p h y s io th e ra p y , F e b ru a ry 1986, vo l 4 2 n o 1 19 Headloading in Africa: Preliminary Findings on the Locom otor Effects o f Occupational H eadload Carriage J. CHARTERIS, P. A. SCOTT AND J. C. WALL SUMMARY Headload w alking is widespread in Africa, potentially medically harmful, but poorly under- | stood. The present pilot study reveals what p ortions of the lo co m o to r pattern deserve detailed fu rth e r study. Basically under the headload con d itio n , shorter, q u ic k e r more mincing steps are taken, raising the energy- cost of locomotion. Shock-absorption mecha­ nisms are impaired. Propulsive mechanisms are altered. OPSOMMING Van stap met ’n las op die kop, wat wyd verspreid in Afrika voorkom en potensieel medies skadelik is, word min verstaan. Die huidige aanvoorstudie dui aan watter dele van die lokomotoriese patroon gedetailleerde ver- dere studie verdien. Basies word daar by die dra van 'n koplas korter, vinniger, “ trippel” - stappies geneem, wat die energievereistes van die stapbeweging verhoog. Die skokbreek- meganismes word beskadig. Aandryfm ega- nismes word gewysig. IN T R O D U C T IO N H e a d - l o a d i n g is a u b i q u i t o u s A f r i c a n p h e n o m e n o n p a r t i c u l a r l y a m o n g w o m e n , as a m e a n s o f h e a v y - l o a d t r a n s p o r t i n g . Its r o o t s , h o w e v e r , a r e t o be f o u n d in e c o n o m y o f e f f o r t , n o t c u l t u r a l o r e t h n i c t r a d i t i o n , f o r h e a d l o a d i n g is c o m m o n l y p r a c t i s e d in T i b e t , N e p a l , the hi gh A n d e s , P a p u a a n d a c r o s s A f r i c a . As D a t t a a n d R a m a n a t h a n 1 h a v e s h o w n , it is o n e o f t h e l eas t e n e r g y e x p e n s i v e m e a n s o f l o a d c a r r i a g e , a h e a d o f b a c k ­ p a c k i n g , b a c k - a n d h e a d - s l i n g ( S h e r p a ) l o a d i n g , the s h o u l d e r y o k e m e t h o d , a n d b i - m a n u a l l o a d c a r r y i n g . kCl ear ly m il l e n i a o f a r d u o u s l o a d b e a r i n g h a s r e s u l te d in ”this n e a r - u n i v e r s a l a d o p t i o n o f t h e le a st f a t i g u i n g fe a ­ sible m e t h o d o f c a r r y i n g a w k w a r d l oa d s . T h a t h e a d - l o a d c a r r y i n g is p h y s i o l o g i c a l l y e ffi c ie nt is e s t a b l i s h e d ; w h a t h a s n o t b e e n a d e q u a t e l y c o n s i d e r e d are t h e l o n g - t e r m o r t h o p a e d i c effe cts o f t h e p r a ct ic e . E k e - O k o r o a n d S a n d l u n d 2 s t u d i e d t h e w a l k i n g p a t t e r n s o f p e o p l e in t h e s t r e e t a n d f o u n d t h a t t h o s e c a r r y i n g s h o p p i n g b a g s o r s u i t c a s e s e x h i b i t e d s h o r t e r s t r i d e J. C H A R T E R I S , B.A., M.Sc. Professor, a n d H e a d o f the D e p a r t m e n t of H u m a n M o v e ­ ment Studi es, R h o d e s University, G r a h a m s t o w n P. A. S C O T T , B. A., M . A . , L e c tu r e r , D e p a r t m e n t o f H u m a n M o v e m e n t Studies, R h o d e s University, G r a h a m s ­ town J. C. W A L L , P h . D . , A sso c ia te P rofessor, S c h o ol o f P h y ­ siotherapy, D al h o u si e University, Ha lifax, C a n a d a Fig. I. H ea d lo a d carriers in th e fie ld . 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 3. ) 20 F is io t e r a p ie , F e b r u a r ie 1986, d e e I 4 2 n o 1 l e n g t h s a n d s h o r t e r s t r i d e t im e s , i n d i c a t i n g t h a t s m a l l e r s t e p s w e r e b e i n g t a k e n a t a h i g h e r f r e q u e n c y , i.e. “ m i n c i n g ”. P r e s e n t e d h e r e a r e s o m e p r e l i m i n a r y f i n d i n g s f r o m o u r o n - g o i n g s t u d y o f n o r m a l v e r s u s h e a d - l o a d e d w a l k i n g . H e a v y l o a d t r a n s p o r t i n g by th e h e a d is a p r a c t i c e w h i c h i n tu i t iv e l y o n e w o u l d e x p e c t m a y be m e d i c a l ly h a z a r d o u s , p a r t i c u l a r l y c o n s i d e r i n g th e gr aci le n a t u r e o f n u c h a l s t r u c t u r e s a n d th e fa ct t h a t l o a d s m u s t be s u p p o r t e d in d y n a m i c e q u i l i b r i u m a n d this o v e r c o n ­ s i d e r a b l e d i s t a n c e s a n d v a r i a b l e e n v i r o n m e n t a l c o n d i ­ t i o n s o f g r a d i e n t , s u r f a c e i r r e g u l a r i t y a n d a m b i e n t t e m ­ p e r a t u r e , t o m e n t i o n b u t a few. T h e c h r o n i c e ffe c ts o f o c c u p a t i o n a l h e a d - l o a d i n g c a n a t th is t im e o n l y be g u e s s e d at. O r t h o p a e d i c a n d p h y s i c a l m e d i c a l h e a l t h c a r e a c r o s s A f r i c a is n o w h e r e n e a r p a r i t y wi th t h a t e n j o y e d in a f f l u e n t m o d e r n s o c ie ti es , w h i c h m e a n s that' h a z a r d o u s p r a c t i c e s a re p o o r l y o r n o t at all r e s e a r c h e d , let a l o n e d i s c o u r a g e d b e f o r e t he fa ct o r t r e a t e d a f t e r the fact. T h e r e is n o r e a s o n t o be li e v e t h a t A f r i c a will m e c h a ­ nise in t h e f o r s e e a b l e f u t u r e t o th e e x t e n t t h a t he ad c a r r i a g e o f h e a v y l o a d s is likely t o die out . M A T E R I A L S A N D M E T H O D S W e h a v e de sc ri b e d e ls ew h er e t e c h n i q u e s f o r m e a s u r i n g t h e t e m p o r a l a n d d i s t a n c e k i n e m a t i c s o f th e p a t t e r n s o f f o o t - f l o o r c o n t a c t in n o r m a l a n d p a t h o l o g i c a l ga its . ’ U se o f t h e s e a n d v a r i o u s o t h e r t e c h n i q u e s f o r the m e a s u r e m e n t of k i n e m a t i c p a r a m e t e r s in h u m a n l o c o ­ m o t i o n h a v e re s u l te d in a rich l i t e r a t u r e o n the s u b j e c t o f t e m p o r a l - d i s t a n c e a n d a n g u l a r k i n e m a t i c s , o f w h i c h C h a r t e r i s a n d T a v e s , 5 R o s e n r o t , W a l l a n d C h a r t e r i s fl a n d W a l l a n d C h a r t e r i s ; 7,8 a r e a few e x a m p l e s . In this p r e l i m i n a r y a n a l y s i s f o u r Bl ac k fe m a le o c c u p a ­ t i o n a l w o o d c a r r i e r s e a c h u n d e r w e n t t w o c o n d i t i o n s : a) n o r m a l ( u n l o a d e d ) w a l k i n g b) h e a d - l o a d e d w a l k i n g e a r r i n g a l o a d o f f i r e - w o o d 4 0 % o f b o d y m a s s a n d 160% o f s t a tu r e . E a c h s u b j e c t t r a v e r s e d a w a l k w a y o f 2 0 m several t im e s, at w a l k i n g s p e e d s s p a n n i n g t h e n o r m a l h u m a n r a n g e f r o m s l o w to fast. T h e s e tr a v e r s e s we re d o n e w i t h o u t c a r r y i n g a n y o b j e c t s a n d b a r e f o o t e d . A t o t a l of 10 t r a v e r s e s by e a c h s u b j e c t e s t a b l i s h e d a p r o f i le of n o r m a l w a l k i n g t h r o u g h th e r a n g e o f s p e e d s . E ac h s u b j e c t t h e n r e p e a t e d th e p r o c e d u r e c a r r y i n g the h e a d ­ lo a d . T h e t e c h n o l o g y u se d c o n s i s t e d o f a f o o t - s w i t c h t e l e m e t r y s y s t e m (B a n d L E n g i n e e r i n g ) * d e s i g n e d to d i f f e r e n t i a t e c o n t a c t p e r i o d s a t the heel, f o r e - f o o t ( m e t a ­ t a r s a l s 5 a n d I) a n d big toe, a n d c o m b i n a t i o n s o f these. A s m a l l t r a n s m i t t i n g s y s t e m , w o r n o n a w a i s t belt , sent s i g n a l s to a r e c e i v i n g / d e c o d i n g u n i t , c r e a t i n g i n p u t f r o m b o t h feet as v o l t a g e c h a r g e s o n t w o c h a n n e l s o f a b i o l o g i c a l r e c o r d e r ( P h y s i o g r a p h ) . T h e r e c o r d e r ( p a p e r s p e e d 5 c m . s ’ 1) p r o d u c e d f o o t - c o n t a c t t r a c e s which we r e a n a l y s e d o v e r a 6 m d i s t a n c e o f the w a l k w a y b o u n d e d by p h o t o - c e l l s set u p to d e t e r m i n e the a v era g e w a l k i n g v e lo c i ty in th is c e n t r a l p o r t i o n o f the w a lk w ay . T e m p o r a l p u ls e s f r o m e a c h f o o t - s w i t c h w e re m e a s u r e d i m a n u a l l y a n d t h e d a t a i n p u t i n t o a n A p p l e He m i c r o ­ p r o c e s s o r to as si st in d a t a - r e d u c t i o n a n d stati sti cal an al y si s. T h r o u g h o u t this s p e e d - r e l a t e d s t u d y we hav e e x ­ p r e s s e d w a l k i n g s p e e d in u n i ts , n o t o f m . s ' 1, b u t in s t a t u r e s .s ', w h i c h al l o w s c o m p a r i s o n s u s i n g subjects o f d i f f e r e n t b o d y - l e n g t h . R E S U L T S A. T h e O v e ra ll P a t te r n T h e h e a d - l o a d p a t t e r n vi ew ed as a w h o l e , is o n e of m in c e d s t e p s , s h o w n as s h o r t e r st r i d e ti m e s, h i g h e r step f r e q u e n c i e s a n d s h o r t e r s t e p l en gt h s. T h e s e va r io u s w a y s o f s a y i n g t h e s a m e t h i n g viz t h a t h e a d l o a d e r s m i n c e , o r clip , t h e i r s t e p s , a r e d e p i c t e d in g r a p h s (A) (B) a n d ( C) o f F i g u r e 3. In h u m a n w a l k i n g , c o n t a c t t im e is a lw a y s long er t h a n s w i n g p h a s e , b u t as s pe e d i n c r e a s e s so the p e r c e n ­ t a g e o f s t r i d e t im e d e v o t e d to c o n t a c t d e c r e a s e s , while t h a t d e v o t e d to sw in g in cr e as es a n d th e s w in g - t o - s u p p o r t r a t i o c o n s e q u e n t l y g r o w s lar ge r. T h e s e r e l a t i o n s h i p s are s h o w n in F i g u r e 4. In fact , u n d e r h e a d l o a d i n g all thel a b o v e p a t t e r n s are m a i n t a i n e d , t h o u g h at v er y d i f f e r e n t ’ levels, a n o t a b l e e x c e p t i o n b e i n g g r a p h ( D ) o f F i g u r e 3; r a w c o n t a c t t i m e is u n a f f e c t e d b y h e a d l o a d i n g . B e c a u s e th e r a w c o n t a c t s a r e th e s a m e b u t the head- lo a d e d st r i d e t im e a lw a y s s h o r t e r , it f o llo w s t h a t u nd e r the h e a d l o a d c o n d i t i o n c o n t a c t is re la tiv e ly l o n g e r as a p e r c e n t a g e o f s t r i d e t i m e , as i m p l i e d in F i g u r e 3 (D). S o t h e m in c e d s t e p p i n g p a t t e r n u n d e r h e a d l o a d is one in w h i c h th e r e c o v e r y ( sw in g ) is n o t o n l y s h o r t e r with th e s h o r t e r st e p , b u t f a s t e r re la tiv e to th e st r i d e cycle. T h e r e d u c e d s w i n g - t o - s u p p o r t r a t i o u n d e r h e a d l o a d s h o w s t h e b a s i c o v e r a l l p a t t e r n d i f f e r e n c e : in h e a d l o a d w a l k i n g th e a i m is to r e d u c e th e less s t a b le single s u p p o r t (c.f. s w in g ) p h a s e , b o t h a b s o l u t e l y a n d rela- Fig. 2. S u b j e c t in t h e l a b o r a t o r y at s ta r t o f a l o a d e d - c o n d i t io n tra v e rse . * B and L Engineering, 9618 Same Fe S prings Rd., Sante Fe Springs, C a lifo rn ia 90670, U SA. 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 3. ) P hysio th e rap y , F e b ru a ry 19 86 , vo l 4 2 n o 1 21 SPEED (S ta tu re s.s 1) SPEED (S tatures, s ' 1) SPEED (Statures, s 1) SPEED (Statures. s_1) Fig. 3. T e m p o ra l, d ista n c e a n d rate p a r a m e te r s o f th e o v e r a ll p a tte r n . B r o k e n line re p re se n ts u n lo a d e d c o n d itio n ; s o lid line represents lo a d e d c o n d itio n . tively, an d to increase th e sta b le p o r tio n o f th e cycle. By inference, if single s u p p o r t (hence sw ing) is sh o rte r, b u t o v erall c o n ta c t (F ig . 3(D )) is a b so lu te ly th e sam e and relatively lo n g er, it m u st m ean th a t th e p e rio d s o f d o u b le s u p p o r t, necessarily th e m o st s ta b le , are a b s o ­ lutely an d relatively longer. S e p a ra te m e a s u re m e n t o f raw d o u b le s u p p o r t tim es reveals th a t these a re alw ays lo n g er in th e h e a d lo a d c o n d itio n (F ig u re 5). G iven th a t o v erall c o n ta c t tim es are id en tical betw een c o n d itio n s , it follow s th a t, relative to to ta l c o n ta c t, d o u b le s u p p o r t is a bigger p e rc e n ta g e value h e a d lo a d e d , th a n n o rm a l. 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 3. ) 22 F is io te ra p ie , F e b ru a rie 19 86 , d e e l 4 2 n o 1 I “ * SB I I I I ! MEDIUM I ! FAST ■ 0.8 1.0 1.2 1.4 1.6 SPEED ( S U tu r c s .* '1) 0-2 0.4 OB O.e 1.0 1.2 . 1.4 SPEED (Statures, s ' 1) 0.6 0.8 1.0 1.2 SPEED ( S ta tu r e * .* '1) Fig. 4. Support-tim e, swing tim e relationship. B roken line represents unloaded condition; solid line represents loaded condition. B. Breakdown o f F o o t-F lo o r Contact C om ponents B re a k d o w n o f th e sequence o f fo o t-to -flo o r co n ta c ts reveals how the m in cin g p a tte rn is co m posed: we ex p ect th a t at fa s te r speeds the s h o c k -a b so rb in g ph ase fro m h e e l- s tr ik e to f o o t - f l a t (w h ic h we c all th e b r a k in g m ech a n ism ) will red u ce in n o rm a l circu m stan ces. H o w ­ ever, u n d e r heavy h ead lo a d in g , th e sam e sm all pre- tib ia l m uscles, now w o rk in g as sh o ck ab so rb e rs a g ain st a lo ad c o n sid e ra b ly clo ser to th e ir m a x im a l capacity, are less effective in cu sh io n in g the im p act o f heel-strike. T h u s, in an a b so lu te an d relativ e sense w ith respect to to ta l c o n ta c t tim e, the b ra k in g m ech a n ism is less effec­ tive u n d e r h e a d lo a d in g ; th e fo o t-sla p is e a rlie r and sh a rp e r. O ne p ositive effect o f this is th a t a g re a te r su rface a re a ( th a t o f th e w hole fo o t), is e a rlie r posed to th e w alk in g su rfa c e , in creasin g sta b ility an d d issip atin g p ressures (F ig u re 5B). T h e fo o t-fla t p h a se , in w hich heel a n d a t least b all are in c o n ta c t w ith th e s u b s tra te , is alw ays relatively lo n g e r as a p e rc e n ta g e o f c o n ta c t in the h ead lo a d c o n d itio n (F ig u re 5C). T his is especially significant since th e heel d isen gages fro m the w alk in g surface relatively ea rlie r in th e h ead lo a d c o n d itio n . T h is im plies th a t g re a te r p ro p u lsiv e e ffo rt is required to m ove w alk er plus h ead -lo ad ca rrie d , an d th a t p la n ta r th r u s t fro m th e c a lf m uscles causes an ea rlie r th a n n o rm a l rise o f th e heel. I t m u s t be p o in te d o u t th a t heel-rise d o es n o t itself m ean th a t c a lf p ro p u lsio n is the cause; fo r th e heel m ay disengage passively w ith o u t m uscle activ ity fro m the c a lf g ro u p . H ow ever, th e step is s h o r te r u n d e r h e a d lo a d , so th a t th e ce n tre o f m ass is n o t fa r fo rw a rd o f th e re a r leg a t this tim e, w hich w o u ld a rg u e ag a in st a passive heel-rise: it is m ore likely th a t th e heel rises ab so lu tely an d relatively ea rlie r under h e a d lo a d in g b ecause o f a g re a te r s tra in on the calf g ro u p . D IS C U S S IO N H e a d lo a d w alk in g is a p a tte rn in w hich the dictates o f lo a d -b a la n c e an d lo ad m ass c o m b in e to p ro d u ce a lo n g er d o u b le -su p p o rt ph ase, a relatively lo n g er co n tac t ph ase, a sh o rt, q u ic k sw ing an d a sm aller, faster, m ore m in c in g p ace a t the sam e o v e rg ro u n d velocities of w alking. U nder h ead lo a d in g , the fo o t slaps do w n earlier, im p ly in g less effective cu sh io n in g o f th e h eel-strike, a n d / th e heel rises earlier fro m the g ro u n d th a n u n d e r n o rm a ls c o n d itio n s . T h e p erio d o f fo o t-fla t betw een th e bra kin g an d the p r o p u ls iv e phases a t each end o f th e co n tac t p e rio d , is lo n g e r u n d e r h e a d lo a d in g . A ll these p h e n o ­ m e n a help to ex p lain how b alan c e is m ain tain ed and heavy loads are su stain ed by h e a d lo a d carriers. T h e a d a p ta tio n s o f h e a d lo a d ca rrie rs are com plex an d involve significant differences fro m n o rm a l w alking; b u t these are alw ays differences o f degree, n o t o f kind; p a tte rn s are accen tu ated o r a tte n u a te d , b u t n o t reversed o r o b lite ra te d . T h is overall fin d in g p ro m p ts an o b serv a­ tio n in reverse fro m em phasis on th e differences be­ tw een n o rm a l an d h e a d lo a d w alking: given th e nature o f th e lo a d s carried in this stu d y , co m p risin g w ood- b u n d le s 160% o f sta tu re in length and 40% o f body m ass in lo a d , it is re m a rk a b le how n a tu r a l th e elicited g a it p a tte rn is; how stab le the n o rm a l p a tte rn o f hu m an lo c o m o tio n is to be so little d isru p ted . 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 3. ) p h y s io th e ra p y , F e b r u a r y 19 86 , vo l 4 2 n o 1 23 SPEED (S tatures.s-1) SPEED (Statures s71) (C) SPEED (S tatures.s 1) Fig. 5. Breakdow n o f fo o t-flo o r contact com ponents. Broken line represents unloaded condition; solid line represents loaded condition. 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 3. ) 24 F is io te ra p ie , F e b ru a rie 7986, d e e l 4 2 n o 1 C O N C L U S IO N T h e s i g n if i c a n t c o n t r i b u t i o n o f th is p r e lim in a r y an alysis is th a t it stro n g ly suggests th a t th e m o st p r o ­ d u ctiv e a re a s fo r d e ta ile d research in fu tu re sho u ld c o n c e n tra te o n th e causes o f red u ced s h o c k -a b so rp tio n (fro m h eel-strik e to fo o t-fla t) an d o n th e q u e stio n o f w h e th e r heel-rise is cau sed by passive ‘o v e r-rid e ’ o f the r e a r lim b o r active m u s c u la r p ro p u ls io n by th e g a stro c - n em iu s-so leu s c o m p le x , o r is ju s t a n a rte fa c t o f th e fast step p in g freq u en cy . A n g u la r k in e m a tic analysis, c o n c e n tra tin g on the kn ee and th e h ip , sho u ld assist in o b ta in in g answ ers to th e ab o v e q u e stio n s, as well as in suggesting w h at th e effects m ig h t be o n these jo i n ts o f the h a b itu a l p ractice o f h e a d -lo a d w alking. T hese are th e su b jects of o u r o n ­ g o in g analysis. References 1. D a tta SR and R a m anathan NL. Ergonom ic com parison of seven m odes of carrying loads on the horizontal plane. E rgonomics 1971; 14(2): 269-278. 2. E ke-O koro ST and S andlund B. The effects of load, shoes, sex and d irection on the gait characteristics o f street pedestrians. Journal o f H um an M o v em e n t Studies 1984; 10:107-114. 3. W all JC , C harteris J and H oare JW . An auto m a te d on­ line system fo r m easuring the tem poral p a tte rn s of fo o t/ floor contact. J M e d E ng Technol 1978; 2(4): 187-190. 4. Wall JC , C harteris J and H oare JW . An autom ated system for the analysis of gait. Proceedings: X I I International C onference on M edical a n d Biological E ngineering a n d V International Conference on M edical Physics Aug 19-24 1979; Jerusalem , Israel. 5. C harteris J and Taves C. The process of ha b itu a tio n to treadm ill walking: a kinem atic analysis. Percept M ot Skills 1978; 47:659-666. 6. R osenrot P, Wall J C and C harteris J. The relationship between velocity, stride tim e, su p p o rt tim e and swing time d uring norm al walking. Jo urnal o f H um an M ovem ent Studies 1980; 6: 323-335. 7. W all J C and C harteris J. The process of ha b itu a tio n to treadm ill w alking at different velocities. Ergonom ics 1980; 23(5): 425-435. 8. W all J C and C harteris J . A kinem atic study of long-term ha b itu a tio n to treadm ill walking. Ergonom ics 1981; 24(7): 531-542. Bibliography C harteris J. H um an gait cyclograms: conventions, speed rela­ tionships and clinical applications. Int J R ehabil R es 1982; 5(4): 507-518. NEWS OF COURSES & CONGRESSES W C P T 1 0 T H IN T E R N A T IO N A L CONGRESS: A U S T R A L IA M A Y 1987 P re-C ongress Courses 11-15 S p in a l M a n ip u la tiv e T h e ra p y 11-12 A c tio n , M o v e m en t a n d M o to r P rocesses 13-15 H e a lth E d u c a tio n in th e W o rk p la c e — T o p ic s a n d T ec h n iq u e s 14-16 M o t o r T ra in in g F o llo w in g S tro k e P ost-C on gress Courses 24-28 I n tro d u c tio n to M a n u a l T h e ra p y 24-27 W o m e n ’s H e alth : M a n a g in g L ife’s S tages a n d T ra n s itio n s — T he P h ysicial T h e ra p is t’s C o n trib u tio n 24 C lin ical R e a s o n in g a n d C linical D e cisio n M a k in g 25-27 H e a lth M a n a g e m e n t fo r th e A ged — Issues a n d In itia tiv es 25-27 A sse ssm e n t o f M o to r D e v e lo p m e n t and F o llo w u p o f th e P re te rm and A t R isk In fa n t 25-27 T he M a n a g e m e n t o f S p o rtin g Injuries: D ire c tio n s fro m R e se arc h 29 E x erc ise a n d R e h a b ilita tio n F o r fu r th e r in fo rm a tio n w rite to: P re a n d P o s t C o n g re ss C o u rse s A u s tra lia n P h y s io th e ra p y A sso c ia tio n P .O . B ox 119, C o n c o rd A u s tra lia 2137. D E P A R T M E N T OF H E A L T H A N D W ELF A R E CO U RSE I N H U M A N G ENETICS 12-23 M A Y 1986 Venue: O p e ra P la z a B uilding, P re to ria . Content: T h e basic principles o f H u m a n G enetics a n d th e p ra c tic a l a p p lic a tio n th e r e o f in th e p rovision o f a co m p re h en siv e h ealth service. Expenses: T h e c o u rs e is fre e . P a r t ic i p a n t s are re sp o n sib le fo r th e ir ow n a c c o m m o d a ­ tio n a n d trav e l expenses. A pplications: C losing d a te 7 M a rc h 1986. P le a se a p p ly to M rs. E. v a n d e r M e rw e , D e p a r t­ m e n t o f H e a lth a n d W elfare , P riv a te Bag X63, P r e to r ia 0001. P le a se note: (1) A ll a p p lic a t io n s a re s u b je c t to selection. (2) A p re-requisite fo r the course is a basic know ledge o f cell physiology, in clu d in g m ito sis a n d m eiosis. CO N G RESS H A L L IW IC K I N 1986 TH E R E A L IT IE S OF M O V E M E N T I N WA TER D ate: 13-15 A u g u s t 1986. Venue: U niversity o f N ijm egen, N e th e rla n d s. Language: E nglish. N um ber o f participants: ± 4 0 0 D e ta ils from: H a lliw ick in ’86, c / o M rs. L. van H e rk , P .O . B ox 9101, 6500 H B N ijm egen, N e th e r­ lan d s. 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 3. )