Therapeutic Exercise for Lumbopelvic Stabilisation 2nd edition By Carolyn Richardson

S t i ffn ess o f t h e l u m bo p e l v i c reg i o n fo r l o a d tran sfe r 85 � :TS� � I I I I I I A (a) � £�� I I I I I I I I I 18 A(b) F i g u re 5 . 7 U l traso u n d i m a g e s of t h e l u m b a r m u l t i fi d u s i n l o n g i t u d i n a l se ct i o n : ( a ) re l a x ed sta t e ; ( b) a ft e r i s o m e t r i c c o n t ra c t i o n . The l i n e AB re p rese n ts t h e d ep th o f t h e m u s c l e fro m its s u pe r i o r as pect t o t h e su pe rior a s pect of t h e L4- L5 zyg a p o p hys e a l j o i n t. In t h e re l axe d state (a l . t h i s i s 2 . 3 7 cm ; o n c o n t ra c t i o n ( bl . t h i s d e pt h i n c reases to 2 . 7 3 c m . S, s k i n ; ST, s u b c u ta n e o u s t i s s u e ; H, t h e d i rect i o n of t h e fi b re s i n t h e m u l t i fi d u s . copy (Fig. S . l l a , b ) . A t t h i s poin t, i t is releva n t to Sacro-iliac joint laxity was measured using emp h a s i ze, as explai ned ea rli er in th i s chap ter, tha t the concept of a shorten i n g con tra c ti on of tra n sver­ Doppler i m a gi ng of v ib rations. This is a new sus a bd om i n i s d u ring th e d raw in manoe u v re is c u r rentl y bei ng v a lid a ted i n o ur fu nc tional M RI measurement tech n ique from Erasmus Universi ty stu d ies. in w h ic h la x i ty is assessed in the p rone, non­ T h e s u bj e c ts w e r e a l so req u i red to d o a ' b ra cing' vv eightbea ring posi t i o n . By a d d ing a known vibra­ tion to the pelv is from below ( v i a the region o f the con traction, involving all o f the abdom inal m u scles, so tha t t h e effect o f two d i fferen t m u s c l e a n te r i o r superior iJ i clC spine), th e di ffere nce in the recru itment patterns on pelvic support could be resultan t frequency of v ibration between the sac r u m com p a red . Thi s second a b d o m in a l muscle pa ttern and i l i um is measu red u s i n g Doppler i m a g i ng . As these two bones are connected via the sac ro-i liac was a lso assessed v i s u a l l y then record ed using real­ joi nt, the larger the d i fference i n res u l tant frequ ency t i me u l trasound (Fig. S . l l a ,c ) . I n ad d ition , surface EMe on the abdominal muscles allowed the global a s it passes th rough each bone, the greil ter the lax i ty resp onse of these mus c l e s , as a res u l t of manoe u­ in the j o i n t . v res, to be q u a n tified . The results demonstrilted tha t a spec i fic con trac­ tion of the tra nsversus abd ominis and m u l ti fid u s (con firmed u sing real-time ul tra sound) w i th

8 6 T H E JOI N T PROTECTION MECHA N IS MS F i g u re 5 . 8 T h e m u sc l e c o n t ra c t i o n of ' d ra w i n g i n ' o f 7 the abdom i n a l wa l l with a n isometric con traction of the l u mbar m u l tifidus. The i nterre lationsh i p and the F i g u re 5 . 1 0 Cross-sect i o n of t h e p e l v i s a t t h e l ev e l i n te r a c t i o n betwe e n t h ese two m u sc l es a n d t h e fa sc i a l of t h e sa c ra- i l i a c j o i n ts. T h e a p p l i c a t i o n of fo rce b y t h e system ca n be a ppreciated, a n d t h e d i a g ra m i l l ustra tes how t h ey ca n work together to g ive s p i n a l support. tra nsversus a bdom i n i s and oblique abdom i n a l m u scles ( Fa ) . i n co m b i n a t i o n w i t h s t i ff d o rsa l s a c ra - i l i a c l i g a m e n ts ( Fi ) . c o m p resses t h e s a c r o- i l i a c j o i n ts ( Fi ) . Beca use t h e l e v e r a rm s of t h e m u sc l e a n d l i g a m e n t fo rce a re d i ffe r e n t , t h e j o i n t react i o n fo rce i s m u c h g re a t e r t h a n t h e m u sc l e fo rce. 1 , S a c r u m ; 2 , i l i a c b o n e ; 3 , j o i n t c a r t i l a g e ; 4 , j o i n t space; 5, ventra l sacro i l ia c l ig a m e n t ; 6, i nterosseous sacro­ i l i a c l i g a m e n t s ; 7 , d o rsa l sacro- i l ia c l i g a m e n ts. ( R e p rod u ced with perm iss i o n from S n ij d e rs et al 1 995, p . 423.) con traction i n v o( Flvigi n. 5g. al l the mu scles of the abdominal wall 1 2) . These fi n d i ngs confirm the b i omecha n ica l m o d e l jo f t h e m echil n i cs o f t h e s a c ro- i l i a c oi n t p ro posed by Snij ders et al ( 1 995) i n which the tra nsverse ly or i e n ted m u sc l e s s u c h a s tra n s vers u s il b d n m i n i s Me w e l l a b l e to inc rease t h e s t i ffness o f t h e S ,lC[(1- i l i il c j o i n ts for w e i g h tbeil ri n g w he rL'as the s u pe r fi­ c i a l a bd om i n a l s a re n o t ,1 S effi c i e n t . Th i s s t u d y ha ..:; ... prov ided some i n i tia l c v i d encL' of how the tr,l n s­ versus a bd o m i n i s can d i rectl y h e l p to st,l b i �i zc Fi g u re 5.9 C o n ce p t t h a t co m p ress i o n of j o i n t s u rfa ces by m u s c l e fo rce h e l ps to p reve n t s h e a r i n g . ( R e p rod u ced a n d con trol the p e l v i s for weigh tbed r iJ1 g, il n d il l s o explil ins how specific activation o f the deL'p local with perm issi o n fro m S n ij d ers et al 1 9 9 5 , p. 420.) m u s c les c ou ld exert an e ffec t on p a in a n d P J th o l­ m in im a l contraction of the superfi c i a l a bd o m in a l ogy of the s a c ro- i l i il c j oints . m u sc les ( co n firmed w i th EMG) increased s ti ffn ess (or d ecrei1sed l<l x i ty) of the s a c ro- i l ii1c j o i n ts to The a rgu ments presented i n th i s chil p ter have led a grci1 t L' r d eg rec th il n il high e r level ' b r il ci n g' to two recom m e n d e d m a not' u V rL'S thM a n' essen­ t ia l for loa d ed fu nction of the l u m bo pel v i c regi o n . Stiffe n i n g m a noe uvres to p rote ct and s u p port th e l u m bop e lvic reg ion for weig htbe a ring The a rg u m en ts p resentL'd i n th i s c h a p ter h a w led to tw o rec o m m e n d e d m a n oe U V fL' S th a t ilt\"L' e s s e n ­ tial fo r 1 0 ,l d ed fu nc t i o n o f t h e l u mbofx' i v i c reg i o n .