procedures Evaluating Flexibility 1. Take the flexibility tests outlined in Lab Resource Materials, pages 211–212. 2. Record your scores in the Results section below. 3. Use Chart 1 in Lab Resource Materials (previous page) to determine your ratings on the self-assessments; then place an X over the circle for the appropriate rating. Results Record Ratings Flexibility Scores and Ratings High Performance Good Fitness Marginal Low Record Scores Modified sit-and-reach Test 1   Left Right Zipper Test 2   Left Right Hamstring/hip flexor Test 3   Left Right Trunk rotation Test 4   Left Right 213

Do any of these muscle groups need stretching? Check yes or no for each muscle group. Yes No Back of the thighs and knees (hamstrings) Lab 11A Calf muscles Evaluating Flexibility Lower back (lumbar region) Front of right shoulder Back of right shoulder Front of left shoulder Back of left shoulder Most of the body Trunk muscles Conclusions and Implications: In several sentences, discuss your current flexibility and your flexibility needs for the future. Include comments about your current state of flexibility, need for improvement in specific areas, and special flexibil- ity needs for sports or other special activities. 214

Lab 11B  Planning and Logging Stretching Exercises Name Section Date Lab 11B Purpose: To set 1-week lifestyle goals for stretching exercises, to prepare a stretching for flexibility plan, and to self- monitor progress in your 1-week plan Procedures Planning and Logging Stretching Exercises 1. Using Chart 1, provide some background information about your experience with stretching exercise, your goals, and your plans for incorporating these exercises into your normal exercise routine. 2. Using Chart 2, select at least 8–10 flexibility exercises as directed. Perform the exercises for 3–6 days over a 1-week period. Be sure to plan your exercise program so that it fits with the goals you described in Chart 1. For best results, take the log with you during your workout, so that you can record the exercises you performed. 3. Answer the questions in the Results and Conclusions and Implications sections. Chart 1  Stretching Exercise Survey 1.  Determine your current stage for flexibility exercise. Check only the stage that represents your current activity level. Precontemplation. I do not meet flexibility exercise guidelines and have not been thinking about starting. Contemplation. I do not meet flexibility exercise guidelines but have been thinking about starting. Preparation. I am planning to start doing regular flexibility exercises to meet guidelines. Action. I do flexibility exercises, but I am not as regular as I should be. Maintenance. I regularly meet guidelines for flexibility exercises. 2.  What are your primary goals for flexibility exercise? General conditioning Sports improvement (specify sport:___________________) Health benefits 3. Are you currently involved in a regular stretching program? Yes No Results Yes No Did you do eight exercises at least 3 days in the week? Did you notice any changes in flexibility? 215

Conclusions and Interpretations: Do you think you will use stretching exercises as part of your regular physical activ- ity plan, either now or in the future? What modifications would you make in your program in the future? Lab 11B Chart 2  Stretching Exercise Log Planning and Logging Stretching Exercises Check (√) the exercises you plan to perform in the first column. Choose 8–10 or more exercises from the three lists (truck, leg, and arm). Be sure to include at least two from each of the three lists. Perform the exercises for 3–6 days over the 1-week period. Write the date (month/day) in the day column for the date you performed the exercise. Exercises Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Trunk Stretching Exercises (Table 3, pages 206–207)  1 Upper trapezius/neck stretch  2 Chin tuck  3 Pectoral stretch  4 Lateral trunk stretch  5 Leg hug  6 Cobra and child’s pose  7 Trunk twist  8 Spine twist Leg Stretching Exercises (Table 4, pages 208–209)  1 Calf stretch  2 Shin stretch  3 Back-saver hamstring stretch  4 Hip and thigh stretch  5 Groin stretch  6 Lateral thigh and hip stretch  7 Inner thigh stretch  8 Deep buttock stretch Arm Stretching Exercises (Table 5, page 210)  1 Forearm stretch  2 Back scratcher  3 Overhead arm stretch  4 Arm hug stretch 216

Physical Activity: Special Considerations  c  Section IV Concept 12 Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck LEARNING OBJECTIVES After completing the study of this Concept, you will be able to: c Identify and describe the anatomy and function of the spine. c Identify and describe the anatomy and function of core muscles. c Clarify the causes and consequences of back and neck pain. c Describe how to prevent and rehabilitate back and neck problems. c Explain why posture is important to back and neck health and ways to improve posture. c Explain why good body mechanics is important to back and neck health and ways to improve body mechanics. c Indicate the exercise guidelines for back and neck health and ways to implement the guidelines. c Name questionable exercises and safer alternatives. c Determine self-assessments to identify potential back, neck, and posture problems and risks, and plan a self-monitored personal program that includes exercises for reducing these problems. The health, integrity, and function of the back and neck are influenced by modifiable as well as nonmodifiable factors. Maintaining a healthy back and neck can be attained by using good posture, good body mechanics, and safe exercise technique. 217 217

218 Section 4  c  Physical Activity: Special Considerations Cervical lordotic curve C7 The back and neck serve vital roles in supporting the T1 weight of the head and body, producing movement, car- rying loads, and protecting the spinal cord and nerves. These Thoracic kyphotic curve roles are facilitated by optimal alignment of the vertebrae Vertebrae and a balance between muscular strength and flexibility. Intervertebral disc Impairment of one or more of these functions can lead to T12 injuries to the muscles, vertebrae, discs, ligaments, or nerves L1 of the spine. Back and neck pain are common in today’s Lumbar lordotic curve society, with nearly 80 percent experiencing an episode of L5 low back pain sometime in life. Back pain is second only S1 to headache as a common medical complaint, and an esti- Sacrum mated 30 to 70 percent of Americans have recurring back problems. The multiple functions of the spinal column may Coccyx predispose this area to injuries. The spine helps to produce an array of movements while bearing significant loads. Figure 1  c  Curvatures of the spinal column. Chronic back and neck pain are associated with many the intervertebral discs is critical in distributing force and personal health problems. Some cases of back pain are absorbing shock. The bony structure of the spine bears loads “idiopathic” (no known cause), but others are clearly pre- and provides protection to the spinal cord and spinal nerves. ventable. This Concept provides information about the inter- Poor posture and poor body mechanics can damage discs related function of the spine and trunk musculature. Specific and vertebrae, resulting in pain and disability. information about core training, posture, body mechanics, and safe exercise performance will help you adopt preven- Anatomy and Function tive measures that may reduce your risk for back and neck of the Core Musculature problems. As this information is intended to provide a basic foundation of knowledge, persons with back or neck The core is part of an integrated system that provides pain should always seek direction from their own medical stability to the spine. The core includes musculature of provider. the abdominals, back extensors, lateral trunk flexors, dia- phragm, pelvic floor, and hips. A few of the more familiar Anatomy and Function muscles of the core include the lumbar multifidus, trans- of the Spine versus abdominis, and internal oblique. There is no defini- tive list of muscles belonging to the core. Some sources may The spinal column is arranged for movement. The describe the core in terms of 6 or fewer key muscle groups, bones that make up the spine are called vertebrae. There are while other sources may include as many as 20 different 33 vertebrae in the spine, and most are separated from one another by an intervertebral disc (see Figure 1). The verte- brae are divided into three main regions commonly referred to as cervical (neck), thoracic (upper back), and lumbar (low back). The fused vertebrae that form the tailbone are called the sacrum and coccyx. The connections among the verte- brae of the cervical, thoracic, and lumbar spine allow the trunk to move in complex ways. The spine is capable of flex- ion (forward bending), extension (backward bending), side bending, and rotation, but functionally, these movements often occur in combination. For example, in executing a ten- nis serve, the spine both extends and rotates. The spine is at risk for injury when movements are performed repetitively, performed beyond a joint’s healthy range of motion, or per- formed under conditions of heavy or inefficient lifting. The spinal column has an important role in bearing loads and protecting the back and neck from injury. The widest portion of each vertebra articulates with the intervertebral disc to form a strong pillar of support extend- ing from the skull to the pelvis. The unique structure of

Concept 12  c  Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck    219 Lumbar spine (L3) Multifidus Diaphragm Rectus Transversus abdominis abdominis Psoas major External oblique Muscles of Internal oblique pelvic floor Transversus abdominis Quadratus lumborum Erector spinae Multifidus Figure 2  c  Cross section showing layers of core musculature. muscle groups. Regardless, muscles of the core all share a The local core stabilizers provide stiffness and stabil- common anatomical trait: their location and attachment to ity to the spine. They include muscles that possess a small the spine, pelvis, or rib cage. Collectively, the core muscu- cross-sectional area, are deeply located, and may span lature form a three-dimensional cylinder that encompasses just one or two vertebral levels at a time. Functionally, the body’s center of gravity. This three-dimensional cylin- these muscles provide local spinal support, control motion der is inclusive of the lumbar spine, pelvis, and hips (see between adjacent vertebrae, increase intra-abdominal pres- Figure 2). sure, and provide proprioceptive input to the body to avoid injury. The most notable example of a local core stabilizer Core stability refers to the body’s ability to maintain is the lumbar multifidus. Also included in the group are the spine in a “neutral” postural zone, one in which muscles that indirectly influence the stability of the spine the physiologic load on the spine is minimized. The due to their role in increasing intra-abdominal pressure and overall function of the spinal stabilization system depends on their supportive attachment to the fascia of the back. These the contribution of three components: a passive restraint sys- muscles include the transversus abdominis, internal oblique, tem (ligaments, discs, vertebrae, and joints), active restraint diaphragm, and pelvic floor muscles. The local core muscles system (muscle-tendon units), and neural control system are believed to maintain the spine in “neutral” via isometric (proprioception and feed-forward mechanisms of the ner- co-contractions, thereby minimizing excessive loading of vous system). Core muscles incorporate functions of both the the spine. active restraint and neural control systems to maintain ideal postural alignment, thereby minimizing excessive stress and The global core stabilizers function to produce trunk strain to the spine. motion as well as trunk stability based on their attach- ments to the pelvis. These muscles tend to have a larger Muscles of the core are commonly classified as either mobilizers or stabilizers. In general, the mobilizers are Intervertebral Discs  Spinal discs; cushions of cartilage between those muscles that are more superficial and contract con- the bodies of the vertebrae. Each disc consists of a fibrous outer centrically to produce trunk movements. The stabilizers are ring (annulus fibrosus) and a pulpy center (nucleus pulposus). muscles that are more deeply located and contract isometri- Local Core Stabilizers Deep core muscles that provide stiff- cally or eccentrically to stabilize the trunk during arm and ness and stability to the spine. leg movements. The stabilizer group is further divided into Global Core Stabilizers  Superficial core muscles that produce two categories, local and global. These groups are distin- motion and aid in stabilization. guished by differences in anatomy and function.

220 Section 4  c  Physical Activity: Special Considerations A CLOSER LOOK Functional Movement Tests that can correct muscle imbalances or weaknesses. Despite the popularity of functional movement training, evidence hasn’t The topics of “functional fitness” and “functional movements” fully supported the effectiveness of the screening programs or are popular in the fitness world. It is believed that functional fit- functional-type exercise for reducing risks of injury. (See link in ness training techniques better prepare the body to handle the Suggested Resources and Readings.) forces, postures, and actions involved in real-life activities and sports and ultimately lead to reduced risk of injuries. Functional Do you see the potential for this type of screening movement tests are now commonly used by athletic teams to assessment to reduce injuries? try to predict which athletes might be at risk for injury. In theory, this type of screening can help to identify appropriate exercises cross-sectional area, are more superficially located, often ACTIVITY span multiple vertebral levels, and possess attachments to the pelvis, rib cage, and/or thoracic spine. Examples include congenital anomalies, and direct trauma (e.g., a fall or rough the rectus abdominis, external oblique, athletic activity when young). Lab 12A provides a question- quadratus lumborum, and erector spi- naire for assessing your potential risk for back and neck pain. nae. Also included are muscles of the The nervous system and various pain-sensitive hip, which indirectly influence lumbar VIDEO 1 structures contribute to back pain. Back pain can result from direct or indirect causes. Direct causes are typically stability by altering tilt of the pelvis. the result of tissue trauma to areas in or around the spinal Functionally the global core stabilizers generate movement column. The most common sources of pain are ligaments, of the trunk as well as provide stabilization. intervertebral discs, nerve roots, spinal joints, and muscles. Indirect causes stem from the release of pain-causing chemi- Causes and Consequences cals from injured tissues. These chemicals cause nerves in the of Back and Neck Pain area to remain irritated and sensitive. Processes within the brainstem, spinal cord, and peripheral nerves can also mod- Most back and neck pain stems from lifestyle choices ulate the sensation of pain, either increasing or decreasing or life experiences. The original cause (or causes) of it. For example, some back pain can be caused by abnormal back and neck pain are typically hard to identify. Although feedback loops that enhance or maintain the perception of back and neck problems can result from an acute injury pain—even when the original cause or problem is corrected. (e.g., a diving accident or car accident), most are caused by The integrity of the back and neck are jeopardized by accumulated stresses over a lifetime. These factors include excessive stress and strain. Forces are constantly at work the avoidable effects of poor posture and body mechanics to bend, twist, shear, compress, or lengthen tissues of the as well as questionable exercises that put the back at risk. (Exercises to avoid are discussed later in this Concept.) HELP Health is available to Everyone Musculoskeletal injuries and degenerative changes to the for a Lifetime, and it’s Personal discs, vertebrae, joint surfaces, muscles, or ligaments can According to the National Institutes of Health, the most predispose you to back and neck problems. Depression, common medical problem in the United States is back cancer, infections, and some visceral diseases (kidney, pel- pain, which is very often caused by degeneration of the vic organs) can also contribute to back problems. Although disks in the spine. Preventive measures include maintain- people have some control over these causes, some back pain ing a healthy weight over the lifespan, using proper lifting stems directly from structural or functional disorders that a techniques, and engaging in regular exercise, particularly person is born with. Inherited causes include anomalies of strength training and flexibility exercises. the spine and some forms of scoliosis. What steps are you taking today to help prevent back problems later in life? To reduce risk for back pain, reduce the risk factors that you have control over. Modifiable risk factors (factors you ACTIVITY can change) include regular heavy labor, use of vibrational tools, routines of prolonged sitting, smoking, a hypokinetic lifestyle, depression or anxiety, and obesity. Nonmodifiable risk factors include a family history of joint disease, age,

Concept 12  c  Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck    221 body. Stress on these tissues may eventually create strain, a excessive loads can irritate and damage the rotator cuff ten- change in the tissue’s size or dimension. Healthy tissues typ- don of the shoulder. The initial wear and tear of microtrauma ically return to their normal state once the force is removed. is not something typically noticed. However, over many Injury occurs when excessive stress and strain prevent the years, microscopic changes occur in the joint. Examples tissue from returning to its normal state. A number of factors include swelling, fibrosis of the synovial lining, abnormal can contribute to stress and strain on the back. thickening of the surrounding joint capsule, calcifications in ∙ Poor posture can cause body segments to experience the tendons, and thinning and roughening of the cartilage cushioning the joint surfaces. Because these changes are stress and strain. When body segments are in poor align- unseen and often unfelt, the offending exercise or activity is ment (e.g., slouching or forward head positions), the often viewed as harmless. However, later in life the effects muscles in the back and neck must work hard to com- from the microtrauma become more apparent, manifesting in pensate. This creates excessive stress and strain in the tendonitis, bursitis, arthritis, or nerve compression. Chances affected area(s). Over time, tension in these muscles can are, when the injury reaches a painful stage, the cause is not lead to myofascial trigger points, causing headache or identified and instead is attributed to aging. referred pain in the face, scalp, shoulder, arm, and chest. The chronic stress from poor alignment can also lead The lumbar intervertebral discs are particularly to other postural deviations and degenerative changes in susceptible to injury and herniation. The intervertebral the neck. discs located between the vertebrae of the spine are com- ∙ Bad body mechanics contribute to stress and strain on posed of a tirelike outer ring (annulus fibrosus) surround- the spine. Activities that involve heavy lifting, bending, ing a gel-like center (nucleus pulposus). The greatest risk or twisting present risks, as do repetitive motions and for injury to the discs occurs during excessive loading and those that involve vibrations. The lumbar vertebrae and twisting motions of the spine. Most people think that disc the sacrum are most vulnerable to this type of injury due injuries occur from an acute injury, but herniation typically to the significant weight they support and the thinner lig- reflects a degenerative process that takes place over time. amentous support at this level. With repeated microtrauma, small tears begin to occur in the ∙ Being overweight or obese increases the risk of back inner fibers of the annulus. The nucleus begins to move out- pain. Obesity and overweight status are hard on the body ward (herniated disc), much like toothpaste moving within because they overload the bones, discs, tendons, and liga- a squeezed tube. Disc herniation is termed incomplete ments of the body. Added wear and tear on joint surfaces or contained as long as the migrating edge of the nucleus can lead to osteoarthritis. Postural changes accompany remains within the fibers of the annulus. As damage contin- weight gain and create additional stress and strain on ues (often the result of years of cumulative microtrauma), joints. For example, a large protruding abdomen often the annular fibers may reach a point of rupture at their causes forward tipping of the pelvis and excessive arch- periphery (see Figure 3). At this point (termed disc extru- ing of the low back that can lead to back pain. sion), the nucleus pulposus moves into the space around the spinal cord or nerve root. At this stage, herniation is termed Some exercises and movements can produce complete or noncontained. microtrauma, which can lead to back and neck pain. Most people are familiar with acute injuries, such as ankle The risk of disc herniation is greater for younger sprains. These injuries are associated with immediate onset adults. Disc herniation is frequently listed as a cause of of pain and swelling. Microtrauma is a “silent injury”—a back pain, but studies show that only 5 to 10 percent of per- subtle form of injury that results from accumulated damage sons with herniated discs experience pain. The reason for over time. It can result from repetitive motion, repeated force- ful exertion, long-term vibration, or working with awkward Scoliosis  A curvature of the spine that produces a sideways postures. When microtrauma occurs as the result of activities curve with some rotation; while typically mild, this condition can at work, it is often referred to by the medical terms repetitive sometimes be painful. stress injury (RSI) or cumulative trauma disorder (CTD). Myofascial Trigger Points  Tender spots in the muscle or mus- One common example is carpal tunnel syndrome, a painful cle fascia that refer pain to a location distant to the point. irritation of the median nerve at the wrist, often brought on Referred Pain Pain that appears to be located in one area, by repetitive motion of the wrist during long and extended though it originates in another area. periods of typing, assembly line tasks, or construction work. Microtrauma  Injury so small it is not detected at the time it occurs. Microtrauma can also result from the repetitive perfor- Herniated Disc The soft nucleus of the spinal disc that pro- mance of unsafe exercises or contraindicated movements. trudes through a small tear in the surrounding tissue; also called For example, regular performance of full deep knee squats prolapse. or full neck circles may irritate the joint surfaces and eventu- ally cause knee or neck pain. Repeated overhead lifting with

222 Section 4  c  Physical Activity: Special Considerations Spinal cord Spinal cord Spinal nerve Normal disc Nerve root Fibrous ring Body of Nucleus pulposus vertebra (a) (a) Bulging nucleus Spinal cord Arthritis presses on spinal nerve Bone spur Narrowed Degenerated space (b) disc Nerve root Figure 3  c  Normal disc (a) and herniated disc (b). (b) this is that pain is often not experienced until complete her- niation occurs. Pain is felt as the nuclear material begins to Figure 4  c  Normal disc (a) and degenerated disc with press on pain-sensitive structures in its path. Interestingly, nerve impingement and arthritic changes (b). the risk for disc herniation is greatest for individuals in their 30s and 40s. Risk decreases with age as the disc degenerates participation in a program of core training exercise has also and becomes less soft and pliable. been shown to improve pain tolerance and function. Reha- Degenerative disc disease is a common part of aging bilitation of the lumbar multifidus appears critical in the and a source of back pain. Many elderly adults get recovery period following back pain. shorter as they age, often due to degenerative changes within Medical intervention is sometimes needed for back or the vertebral bodies and discs. One notable change is flatten- neck pain. Most cases of back pain resolve spontaneously, ing of the discs as a result of lost water content. This reduces with 70 percent having no symptoms at the end of 3 weeks the space between vertebrae and increases the compressive and 90 percent recovered after 2 months. However, medi- forces on the small facet joints and the large vertebral bodies. cal approaches have been shown to speed up recovery from This results in a decrease in the size of the spinal canal, which acute back or neck pain and to improve pain tolerance and in turn increases the likelihood of nerve impingement, bone function in chronic cases. Conservative treatment typically spur development, and arthritis, all of which can contribute involves the use of anti-inflammatory medications, muscle to back pain and disability (see Figure 4). relaxants, heat, cryotherapy, traction, or electrical stimula- Injury to the spine negatively affects the function of tion. It can also include therapeutic exercise, massage, and the core musculature. One of the more important core joint mobilization. When this treatment is unsuccessful, muscles, the lumbar multifidus, is adversely affected by referral to an alternative therapy, such as acupuncture, or to back pain. Studies demonstrate that with low back pain, the a pain clinic for steroidal anti-inflammatory injections may muscle becomes inhibited (exhibiting decreased levels of occur. As a last measure, surgery may be needed for removal activation and increased fatigability), is subject to atrophy, of a herniated portion of a disc. and becomes infiltrated with fatty deposits. In the healthy individual, the multifidus is believed to be responsible for Prevention of and Rehabilitation providing more than two-thirds of the dynamic rigidity to from Back and Neck Problems the lumbar spine and serves an important role in proprio- ception and kinesthetic awareness. Research studies have Exercise is a frequently prescribed treatment for back shown specific spinal stabilization exercises to be effective or neck pain. Exercise, such as resistance and aerobic exer- in reversing some of the adverse changes to the multifi- cises, has been found to be helpful in treating many types of dus, including positive gains in cross-sectional area/muscle bulk and improved neural recruitment. More important,

Concept 12  c  Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck    223 Following recommended preventive strategies can reduce the Core stability training and core strength training can likelihood of back and neck pain. promote good back health. Building core strength is important for overall muscular fitness. However, to reduce chronic pain. Exercises that are selected specifically to help the risks for back and neck problems, you need to train the correct pain-related problems are classified as therapeutic. muscles involved in core stabilization. There are two main These exercises are aimed at correcting the underlying cause types of core training programs, and each requires some- of back or neck pain by strengthening weak muscles, stretch- what different methods. ing short ones, and improving circulation to and nourishment of tissues of the body. Both therapeutic and health-related Core stability training refers to the training of the deeper fitness exercises may be considered preventive. Done faith- (“local”) core musculature. Physiologically, the local core fully, and with the appropriate FIT formula, they improve stabilizers are slow-twitch endurance muscles that are poorly the health of the musculoskeletal system, allowing greater recruited, demonstrate low force production, and often sag efficiency of function and reduced incidence of injury. or lengthen due to weakness. Training principles for the Use of specific core stabilization exercises may local core stabilizers are based on the respective physiology reduce low back pain and functional disability. The of the muscles. In general, exercises should involve slow integrity of individual vertebral segments of the spine is and controlled movements and be held for long durations. often compromised with injury to the back or neck. One or The focus should be on improving trunk muscle endurance, more components of the passive restraint system (ligaments, since endurance of the trunk musculature appears to be discs, vertebrae, or joints) may be damaged, creating a weak more important than strength for reducing the risk of low link in the stabilization system. In addition, optimal function back pain. Therefore, exercises should emphasize lower of the dynamic and neural control systems is often adversely resistance and involve more repetitions. Three sets of 8 to affected by injury. This may make a specific segment of 12 repetitions at very light to moderate intensity are appro- the spine more vulnerable to delayed healing or further priate for improving the endurance of core stabilizers. Exer- injury. Core training may enhance stability to the injured cises for improving local core stability are described and area by improving the function of the dynamic and neural illustrated in the exercise section at the end of this Concept. control systems. Core training programs are also effective in treating low back pain. Studies have shown significant Core strength training refers to the training of the more improvements in pain level and functional status follow- superficial “global” core musculature. Physiologically, ing a program of spinal stabilization exercises, but positive these muscles are fast-twitch in nature, contract at higher results have also been obtained from more general exercise resistance levels, possess greater potential for force pro- interventions. Future research may help identify subsets of duction, work in a noncontinuous fashion, and are prefer- people who may benefit from one type of exercise program entially recruited over the local stabilizers. They are often over another. in a shortened (tight) position. Based on the physiological function of the global core muscles, recommended train- ing principles include shorter duration holds, faster speeds of concentric contractions, greater resistance, and fewer numbers of repetitions. Several sets of exercise (2 to 4 sets of 8 to 12 repetitions at moderate to hard intensity) are recommended to improve the core strength of the global core stabilizers. Traditional abdominal and trunk extensor strengthening exercises are included in the exercise section at the end of this Concept. Resistance exercise can often correct muscle imbalance, the underlying cause of many postural and back problems. If the muscles on one side of a joint are stron- ger than the muscles on the opposite side, the body part is pulled in the direction of the stronger muscles. Corrective Core Strength Strength of muscles that demonstrate optimal firing patterns and tension-generating capabilities to create move- ment of the trunk. Core Stability Strength of muscles that demonstrate optimal firing patterns and tension-generating capabilities to “brace” the trunk in anticipation of, and during, movement of the head, arms, or legs.

224 Section 4  c  Physical Activity: Special Considerations exercises are usually designed to strengthen the long, weak The degree of curvature is influenced by the tilt of the muscles and to stretch the short, strong ones in order to have pelvis. A forward pelvic tilt increases curvature in the neck equal pull in both directions. For example, people with lum- and lower back, whereas a backward pelvic tilt flattens the bar lordosis may need to strengthen the abdominals and glu- lower back. The most desirable position is a neutral spine teal muscles and also stretch the lower back and hip flexor in which the spine has neither too much nor too little lor- muscles. dotic curvature. The forces across the spine are balanced and muscular tension is at a minimum. Good Posture Is Important Awareness of good standing posture is important to for Back and Neck Health a healthy spine. In the standing position, the head should be centered over the trunk with forward gaze, the shoulders Good posture has aesthetic benefits. Posture is an should be down and back but relaxed, with the chest high important part of nonverbal communication. The first impres- and the abdomen flat. The spine should have gentle curves sion a person makes is usually a visual one, and good posture when viewed from the side but should be straight when seen can help convey an impression of alertness, confidence, and from the back. When the pelvis is tilted properly, the pubis vitality. falls directly underneath the lower tip of the sternum. The Proper posture allows the body segments to be knees should be relaxed, with the kneecaps pointed straight balanced. Segments of the human body (i.e., the head, ahead. The feet should point straight ahead or slightly out- shoulder girdle, pelvic girdle, rib cage, and spine) are bal- ward, and the weight should be borne over the heel, on the anced in a vertical column by muscles and ligaments. Proper outside border of the sole, and across the ball of the foot and posture helps maintain an even distribution of force across toes (see Figure 5). the body, improve shock absorption, and minimize the Awareness of good seated posture is important to degree of active muscle tension required to maintain upright a healthy spine. A large percentage of our days is spent posture. When viewed from the side, three normal curva- sitting as we attend class, commute to work, sit at a com- tures of the spine are present, causing the vertebral column puter, dine out, or relax in front of the television. Good to appear S-shaped. These curvatures are created by the lordotic (inward) curve of the cervical and lumbar spines Forward and the kyphotic (outward) curve of the thoracic spine head (see Figure 1). The curves help balance forces on the body Kyphosis and and minimize muscle tension. They are also responsible for rounded shoulders humans’ unique ability to walk upright on two legs while Lordosis maintaining a forward gaze. Abdominal ptosis Hyperextended knees Movement disciplines like yoga and tai chi can promote body Flat arches awareness and contribute to back health. Bad posture Good posture Figure 5  c  Comparison of bad and good posture.

Concept 12  c  Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck    225 Table 1  c  Health Problems Associated with Poor Posture Posture Problem Definition Health Problem Forward head The head aligned in front of the center of gravity Headache, dizziness, and pain in the neck, shoulders, or Kyphosis Excessive curvature (flexion) in the upper back; also arms called humpback Lumbar lordosis Excessive curvature (hyperextension) in the lower Impaired respiration as a result of sunken chest and pain in back (sway back), with a forward pelvic tilt the neck, shoulders, and arms Flat back Reduced curvature in the lower back Back pain and/or injury, protruding abdomen, low back Abdominal ptosis Excessive protrusion of abdomen syndrome, and painful menstruation Hyperextended The knees bent backward excessively Back pain, increased risk for injury due to reduced shock knees absorption Pronated feet The longitudinal arch of the foot flattened with increased pressure on inner aspect of foot Back pain and/or injury, lordosis, low back syndrome, and painful menstruation Greater risk for knee injury and excessive pelvic tilt (lordosis) Decreased shock absorption, leading to foot, knee, and lower back pain seated posture decreases pressure within the discs of the be 2 to 3 inches above the eyes.) The seat of the chair should lower back and reduces fatigue of lower back muscles. In be at an angle that allows the knees to be positioned slightly sitting, the head should be centered over the trunk, the shoul- lower than the hips. The feet should be supported on the ders down and back. If one is using a computer, the screen floor (see Figure 6). should be positioned at arm’s reach from your eyes or a little Poor posture contributes to a variety of health problems. farther if using a large monitor. (The top of the screen should When posture deviates from neutral, weight distribution becomes uneven and tissues are at risk for injury. Examples of common postural deviations are described in Table 1, along with associated health problems. Two of those highlighted are lumbar lordosis (excessive curvature of the lower back) and flat back (reduced curvature of the lower back). Lumbar lordosis posture occurs when the pelvis is tipped forward from a position of neutral tilt. With this posture, the hip flexor muscles become shortened and tight, while the abdominal muscles become weak and long (with a reduced ability to “hold” within inner range). This muscle imbalance shifts body segment alignment toward a position of uneven Taking a break when using a laptop or tablet helps reduce back Posture  The relationship among body parts, whether standing, and neck strain. lying, sitting, or moving. Good posture is the relationship among body parts that allows you to function most effectively, with the least expenditure of energy and with a minimal amount of stress and strain on the body. Lordotic Curve The normal inward curvature of the cervical and lumbar spine. Kyphotic Curve  The normal outward curvature of the thoracic spine. Neutral Spine  Proper position of the spine to maintain a nor- mal lordotic curve. The spine has neither too much nor too little lordotic curve.

226 Section 4  c  Physical Activity: Special Considerations • Sit upright with eyes looking straight Sitting ahead, chest lifted, shoulders down and back, slight arch in lower back, knees Standing slightly lower than hips, feet supported on a firm surface. • Stand upright with forward gaze, shoulders down and back, chest • If you cross your legs, alternate which leg raised, stomach pulled up and in, is crossed on top. slight arch in the lower back, slight bend in the knees, feet shoulder • When sitting for longer periods of time, use width apart, and toes pointing straight chair with armrests, an adequate seat ahead or slightly outward. cushion, and lumbar support. • If you stand with weight shifted to • When driving, adjust seat to allow easy one side, alternate which leg you reach of foot pedals with slight knee bend; lean on. recline seat to allow gentle arch in low back. • If you stand in one place for a prolonged time, prop one foot on • Reading material should be elevated or small step stool. supported at eye level. • Height of work surface should be • The o ce desk should be about 29 to 30 about 2 to 4 inches below the waist. inches high for the average man and about 27 to 29 inches high for the average woman. The computer screen should be positioned at arm’s reach from your eyes (or a little farther if using a large monitor) and slightly below eye level. Elements of Good Posture Lying • Use a pillow between the knees when lying on your side and under the knees when lying on the back. • Choose a pillow that supports the head and neck in neutral alignment. • Avoid reading in bed. Figure 6  c  Characteristics of good posture for sitting, standing, and lying. loading, increasing pressure on the facet joints of the verte- Flat back posture, on the other hand, occurs when the brae. Over time, degenerative changes may occur, including pelvis is tipped backward from a position of neutral tilt. a narrowing of the openings where spinal nerves exit, thus With this posture, the lumbar spine is flexed, the lower increasing risk for pain. back muscles are in a lengthened (weak) position, and the

Concept 12  c  Body Mechanics: Posture, Questionable Exercises, and Care of the Back and Neck    227 eventually leads to muscles on one side of the joint becoming inflexible due to facilitation and muscles on the opposite side TECHNOLOGY UPDATE becoming weak due to inhibition. Postural correction can be achieved by improving body awareness, increasing flexibility New Training Aids for Core Training of tight muscles, and improving strength of weak (inhibited) muscles. For example, a slouched posture with rounded and Core training is an immensely popular concept across the forward shoulders can be improved by elongating the pecto- fields of sport, fitness, and rehabilitation. The popularity of ralis (chest) muscles and strengthening muscles of the upper core training programs and classes has led to an expand- back. A lumbar lordosis posture can be improved by stretch- ing array of core training devices and functional fitness ing the hip flexors and back extensors that keep the top of classes. One category of devices includes those that pro- the pelvis tipped forward, followed by vide an unstable surface for challenging balance and sta- strengthening of the abdominal and bility. Rocker boards, air-filled domes, therapy balls, foam gluteal muscles that help tip the pelvis rollers, and sliding disks are a few examples. Participants backward (see Figure 7). VIDEO 2 creatively position themselves on these devices in various postures—standing, lunging, kneeling, or on hands and Hereditary, congenital, and disease conditions, as knees. A second category of devices includes equipment well as certain environmental factors, can also cause that provides a dynamic challenge to the arms or legs. poor posture. Some environmental factors that contribute Elastic tubing, stretch cords, vibrating wands, kettlebells, to poor posture include ill-fitting clothing and shoes, chronic and medicine balls are used to overload the extremities fatigue, improperly fitting furniture (including poor chairs, and elicit a corresponding and supportive contraction of beds, and mattresses), emotional and personality problems, the core stabilizers. Creative new devices enter the fitness poor work habits, poor physical fitness due to inactivity, and market on a monthly basis, giving exercise participants lack of knowledge relating to good posture. Some posture fresh new ideas for their workout regimens. problems, such as scoliosis, may be congenital, hereditary, or Do you enjoy trying out new training devices or do you prefer to stick with your own regimen and routine? ACTIVITY hamstring muscles are shortened and tight. A reduced lum- Long /flexible Short /strong bar curvature increases pressure on the intervertebral bodies back muscles abdominal and decreases shock absorption capabilities. Relative differ- Short/strong muscles ences in flexibility between tight hamstring and long trunk hip extensors Long /flexible muscles may also increase risk for injury. Laws of physics hip flexor demonstrate that the body takes the path of least resistance Long/flexible muscles during a chain of movement (e.g., forward bending), with hamstring the most flexible segment (i.e., the back) providing a greater muscles contribution to the total range of movement. It follows that regions of greater movement will experience greater tissue Figure 7  c  Balanced muscle strength and length permit strain. In the case of flat back posture, tight hamstrings may good postural alignment. limit the contribution of hip motion during forward bending tasks, thus predisposing the lower back to become the ful- crum for movement and the site of injury. Correcting postural deviations begins with restoring adequate muscle fitness and muscle length. Most of us have a natural tendency to sit or stand with poor posture. For the most part, we can correct our posture with conscious effort. However, if poor posture is maintained for very long or very frequent periods of time, the body loses resiliency. With poor posture, muscles on one side of a joint or body segment can become shortened or tight while muscles on the opposite side can become lengthened and weak. Poor pos- ture can also result following muscle injury. This may mani- fest itself in guarded postures or muscle dysfunction, which