SPORTS MEDICINE SPORTGENEESKUNDE JO U R N A L OF T H E S.A. SPO RTS M E D IC IN E ASSOCIATIO N TY D SK R IF V A N DIE S.A. SPORTGENEESKUNDE-VERENIGING ISSN 1015/5163 VOL 5/NO 1 FEBRUARY 1990 PRICE R5.00 + GST The influence o f a shock-absorbing innersole on the incidence o f exertion-related injuries Energy value o f food D ie waarde van pre-seisoensevaluering en post- traumatiese fisieke rehabilitasie R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Beat the pain.Go the distance. c i b a — g e i g y Ddophenac diethylammonium 1,16 g/100 g f e g . N o . U / 3 . 1 / 7 7 W i l s e n a c h * 8 8 I > New \bltaien Emulgel.The unique Gel Cream combination to beat pain and inflammation. • E m u l g e l k e e p s you in actio n . It is th e ideal a n t i - i n f l a m m a t o r y t r e a t m e n t fo r the relief o f localised i n f la m m a ti o n a n d pain in s p o r ts inju ri es d u e to s p ra i n s , str ai n s a n d bruises. • ' E m u l g e l ’s u n iq u e c o m b i n a t i o n o f c r e a m a n d gel allow s for the p e n e t r a t i v e effect o f r u b b i n g in, whil e the gel fo rm s a lay er to al p e rs i st e n t p e n e t r a t i o n . • E m u l g e l ’s d e e p - p e n e t r a t i n g ac tio n c o n fi n e s itself to t h e local p r o b l e m , giving relief, wi th m i n i m u m lik eliho o d o f side- cffect s. • ' E m u l g e l p ro v id e s o n - t h e - s p o t , c o n v e n i e n t m e d i c a t i o n . • F r o m C ib a-G eig y . L e a d e r s in t r a n s d e r m a l th e ra p y . S o o t h i n g e m u l s i o n creati f o r t h e p e n e t r a t i v e effec o f r u b b i n g in C o o l i n g G e l f o r m s a la y e r l o r g r a d u a l p e n e t r a t k Votiaren N o w a v a i l a b l e a l y o u r p h a r m a c y w i t h o u t p r e s c r i p t i o n . emulgel R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS MEDICINE SPORTGENEESKUNDE J O U R N A L O F T H E S.A. S P O R T S M E D I C I N E A S S O C IA T IO N T Y D S K R I F VAN D IE S.A. S P O R T G E N E E S K U N D E -V E R E N IG IN G V O L U M E S N U M B E R 1 F E B R U A R Y 1989 E d ito r in C h ief: D r C N o ble M B B C h , F C S ( S A ) A ss o c ia te E d ito rs: P r o fT N o a k e s , M B C h B , M D D r D a w ic v a n Vclden M B C h B (S tell) M P ra x M e d (Pretoria) A dvisory B oard : M e d i c i n e : D r I Cohen M B C h B , D .O b si. R C O G O r t h o p a e d i c t r a u m a t o l o g y : D r P F irer B S c (Eng) , M B B C h ( W i t s ) ,M M e d (Ortho) (W a s) B n g E H u g o M B C h B ,M M c d ( C h ir ) O r t h o p a e d i c s : D r J C Usdin M B B C h , F R C S (E d in ) C a r d i o l o g y : C o l D P M y burgh S M M B C h B F A C C P h y s i c a l E d u c a t i o n : P r o f H an nes B o th a D P h il (P h y s E d) G y n a e c o l o g y : D r J a c k A d n o M B B C h (W its ), M D (M e d ), D i p O & G ( W hs) CONTENTS Editorial Comment ............. 3 Preventative Sports M edicine T he influence of a shock-absorbing innersole on the incidence o f exertion-related inj uries ..................... ............. 4 Nutrition 10 Sportbeserings D ie waarde van pre-seisoensevaluering en 12 Sports Physiology An evaluation o f hamstring/quadricep strength ratios in elite long distance runners and 16 Pictures courtesy o f Photofile/1 mage B a n kP U B L I S H E D B Y T H E S O U T H A F R I C A N S P O R T S M E D I C I N E A S S O C I A T I O N H A T F I E L D F O R U M W E S T 1067 A R C A D IA S T R E E T H A T F I E L D P R E T O R I A . 0 0 8 3 T h e j o u rn a l o f t h e SA S p o n s M e d i c in e A s s o c ia tio n is p u b li s h e d b y M e d p h a r m P u b l ic a ii o n s , 3 rd F lo o r N o o d h u l p l ig a C e n t r e , 2 04 B H F V e rw o e rd D r i v e , R a n d b u r g 2 1 9 4 . T el: (0 1 1 ) 7 8 7 -4 9 8 1 /9 . T h e v ie w s e x p r e s s e d in t h is p u b li c a t io n a r e t h o s e o f t h e a u t h o r s a n d n o t n e c e s s a r i ly th o s e o f t h e p u b li s h e rs . P r in te d b y T h c N a ia l W itn e s s P r im in g and P u b lis h in g C o m p a n y ( P t ' ) L td S P O R T G E N E E S K U N D E VOL S. N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Van Bencard S3 RELIFEN 500 mg per tablet Reg Nr R/3.1/265 oorRELIFEN 500 i die anti-inflammatoriese middel ^ wat beweeglikheid verbeter Bemarkdeur Bencard Afdeling van RBeege NC h ^ 0 3 9 h6 8 ^ a C e U tiC a lS (E d m S > B P K Posbus 347. Bergvlei 2012 Rellfen 500 en die Bencard logo is handelsmerke Jndikasies.- Rumatoiede a rtritis en osteoartntis/artrose. Newe-effekte en spesiafe voorsorgmaatreels- S a t m e s 9e'yktydl9e t0ed'emn9 Van sulf“ m en h,dantoiene pept,ese u,kus- n ^ ede- Verdere inligting is van die Mediese Departement verkrygbaar. R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) e d it o r ia l SPORTS MEDICINE IN SOUTH AFRICA T h e Sp o rts M e d i c i n e A sso ci at ion o f S o u th Africa ( S . A . S . M . A . ) is only six yea rs old . T h o s e o f us w h o w ere involved in its f o u n d a t i o n k n o w that it to o k as m a n y years before S . A . S . M . A . ’s fo u n d a ti o n to finally start an association. N o w al m o st six years later o n e m u s t look at w h at we h av e ac h iev ed a n d a t t e m p t to assess o u r fu ture. W h e n we first b eg an w e s ta rte d as a g r o u p o f d o cto rs u n d e r th e au sp ic e s o f t h e S o u t h A fr ica n M ed ic a l A sso ci­ ation. T h i s m e a n s th a t o n ly m e m b e r s o f the m e dical p r o ­ fession ar e allowe d to vo te b u t affiliate m e m b e r s ca n be co -o p te d o n to the as s ociation. T h e s e affiliate m e m b e r s m u s t be p eo p le o f s t a n d i n g in s p o r ts s ci en ce , e.g . s p orts p h y s i o th e r a p is t s . As on ly a small n u m b e r o f d o c to rs have a special intere st in s p o r t s m e d i c i n e this m e a n s th a t o u r association will always r e m a i n s m a l l . T h e r e are h o w e v e r a n u m b e r o f ways that we can ch an g e this sit u at io n . F irs tly w e can e d u c a t e m o r e d o c to rs so that a g re a t e r g en era l in te re st in s p o r ts m e d i c i n e can be s t i m u ­ lated. T h i s can be d o n e in a n u m b e r o f ways. T h i s jou rn al is a m a jo r asset in this re g a r d . By p u b l i s h i n g in te re stin g articles m o r e a n d m o r e d o c to rs m a y b e c o m e intere st ed a n d join o u r asso cia tio n. L e c t u r i n g a n d co n g re sse s by s p orts m e d i c i n e sp ec ia lis ts m a y also h e lp in this re g ar d . U n f o r t u n a t e l y C a p e T o w n U n iv e r s i t y hav e th e only fa­ cility u n d e r g u i d a n c e o f P r o f ess o r T i m N o a k e s th a t has a d ir e c t i n v o l v e m e n t with s p o r t s scien ce. O t h e r u niversities re q u i r e s im i la r e s t a b li s h m e n t s . At g ra s s ro o ts level s p o r ts m e d ic in e s h o u l d be t a u g h t to u n d e r g r a d u a t e s tu d e n t s . At p re s e n t I k n o w o f no s u ch te a c h in g . W i t h le isure tim e in ­ cre asing m o r e a n d m o r e p eo p le ar e ta k in g p a rt in spor t a n d th e re fo re s p o r ts m e d i c i n e will b e c o m e pro g re ssi v el y m o re i m p o r t a n t . F in ally o n e m u s t c o n s id e r a s p o r ts m e d i c i n e association that will i n c lu d e all i n t e re st e d p a rt ie s a n d n o t just d o c ­ tors. In th e U . S . A the A m e r ic a n College o f Sp o rt s M e d ic i n e fulfills this role. H e r e c o a c h e s , t r a i n e r s , p h y s i o ­ t h e ra p is t s , d ie ti c ia n s , d o c t o r s , etc. all m a y b elo n g to this Asso ci at ion. Po ssibly ev en two ass ociatio ns m a y be feas­ ible. It is i m p e ra t i v e th a t in this nex t d e c a d e l ead ing u p to the yea r 2000 s p o r ts m e d i c i n e a n d its associatio n s h o u l d go fro m s t r e n g t h to s tr e n g t h . Dr. Clive N o b l e M B B C h , F C S ( S A ) E d it o r - i n - C h i e f l * * . *m c o H S P O R T G E N E E S K U N D E VOL 5. N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) PREVENTATIVE SPORTS MEDICINE THE INFLUENCE OF A SHOCK-ABSORBING INNERSOLE ON THE INCIDENCE OF EXERTION-RELATED INJURIES SUSTAINED BY MILITARY RECRUITS HJ van Heerden, PE Kruger, NF Gordon, JF Cilliers, AD Hales, AR Oberholzer ABSTRACT K eyw o rd s: shock-absorbing innersole, exertion-related injuries, m ilitary recruits T he aim o f this study was to determine the influence o f a shock-absorbing innersole on the incidence o f exertion-related injuries, of the lower extremities, among recruits during basic training in the South African Army. Injuries were classified according to the presence (group 1) or absence (group 2) o f an obvious precipitating event, which allowed for the respective interpretation o f a traumatic or overuse injury. Group 1- injury incidence (G l) was lower than the group 2-injury incidence (G2) for both the Standard boot (ST ) and the shock-absorbing boot (SO) (ST-G1 = l,l% v s G 2 = 16,0%;SO-G1 = 1,0%v s G2 = 9,8%), indicating a predominance o f overuse injuries. T he variation in Gl-injury incidence per boot type was negligible and insignificant ( p > 0 ,l) . T he difference between the STG2 and SOG2 injury incidence was significant (p=s0,05), as was the case for total recruit injury incidence (S T = 17,l% v sS O = 10,8%) but to a lesser degree (p < 0,1). T he SO thus provided significantly better protection against the risk o f exertion-related injuries. T his was especially the case in respect o f overuse injuries o f the lower extremities during basic training. T his observation was attributable to the effective functioning of the shock-absorbing innersole within the boot. H J van H eerden, M A B iokinetics, 1 M ilita r y H ospital B io kin etics Centre P E Kruger, P H . D U niversity o f Pretoria N F G ordon, M B B C H , P H . D . , 1 M ilita ry H o spital B io kin etic s Centre J F Cilliers, P H . D . , 1 M ilita r y H o spital B iokinetics Centre A D H a les, B A (H ons) P h y s E d , 1 M ilita r y H o sp ita l B io kin etics Centre A R Oberholzer, N a t D ip Chir, P odiatry D epartm ent, 1 M ilita r y H o sp ita l A uthors address: H J van H eerden D epartm ent o f H u m a n M o ve m e n t Science, U niversity o f Z u lu la n d P riva te B a g X I 0 0 1 , K W A D L A N G E Z WA 3886 T h e s t r e n u o u s d e m a n d s pla ced on the m u s cu l o s k e l e t a l s t r u c t u r e o f m ilita ry r e ­ c ru its u n d e r g o i n g t h e i r initial p e r i o d of int en sive t r a i n i n g a n d p h ys ic al c o n ­ d it i o n i n g (bas ic tra i n i n g ) ca n at tim es be excessive. T h i s o b s e r v a ti o n is reflected b y t h e hig h in c id e n c e o f inju ry, p r i m a r ­ ily to the low er e x t r e m i t ie s , th a t have b e e n r e p o r t e d for b o th fore ig n f o r c e s , 1'3 a n d the S o u t h A fr ican A r m y . 4 B e n s e l 1 a n d K o w a l 2 n o te d a 3 7 % a n d 2 6 % in j u r y rate for A m e r ic a n M a r i n e s a n d A r m y r e ­ cru i ts respectively, w h il e Stacy a n d H u n g e r f o r d 3 r e c o r d e d an a l a rm in g 6 5 ,4 % i n c id e n c e o f “w o r k - r e l a t e d ” i n j u ­ ries a m o n g N e w Z e a l a n d A r m y re cr u its . In the S o u t h A frican A rm y , G o r d o n et al4 d o c u m e n t e d a 3 7 , 9 % in c id e n c e o f ex e rt i o n -r e la te d in j u ri e s s u s t a i n e d by r ecr u its d u r i n g basic tra i n i n g . T h e tra n s it i o n fro m civilian fo otw ear to m ilita ry fo o tw e ar has b e e n im p lic a te d by v a ri o u s r e s e a r c h e rs as an i m p o r t a n t factor in c o n t r i b u t i n g to th e in c id e n c e o f e x e r t i o n - r e la te d in j u r i e s , o f th e low er e x t r e m i t ie s , a m o n g r e c r u i t s . 5'7 T h e fact tha t civilian fo o tw e ar c o n s t r u c t e d fro m m a te ria ls th a t ar e lig h t e r a n d hav e b e t te r s h o c k a b s o r p t i o n q u ali tie s t h a n m ilita ry footwear, m a y h av e an influ en ce o n the a m o u n t o f str es s i n c u r r e d by i n d i v id u a l s e n g a g e d in t r a i n i n g . 8 As a r e s u lt t h e re has b e e n g r o w i n g s u p p o r t for the use of ath le tic fo o tw e ar s u c h as r u n n i n g sh oe s, for ph ysical c o n d it i o n i n g by m a n y mili­ tary u n i t s . 7'9,l0'n W h il s t this a p p r o a c h has b e e n a c c e p te d a n d i n t r o d u c e d in the S o u th A fr ic an A r m y , 12 s o m e foreig n c o m m a n d e r s h a v e c o u n t e r e d this a d v o ­ cacy, by r e a s o n i n g t h a t since the so ld ier fights in the b o o t , he s h o u l d t ra i n in the b o o t . " As a f u r t h e r p r o p h y l a x i s , at ten - 4 ---------------------------------------------------------S P O R T S M E D I C I N E VOL 5. NO I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) PREVENTATIVE SPORTS MEDICINE tion h as b e e n focu sed on th e m o d i fi ­ cation o f th e m ilita ry b o o t as a n o t h e r me an s o f d e c re a s i n g t h e in c id e n c e o f in- ju r v a m o n g r e c r u i t s . , i !S1013 In o r d e r to inv es tiga te t h e effect of such a p r e v e n t iv e m e a s u r e , a s t u d y was c o n d u c te d to d e t e r m i n e the influ en ce of two d iffe re n t b o ot t y p e s , on th e inc i­ d en ce o f e x e rt i o n -r e la te d i n ju ries o f the lower ex t re m i t ie s a m o n g r e c r u i t s d u r i n g basic t r a i n i n g in the S o u t h A fr ic an Army. SUBJECTS A N D M ETH O DS In this s t u d y N a t io n a l S e r v ic e m e n th a t p re s e n t e d th e m s e l v e s for t h e F e b r u a r y 1987 in ta k e at a S o u th A fr ican A r m y b a ­ sic t r a i n i n g c e n t r e s erv ed as s u b j e c t s . All s ubjec ts u n d e r w e n t a c o m p r e h e n s i v e medica l e x a m in a t i o n b efo re c o m m e n c ­ ing w i th basic t r a i n i n g a n d on ly tho se tha t w e re classified as m e d i c a l l y fit, w e re c o n s id e re d for th e study. Ini tially a total of 750 s u b j e c t s fo rm e d th e s a m p l e , b u t p ri m a ri l y as a re su lt o f t ra n s fe rs to o t h e r u n it s , 280 s u b jects w e re w i t h d r a w n w ith in the d u r a t i o n o f t h e study. T h e s u b j e c t ’s av er ag e age w as 19,8 years. B e­ fore t h e start o f th e p ro je c t all su bjects were i n f o r m e d a b o u t t h e p u r p o s e o f the stu d y a n d th e p r o c e d u r e t h a t was to be followed. T h e s u b jects w e re iss u ed r a n d o m l y wi th o n e o f t h e tw o typ es o f b o o t s , until an e x p e r i m e n t a l g r o u p o f 250 a n d one co n tr ol g r o u p o f 500 s u b j e c t s was fo rm e d . D u r i n g t h e iss u ein g p r o c e d u r e recr u its h a d t h e ir feet m e a s u r e d by m e m b e r s o f t h e S o u th A fr ican B u re a u o f S t a n d a r d s on a m e a s u r i n g devic e d e ­ sign ed specifically for th e m i l i ta ry last a cc o rd in g to t h e m o n d o p o i n t sy st em . A n y f u r t h e r p r o b l e m s w e re re s o lve d by the p e rs o n a l a t t e n ti o n o f a P o d i a t ris t . Figure 1: T h e s t a n d a r d l eath er bo ot typ e Figure 2: T h e s h o c k - a b s o r b i n g in n er so le DESCRIPTION OF THE D IFFE R E N T BOOT TYPES (A s docum ented by the S o u th A frica n B ureau o f S ta n d a r d s ).14 Standard boot type T h e c u r r e n t s t a n d a r d issue le a t h e r bo ot o f t he S o u t h Africa n A rm y, is k n o w n as the “V as b yt” b o ot. T h i s b o o t is refe rred to as t h e S t a n d a r d bo ot (S T ) in this s t u d y a n d was w o r n b y t h e c o n tr ol g r o u p ( F ig u r e 1). Sorbothane boot type T h e e x p e r i m e n t a l bo ot t h e n is r e fe rre d to as t h e S o r b o t h a n e bo ot (S O) in this study. T h i s bo ot was identical to the S t a n d a r d b o o t , e x cep t for th e i n c lu s io n o f a s h o c k - a b s o r b i n g in n er so le. T h e i n ­ nerso le was sp eci ally d e s ig n e d a n d p r o ­ d u c e d fr o m a m a te ria l k n o w n as S o r b o ­ tha ne . S o r b o t h a n e is the t ra d e n a m e for a ty p e o f visco-elast ic p o l y m e r wi th specific p r o p e r t i e s well k n o w n for its u n i q u e c u s h i o n i n g a n d s h o c k - a b s o rb - ing c a p a b i li t i e s . 16'20 A n e x a m in a t i o n ol the i nn erso le reveals a b u i l d - u p in the two m a in a rch es o f t h e f o o t : S P O R T G E N E E S K U N D E VOL 5. N R I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) PREVENTATIVE SPORTS MEDICINE • the m edial l o n g i tu d i n a l a r c h ( M L ); a n d • the t ra n s v e rs e m e ta ta rs a l a r c h (T M ) . T h e in n e r s o l e p r o c e e d s fr o m the heel o f t h e foot to just p o s t e ri o r o f t h e m e ta ta rs al h e a d s ( F i g u r e 2). THE BASIC T R A IN IN G PROGRAMME wee ks a n d wa s o f a cy clic-p ro gress iv e n a t u r e . 12 All ex erci ses w e re p e r f o r m e d str ictly a c c o r d i n g to p r e s c r i p t i o n . 21 D u r i n g all o rg a n is e d p h ys ic al train in g p e ri o d s r u n n i n g s h oe s are w o r n a n d not boots o r “ t a k k i e s ”. RESEARCH PROTOCOL F o r t h e p u r p o s e s o f this s t u d y th e s am e pro to co l was followed as wa s u s e d by T h e g r o u p 1-injury i n c id e n c e (i.e. i n ­ jur y in t h e p r e s e n c e o f an o b v i o u s s u d ­ d e n p r e c i p it a t i n g ev en t) wa s low er th a n th e g r o u p 2 - i n j u r y in c id e n c e (i.e. i n ju ry in t h e a b s e n c e o f an o b v i o u s s u d d e n p re c i p it a t i n g ev en t) for b o th t h e S t a n ­ d a r d (S T) a n d t h e S o r b o t h a n e (SO) boot ty p es ( S T = 1,1% vs 16,0%; S O = 1,0% vs 9 , 8 % ). T h e d if feren ces in the g r o u p 1-injury in c id e n c e b e tw een the tw o bo ot t yp es ( S T = 1,1% vs S O = 1,0%) was n eg ligible a n d insig nifican t ( p > 0 ,1 ). T h e v a ria tio n in th e g r o u p 2 -i n j u ry in c id e n c e s h o w e d a significan t d if fe re n ce ( S T = 1 6,0% vs SO = 9 ,8 % ; p=s0,05), as was t h e case for th e total r e c r u i t i n j u r y in c id e n c e ( S T = 1 7,1% vs SO = 10,8%) b u t to a lesser d eg ree ( p < 0 , l ) . ANATOMICAL SITES OF INJURY PER BOOT TYPE G r o u p 1-i n ju ri es w e re s u s t a i n e d at on ly t h r e e an a t o m i c a l sites, n a m e ly th e an k le (S T = 3 3 ,3 % ), k n e e (S T = 6 6 ,7 % ; SO G o r d o n el a l ,4 as r e g a rd s t h e defin ition o f an injury, classification o f injuri es a n d th e m e t h o d o f data c o l l e c t i o n . RESULTS Recruit injury incidence and type of injury per boot type (Table 1) T h e basic t r a i n i n g p r o g r a m m e was p e r ­ f o rm e d o v er a 10 w eek p e r i o d . D u r i n g p ract ic al t r a i n i n g re c r u i t s w ere s u b ­ jected to p h ys ic al c o n d i t i o n i n g follow ­ ing activities: • m ilita ry d rill ; • field t r a i n i n g ; a n d • p hys ic al tra i n i n g . Drill tra in in g t o o k pla ce for o n e or m o r e p e ri o d s o f 40-55 m i n u t e s each p e r day. D u r i n g field t r a i n i n g re c r u i t s c o m ­ ple te d s t r e n u o u s nav ig atio na l a n d ro u te m a r c h e s o f 10-20 k m . In a c c o rd a n c e with fo o tw e ar re g u l a ti o n s re c r u i t s w o re boots t h r o u g h o u t dri ll a n d field t r a i n ­ ing. T h e p hys ic al t r a i n i n g p r o g r a m m e was followed for at least 4 p e r i o d s o f 40 m i n ­ utes eac h p e r w e e k o v e r t h e full 10 Table 1: T he recruit injury incidence and type o f injury per boot type Type Boot type Significance of by injury Standard Sorbothane Fisher’s (N = 275) (N = 195) Exact Test n % n % Group 1 3 1,1 2 1,0 N S Group 2 44 16,0 19 9,8 p=s0,05 Total 47 17,1 21 10,8 P<0,1 n = N o. o f in ju red recruits N = N o. o f re cru its p e r boot type S P O R T S M E D I C I N E VOL S. N O I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Nothing will give you i more x jm a t o l o g y U l t t o e s H m e n freedomtowalk,jump,runandwork 88/4 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) PREVENTATIVE SPORTS MEDICINE = 33 ,3% ) a n d t hig h (S O = 6 6 ,7% ). G r o u p 2 -in ju ries ( F i g u r e 3) p ri m a ri l y affected t h e k n e e ( S T = 3 2 ,6% ; SO = 3 8 ,1% ), low er leg ( S T a n d S O = 28 ,6% ) a n d Achilles t e n d o n ( S T = 16,3%; SO = 14,3%) for b o t h boot t yp es w h ile the re m a i n i n g an a t o m i c a l sites, n a m e ly the foot, heel, an k le a n d th ig h followed in f r e q u e n c y w i th a lower i n c id en ce. LOSS OF BASIC-TRAINING TIME PER BOOT TYPE T h e dif fe re n ce in t h e total i n c id e n c e o f tra in in g d ay s lost as a re su lt o f exercise- relat ed inju ri es p e r boot ty p e was n eg li ­ gibl e ( S T = 2 , 8 % ; S O = 2 ,2 % ). T h e i n ­ ci d en ce o f t r a i n i n g d ay s lost d u e to g r o u p 1-i n ju ri es was n o ta b l y less t h a n that for g r o u p 2 -in ju ries for b o th boot typ es ( S T = 8 , 2 % vs 9 1 , 8 % ; SO = 6 , 3 % vs 93 ,7% ). F i g u r e 4 reflects the i n c i ­ d e n c e o f tra i n i n g d a y s lost d u e to g r o u p 2-inju ries p e r bo ot t y p e at the var io us a n ato m ical sites. D ISC U SSIO N T h e vast m a jo ri t y o f exer ci se- re late d i n ­ ju rie s i n c u r r e d by re c r u i t s in this s tu d y w e r e inflicted in the a b s e n c e o f an o b ­ v ious s u d d e n p r e c i p it a t i n g even t a n d c a n , for p ract ic al p u r p o s e s , be re g a rd e d as o v e ru s e inju ri es. T h i s fin ding is in a c c o r d a n c e w i th th a t o f G o r d o n et al4 for S o u th A fr ic an A r m y re cr uits . In this s tu d y th e S O fared significantly b e tte r t h a n the S T ( S T = 16,0% vs SO = 9 , 8 % ; p=£ 0 ,0 5) as re g a rd s t h e in c i­ d e n c e o f o v e ru s e inju ri es ( g r o u p 2). A n u m b e r o f re s e a r c h e r s 22 24 r e g a rd an ac­ c u m u l a t i o n o f m i c r o t r a u m a d u r i n g ste ­ r e o t y p e d , cyclic activities s u ch as r u n ­ n in g as a m a jo r etiological factor in the in c id e n c e o f o v e ru s e in ju ri es , whil e o th e r s 25 27 su gg es t tha t a lack o f shock- a b s o r b ti o n in tra i n i n g fo otw ear a c c e n ­ tu a te s thi s p r o b l e m . T h e effective f u n c ­ t io n i n g o f t h e s h o c k - a b s o r b i n g S o r b o ­ t h a n e in n e r so le in t h e SO as o p p o s e d to the S T in this study, t h u s e n co u ra g es s u p p o r t for t h e a b o v e o p i n i o n s . 22 77 T h e an a to m ic a l d is t r i b u t i o n o f g r o u p 2-i nju ri es in this s t u d y s h o w s sim ila ri­ ties w i th b o th civili an28'31 a n d mili- ta ry 2-4'7 p o p u l a t i o n s w h e r e the k n e e , INCIDENCE OF TRAINING-DAYS LOST (%) 50 4 0 30 20 10 Standard Boot V / A Sorbothane Boot Thigh Foot Heel Ankle Achilles Lower leg Knee ANATOMICAL SITE Figure 4: A n a t o m i c a l d is t r i b u t i o n o f tra i n i n g days lost d u e to G r o u p 2 - in j u ri e s p e r bo ot typ e S P O R T S M E D I C I N E VOL S. N O 1 Thigh Foot Heel Ankle Achilles Lower leg Knee ANATOMICAL SITE Figure 3: A n a t o m i c a l d i s t r i b u t i o n o f G r o u p 2-inju ri es p er bo ot typ e INCIDENCE OF INJURY (%) Standard Boot V '/ A Sorbothane Boot R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) PREVENTATIVE SPORTS MEDICINE lower leg a n d Achilles t e n d o n suffered the h ig h es t i n c id e n c e o f o v e r u s e injury, c o m p a r e d to o t h e r an a t o m i c a l sites o f the lower e x trem itie s. A l t h o u g h the SO s h o w e d low e r overall o v e ru s e in ju ry in­ c id en ce t h a n the S T , it d id ho w ev er have a h ig h e r in c id e n c e o f g r o u p 2-knee inju ri es t h a n the S T ( S T = 3 2 ,6 % vs SO = 3 8,1% ). T h i s co u ld p oss ib ly b e at­ t r i b u t e d to t h e d es ig n o f t h e SO inn er- sole ( F i g u r e 2), w h e r e t h e b u i l d - u p o f the m e d ial l o n g itu d in a l a r c h may have c au s ed an al ter ed foot po si tio n in a r e ­ crui t w ith n o foot a b n o r m a l i t y . 34 Such an i n d u c e d an a to m ic a l m a la li g n m e n t co u ld have p r e d i s p o s e d th e w e a r e r to in ju ry in t h e area o f the k n e e . 26-3233 W h i l e th e k n e e s u s t a i n e d the hig hes t g r o u p 2 - i n j u r y i n c id en ce for b o th boot typ es in this s t u d y ( F i g u r e 3), low er leg inju ri es ca u s e d t h e gre a te s t loss o f t r a i n ­ ing d ay s ( F i g u r e 4). T h i s o b se rv a ti o n i m p lie s that o v e ru s e o f the lower leg w ere o f a m o r e serious n a t u r e t h a n kn ee injuries . T h i s findin g is in a g re e m e n t w ith a p re v i o u s s tu d y 4 a m o n g So u th A f­ rican A r m y recruits. O n ly a few stu d ies hav e b e e n p u b ­ lis hed th a t specifically c o n c e n t r a t e on i m p r o v i n g the s h o c k - a b s o r b i n g c a p a ­ bilities o f t h e c o m b a t b o o t , in an a t ­ t e m p t to re d u c e the in c id e n c e o f inju ry a m o n g re c r u i t s d u r i n g basic t r a i n ­ i n g . 81013 In m a k i n g a b io m e c h a n i c a l c o m p a r i s o n b e t w e e n r u n n i n g shoes a n d c o m b a t b o o ts , d e M o y a 10 f o u n d tha t ca­ d ets w e a ri n g c o m b a t b o ots ex p e ri e n c e d m a x i m u m vertical fo rce re a d i n g s o f o v e r 3 tim es b o d y w e i g h t , w h ile th e use o f i ns erts (S ar an ) w i th i n the bo ot s ig n i­ ficantly i m p r o v e d the c u s h io n i n g re ­ sp o n s e to im p a c t . M i l g r o m et a ln c o n ­ d u c t e d a s t u d y to ev alu ate th e effect o f a s h o c k - a b s o r b i n g o rt h o t i c ( P P T - L a n g e r ) on t h e i n c id e n c e o f stress fra c tu re s in m ilita ry re c r u i t s . T h e i r fi n din g s s h ow ed tha t the co n c e p t o f o rt h o t i c p ro p h y la x is significantly low ered t h e in c id e n c e o f femoral str es s frac tu re s w h ic h th e y c o n ­ s id e r e d to be pote n tiall y the m o s t d a n g ­ e r o u s ; d u e to th e ir t e n d e n c y to b e “ si­ l e n t ” for long p e ri o d s a n d t h e ir risk to ev olve int o d is p laced stress f r a c t u r e s . 13 F o r th e p u r p o s e o f d e t e r m i n i n g w h e t h e r fe w er inju ri es w o u ld o ccu r f ro m u sing c u s h i o n e d inner sole s (S p e n c o a n d P o r o n ) , S m i th et aP m o d ­ ified th e b o ot u s ed for all tra i n i n g and m a r c h i n g by t h e U n it e d States Coast G u a r d . T h e i r fin dings s h o w e d th a t the c o n tr ol g r o u p has th e hig h es t i n j u ry i n ­ cid e n c e (6 2 ,5 % ) d u r i n g basic t r a i n i n g , 9 fo llowed b y the P o r o n a n d Sp en co 10 g r o u p s w i th 2 6 % a n d 14,2% r e s p e c ­ tively, w h il e th e overall co m f o r t o f the bo ot was also e n h a n c e d wi th the use o f th e s h o c k - a b s o r b i n g inn er so le s. CO NCLUSION T h e re su lts o f o u r a n d t h e a b o v e s t u d ­ ies810-13 in d i c a t e th a t an i m p r o v e m e n t in the s h o c k - a b s o r b i n g cap ab ili ties o f the c o m b a t b o ot is r e q u i r e d , if t h e hig h i n ­ c id en ce o f i n j u r y a m o n g r ecr u its d u r i n g basic t r a i n i n g 1'4 is to b e r e d u c e d . A l­ t h o u g h d if fe re n ce s in re search p ro to co ls a n d the m a te ri al u sed in th e se s tud- jes8.io,i3 d isqual ifies an a c c u r a te c o m ­ pa rison w ith each o t h e r a n d with th e re ­ sults o f this stud y, a m e a s u r e o f c o rr elation can b e d e d u c e d . I n this a n d the s tu d ies o f d e M o y a , 10 M i l g r o m et a ln a n d S m i th et a l,g the m o d ificatio n o f pla cing s h o c k - a b s o r b i n g in n er so les w ith in c o m b a t b o o t s , r es u lte d in a lower in c id e n c e o f injury, c o m p a r e d to the s t a n d a r d c o m b a t b o o t, c o n fi rm i n g the su ccess o f this p r o p h y l a c t i c a p ­ p roac h. R E F E R E N C E S 1. B e n s e l C K . T h e e f f ec t s o f t r o p i c a l a n d l e a t h e r c o m b a t b o o t s o n l o w e r e x t r e m i t y d i s ­ o r d e r s a m o n g M a r i n e C o r p s r e c r u i t s . 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P h i l a d e l p h i a : W B S a u n ­ d e r s , 1987. 2 5. N o a k e s T . L o r e o f R u n n i n g . C a p e T o w n : O x f o r d U n i v e r s i t y P r e s s , 1985. 26. M c K e n z i e D C , C l e m e n t D B , T a u n t o n J E . R u n n i n g s h o e s , o r t h o t i c s a n d i n j u r i e s . S p o r is M e d 1 9 8 5 ; 2 : 3 3 4 - 3 4 7 . 2 7 . N i g g B M . Biom echanics o f R u n n in g Shoes. C h a m p a i g n : H u m a n K i n e t i c s , 1986. 28. J a m e s S L , B a t e s B T , O s t e r n i g L R . I n j u r i e s t o r u n n e r s . A m J S p o rts M e d 197 8; 6: 4 0 - 5 0 . 29. K r i s s o f f W B , G e r r i s W D . R u n n e r ’s i n j u ­ ri es . P h y sS p o rlsm e d 1979; 7: 5 5 - 6 4. 30. C l e m e n t D B , T a u n t o n J E , S m a r t G W , M c - N i c o l K L . A s u r v e y o f o v e r u s e r u n n i n g i n j u ­ ri es . P h y sS p o rlsm e d 1980 ; 9: 4 7 - 58 . 31 M a u g h a n R J , M i l l e r J D B . I n c i d e n c e o f t r a i n i n g - r e l a t e d i n j u r i e s a m o n g m a r a t h o n r u n n e r s . B r J S p o r i s M e d 19 81 ; 17: 1 6 2- 16 5. 32. L u t t e r L D . F o o t - r e l a t e d k n e e p r o b l e m s in t h e l o n g d i s t a n c e r u n n e r . F oot & A n k le 198 0; 1: 113 -1 1 6. 33. S u b o t n i c k S I. F o o t o r t h o s e s : A n u p d a t e . P h ysS p o rlsm ed 19 8 3; 11: 10 3- 1 09 . ---------------------------------------------------------------- 9S P O R T G E N E E S K U N D E VOL 5. N R I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) NUTRITION ENERGY VALUE OF FOOD M Faber ENERGYINTAKE T h e m a in d if feren ce b e t w e e n the a t h ­ letes die t a n d t h e die t o f th e g en eral p o p u l a t io n can be f o u n d in the level o f en e rg y int ak e. E n e r g y r e q u i r e m e n t s o f the at h le te d e p e n d no t on ly on the type o f ex ercise, b u t also on t h e tim e u sed p e r f o r m i n g the activity. In o t h e r w o r d s , the en e rg y r e q u i r e m e n t s m a y v ar y over tim e a c c o rd i n g to t h e p hys ic al train in g p r o g r a m m e o f th e ath le te . To m a in t a i n good p e r f o r m a n c e , the e n e r g y inta ke m u s t e q u al t h e e n e r g y e x p e n d i t u r e . T h i s will re su lt in t h e b o d y w eig h t r e ­ m a in i n g m o re o r less sta ble. T h e b o d y weig ht o f an at h le te can be an in d icatio n w h e t h e r he is c o n s u m i n g sufficient e n ­ ergy. E n e r g y i m b a l a n c e will be e v ide nt by ch an g es in b o d y w eig ht. If en erg y im b a l a n c e o c c u r s , t h e in d i v id u a l will eithe r lose or gain w eig ht. I f th e en erg y c o n te n t o f th e food in g es ted is less th an the en e rg y o u t p u t , i.e. if t h e en e rg y bal ­ an ce is n e g a tiv e , e n d o g e n o u s stores n a m e ly g ly co g en , fat a n d b o d y p ro te in are utilised a n d the i n d iv id u a l loses wei ght . If the e n e r g y v al ue o f the food intak e exce eds e n e r g y e x p e n d i t u r e , the b ala nce is po sitive a n d e n e r g y is store d as a d ip o s e tis sue a n d the in d iv id u al g ai ns w ei g ht. E a c h k il o g ra m o f ad ipo s e tissue (fat) r e p r e s e n t s th e sto ra ge o f M ie k e F aber Research In stitu te fo r N u tn d o n a l Disease M ed ica l Research Council, T Y G E R B E R G . a b o u t 7000 kcal (2 9 3 00 k j) . I f th e a t h ­ lete is o v e rw e ig h t a n d s h o u l d lose w e i g h t , a ste ad y w e i g h t loss o f 0,5 to 1,0 kg p e r w e e k is r e c o m m e n d e d . To achieve this wei g ht loss, the e n e r g y d e ­ ficit s h o u l d be b e t w e e n 3500 a n d 7000 kcal( 14650 a n d 29300 k j ) per w ee k. WHERE DOES TH E ENERGY IN THE DIET COME FROM? T h e en e rg y value o f t h e diet is ex p res s ed in e ith e r calories (kcal) o r kilojoules ( k j ) . O n e kcal e q u als 4 , 1 8 6 k j . T h e e n ­ erg y v al ue o f dif fe re n t food i te m s is d e ­ t e r m i n e d by t h e c a r b o h y d r a t e , p ro te in a n d fat c o n te n t o f food. A lcoho l m a y also c o n t r i b u t e to the e n e r g y c o n te n t o f t h e d i e t . 1 g c a r b o h y d r a t e s u p p l i e s 4 kcal( 17 k j ) 1 g p ro te in s u p p l i e s 4 kcal( 17 k j ) 1 g fat su p p lies 9 kcal(37 k j ) 1 g alcohol su p p lies 7 kcal (29 k j ) A calo rie is a calo rie, w h e t h e r it co m e s fr o m c a r b o h y d r a t e , p r o te in o r fat. M o s t o r d i n a r y foods are c o m b i n a t i o n s o f p r o ­ tein, c a r b o h y d r a t e , fat, a n d it also c o n ­ tains v a ria b le a m o u n t s o f w a t e r (s o m e as h ig h as 9 0 % ). It also c o n ta in s v it a m in s a n d m in era ls . F o o d s th a t hav e a hig h w a t e r c o n t e n t , s u c h as fruit a n d ve g­ et ab les, h av e small q u a n t i t i e s o f p r o ­ te in, c a r b o h y d r a t e s a n d fat a n d are th e re fo re relativ ely low in calories. F o o d s w h i c h c o n ta in little or no water, eg s u g a r (with p le n t y c a r b o h y d r a t e s ) , oil a n d fats (with p le n t y fat) ar e loaded with energy. A g re at d is a d v a n t a g e o f m a n y o f the e n e r g y loa de d foo ds is that th e y often p ro v id e little m o r e t h a n e n ­ ergy. A n i m b a l a n c e b e t w e e n th e en erg y intak e a n d n u t r i e n t in t a k e is th e re fo re the result. T h e fact th a t food co n ta in s w ater can lead to m a n y m i s c o n c e p t io n s c o n c e r n i n g t h e energy, p r o te in a n d c a r b o h y d r a t e c o n te n t o f food. F o r e x a m p l e , m e at is k n o w n as a hig h p r o ­ tein food. T h i s d o es n o t m e a n th a t 30 g o f m e at eq u als 30 g o f p r o te in . In fact, 30 g m e at s u p p l i e s on the a v era g e on ly 7 g p r o te in a n d 5 g fat. T h e r e m a i n i n g 18 g (60 %) is m o s t ly water, w h ic h s u p ­ plies no energy. E v en w h e n all t h e vis­ ible fat is re m o v e d fro m m e a t , it still co n ta in s v a ria b le p r o p o r t i o n s o f inv is ­ ible fat w h ic h are closely as sociated w i th o th e r c o n s t i t u e n t s in an e m u l s i o n or as p a rt o f th e tissue. W h e n p l a n n i n g an ea tin g p a t t e r n , e n e r g y in ta k e is no t the on ly d e t e r m i n i n g factor. F a c to r s s u c h as p ro te in n e e d s , v it a m in a n d m in era l re ­ q u i r e m e n t s a n d ad v e rs e effects o f high fat i ntak es s h o u l d also be t ak en into c o n s id e ra ti o n . A B A L A N C E D die t, c o m p o s e d o f t h e t h r e e m a c r o - n u t r i e n t s ( c a r b o h y d r a t e s , p r o te in a n d fat) p lu s vi­ t a m i n s a n d m i n e r a l s , is n eces s ary for p r o p e r n u tr i t io n . It is q u it e p o ss ib le to c o n s u m e a d e q u a t e a m o u n t s o f energy, b u t b ecau s e o f p o o r food ch o ic es, be m a l n o u r i s h e d d u e to ce rt ai n n u t r i e n t deficiencies. It m u s t be k e p t in m i n d that fats a n d s u g a r do no t c o n ta in p r o ­ tein a n d m i n e ra l s . W h e n t h e y c o n s ti t u t e a large p r o p o r t i o n o f t h e total e n e r g y i n ­ tak e, t h e re is a d a n g e r th a t o t h e r n u t r i ­ ent n e e d s will not be m e t. A s s u m i n g tha t en e rg y n e e d s ar e m e t , t h e follo wi ng en e rg y d i s t r i b u t i o n is r e c o m m e n d e d : • at least 5 5 % o f the e n e r g y s h o u l d be s u p p l i e d by c a r b o h y d r a t e s ; • 12-15% o f th e en e rg y s h o u l d be s u p ­ plied by p r o te in ; 10 ---------------------------------------------------------- S P O R T S M E D I C I N E VOLS. N O 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) NUTRITION • fat s h o u l d n o t ex ce ed 3 0 % o f the t o ­ tal e n e r g y int ak e. T h e q u a n t i t y o f food is defi n it el y no i n ­ dication o f e n e r g y intak e. To inc re as e the b u lk o f th e d ie t, foods w i th a low er en erg y d e n s it y (fe wer k c a l / 100 g) ca n be c o n s u m e d . A n e x a m p l e o f a food ite m with a low en e rg y d e n s it y is an ap p le (58 k c a l / 1 OOg) c o m p a r e d to ch oco la tes wh ic h has a hig h e n e r g y d e n s it y (520 k c a l / 1 OOg). T h e g re a te s t pitfall in en e rg y int ake is the fats o n e is not a w a r e o f (in ­ visible fats), s u c h as fat in fri ed fo ods, me lted b u t t e r in ho t v e g e t a b le s , cre a m in s o up s a n d s au ces , salad d r e s s in g s a n d rich b a k e d p r o d u c ts . F o o d s ca n be g r o u p e d t o g e t h e r a cc o rd in g to t h e i r c a r b o h y d r a t e , p r o ­ tein a n d fat co n te n t . E a c h g r o u p c o n ­ tains foods th a t ar e m o r e o r less alike. T h e a v era g e m a c r o - n u t r i e n t c o n te n t for these g r o u p s are s u m m a r i s e d in th e fol­ lowing table. T h i s tab le can be u sed as a guid el ine in p l a n n i n g t h e d aily en e rg y intake. Table 1: Kcal a n d m a c r o - n u t r i e n t c o n te n t o f foods Q u a n tity C H O (g) P ro te in (g) F a t (g) E nergy (kcal) S tarch/bread 30g b read or 125 m L cereal or 125 m L pasta* or 125 m L grain* o r 125 m L rice* 15 3 trace 80 Lean m eat 90 g • 21 9 165 M edium -fat m eal 90 g - 21 15 225 H igh-fat meal 90 g - 21 24 300 Vegetables 125 m L cooked or 250 m L raw 5 2 - 25 F ru it 125 m L fresh fruit o r 125 m L juice or 62 m L d ried fruii 15 60 Skim m ilk 250 m L 12 8 trace 90 Low-fat m ilk 250 m L 12 8 5 120 W hole m ilk 250 m L 12 8 8 150 Fai 5 g 1 teaspoon - • 5 45 * Cooked values S P O R T G E N E E S K U N D E VOL S. N R I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) DIE WAARDE VAN PRE-SEISOENSEVALUERING EN POST- TRAUMATIESE FISIEKE REHABILITASIE DDJ Malan IN LEID ING D ie afgelope dekade is die sportwereld en deelname aan fisieke aktiwiteit ge- kenmerk deur die “fitness boom ” wat voorgekom het. N ie alleen het die nuwe bedrywe tot stand laat kom nie, maar ook ’n deels onverwagte uitdaging aan die sportgeneeskundige professie gestel. D ie voorkoms van beserings tydens deelname aan sport en fisieke aktiwiteite het weens die deelnemerstal bykans maandeliks toegeneem . Gepaardgande hiermee is die sport- geneeskundiges en lateraan ook die oe- fenkundiges met ’n andersoortige bena- dering ten opsigte van die beoordeling en behandeling van beserings tydens deelname gekonfronteer. Gedurende die sestiger- en sewentigerjare het die klem hoofsaaklik geval op die diagnose en behandeling van akute beserings, ter- wyl die analise van die voorkom ende as- pekte weinig aandag geniet het (Stanish, 1984:1). Hierdie aanvanklike gebrek en eensydige benadering het egter bygedra tot die meer professionele spanbenader- ing in die voorkom ende en rehabilite- rende fases van sportbeserings. Op verskeie terreine van sport en fisieke ak­ tiwiteit is doelgerigte opleidingspak- kette ter verbetering van afrigters en programleiers se basiese kennis oor oe- fenkundige aspekte tydens deelnam e, daargestel. Binne ’n bestek van sowat 5 jaar het daar veral op die terrein van die oefenkundige aspekte, ’n meer bewuste en kundige benadering voorgekom . D it is egter ook waar dat die gevare ver- D r D D J Malan Instituut v ir Biokinetika Departement Menslike Bewegingskunde P U v ir C H O S P O R T S M E D I C I N E V O L 5. N O I bonde aan oefenprogram voorskrif deur verskeie aanbieders geignoreer word weens die gebrek aan opleiding, met ’n gevolglike hoe insidensie van beserings wat by diesulke persone se groepe voor- kom. D ieselfde tendens word volgens Stanish (1984:1) ook in Kanada aange- tref, waar daar selfs meer aandag aan opleiding gegee word. Selfs op skool- vlak word daar tans ’n voorkomende benadering tot fisieke aktiwiteitsdeel- name gevolg. ’n Verdere uitvloeisel van hierdie toe- nem ende probleem waarmee sportge- neeskundiges en oefenkundiges worstel, is die daarstelling van semi- naargeleenthede waar kundiges ge- dagtes kan uitruil en kennis oor die voorkoming en behandeling van beser­ ings kan oordra. D ink maar net in hier­ die geval aan die totstandkom ing van ons eie Sportgeneeskundige Vereniging, asook die werksaamhede van SAVSLOR (Suid-Afrikaanse Vereniging vir Sportwetenskap Liggaamlike Op- voedkunde en Rekreasiekunde) op die terreine van O efenkunde en Biokinetika in die geval van laasgenoemde organisa- sie. In m eeste opsigte is die dienste van die multidissiplinere span op die ge- sondheidsorg van die deelnem ers inge- stel. Beserings in sport en fisieke aktiwiteit toon groot w isseling. Kontaksport is al- gem een bekend vir die hoe insidensie van beserings, maar niemand het ge- dagte gehad dat die deelnam e aan aero- biese dansoefeninge so ’n magdom be­ serings tot gevolg sal he nie. Wat in hierdie twee uiterstes van aktiwiteite veral opvallend is, is dat die voorkoms van dieselfde tipe besering, aan totaal verskillende oorsake toegeskryf kan word. So byvoorbeeld kan ’n swak fisieke spiervermoe in die geval van die rugbyspeler aanleiding gegee het tot die besering, terwyl onkundigheid oor pro- gramuitvoering in die geval van die aerobiese dans deelnem er as oorsaak voorgehou kan word. Daar is bereken dat gedurende 1983 sowat 20% van die Amerikaanse be- volking aan hardloopaktiwiteite deelge- neem het (Stanish, 1984:1). ’n Verdere 10% het aan ’n verskeidenheid ander sport en fisieke aktiwiteite deelgeneem wat potensieel tot beserings kon aan­ leiding gee. D it mag dalk die indruk van ’n baie gesonde gem eenskap gee, wat wel ook waar is, maar weens die toe- name is beseringsinsidensie blyk dit eerder ’n “beseerde” gesonde gem een­ skap te wees. Op geen w yse is m edici in staat om bo-en-behalwe hul normale be­ handeling van siektetoestande ook nog met die behandeling van beserings ty­ dens fisieke aktiwiteit vol ten hou nie. O p een o f ander wyse genoodsaak dit ’n profilaktiese benadering. D eelnam e aan sport en selfs fisieke aktiwiteite in die algem een kan soms bom enslike eise aan die fisieke vermoe van die liggaam stel. D it het daartoe by­ gedra dat die voorbereiding van veral sportlui meer gesofistikeerd en gespe- sialiseerd geraak het, vanwee die meer wetenskaplike benadering van afrigters. D it is oor die afgelope 40 jaar sterk aan- gespoor en ondersteun deur ’n “navor- singsontploffing” op die terrein van die sportgeneeskunde. Ten spyte van die meer wetenskaplike benadering van sportafrigting, is dit by­ kans onm oontlik om die sportdeel- nemer se “spook” - ’n sportbesering - tydens deelnam e weg te hou. Ongeag na watter sportsoort gekyk w ord, bly die traumatiese ervaring van ’n besering die grootste terugslag wat ’n deelnem er kan ervaar. Suid-Afrika gaan deels nog gebuk onder afrigters/programleiers wat nie vatbaar vir “inm enging” is nie en so- doende hulself as alwetend beskou. So- R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) danige benadering weerspieel ’n gebrek aan kundigheid en stel h u lself en onge- lukkig ook die sportlui aan gebrekkige vordering en ander problem e bloot. D ie teenoorgestelde is egter ook waar. D ie afrigter/programleier beskou hulself as spesialiste op hul terrein, maar ag dit nodig om ander ondersteunende kun- diges te nader ter w ille van die voordele daarvan aan die deelnem ers. Sodanige wisselwerking is ’n direkte aankno- pingspunt tot die profilaktiese benade­ ring tot beserings tydens deelnam e aan sport en fisieke aktiwiteit. PRE-SEISOENSE VALUERIN G Verskeie wetenskaplikes (o.a. H unter et al., 1979:205; N o b le , 1980:12; Watson, 1981:47 & Rice, 1984:192) maak m eld­ ing van die verskeidenheid van wyses waardeur beserings tydens deelname voorkom kan word. Voorstelle in hier- die verband het gewissel van wetenskap- like opleiding van afrigters/program - leiers tot verandering aan die reels van die spel. Een van die uitstaande faktore wat in die navorsing na vore gekom het, is die eenstem m igheid oor die belang- rikheid en waarde van pre-seisoenseva- luering. N ie alien word dit as ’n voorko- mende maatreel gestel nie, maar hou dit ook bepaalde voordele in indien die deelnemer later beseer sou raak. Appen en Duncan (1986:232) ver- klaar dat pre-seisoensevaluering a riglyn gebruik kan word om die deelnem er se gereedheid vir deelnam e aan ’n bepaalde sport te kan bepaal. H ieruit kan afgelei word dat die deelnem er se fisieke toe- rusting net so belangrik is as die toerus- ting waarmee die aktiwiteit beoefen m oetword. Pre-seisoensevaluering dien ook as metode waardeur “swak skakels” in die fisieke m ondering van deelnem ers ge- identifiseer kan word. Sodoende kan daar dan met die korrekte inoefen- ingsm etodes, ’n regstelling van die te- kortkominge gemaak w ord, waardeur die m oontlike oorsaak van beserings verminder kan word. Watson (1981:417) beklem toon die voorafbepaling van sportdeelnem ers se fisieke toestand. In hul navorsing is 0/15 en 0/16 rugbyspelers aan ’n fisieke pre- seisoensevaluering onderwerp. Sy be- vinding was dat die deelnem ers se krag, grootte en sukses tydens deelnam e nie as waarborg moet dien vir die afwesig- heid van fisieke tekortkom inge nie. D ie navorsing het duidelik gedui op die noodsaaklikheid van preseisoenseva- luering reeds op jong ouderdom , ten einde individuele verskille te kan aandui asook om op daardie ouderdom reeds fisieke tekortkom inge te kan regstel. Watson (1981:421) beklem toon die noodsaaklikheid na evalueringsm etodes wat vinnig en effektief deur afrigters/ programleirs uitgevoer kan word. Rice (1984:192) m eld dat aanbevelings deur die sportgeneeskundiges en sportvere- nigings in die V .S .A . daarop is om alle deelnem ers aan sport op Hoerskool- vlak, jaarliks aan ’n pre-seisoensevaluer­ ing bloot te stel. In hul ondersoek is vasgestel dat 70% van die persone wat na ’n jaar ge-herevalueer is, bepaalde diskwalifiserende probleme vertoon het, waarvan 55% een o f ander vorm van m uskulo-skeletale o f ortopediese probleem was. Strydom (1985:7) verwys ook na die neiging dat afrigters meer spesifiek is in hul voorbereidingsm etodes van sport­ lui. T w ee provinsiale rugbyspanne het in 1984 ’n poging aangewend om hul spelers aan pre-seisoensevaluering te onderwerp. Weens die belangrikheid van die kom petisie en die gesindheid van die spelers is die navorsing nie na wense voltooi nie, en is daar nog w einig inligting hieroor beskikbaar. N avorsing deur die Instituut van Sportnavorsing en -O pleiding het in 1985 resultate verkry wat dui op die afname van fisieke vermoe namate die seisoen verloop het. Sonder preseisoensevaluering sou soda­ nige afleiding nie gemaak kon word nie. Uit gesprekke met m edici en ortope- diste het dit geblyk dat preseisoense­ valuering van groot waarde is in die diagnose van ’n beseerde deelnemer. D it is egter nie haalbaar om sodanige evalu- ering op elke deelnem er toe te pas nie, maar kan dit aanvanklik veral op deel­ nemers van hoe standaard toegepas word ten einde ’n verwysingsraamwerk daar te stel. Op verskeie geleenthede is die opm erking al gemaak dat die evalu- ering van ’n besering meer doeltreffend sou gewees het indien die resultaat van ’n preseisoensevaluering bekend was. So byvoorbeeld word, waar m oontlik, by 1 Mil. Hospitaal ’n pre-operatiewe evaluering gedoen van pasiente met ’n besering, ten einde fisieke rehabilitasie meer doeltreffend te kan maak. D ie noodsaaklikheid van pre-seisoen­ sevaluering blyk duidelik uit die boge- noem de argumente en resultate. Ter op- som ming kan die waarde van sodanige evaluering net weer kortliks aangestip word. • D it dien as m etode waardeur fisieke tekortkom inge waargeneem kan word; • Identifisering en rem ediering van “swak plekke” kan daartoe bydra dat die voorkoms van beserings verm in­ der kan word; • D it stel die afrigter/programleier in staat om meer doelgerig met die inoefeningsprogram te handel; • D it dien as wyse waardeur delnem- ers op individuele grondslag beoor- deel kan word en programvoorskrif daarvolgens kan geskied; • D it dien as basis waarteen opvolge- valuerings vergelyk kan word; en • Tydens rehabilitasie dien dit as norm waaraan die herstelproses meer objektief beoordeel kan word. POST-TRAUM ATIESE FISIEKE REHABILITASIE Dit is nie die oogm erk van hierdie lesing om verdiep te raak in die rehabilitasie- prosedures en resultate van ’n enkele o f wye verskeidenheid van muskulo-skele- tale problem e nie. D ie doel is meer op die waarde wat post-traumatiese fisieke rehabilitasie vir sportlui in die algemeen in h o u ,u it te lig. Soos in die geval van ’n multidissipli- nere spanbenadering in die voorkoming van beserings, behoort dieselfde weg ook opgegaan te word in die rehabilita­ sie van ’n beseerde deelnemer. D ie om- vang van deelnam e, die toename in be- seringsinsidensie en die kom pleksiteit van rehabilitasie na die besering ge- noodsaak sodanige benadering. Verskeie sentra in ons land kan as dui- delike voorbeeld van die suksesvolle samewerking van m edici, fisioterapeute en biokinetici in die rehabilitasie van be- seerdes voorgehou word, ’n Praktiese voorbeeld van spanwerk in hierdie ver- S P O R T G E N E E S K U N D E V O L S . N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTBESERINGS b an d ka n in d ie re h a b i l i t a s i e s e n t r u m by I Mil. H o s p . gesie n w o r d . D i e s p an be- haal u it s t e k e n d e res u lta te m e t beseerd e p asie nte wat m u s k u lo - s k e l e t a le b e s e r ­ ings o p g e d o e n het. T y d e n s ’n p e r s o o n l i k e b es o ek aan die VSA is gev in d d a t so o r tg ely k e d ie ns te aa n ver skei e s p o r t k l u b s en p ri v a a tp ra k - tyke g el ew er w o r d . Dit is nie v r e e m d o m o.a. by va n die A m e r ik a a n s e v o e tb a l s p a n n e so ’n s p o r t g e n e e s k u n - dig e s p a n aan te t r e f nie. Ten voile toe- g e ru s te r e h a b i li t a s ie k a m e r s w a a r ak u te en finale fase fisieke re h ab ili tas ie uitge- v o er w o r d , is aa n die o r d e van die die dag. Die w a a r d e va n re h ab ili tasie vir h ie rd ie s p o r t s p a n n e m o e t gelees w o rd in d ie effektiwiteit w a a r m e e r die sp elers tot die spel t e ru g g e p l a a s w o r d , ’n Alge- m e n e u i t d r u k k i n g is d at die sp ele r in ’n b e t e r to e stan d aan die s p an t e r u g b e s o r g w o rd as w aarin hy was v o o r d ie b e s e r ­ ing. E en van die h o o f d o elste lli ngs van r e ­ habili tasie is o m die p ers o o n se funsio- nele v e rm o e te h er stel. In d ie geval van profe ssionel e s p o r t d e e l n e m e r s , is s o d a ­ nige doelstel lin g nie v o ld o e n d e nie. D a a r w o rd vereis dat die d e e l n e m e r so gou as m o o n t li k tot d ie spel m o et te- rugkeer. Die psigologie se i m p a k van so 'n eis kan eg ter s o m s g r o t e r s k a d e aa n ri g as d ie insid en sie van die b e s e ri n g self. Effe ktie we reh ab ili tasie k a n s o m s ’n ty- d r o w e n d e p ro s es wees w a a r t y d e n s die d e e l n e m e r som s nie g e d u l d het o m voile fu nsionel e v e r m o e te h e r w i n nie. D a a r is gevalle in d ie VS A o p g e t e k e n w aar sp elers v o orge ge e het d at h u ll e ten voile herstel h e t , m a a r o n d e r s o e k e a a n g e d u i het dat fu n k s i o n e l e v e r m o e n o g nie ten voile h e rw i n is nie. D o e l g e rig t e post- t ra u m a t i e s e re h a b ili ta s ie k a n in so m- mi ge opsi g te h ie rd ie soor t van pro- ble em o o r b r u g en d ie s p e le r in die spel te ru g ge plaas s o n d e r verlies aan fisieke verm oe . Die w a a r d e v a n p o s t - t r a u m a ti e s e fisieke re h ab ili tas ie le o p g e t e k e n in die su ks es se wat m e t s o d a n i g e p r o g r a m m e behaal is. Die in t e ra k s i e tu s s e n d ie reha- b il i t a s i e p ro g ra m e n die k o r r e k t e d ia g ­ nose van d ie b e s e ri n g e n / o f d ie ge- sla ag dh eid van die c h i ru rg ie s e p r o s e d u r e ka n in ’n g ro o t m a te die suks es van fisieke re h ab ili tas ie bepaal . Fi siek e re h ab ili tas ie w o rd s o m s ook ge- b r u i k o m d ie g e s la a g d h e i d v an die oper - asie in die her stel v an fu n k s i o n e l e v e r ­ m o e te b e o o rd eel. O n g e a g na w a ite r k an t van die skaal g e k y k w o r d , het n a ­ v o rs in g die w a a r d e v an finale fase fisieke rehab ili ta sie l a n k gel ed e reed s bev estig . Ver d ik el al (1 967) en W oo el al. (1979) het a a n g e t o o n dat g e d u r e n d e s u b m a k s i m a l e iso k in et ies e w e e rs t a n d - s in o e fe n i n g , v e r s t e r k in g van l ig am en te en te n d o n s k a n v o o r k o m . Ter o n d e r s t e u n i n g h ie rv a n het Z u k e r m a n et al. (1969) en T i p t o n et al. (1970) vroee ree ds b ev in d dat w e e r s t a n d s o e f e n m g die b r e e k k r a g en k r a g d r a v e r m o e van li­ g a m e n t e ka n v e rh o o g . S o d o e n d e ka n g e g r a d e e r d e p r o g r e s s i e w e w e e r s t a n d - s o ef en inge va n s u b m a k s i m a l e tot maksi- m a le inten site it as s t i m u l u s vir groei en v e r s t e r k in g van d ie l ig am en te d ie n. H i e ru it k an afgelei w o r d dat in gevalle m e t lig a m e n tl a k s i te i t , - r e k o n s t r u k s i e en t e n d o n s k e u r i n g s , effe ktie we fu n k s i o ­ nele h erstel d e u r finale fase fisieke r e h a ­ bilitasie bew erk s te ll ig k a n w o rd . Da vie s (1 9 8 5:2 2 4 -2 2 8 ) het a a n g e t o o n dat p e r s o n e met patella s u b l u k s a s i e na slegs 6 w ek e va n iso k in eti ese w e e rs t a n d - sin o efe n in g ’n m e r k b a r e v e r b e t e r i n g in k ra g l e w e ri n g o n d e r v i n d het. In hie rd ie stu d ie is a a n g e t o o n dat a b n o r m a l i te it e in die k r a g l e w e r i n g s k u r w e , wat t ip e re n d van h ie r d ie p r o b l e e m is, m e t fisieke r e ­ habili tasie v e r w y d e r k an w o r d . Die s tu d i e het o o k a a n g e t o o n dat v e r b e t e r ­ ing in d ie sta bilit ei t van die q u a d r i - c e p s m e g a n i s m e en - k r a g l e w e r i n g , in ’n g ro ot m a te k an k o m p e n s e e r vir d ie s u b ­ luksasie van die p at el la. O o k in d ie geval van c h o n d r o m a l a c i a pat el lae en patello- fem o ra le p y n is g e v in d dat fisieke r e h a ­ bilitasie ’n eff ektie w e v e r m i n d e r i n g en selfs v e r d w v n i n g v an p y n k an teweeg- b ri n g (D a v i e s , 1985:237). Da vie s (1985) het o o k g ev in d dat p e r ­ so ne m e t a n t e r i o r k r u i s l i g a m e n t r e k o n ­ s tr u k s i e , m e t a a n v a n g v an p o s t - t r a u m a - tiese re h ab ili tas ie s te ed s soveel as 4 0 % verlies v an k r a g l e w e r i n g het. D o e l g e ­ ri gte fisieke r e h a b i li t a s ie k an h ie rd ie v e r s w a k k in g eg ter b i n n e e n k ele w eke verwyder. F is iek e re h a b i li t a s ie sal egte r nie net die pas ie nt se s p i e r k r a g va n die b e s e e rd e b ee n n o r m a l i s e e r n ie , m a a r oo k t e g e l y k e rt y d v e r s t e r k i n g van die ge- r e k o n s t r u e e r d e l i g a m e n t laat pla asvin d . Die w a a r d e va n p o s t - t r a u m a ti e s e fisieke re h ab ili tas ie w o r d o o k in ’n on- v a t te n d e o n d e r s o e k d e u r Cilliers (1985) a a n g e d u i. In h ie rd ie n a v o rs in g me t o o rl o g s b e s e e rd e s is a a n g e t o o n d at selfs in ’n wy e s p e k t r u m van b es erin g s e n pa- to lo g ie s/ o rt o pe diese t o e s t a n d e , finale fase fisieke reh abili ta sie o p ’n w y e ter- rei n van w a a r d e k an wees. Dit herstel nie net die f u n k sio n e le v e r m o e van die p as ie nt nie, m a a r lewer o o k ’n b y d r a e in die v e r h o g in g van die i n d i v id u se self- beeld , selfv ertro u e en psigiese inge- s te ld h eid ten opsi g te van s y /h aar situa- sie. Ter o p s o m m i n g ka n d ie g ed ag te van “ ’n b e t e r e i n d p r o d u k ” na fisieke r e h a b i l ­ itasie as k e r n g e d a g t e v o o r g e h o u w o rd . D e u r die res u lta te va n g e re h a b i li t e e rd e d e e l n e m e r s aan a n d e r b e s e e rd e sp ortl u i te to o n , sal die w a a r d e va n h ie rd ie be- lan gr ike fase in die b e h a n d e l i n g van die p ers o o n inslag v in d. B IB L IO G R A F IE 1. A p p e n L e n D u n c a n P W . 19B6. S t r e n g t h r e ­ l a t i o n s h i p o f t h e k n e e m u s c u l a t u r e : ef fe ct o f g r a v i t y a n d s p o r t . J O rth en Sp o rts P hvs Ther, 7/5: 2 3 2 - 2 3 5 . 2. C i l l i e r s J F 1985. D i e b y d r a e v a n g e p r o - g r a m m e e r d e i n o e f e n i n g in d i e n a - m e d i e s e f isi eke r e h a b i l i t a s i e v a n b e s e e r d e s ui t d i e mi l- i te r e o p e r a s i o n e l e g e b i e d . Geklassifiseerde p ro efskrif, P U v i r C H O , P o t c h e f s i r o o m . 3. D a v i e s G J . 1985. A c o m p e n d i u m o f I s ok i - n e t i c s in c l i n i c a l u s a g e . 2 n d E d . W i s c o n s i n , U S A . 5 5 2 p . 4. H u n t e r S , C a i n T E e n H e n r y L 197 9. P r e ­ s e a s o n i s o k i n e t i c k n e e e v a l u a t i o n i n p r o ­ f e ss io n al f o o t b a l l a t h l e t e s . Athletic Training, W i n t e r , p . 2 0 5 - 2 0 6 . 5. N o b l e C . 198 0. P r e v e n t i o n o f r u g b y i n j u r i e s . S A J o u r n a l o f Sp o rts M e d icin e . 9: 12-14. 6. R i c e S G . 1984. P r e p a r t i c i p a t i o n e v a l u a t i o n o f r e t u r n i n g h i g h s c h o o l a t h l e t e s ( a b s t r a c t ) . Ai c d S c iS p o r ts en E xercise, 16/2: 192. 7 S t a n i s h W D . 1984. O v e r u s e i n i u r i e s in a t h ­ let es: a p e r s p e c t i v e . M e d S e t Sp o rts en E xe r­ cise, 16/1: 1-7 8. S t r y d o m G L . 1985. D i e v o o r b e r e i d i n g v a n d i e s p o r t m a n t e r v o o r k o m i n g v a n s p o r t - b e s e r i n g s . Voordrag: Sponbescringsim po- sium , P o t c h e f s i r o o m . 8 p . 9. T i p t o n C M . et al. 1970. I n f l u e n c e o f e x e r c i s e o n s t r e n g t h o f m e d i a l c o l l a t e r a l l i g a m e n t o f d o g s . A m e r'J P h y sio l. 2 18: 8 9 4 - 9 0 2 . 10. V e r d i c A . et al. 1967. T h e e ffe ct o f t r a i n i n g o n l h e t e n s i l e s t r e n g t h o f i s o l a t e d r a b b i t t e n ­ d o n s . S c a n d J P lus R econst S u rg , 1. 141- 147. 11. W a t s o n A W S . 1981. F a c t o r s p r e d i s p o s i n g to s p o r t s m i u r y in s c h o o l b o v r u g b y p l a y e r s . J S p o r is M e d , 2 1 : 4 1 7 - 4 2 2 . 12. W o o S. L - V . et al. 1979. L o n g t e r m e x e r c i s e e f f e c t s o n t h e b i o c h e m i c a l a n d s t r u c t u r a l p r o p e r t i e s o f s w i n e t e n d o n s . Transactions o f the 25th A n n M eeting, O rth. Research S o c, 4: 23. 13. Z u c k e r m a n J . et al. 1969. E f f e c t s o f e x e r c i s e o n k n e e l i g a m e n t s e p a r a t i o n f o r c e i n r a t s . J A p p lP h y sio l, 2 6: 7 1 6 - 7 1 9 . 14 ----------------------------------------------------------S P O R T S M E D I C I N E VOL5. N O I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) q o ---- PAN AMOR' 25 Erdenc coaled tablet containing 25mg diclolenac sodium - T L j Rey No R/3 1'49 o o ---- PANAMOR' AT - 50 Entenc coaled tahtet containing 50mg dciolenac sodium ------- --Reg No Ri3 1/50 PANAMOR' - 75 Injection Each 3m f ampoule contains 75mg diclofenac sooium with 4% v/v banzy alcohol as preservative Reg No W/3 1/52 Is your patient being held prisoner to pain and immobility? There is a release... Diclofenac A non-stcroidal anti-inflammatory . RELIEVES PAIN . REDUCES INFLAMMAT . RESTORES MOBILITY . REDUCES THE COST O TRAUMA THERAPY ‘*Tv A v a ila b le now in. three PANAMOR? ~ 2 5 TABIJSy^y PANAM OR**1 A T ^ g j M t e PANAMOR® - 7 5 IN J E C T ^ m RELEASE FROM INFLAMMATORY PAIN Gray indepenR ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS INJURIES AN EVALUATION OF HAMSTRING/QUADRICEP STRENGTH RATIOS IN ELITE LONG DISTANCE RUNNERS AND SPRINTERS L D avim es and I Levinrad ABSTRACT K eyw o rd s: H am string/quadriceps strength ratios, normative, endurance runners, sprinters, cybex The purpose o f this study was to investigate hamstring/quadricep strength ratios in long distance runners and sprinters. Hamstring/quadriceps strength ratios were obtained in twenty five elite long distance runners and twenty one sprinters at a testing speed o f 60 degrees/sec on the Cybex II. Hamstrings were found to be 62% and 59% o f quadriceps in sprinters and long distance runners respectively. Sprinters generated significantly greater knee flexor and extensor muscle torque than long distance runners for both legs even when strength was expressed relative to body weight. N o significant difference in strength between the dominant and nondominant legs was observed in sprinters. Dominant knee flexors were significantly stronger than nondominant flexors in long distance runners. The study established normative data on hamstring/quadriceps strength ratios in the two types o f running discipline. T he ratio may provide a guide for prophylactic measures athletes can follow for safe participation in sprinting or running. IN TR O D U C T IO N I s o kinet ic s t r e n g t h t es ti n g can be u s e d to id e ntify m u s c l e s t r e n g t h i m b a l a n c e o r w eak n ess. T h e flex o r/ e xten s o r s tr e n g t h b alan ce is i m p o r t a n t in th e s ta biliz atio n o f t h e k n e e a n d m a y b e a factor in k n e e joint i n ju ry s h o u l d th e rat io be a b n o r - Lee D avim es D epartm ent o f P h y s io th e r a p y 1 a n d Physiology2 U niversity o fW itzua tersra n d M ed ica l School Johannesburg Iv a n L e vin ra d 104 H ig h la n ds N o r th M ed ica l Centre H ighlands N o r th Johannesburg mal. T h u s m u s c l e s o r join ts m a y be m o r e p r o n e to i n j u r y if th e ag o n is t a n d a n tag on is t differ signific an tly in s tr e n g t h . E s t a b l i s h m e n t o f n o r m a l k n e e flexor/exten sor rat ios m a y be a n eces s ­ ary p ro p h y l a c t i c m e a s u r e ag ai n st injury. It m a y b e p o ss ib le to id e ntify an a b n o r ­ mal ratio early a n d this ca n b e u sed as a w a r n i n g sign to p r e v e n t injury. H o w ­ ever, it is no t clear at this stage wh at c o n s ti tu te s a n o r m a l a n d a b n o r m a l ratio. I f re search is to b e d o n e on i d e n t i ­ fying a b n o r m a l ra tios t h e n it is essential to es tab li sh a n o r m a l ratio. In a d d i t i o n , in r e h a b i li t a t io n o f an i n ­ j u r e d k n e e , p ro g re s s is u s u a ll y assessed by a c o m p a r i s o n o f s t r e n g t h o f the i n ­ j u r e d k n e e w ith t h e n o n - i n j u r e d c o n t r a ­ lateral k n ee. H o w e v e r, in bilateral kn ee inju ri es it is no t k n o w n at w h a t p o in t the p a t ie n t is r e h a b i li t a t e d a n d a c o m p a r i ­ son o f th e k n e e s t r e n g t h s will not allow a d e t e r m i n a t i o n o f re a s o n a b l e r e h a b i li ­ ta tio n goals. It is t h e re fo re i m p o r t a n t to k n o w w h a t n o r m a l rat ios a re befo re r e ­ t u r n i n g to s p o r ti n g activities. C a m p b e l l a n d G l e n n 3 c o n c l u d e d t h a t a t t e n ti o n s h o u l d b e d ir e c t e d to t h e h a m s t r i n g / q u a d r i c e p s t r e n g t h rat io in re h a b i l i ­ tat ion o f th e k n ee. G oslin g 13 et al c o n ­ t e n d e d tha t k n e e r e h a b i li t a t io n is not c o m p l e t e u n le s s ex ten sio n :f le x io n was 2 : 1. N o r m a t i v e data m a y d if fe r in p eo p le inv o lv ed in dif fe re n t s p o r ts since th e re are specific skills r e q u i r e d in d if ferent s p o r ts a n d specific t o r q u e str esses an at h le te is r e q u i r e d to e n d u r e . 10 T h e r e m a y be a m i n i m u m h a m s t r i n g / q u a d r i ­ cep s tr e n g t h rat io an a th le te s h o u l d ach iev e in o r d e r to safely p a r t ic ip a t e in a specific s p o r t. T h e r e f o r e it m a y be nec es sar y to test h a m s t r i n g / q u a d r i c e p s tr e n g t h rat ios in d if fe re n t sp o r ts . T h i s s t u d y inv es tigate s s t r e n g t h ra tios in r u n ­ ners. A rev ie w o f t h e lit e r a t u r e has i n d i ­ cat ed th a t no n o r m a t i v e data for h a m ­ s t r i n g / q u a d r i c e p s s t r e n g t h rat ios are av ailable for long d is tan ce r u n n e r s a n d 16 ---------------------------------------------------------S P O R T S M E D I C I N E VOL 5. N O I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS INJURIES s printer s. T h e p u r p o s e o f this s t u d y was to establish n o r m a t i v e h a m s t r i n g / q u a d ­ riceps s t r e n g t h rati os in lo n g d is tan ce r u n n e rs a n d s p r in t e r s . In a d d i t i o n , the knee flexors a n d e x t e n s o rs o f lon g d i s ­ tance r u n n e r s a n d s p r i n t e r s will b e c o m ­ p ared . T h e d o m i n a n t leg s t r e n g t h will be c o m p a r e d w i th t h e n o n d o m i n a n t leg in each g r o u p o f su bjects. m e t h o d Selection o f Subjects T w e n ty five lo n g d is t a n c e r u n n e r s (m a ra t h o n r u n n e r s o r h a l f m a r a t h o n ru n n ers ) a n d t w e n ty t h r e e s p r i n t e r s ages 17-32 years s e rv e d as s u b j e c t s in the study. T h e pro to co l was p as sed by th e c o m ­ mittee for R e s e a r c h on H u m a n S u b ­ jects. Testing D evice T h e C y b e x II was u sed as th e testi n g d e ­ vice to d e t e r m i n e s t r e n g t h d e v e l o p e d by the lim b d u r i n g k n e e flexion a n d e x t e n ­ sion (C yb ex D i v i s i o n , L u m e x I n c . , Bay- shore, N . Y . ) . T h e d y n a m o m e t e r was cal ibrate d a c c o r d i n g to the p r o c e d u r e suggested by the C y b e x m a n u fa c tu re r. T h e cy b ex a p p a r a t u s m e a s u r e s kn ee flexion a n d e x t e n si o n at a p re s e t sp eed . D u r i n g co n v e n ti o n a l exer ci se e n e r g y is mainl y d is s i p a te d w ith acc ele ra tio n s in the exercise. T h e c y b e x m e c h a n ic a ll y p re v en ts this d is s ip ati o n o f e n e r g y a n d conver ts it to a resisti ng force w h ic h is p ro p o r ti o n al to t h e m u s c u l a r force. Experimental Procedure G ravitational E ffec t Torque (G E T ) T h e G ra v ita ti o n al Effect T o r q u e is the torqu e re s u l ti n g fro m t h e effect o f the gravity on th e c o m b i n e d w e i g h t o f the leg a n d th e d y n a m o m e t e r a r m . G E T w as d e t e r m i n e d in o r d e r to as­ certain c o rre c tl y th e relative s t r e n g t h o f the an t a g o n i s ts in v er se ly affecte d by gravity. G E T in ftlbs was o b ta i n e d b y loc king the su bjects k n e e i n t o full ex ten sio n a n d the n i n s t r u c t in g h im to relax his q u a d r i ­ ceps m u s c le . T h i s was re p e a t e d again such tha t a c o n s is t e n t v al ue was o b ­ tained. Test on the C ybex after adequate w arm up T h e test wa s p e r f o r m e d at 60 d e g re e s / sec to d e t e r m i n e s t r e n g t h o f t h e h a m ­ strings a n d q u a d r i c e p s as in d i v id u a l m u scles a n d as a ratio. Analysis o f V ari ance tests w e r e u sed to c o m p a r e r u n n e r s w i th re sp ec t to age, m a ss , h a m s t r i n g / q u a d r i c e p s ratios a n d flexion a n d e x t e n si o n e x p re s s e d relat ive to b o d y w eig ht. Analysis o f CoV ari an ce tests w ere u s ed to c o m p e n s a t e for th e effect o f mass in flexion a n d ex ten sio n . D o m i ­ n a n c e was c o m p a r e d w ith n o n d o m i ­ n an ce by a p airw is e c o m p a r i s o n o f m e an s. A lin ea r re g res s io n an alysis was c o m p l e t e d for h a m s t r i n g a n d q u a d r i ­ ceps m u s c l e t o r q u e v ers u s total b o d y wei ght . P e a rs o n C o rr e la ti o n s w e re ca l­ cu lat ed on e ac h vari able. RESULTS Physical c h a ra c te r is t ic s o f t h e su bjects are p r e s e n t e d in T ab le 1. T h e r e w ere sig­ nificant d iffe re n ces in w eig h t b e tw een s p rin t e rs a n d long d is t a n c e r u n n e r s . T h e m e a n s a n d s t a n d a r d d evia tio ns for p e a k h a m s t r i n g a n d q u a d r i c e p s t o r ­ q u e for left a n d rig ht legs ar e p r e s e n t e d in Table 2. T h e q u a d r i c e p s possessed h ig h e r m e a n p e a k t o r q u e va lues th an t he h a m s t r i n g s in b o th g r o u p s o f s u b ­ jects. D iff ere n ces in h a m s t r i n g a n d q u a d r i c e p m e a n t o r q u e b e t w e e n s p r i n t ­ ers a n d long d is t a n c e r u n n e r s w e r e a n a ­ lysed. S p r i n t e r s were f o u n d to p r o d u c e sign ificantly g r e a t e r m e a n peak h a m ­ s tr in g a n d q u a d r i c e p s t o r q u e t h a n long d is tan ce r u n n e r s . Peak flexor a n d e x t e n ­ sor t o r q u e e x p re s s e d relativ e to bo dy w ei ght was s ig n if ic an tly g r e a t e r in s p rin t e rs th a n in long d is t a n c e r u n n e r s (Table 2). Table 3 s h o w s the m e a n s a n d s ta n ­ d a rd d e v ia ti o n s for t h e h a m s t r i n g / q u a d ­ ricep s s t r e n g t h rat ios in b o th g ro u p s . T h e rig h t h a m s t r i n g / q u a d r i c e p rat io did not differ signific an tly in th e two g ro u p s . T h e left h a m s t r i n g / q u a d r i c e p ratio wa s significantly h i g h e r in s p r i n t ­ ers t h a n in lon g d is t a n c e r u n n e r s (p < 0,05). T h e m e a n s a n d s t a n d a r d d e v ia ti o n s o f p eak t o r q u e v al ues for the d o m i n a n t a n d n o n d o m i n a n t q u a d r i c e p s a n d h a m - Table 1: M e a n s a n d s t a n d a r d d ev ia ti o n s for ag e, w eig h t a n d p e r f o r m a n c e in long d is t a n c e r u n n e r s a n d s p rin t e rs . Age (Years) Weight (kg) Best Performance Long 26,24±0.70 66,90+10 42km : 158 min Distance 21km: 74 min Runners Sprinters 22,00±0,90 70,82± 1,84 200m :21,8±0,15sec 100m: 10,7±0,05sec Table 2: M e a n s ( ± s D ) o f p e a k t o r q u e (ft lbs) a n d p e a k t o r q u e / k g b o d y w eig h t for q u a d r i c e p s a n d h a m s t r i n g s o f ri g h t a n d left legs Group Muscle Group Peak Torque (ftlbs) Right Leg Left Leg Peak Torque/kg (ft lbs/kg) Right Leg Left Leg Sprinters (n = 21) Long Dist Runners (n = 25 Quadriceps Hamstrings Quadriceps Hamstrings 170,24±7.10 106.33±4.50 139.64±3.26 85.4 ±2.26 169.71 ±6.74 105.57±4.98 140.12±3.82 80.00±2.81 2.4±0.07 1.49+0.04 2.08±0.05 1.28±0.03 2.40±0.08 1,48±0.05 2.11 ±0.06 120±0.04 S P O R T G E N E E S K U N D E V O L 5 . N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS PHYSIOLOGY strings m u s c l e g r o u p s ar e p r e s e n t e d in Table 4. N o significan t dif fe re nce s in p e a k t o r q u e o f the h a m s t r i n g s a n d q u a ­ d ri c e p s a n d t h e re fo re in s tr e n g t h rat ios (Table 5) b e t w e e n t h e d o m i n a n t a n d n o n d o m i n a n t leg for s p r in t e r s were fo u n d . In lo n g d is t a n c e r u n n e r s , the d o m i n a n t h a m s t r i n g s w ere significantly s tr o n g e r t h a n t h e n o n d o m i n a n t h a m ­ str ings b u t t h e q u a d r i c e p s did not differ significantly. T h i s r es u lte d in t h e d o m i ­ n a n t leg c re a ti n g a significantly h ig h e r fl ex or/e xten sor rat io, c o m p a r e d w ith t he no n d o m i n a n t leg (Table 5) in lon g dis tan ce r u n n e r s . T h e re la t io n s h ip o f total b o d y w eig ht to rig ht a n d left q u a d r i c e p s m u s c l e t o r ­ q u e in s p r in t e r s w as sign ificant (r = 0,7 7 an d r = 0 .6 0 re sp ec tively ). T h e r e was a significant co rre l a t i o n b e t w e e n rig ht a n d left h a m s t r i n g t o r q u e a n d bo dy we ig ht in s p r in t e r s (r = 0.7 5 ; r = 0.60). In lon g d is tan ce r u n n e r s , a significan t co rrelation o f b o d y w eig h t a n d p ea k h a m s t r i n g m u s cle t o r q u e on the rig ht leg was fo u n d (r = 0.63). N o r o t h e r sig­ nificant c o rre la tio n s o f m u s c l e t o r q u e w ith b o d y w eig h t w e re f o u n d in long d is tan ce r u n n e r s . H a m s t r i n g / q u a d r i c e p s m u scl e s tr e n g t h rati os w ere not significant co r­ relat ed w ith b o d y weig ht in eithe r g r o u p s o f r u n n e r s (p < 0.05). D ISC U SSIO N T h e at h le te s u sed in this s t u d y were tested d u r i n g the c o m p e t i ti v e p e ri o d of the r u n n i n g season. T h e y w e re well t ra ine d a n d in ex cel lent p h ys ic al c o n ­ d iti on wi th no k n e e c o n d it i o n o r thigh m u s cle s tr ain for at least a 3 m o n t h pe ri o d p r i o r to the study. T h e i r i n ju ry h is to ry in d ic a te d a low in c id e n c e o f i n ­ ju ry o v er th e past y ear a n d no p a r t ic i ­ p a n ts h ad a n y m u s c l e i m b a l a n c e p r e d i s ­ posi n g t h e m to injury. Isokinetic Strength N o significan t age re lat ed d iffe re n ces in isokin etic s t r e n g t h w ere f o u n d fro m an analysis o f v arian ce test in e i t h e r g r o u p s o f su bjects. T h i s is in c o n tr a s t to o t h e r inv es tiga to rs w h o hav e f o u n d significant increases in h a m s t r i n g a n d q u a d r i c e p s m u s cle s t r e n g t h w i th in c re as in g ag e _ 10.21.23.24.29 H o w ev er, this m a y have b ee n the re s u lt o f d if fe re n t age ran ges. M u r r a y (26), for e x a m p l e , fo u n d y o u n g e r m e n (age 20-35 years) to be sig ­ nificantly s tr o n g e r th a n o l d e r m e n (45- 65 y ea rs ), however, q u a d r i c e p s m u s cle s tr e n g t h was as sesse d isometrically, no t isokinetically. S p r i n t e r s h ad signific an tly s tr o n g e r q u a d r i c e p s a n d h a m s t r i n g s t h a n long dis tan ce r u n n e r s . T h e m e a n p e a k t o r ­ q u e values o f t h e q u a d r i c e p s a n d h a m ­ str in g s in lon g d is t a n c e r u n n e r s (13 9 .6 4 ± 3.26 a n d 85.4 ± 2 .2 6 ftlbs o r 189.35 ± 4.4 2 a n d 115.80 ± 3.0 7 N m ) is s im i ­ lar to tha t f o u n d by M o r r i s (25) el a l in d is tan ce r u n n e r s te sted at the same s pee d (i.e. 132.6 ± 16.59 a n d 86.7 ± 12.91 ftlbs o r 179.81 ± 2 2 .5 0 a n d 117.57 ± 17.51 N m ) . Gi lli am 10 el al r e ­ p o rte d sim ila r q u a d r i c e p s a n d h a m ­ str in g s t o r q u e va lues in football lin e m e n to tho se va lues o b ta i n e d b y s p r i n t e r s in this study. T h e dif fe re n ce in s tr e n g t h o b s e rv e d in s p r i n t e r s a n d long dis tan ce r u n n e r s te sted at the s am e s p e e d m a y be rel at ed to m u s c l e fibre co m p o s i ti o n . S tu d ie s have s h o w n a p r e d o m i n a n c e o f slow tw it ch m u s c l e fibres o f e n d u r a n c e a thle tes a n d a h ig h p r o p o r t i o n o f fast Table 3: M e a n s ( ± s D ) o f the h a m s t r i n g / q u a d r i c e p s rat io for left a n d rig h t legs Group Ratio of Mean Right Leg Peak Torque Left Leg Sprinters 62.91 ± 1.68 62.14 ± 1.68 Long Dist 61.32 ± 1.37 57.28 ± 1.42 Runners Table 4: M e a n s ( ± s D ) o f t h e d o m i n a n t a n d n o n d o m i n a n t h a m s t r i n g a n d q u a d r ic e p s Group Muscle Peak Torque (ft lbs) Group Dominant Leg Non dominant Leg Sprinters Quadriceps 171.33+6.78 163.62±7.05 Hamstrings 107.33±4.43 104.5715.00 Long Dist Quadriceps 140,32±3.44 139.44± 3.66Runners Hamstrings 85.56±2.32 79.80±2.71 Table 5: M e a n s (± sD ) o f the h a m s t r i n g / q u a d r i c e p s ratio for the d o m i n a n t a n d n o n d o m i n a n t legs Group Ratio of Peak Torque (Hamstring/Quadriceps) Dominant Leg Non dominant Leg Sprinters 62.99 ± 1.66 62.05 ± 1.70 Long Dist 61.16 ± 1.34 5 7 . 4 4 + 1.47Runners 8 6 % o f s p r i n t e r s a r e r i g h t l eg d o m i n a n t , 1 4 % a r e lef t l e g d o m i n a n t , 8 4 % o f l o n g d i s t a n c e r u n n e r s a r e r i g h t leg d o m i n a n t , 1 6 % a r e left l e g d o m i n a n t . S P O R T S M E D I C I N E VOL 5. N O I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS PHYSIOLOGY twitch m u s c l e fibres in s p r in t a t h ­ letes.561:34 Fa st tw it ch fibres are i m ­ port ant for force o u t p u t d u r i n g fast c o n ­ tractions w h ic h are r e q u i r e d for s p r i n t i n g . 34 H o w ev er, T h o r s t e n s o n 34 et al fo und t h a t h ig h t o r q u e values w ere a t ­ tained by track at h le te s w i th a low p r o ­ p o rt io n o f fast t w it c h fi b re s, a n d thu s there is no co n clusiv e e v i d e n c e that p e r ­ fo rm an ce can be p r e d i c te d on th e d i s t r i ­ b u ti o n o f fibres in the m u s cles . Hamstring/Quadriceps Strength Ratios Values o b ta i n e d for h a m s t r i n g / q u a d r i ­ ceps s tr e n g t h ratios have b e e n re p o rt e d in the l i t e r a t u r e . 27 T h e rat ios o b t a i n e d in this s tu d y ag ree w i th t ho s e r e p o r t e d by o th er a u t h o r s . H o l m e s ' 2 et al fo u n d flexor/e xten so r rat ios o f 0 .5 8 in male high school s tu d e n t s for t h e d o m i n a n t leg. In a s tu d y o f h ig h sch ool football pla ye rs , ratios o f 0 .5 6 at 54 d eg re es /sec were o b t a i n e d . 29 M o r r i s 25 et al fo u n d h a m s t r i n g / q u a d r i c e p s s t r e n g t h rat ios in collegiate m i d d l e d is tan ce r u n n e r s to be similar at low sp eed s (0. 63 at 30 d e ­ grees/sec a n d 0.65 at 60 d egre es /s ec ). S c u d d e r 31 r e p o r t e d h a m s t r i n g s to be 60% o f q u a d r i c e p s irre s p e c t iv e o f the speed o f testin g. It has b e e n su gg es ted that k e e p i n g the t o r q u e o u t p u t o f the h a m s t r i n g s 6 0 % o f the q u a d r i c e p s m i n i ­ mizes the e x t r a o r d i n a r y a m o u n t s o f stress on the k n ee. G osli n a n d C h a r te r is 13 su gg es ted a d ev ia ti o n in the h a m s t r i n g / q u a d r i c e p s s t r e n g t h ratio fro m 1 : 2.25 w o u ld in c re as e the risk o f injury. H o w ev er, the s t u d y i n c lu d e d male a n d fem ale n o n ath le tes. S tu d ie s w h ic h hav e s h o w n a dif fe re n t s tr e n g t h rat io h av e in v o lv ed d if ferent p o p u l a t io n s . W y a t t 35 r e p o r t e d h ig h e r ratios for m e n th a n for w o m e n te sted at 60 d eg re es /sec . E a rl ie r s tu d i e s r e p o r t e d ratios o f 0 . 5 , h o w e v e r t h e s u b jects o f s uch s tu d i e s did n o t inv olv e a t h l e t e s . 17,22 G i ll i a m 10 et al f o u n d football pla yers to have a flex o r/ e xten so r s t r e n g t h ratio o f 0 . 6 . T h u s it w o u ld a p p e a r t h a t flexor/ ex ten so r s t r e n g t h rat ios m a y be specific for dif fe re n t s p o r ts o r for d if fe re n t lev­ els o f skill r e q u i r e d in s p o r t. Rati o s o f 0.62 for s p r in t e r s a n d 0 .5 9 for lon g d i s ­ tance r u n n e r s m a y in d icate a n o r m a l fl exor/exten sor b a la n c e for t h e se a t h ­ letes. F u t u r e re s e a r c h s h o u l d be c o n ­ d u c te d on at h le te s in dif fe re n t s p orts . Body Weight and Peak M uscle Torque Output A re l a t io n s h ip b e t w e e n total b o d y wei ght a n d p e a k q u a d r i c e p s a n d h a m ­ str in g m u s c l e t o r q u e o u t p u t has b ee n p rev iou s ly d e m o n s t r a t e d . 10’29-118 T h e data fro m the p r e s e n t s t u d y also p r o ­ d u c e d signific an t co rre l a t i o n s b e t w e e n peak q u a d r i c e p s a n d h a m s t r i n g s tr e n g t h an d b o d y w eig h t for s p r i n t e r s a n d b e ­ tw een rig ht h a m s t r i n g s for lon g d is tan ce ru n n e r s . W h e n t o r q u e values w ere e x ­ p re s s e d relat ive to b o d y w e i g h t , s p r i n t ­ ers s h o w e d significantly h ig h e r peak q u a d r i c e p s a n d h a m s t r i n g s t r e n g t h values t h a n long d is t a n c e r u n n e r s . T h i s finding c o n t r a d i c t s t h a t o f H o u s h 19 w h o fo u n d little d if fe re n ces in s t r e n g t h b e ­ tw ee n fem ale track a n d field at h le te s w h e n flexor a n d e x t e n s o r t o r q u e was ex ­ p re s s ed relat ive to b o d y w eig ht. S i m i ­ larly no d if fe re n ce in s t r e n g t h b e t w e e n m a le a n d fem al e al p in e sk ie rs was fo u n d w h e n s t r e n g t h was e x p r e s s e d relat ive to lean b o d y w e i g h t . 15 T h e dif fe re n ces in s t r e n g t h b etw een the tw o g r o u p s o f r u n n e r s , h av in g s ta n ­ d a r d i z e d s t r e n g t h rel at ive to b o d y w e i g h t , m a y b e d u e to fa ct o rs o t h e r th a n wei ght d if fe re n ces s u c h as d if fe re n ce s in trainin g . W h e r e a s s p r i n t e r s e m p h a s i z e s t r e n g t h , s p e e d a n d p o w e r t ra i n i n g , long d is tan ce r u n n e r s c o n c e n t r a t e m o re on e n d u r a n c e t r a i n i n g w i th o n ly som e s t r e n g t h tra i n i n g . In a d d i t i o n , a train in g h is to ry o b ta i n e d fro m t h e r u n n e r s i n d i ­ cat ed th a t 8 6 % o f s p r i n t e r s p art ic ip a t e d in wei g ht tra i n i n g 2-3 t im e s a w eek w h ereas on ly 2 0 % o f long d is tan ce r u n ­ n ers too k p art in w eig h t tra i n i n g . T h u s ap art fro m the d iffe ri n g t r a i n i n g re g im es in the two t yp es o f a t h le te s , a s p rin t e rs t h u s p a r t ic ip a t e d in isoto nic s tr e n g t h tra in in g w h ic h re s u l ts in m u s c l e h y p e r ­ trophy. ----------------------------------------------------------------- 19S P O R T G E N E E S K U N D E VOL 5. N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) SPORTS PHYSIOLOGY Dominant and N on dominant Leg Strength T h e long d is t a n c e r u n n e r s d o m i n a n t a n d n o n d o m i n a n t h a m s t r i n g m u s c l e s tr e n g t h d if fered s ig n if ic an tly r e s u lti n g in d is s i m i l a r s t r e n g t h ratios . A l th o u g h n o d if fe re n ce b e t w e e n t h e d o m i n a n t a n d n o n d o m i n a n t q u a d r i c e p s o r h a m s t r i n g m u s c l e s t r e n g t h was f o u n d in s p r i n t e r s , St aff ord 32 et a l f o u n d d if fe re n ces in q u a d r i c e p s m u s c l e s t r e n g t h in football pla yers w h o h a v e s im i la r s t r e n g t h to the s p r i n t i n g p o p u l a t io n . A l t h o u g h the p r e s e n t s t u d y d id no t find t h is , q u a d r i ­ ceps m a y pla y a m o r e i m p o r t a n t ro le in the tra i n i n g activiti es o f s p r i n t i n g r e ­ lated s p o r ts w h e re a s t h e h a m s t r i n g s m a y play a m o r e i m p o r t a n t ro le in lon g d i s ­ t an ce r u n n i n g . It m a y b e s u g g es ted tha t m o r e e m p h a s i s s h o u l d be g iv en o n c o n ­ d it i o n i n g the n o n d o m i n a n t h a m s t r i n g s in long d is t a n c e r u n n e r s , however, th e re is no c o n clus iv e e v i d e n c e o f this. T h e re su lts o b t a i n e d in a c o m p a r is o n o f left a n d ri g h t legs a n d o f d o m i n a n t a n d n o n d o m i n a n t legs i n d icate the left h a m s t r i n g s a n d n o n d o m i n a n t h a m ­ str in g s o f lo n g d is t a n c e r u n n e r s to be sign ificantly w e a k e r t h a n th e rig ht a n d d o m i n a n t h a m s t r i n g s . T h e s im ila r it y in t hese re su lts is p r o b a b l y t h e result o f t h e re b eing an 8 6 % ri g h t leg d o m i n a n c e in long d is t a n c e r u n n e r s . CONCLUSIONS T h i s s t u d y d e m o n s t r a t e d th e following: • H a m s t r i n g s are a p p r o x i m a t e l y 6 0 % o f q u a d r i c e p s t o r q u e at a s p e e d o f 60 d eg re es /s ec in r u n n e r s . • Significant d iffe re n ces in q u a d r i c e p s a n d h a m s t r i n g s m u s c l e s t r e n g t h b e ­ tw ee n s p r i n t e r s a n d lon g d is t a n c e ru n n e r s . • Significant c o rre l a t i o n b e t w e e n b o d y we ig ht a n d p e a k q u a d r i c e p s a n d h a m s t r i n g m u s c l e t o r q u e in s p r i n t ­ ers. • Significa nt d if feren ces in d o m i n a n t a n d n o n d o m i n a n t q u a d r i c e p s a n d h a m s t r i n g m u s c l e s t r e n g t h in long d is t a n c e r u n n e r s b u t n o t in s p r i n t ­ ers. • N o significant age related effect on pe a k m u s c u l a r t o r q u e . R E F E R E N C E S 1. A g r e J C : H a m s t r i n g I n j u r i e s . P r o p o s e d ae- t i o l o gi ca l f a c t o r s , p r e v e n t i o n a n d t r e a t m e n t . Sp orts M edicine, 2: p p 21 - 3 3 , 1985. 2. A n i a n s s o n A , G r i m b y G , R u n d g r e n A: I s o ­ m e t r i c a n d I s o k i n e t i c Q u a d r i c e p s M u s c l e S t r e n g t h in 7 0 y e a r o l d m e n a n d w o m e n . S c a n d J R e h a b M e d , 12: p p 1 6 1 - 1 6 8 , 1980. 3. C a m p b e l l D E , G l e n n W : R e h a b i l i t a t i o n o f k n e e f l e x o r a n d k n e e e x t e n s o r m u s c l e s t r e n g t h i n p a t i e n t s w i t h m e n i s e c i o m i e s , li­ g a m e n t o u s r e p a i r s a n d c h o n d i r o m a l a c i d . P hysical T h e ra p y ,6 2 : p p 10 -1 5, J a n 1982. 4. C o n t a i n s R , W i l l i a m s A K : I s o k i n e t i c Q u a ­ d r i c e p s a n d H a m s t r i n g T o r q u e L e v e l s o f A d o l e s c e n t , f e m a l e s o c c e r p l a y e r s . J o u rn a l o f O rthopaedic an d Sp orts P hysica l T her­ a p y , 5: p p 1 9 6 -2 0 0, 1984. 5. C o s i i l l D L , F i n k W J , H a b a n s k y A J : M u s c l e R e h a b i l i t a t i o n a f t e r k n e e s u r g e r y . Physician an d Sp orts M edicine, 5: p p 7 1 - 7 5 , S e p t 1977. 6. C o y l e E F , C o s u l l D L , L e s m e s G R : L e g E x ­ t e n s i o n p o w e r a n d M u s c l e f i b r e c o m p o ­ s i t i o n . M edicine a n d Science in Sp o rts, 11. p p 1 2- 15, 1979. 7. D e L a t e u r B, L a h m a n n J F , W a r r e n C G : C o m p a r i s o n o f E f f e c t i v e n e s s o f I s o k i n e t i c a n d I s o t o n i c E x e r c i s e in Q u a d r i c e p s S t r e n g t h e n i n g . A rchives o f P hysical M edicine an d R e h a b ilita tio n , 53: p p 6 0 - 6 3 , F e b 1972. 8. F i l l y a w M , B e v i n s T , F e r n a n d e z L: I m p o r t ­ a n c e o f C o r r e c t i n g I s o k i n e t i c P e a k T o r q u e f o r t h e E f f ec t o f G r a v i t y w h e n C a l c u l a t i n g K n e e F l e x o r to E x t e n s o r M u s c l e R a t i o s . Physical Therapy, 6 6 : p p 2 3 - 2 9 , J a n 1986. 9. F l e c k S J , F a l k e l J E : Va l ue o f R e s i s t a n c e T r a i n i n g f o r t h e R e d u c t i o n o f S p o r t I n j u r i e s . Sp o rts M edicine, 3: p p 6 1 - 6 8 , 1986. 10. G i l l i a m T B , S a d y S P , F r e e d s o n P , V i l la n c i J: I s o k i n e t i c T o r q u e L e v e l s f o r H i g h S c h o o l F o o t b a l l P l a y e r s . A rchives o f Physical M cdicine an d R eh a b ilita tio n , 60: p p 1 1 0 - 11 4 , M a r c h 1979. 11. G l e i m G W , N i c h o l a s J A , W e b b J N : I s o k i ­ n e t i c E v a l u a t i o n f o l l o w i n g L e g I n j u r i e s . Physician an d Sp orts M edicine, 60: p p 75- 8 2 , A u g 1982. 12. G o l l n i c k P D , M a t o b a H : T h e m u s c l e f ibr e c o m p o s i t i o n o f s k e l e t a l m u s c l e as a p r e d i c t o r o f a t h l e t i c s u c c e s s . A m erican J o u r n a l o f Sp orts M e dicine, 12: p p 2 1 2 - 2 1 7 , 1984. 13. G o s t i n B R , C h a r t e r i s J: I s o k i n e t i c D y n a - m o m e t r y N o r m a t i v e D a t a f or C l i n i c a l u s e in l o w e r e x t r e m i t y ( k n e e ) c as e s S c a n d in a via n J o u r n a l o f R eha bilitatio n M e d ic in e ,, 2: p p 1 0 5 - 1 0 9 , 1979. 14. G r a c e T G : M u s c l e I m b a l a n c e a n d E x t r e m ­ i ty I n j u r y - A P e r p l e x i n g R e l a t i o n s h i p . S p o rts M edicine, 2 p p 7 7 - 8 5 , 1985. 15. H a y m e s E M , D i c k i n s o n A L : C h a r a c t e r i s t i c o f e l i te m a l e a n d f e m a l e sk i r a c e r s . M edicine a n d S c ie n c e ,, 12: p p 1 5 3 - 1 5 8 , 1980. 16. H e i s s e r T M , W e b e r J , S u l l i v a n G: P r o p h y ­ l axi s a n d M a n a g e m e n t o f h a m s t r i n g , m u s c l e i n j u r i e s i n I n i e r c o l l e g e f o o t b a l l p l a y e r s . A m erican J o u r n a l o f Sp orts M edicine, 12: p p 3 6 8 - 3 7 0 , S e p t 1984. 17. H i s l o p J H , P e r r i n e J J : T h e I s o k i n e t i c c o n ­ c e p t o f E x e r c i s e . P hysica l T h e ra p y , 47: p p 1 1 4 - 1 17 , 1967. 18. H o l m e s J R , A l d e r n i c k G J : I s o k i n e t i c S t r e n g t h C h a r a c t e r i s t i c s o f t h e Q u a d r i c e p s f e m o r i s a n d H a m s t r i n g M u s c l e s i n H i g h S c h o o l S t u d e n t s . Physical Therap y, 64: pp 9 1 4 - 9 1 8 , J u n e 1984. 19. H o u s h T J : I s o k i n e t i c L e g F l e x i o n a n d E x ­ t e n s i o n s t r e n g t h o f E li t e A d o l e s c e n t f e ma le t r a c k a n d field A i h l e t e s . Research Quarterly fo r Exercise a n d S p o r t, 55: p p 3 4 7 - 3 5 0 , 1984. 20. L i e m o h n W : F a c t o r s r e l a t e d to h a m s i r m g s t r a i n s . J o u r n a l o f Sp orts M edicine and Physical F itness, 18: p p 7 1 - 7 6 6 , 1978. 2 1. M i y a s h i t a M , K a n e h i s a H : D y n a m i c P e ak T o r q u e R e l a t e d to A g e , Se x a n d P e r f o r m ­ a n c e . Research Q uarterly fo r Exercise and S p o r t , 5 0 : p p 2 4 9 - 2 5 5 , 1 9 7 9 . 2 2. M o f f r o i d M , W h i p p l e J , L o w m a n E: A s i u d v o f I s o k i n e t i c E x e r c i s e . P hysical Ther­ ap y, 49: p p 7 3 5 - 7 4 6 , 1969. 23. M o l n a r G E , A l e x a n d e r J: O b j e c t i v e Q u a n t i ­ t a t i ve M u s c l e T e s t i n g in c h i l d r e n : A Pilot S t u d y. Archives o f P hysica l M edicine a n d R e ­ h a b ilita tio n, 54: p p 2 2 4 - 2 2 8 , M a y 1973. 24. M o l n a r G E , A l e x a n d e r J: D e v e l o p m e m o f Q u a n t i t a t i v e s t a n d a r d s f o r m u s c l e s i r e n g i h in c h i l d r e n . A rchives o f P hysical M edicine an d R eh a b ilita tio n , 55: p p 4 9 0 - 4 9 3 , N o v 1974. 25. M o r r i s A , M L u s s i e r L , Bell G , D o o l e y J: H a m s i r i n g / Q u a d r i c e p s S t r e n g t h r a t i o s in c o ll e g e m i d d l e - d i s t a n c e a n d d i s t a n c e r u n ­ n e r s . T he Physician an d Sp o rts M edicine 11: p p 7 1 - 7 7 , O c t 1983 26. M u r r a y P , B a l d w i n J , G a r d n e r M : M a x i ­ m u m I s o m e t r i c K n e e F l e x o r a n d E x t e n s o r M u s c l e C o n t r a c t i o n s - N o r m a l P a t t e r n s o f T o r q u e v e r s u s T i m e . P hysical Therap y, 57: p p 6 3 7 - 6 4 3 , J u n e 1977. 2 7. N o s s e L J : A s s e s s m e n t o f S e l e c t e d R e p o r i s o n t h e S t r e n g t h R e l a t i o n s h i p o f t h e K n e e M u s c u l a t u r e . J o u r n a l o f O rthopaedic and S p orts P hysica l T herap y, 4: p p 3 9 1 - 3 9 8 , 1982. 2 8. O s t e r n i g L R : O p t i m a l I s o k i n e t i c l o a d s a n d v e l o c i t i e s P r o d u c i n g M u s c l e P o w e r in H u ­ m a n S u b j e c t s . Archives o f P hysica l M cdicine a n d R eh a b ilita tio n , 5 6: p p 1 5 2 - 1 5 5 , A p r i l 1975. 29. P a r k e r M G , R u h l i n g R O , H o l t D , B a u m a n E , D r a y n a M : D e s c r i p t i v e A n a l y s i s o f Q u a d ­ r i c e p s a n d H a m s t r i n g s M u s c l e T o r q u e in H i g h S c h o o l f o o t b a l l p l a y e r s . J o u r n a l o f O r­ thopaedic a n d Sp orts P hysica l Therap y, 5: p p 2 - 6 , 1 9 8 3 . 3 0 R i c h a r d s C L : D y n a m i c s t r e n g t h c h a r a c t e r i s ­ ti cs d u r i n g i s o k i n e t i c k n e e m o v e m e n t s in h e a l t h y w o m e n . Physical Therap y, 61: p p 6 8 - 7 3 , 1 9 8 0 . 31. S c u d d e r G N : T o r q u e c u r v e s p r o d u c e d at t h e k n e e d u r i n g i s o m e t r i c i s o k i n e t i c e x e r c i s e s . P hysical T h erap y, 6 1 : p p 6 8 - 7 3 , 1980. 32. S t a f f o r d M G , G r a n d WA: H a m s t r i n g / Q u a d ­ r i c e p s r a i i o s in c o l l e g e f o o t b a l l p l a y e r s : A h i g h v e l o c i t y e v a l u a t i o n . A m erican J o u rn a l o f Sp orts M e dicine, 12: p p 2 0 9 - 2 1 1 . M a y 1984. 33. T h i s t l e H G : I s o k i n e t i c c o n t r a c t i o n : A n e w c o n c e p t o f r e s i s t i v e e x e r c i s e . A rchives o f P hysica l M edicine a n d R eh a b ilita tio n , 48: p p 2 7 9 - 2 8 2 , J u n e 1967. 34. T h o r s i e n s s o n A , L a r s s o n L , T e s c h P , K a r l s - s o n J: M u s c l e s t r e n g t h a n d f i b r e c o m p o ­ s i t i o n in a t h l e t e s a n d s e d e n t a r y m e n . M edicine a n d Science in Sp o rts, 9: p p 2 6 - 3 0 , 1977. 35. W y a t l M P : C o m p a r i s o n o f Q u a d r i c e p s a n d H a m s t r i n g s t o r q u e v a l u e s d u r i n g i s o k i n e t i c e x e r c i s e . P h ysica l Therapy: p 9 3 2 , A b s t r a c t . 20 ----------------------------------------------------------S P O R T S M E D I C I N E VOL S. N O I R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) will give yen Ŝ SWl mofc freedom to walk, jump, run and work 15amps SOUTH AFRICAN JOURNAL OF SPORTS MEDICINE SPORTGENEESKUNDE J O U R N A L O F T H E S.A. S P O R T S M E D I C I N E A SS OC I A T I O N T Y D S K R I F VAN D I E S.A. S P OR T GE N E E SK U N DE - V E R E NI G I NG V O L l ' M E S N U M B E R 2 MAY 1990 E ditor in C hief: D r C Noble M B B C h , F C S 'S A ) A s so c ia te Editors: P ro f T N o a k es. M B C h B , M D D r D ozvievan V e ld c n M B C h B (S ie U )M P ra x M e d (P retoria I A d visory Board: Medicine: D r I Cohen M B C h B , D .O b s t, R C O C O rt h o p a e d i c traumatology: D r P F ir e r B S c (E n g ) . M B BC h < W in ), M M e d (O n h o ) < Wits) Brig E Hugo M B C h B , M M e d (C h it) Orth opa edi cs: D r J C Usdin M B B C h , F R C S (Edin) Cardiology: Col D P M yburgh S M M B ChB F A C C Physical Education: P ro f Hannes Botha D P h il i P hys Ed) Gynaecology: D r J ack A dno M B BCh (W its) , M D (M ed), D ip O & G (W its) SA S G V S A S M A CONTENTS Editorial Comment Causation o f injury ................................................. 3 Preventative Sports Medicine Altitude fails to increase susceptibility o f ultramarathon runners to post-race upper respiratory tract infections .................................... 4 Rugby Injuries Rugby injuries o f the cervical spine and spinal cord — has the situation improved? ......... 9 Sport Injuries A survey o f all sport injuries .................................. 16 Sports Medicine Physical examination o f the ankle and the foot 20 P U B L I S H E D BY T H E S O U T H A F R IC A N S P O R T S M E D I C I N E A S S O C I A T IO N H A T F I E L D F O R U M W E S T 1067 A R C A D I A S T R E E T H A T F I E L D P R E T O R I A . 00 8 3 P icturei courtesy o f P hotofileJIm age B o n k T h e lo tir n a l o f ih e SA S p o m M e d ic in e A s s o c ia tio n is p u b lis h e d b y M c d p h a r m P u b lic a tio n s . 3 rd F lo o r N o o d h u lp lig a C e n tr e . 20 4 B H F V e rw o e rd D r iv e . R a n d b u r g 21 9 4 Tel ( 0 1 1 J 7 8 7 -4 9 8 1 /9 T h e v iew s e x p r e s s e d in th is p u b lic a tio n a r e i h o s c o f th e a u th o r s a n d n o t n e c e s s a r ily th o s e o f th e p u b lis h e rs P rim e d b v T h e N a t a l W itn ess P rin t in g m d P u b lish in g C o m p jin ( P i v ) Ltd -------------------------------------- 1 S P O R T G E N E E S K U N D E V O L 5. N R 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. )