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Clinical
Prosthetics
d Orthotics
Vol. 7, N o . 4
1983
Fall ( I s s u e d Q u a r t e r l y )
S-N-S Knees and the Bilateral A/K Amputee
Gustav Rubin, M.D.*
A . H . , a n active bilateral A / K a m b u l a t o r .
W e h a v e u n d e r o u r c a r e at V A R E C eleven adult m a l e
bilateral A / K ambulators. Ten of these u s e S w i n g a n d
Stance ( S - N - S ) knees a n d o n e , a m i s s i o n a r y to a r e m o t e
area in Africa, w a s fitted w i t h single axis k n e e s b e c a u s e
of t h e o b v i o u s n e e d for simplicity in h i s special cir­
c u m s t a n c e s . E i g h t of o u r S-N-S u s e r s a r e active i n d i ­
viduals, b u t t w o are h o u s e h o l d a n d limited c o m m u n i t y
a m b u l a t o r s . A s w o u l d b e a n t i c i p a t e d , all of o u r a b o v e knee a m p u t e e a m b u l a t o r s a r e in g o o d p h y s i c a l c o n d i t i o n
a n d strongly m o t i v a t e d . T h e s e w e r e i m p o r t a n t a s p e c t s in
p r e s c r i b i n g p r o s t h e s e s . T h e S-N-S k n e e s p r o v i d e d the
a m p u t e e s w i t h the s m o o t h gait c h a r a c t e r i s t i c of h y ­
draulics, greater security, i m p r o v e d ease in r e a c h i n g the
sitting p o s i t i o n , i m p r o v e d o p p o r t u n i t y to r e c o v e r from
s u d d e n stops o r potential s t u m b l e s , b e t t e r c o n t r o l w h e n
d e s c e n d i n g stairs, a n d the ability to lock o n e o r b o t h
knees for n e g o t i a t i o n of stairs. W e h a v e also f o u n d the
S-N-S to b e the sturdiest of the h y d r a u l i c units.
*FACS Chief, V A R E C Special Clinic T e a m
N o o n e of o u r a m p u t e e v e t e r a n s d e m o n s t r a t e s t h e
potential of S-N-S knees b e t t e r t h a n A . H . , injured in
V i e t n a m at 2 1 y e a r s of age. A . H . w a s initially e v a l u a t e d
b y the V A R E C Clinic T e a m o v e r o n e y e a r later o n Sept.
24,1970.
A . H . s u s t a i n e d bilateral A / K a m p u t a t i o n s . T h e right
A/K s t u m p w a s e i g h t inches in length a n d multiply
s c a r r e d . T h e left A / K s t u m p , partially c o v e r e d b y healed
split thickness skin grafts, w a s s e v e n a n d one-half
inches in length. A . H . also sustained partial a m p u t a t i o n s
of the fingers of b o t h h a n d s . T h e index a n d m i d d l e
fingers of the left h a n d w e r e a m p u t a t e d ; o n the right
h a n d , the p r o x i m a l p h a l a n g e s o f the fourth a n d fifth
fingers a n d the first m e t a c a r p a l of the t h u m b w e r e r e ­
t a i n e d . A . H . d e m o n s t r a t e d that h e w a s c a p a b l e of
g r a s p i n g c r u t c h e s w i t h b o t h r e s i d u a l h a n d s . O n the right
he could c o m e w i t h i n an i n c h of o p p o s i n g the first
m e t a c a r p a l to the fourth a n d fifth p r o x i m a l p h a l a n g e a l
s t u m p s . O p p o s i t i o n could be a c h i e v e d o n t h e left.
A . H . w a s in excellent physical c o n d i t i o n , v e r y well
m o t i v a t e d , w i t h o u t hip c o n t r a c t u r e s , a n d w i t h g o o d
m u s c l e p o w e r of the trunk a n d residual e x t r e m i t i e s . H e
h a d b e e n w o r k i n g o u t in his g a r a g e , w h i c h h e h a d c o n ­
v e r t e d to a g y m . W h e n seen, h e w e i g h e d 1 6 0 lbs. a n d
indicated t h a t h i s p r e - a m p u t a t i o n h e i g h t w a s 6 feet, l-V2
inches (a h e i g h t that w a s s u b s e q u e n t l y successfully
r e a c h i e v e d at his r e q u e s t ) .
T h e V A R E C Clinic T e a m d e c i d e d to p r e s c r i b e bilateral
A / K partial suction q u a d sockets w i t h w a i s t belt, rigid
u p r i g h t s a n d b a n d , multiplex knees (to allow trial of
several k n e e units "in the r o u g h " ) , a n d , finally, a trial
w i t h first S A C H feet, a n d t h e n single axis feet. T h e S-N-S
knee units a n d single axis feet w e r e selected o n t h e basis
of A . H . ' s p e r f o r m a n c e w i t h t h e m .
O n M a y 1 3 , 1971 A . H . w a l k e d to V A R E C w i t h o u t a
c a n e o r c r u t c h e s . After a s u b s e q u e n t trial w i t h total s u c ­
tion a n d silesian belts h e h a d t o b e r e t u r n e d to his origi­
nal p r e s c r i p t i o n , d u e to s t u m p s c a r r i n g .
A . H . h a d b e e n an a c c o m p l i s h e d skier p r i o r to a m p u ­
tation a n d , o n J a n u a r y 2 5 , 1 9 7 4 , r e q u e s t e d p r o s t h e s e s
w i t h w h i c h h e could ski a g a i n . T h e clinic t e a m n o t e s of
that d a t e follows.
Clinical Prosthetics and Orthotics
Editorial Board
H. Richard Lehneis, Ph.D., C P O , Chairman
Charles H . P r i t h a m , C P O , E d i t o r
D e n n i s Clark, C P O
Charles H. Epps, Jr., M D
J o a n n e Klope S h a m p , C P O
T a m a r a Sowell, R P T
P u b l i c a t i o n s Staff
Charles H. Pritham, C P O , Editor
C h r i s t o p h e r R. Colligan, M a n a g i n g E d i t o r
S h a r a d a Gilkey, A s s i s t a n t E d i t o r
" H e h a s b e e n i n f o r m e d that skiing will b e d a n g e r o u s .
N e v e r t h e l e s s , h e is a n x i o u s to try it, a n d , b e c a u s e of the
m o r a l e factor a n d the intensity w i t h w h i c h this p a t i e n t
w i s h e s to ski, plus the fact that h e w a s a skier p r i o r to his
leg a m p u t a t i o n s , the p r o s t h e s e s h a v e b e e n o r d e r e d . "
O u t r i g g e r ski poles w i t h special a d j u s t m e n t s for the
h a n d grips w e r e also p r e s c r i b e d .
T h e first p r e s c r i p t i o n w a s d e t e r m i n e d after a n o t h e r
bilateral A / K skier w a s invited to visit the clinic t e a m
w i t h his p r o s t h e s e s . T h a t c o n c e p t w a s c o p i e d a n d p r o s ­
theses w e r e s u p p l i e d to A . H . w i t h solid k n e e s fixed at 4 5
d e g r e e s a n d c o r r e s p o n d i n g l y dorsiflexed feet. T h e y w e r e
rejected shortly thereafter b y A . H . since t h e y allowed
h i m to slide d o w n only low slopes.
T h e p r o s t h e s e s w i t h S-N-S k n e e s a n d single axis feet
h o w e v e r , did allow h i m to actively ski. It is n o t e w o r t h y
that the m o s t efficient position of his s t u m p s , s i n c e h e
r e q u i r e d s t r o n g a b d u c t o r p o w e r for skiing, w a s found to
b e in sockets set u p in a l m o s t t w e n t y d e g e e s of a b d u c ­
tion. Since t h e neutral p o s i t i o n of the feet w a s m o r e
efficient for skiing the feet w e r e not o u t - t o e d .
A . H . p r o v e d his proficiency o n skis (see p h o t o ) b y
w i n n i n g the h a n d i c a p p e d Olympics in N o r w a y in 1 9 8 2 .
H e h a s c o m p e t e d in n u m e r o u s e v e n t s in the U . S . a n d
o v e r s e a s a n d h e r e p o r t s that h e c a n n e g o t i a t e 4 0 slalom
gates in 6 0 s e c o n d s .
H e h a s n o t b e e n t r o u b l e free, h o w e v e r . T h e m o s t seri­
ous of his p r o b l e m s o c c u r r e d w h e n a s p u r w a s r e m o v e d
from his left s t u m p a n d overlying soft tissue b r e a k d o w n
o c c u r r e d . A l t h o u g h this healed s e c o n d a r i l y , the clinic
t e a m a d v i s e d that t h e a r e a be c o v e r e d b y a d e q u a t e soft
tissue. This w a s d o n e a n d the a m p u t e e h a d n o further
difficulty. A . H . c o n t i n u e s to b e active a n d , in a d d i t i o n
t o skiing, sails his o w n b o a t .
N o t all a m p u t e e s , h o w e v e r , follow the s a m e r o a d to
successful a m b u l a t i o n . A t o n e t i m e , the clinic t e a m b e ­
lieved they h a d t w o p a t i e n t s w h o h a d the potential a n d
m o t i v a t i o n to a m b u l a t e . The t e a m p r o v i d e d p r o s t h e s e s
b u t the p a t i e n t s b e c a m e o b e s e a n d g a v e u p the effort.
T h e rehabilitation of o n e , a triple a m p u t e e (BE o n o n e
side) w a s , unfortuntately, a notable failure.
The American Academy
of
Orthotists and Prosthetists
10th Annual Meeting
The Dutch Inn
Lake Buena Vista
in Orlando, Florida
January 25-29, 1984
Clinical Prosthetics and Orthotics (ISSN 0279-6910) is published
quarterly by the American Academy of Orthotists and Prosthetists, 717 Pendleton St., Alexandria, VA 22314. Second class post­
age paid at Alexandria, VA and additional mailing offices.
POSTMASTER: Send address changes to Clinical Prosthetics and
Orthotics, 717 Pendleton Street, Alexandria, VA 22314.
An exceptional educational meeting in
sunny central Florida—home of
Disneyworİd and EPCOT Center
®1983 by the American Academy of Orthotists and Prosthetists.
Printed in the United States of America. All rights reserved.
Make plans to attend now!
2/CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O.
Vol. 7, N o . 4
Hydraulics and Above-Knee Prosthetics
A. Bennett Wilson, Jr., B.S.M.E.*
S o m e of the highlights in t h e h i s t o r y of the u s e of
h y d r a u l i c s y s t e m s in artificial legs m i g h t b e useful in
u n d e r s t a n d i n g the p r e s e n t status a n d influencing the
future application of h y d r a u l i c principles in l o w e r - l i m b
prosthetics.
O n e of the p r i m e objectives of the d e s i g n e r s of artifi­
cial legs for a b o v e - k n e e a m p u t e e s is control of the knee
joint, a n d , t h u s , t h e shank to p r o v i d e the a m p u t e e w i t h
the m e a n s to s t a n d a n d walk safely, efficiently, a n d
gracefully. Sporadically since 1 9 1 8 , a n d p o s s i b l y before,
hydraulic principles w e r e p r o p o s e d as a m e a n s for lock­
ing or b r a k i n g the knee to e n h a n c e safety, b u t n o n e of
these ideas s e e m to h a v e r e a c h e d a practical stage until
after W o r l d W a r II.
W h e n t h e N a t i o n a l A c a d e m y of Sciences ( N A S ) in­
itiated a r e s e a r c h p r o g r a m in l i m b p r o s t h e t i c s in 1945 at
the r e q u e s t of the S u r g e o n G e n e r a l of the A r m y , s u r v e y s
of a m p u t e e s i n d i c a t e d that the a b o v e - k n e e a m p u t e e s felt
that their g r e a t e s t n e e d w a s a k n e e lock t h a t w o u l d p r e ­
v e n t s t u m b l i n g . T h i s "finding" p r o m p t e d a n u m b e r of
d e s i g n s in t h e U n i t e d States that u s e d h y d r a u l i c s y s t e m s
to p r o v i d e knee locking o r b r a k i n g o n d e m a n d . C o n c u r ­
rently, a t e a m in G e r m a n y , Ulrich H e n s c h k e , a p h y s i ­
c i a n , a n d H a n s M a u c h , an e n g i n e e r , d e v e l o p e d a leg
p r o t o t y p e that u s e d a h y d r a u l i c lock activated b y m o t i o n
of the a b d o m i n a l wall. After Dr. H e n s c h k e a n d M r .
M a u c h m o v e d to the U n i t e d States at the invitation of the
U n i t e d States A i r F o r c e , t h e y w e r e e n c o u r a g e d b y their
h o s t to c o n t i n u e d e v e l o p m e n t of their d e s i g n , a n d they
b e c a m e active in the N A S Artificial L i m b P r o g r a m .
D u r i n g the 1940's, M r . Jack S t e w a r t , an A K a m p u t e e
a n d i n v e n t o r , d e v i s e d , to m e e t h i s o w n n e e d s , a n a b o v e
k n e e leg w h i c h u s e d a hydraulic s y s t e m to n o t only
p r o v i d e k n e e locking, b u t also to p r o v i d e shock a b s o r p ­
tion at t h e heel, c o - o r d i n a t e d m o t i o n b e t w e e n k n e e a n d
ankle joints, a n d adjustability of t h e h e i g h t of the heel.
S w i n g p h a s e control w a s p r o v i d e d b y h y d r a u l i c fluid
b e i n g forced t h r o u g h a single orifice, a s e r e n d i p i t o u s
sort of c i r c u m s t a n c e .
A b o u t 1 9 5 1 , leaders in the r e s e a r c h p r o g r a m c a m e to
the c o n c l u s i o n , b a s e d o n d a t a d e v e l o p e d at t h e U n i v e r ­
sity of California, that p e r h a p s , m o r e i m p o r t a n t t h a n
control in t h e s t a n c e p h a s e , is control d u r i n g the s w i n g
p h a s e . M r . M a u c h w a s r e q u e s t e d to give h i g h p r i o r i ­
ty to t h e d e s i g n of a m e c h a n i s m that w o u l d p r o v i d e
control of the knee d u r i n g s w i n g p h a s e so t h a t t h e a m ­
p u t e e could v a r y c a d e n c e w i t h o u t c h a n g i n g the friction
control setting. A t a b o u t the s a m e t i m e it w a s r e c o g n i z e d
that t h e c h a r a c t e r i s t i c s of a fluid flowing t h r o u g h a n
orifice h a d t h e possibility of p r o v i d i n g a u t o m a t i c a l l y the
c h a n g e in r e s i s t a n c e to knee flexion a n d e x t e n s i o n
n e e d e d to c o m p e n s a t e for c h a n g e s in the w a l k i n g c a ­
dence.
U s i n g m a n y of t h e s a m e p a r t s d e s i g n e d for the
s t a n c e - c o n t r o l s y s t e m as well as d a t a p r o v i d e d b y the
U n i v e r s i t y of California B i o m e c h a n i c s L a b o r a t o r y c o n ­
cerning knee movements during swing phase, Mr.
Vol. 7, N o . 4
M a u c h p r o d u c e d a unit w i t h a n u m b e r of orifices a r ­
r a n g e d to p r o v i d e c h a n g e s in r e s i s t a n c e to r o t a t i o n at the
knee c o r r e s p o n d i n g to the " n o r m a l . " T h i s d e s i g n ,
k n o w n as t h e M o d e l " B , " after s o m e y e a r s of testing a n d
field u s e , w a s c o m b i n e d w i t h the s t a n c e - c o n t r o l sys­
t e m to p r o d u c e the M o d e l " A , " w h i c h w h e n modified
w a s m a r k e t e d as the H e n s c h k e - M a u c h S'n'S ( S w i n g a n d
Stance) knee unit. D u r i n g the d e v e l o p m e n t of the
H e n c h k e - M a u c h units several less c o m p l e x h y d r a u l i c
a n d p n e u m a t i c units w e r e also d e v e l o p e d b y o t h e r s a n d
m a r k e t e d c o m m e r c i a l l y w i t h s o m e d e g r e e of s u c c e s s .
D u r i n g the early 1950's 18 uniis of the S t e w a r t d e s i g n
k n o w n as the S t e w a r t - V i c k e r s H y d r a u l i c L e g w e r e
e v a l u a t e d b y a t e a m at N e w York U n i v e r s i t y , w h o found
g o o d a m p u t e e a c c e p t a n c e , a n d r e c o m m e n d e d that the
locking feature b e eliminated since t h e cost c o u l d b e
r e d u c e d a p p r e c i a b l y a n d the test subjects didn't s e e m to
m a k e u s e of that feature. This r e c o m m e n d a t i o n w a s fol­
l o w e d b y M r . Stewart, w h o a s h o r t w h i l e later sold all
rights to U . S . M a n u f a c t u r i n g C o . , w h o m a n u f a c t u r e d
a n d m a r k e t e d it as the H y d r a - C a d e n c e L e g . T h e H y ­
dra-Cadence Leg has been a commercial success, but
in spite of a g r e a t deal o f e x p e r i e n c e n o o n e c a n b e s u r e of
the relative i m p o r t a n c e of its m a n y features.
T h e d e v e l o p m e n t of h y d r a u l i c m e c h a n i s m s for artifi­
cial legs h a s b e e n p l a g u e d b y leakage a n d b r e a k a g e ,
w h i c h is only n a t u r a l in an effort that tries to arrive at the
o p t i m u m c o m p r o m i s e b e t w e e n cost, w e i g h t , a n d func­
tion. W h e t h e r o r not this o p t i m u m has b e e n a c h i e v e d
is not yet k n o w n . W e do k n o w , h o w e v e r , that active
above-knee and hip-disarticulation amputees ap­
preciate the s w i n g - p h a s e control function afforded b y
h y d r a u l i c m e c h a n i s m s a n d that the p r e s e n t d a y costs are
not p r o h i b i t i v e for a substantial n u m b e r of a m p u t e e s .
N o definitive studies h a v e b e e n m a d e that w o u l d d e ­
lineate t h e efforts of the v a r i o u s factors a n d features
i n v o l v e d , singly or in c o m b i n a t i o n . W i t h the availability
of 4 - c h a n n e l 2 4 - h o u r physiological surveillance s y s t e m s
a n d o t h e r s o p h i s t i c a t e d i n s t r u m e n t a t i o n , s u c h studies
s e e m to b e q u i t e feasible n o w a n d certainly should b e
considered.
F o r at least thirty y e a r s t h e n e e d for v o l u n t a r y control
of the knee joint h a s b e e n r e c o g n i z e d , b u t until t h e
a d v e n t of the m i c r o c o m p u t e r it w a s difficult to c o n c e i v e
of a practical m e t h o d to accomplish this. W h e n m i c r o ­
c o m p u t e r s b e c a m e available, the first r e a c t i o n of s o m e
d e s i g n e r s w a s simply to a d d the m i c r o c o m p u t e r to p r e ­
sent hydraulic s y s t e m s , b u t these efforts failed m o s t
p r o b a b l y b e c a u s e the s y s t e m s available w e r e n o t de­
s i g n e d for control b y c o m p u t e r . A t a n y rate, it w o u l d
* A s s i s t a n t Director
Rehabilitation R e s e a r c h a n d T r a i n i n g C e n t e r
Dept. of O r t h o p a e d i c s a n d Rehabilitation
U n i v e r s i t y of V i r g i n i a Medical C e n t e r
Charlottesville, V i r g i n i a 2 2 9 0 8 .
CLINICAL PROSTHETICS AND ORTHOTICS :C.P.0./3
s e e m that the w e i g h t alone of p r e s e n t s y s t e m s w o u l d
m a k e v o l u n t a r y control i m p r a c t i c a l , a n d thus a n y project
in this a r e a should b e g i n a n e w .
A t p r e s e n t , v e r y little w o r k s e e m s to b e g o i n g o n in the
area of v o l u n t a r y control s y s t e m s . S o m e w o r k at the
M a s s a c h u s e t t s Institute of T e c h n o l o g y h a s b e e n r e p o r t e d
for n e a r l y a d e c a d e . M o r e recently, the R E C at M o s s
Rehabilitation H o s p i t a l started a project w h e r e p a t t e r n
r e c o g n i t i o n t e c h n i q u e s a r e u s e d to o b t a i n s u b c o n s c i o u s
control of a k n e e m e c h a n i s m b y E M G signals a b o u t t h e
h i p joint, w h i c h s h o w s a g o o d deal of p r o m i s e .
P e r h a p s w h a t w e n e e d m o s t at this p o i n t is m o r e
i n f o r m a t i o n c o n c e r n i n g the c o n t r i b u t i o n of e a c h v a r i ­
able, s u c h as s w i n g - p h a s e control, s t a n c e - p h a s e c o n t r o l ,
ankle a c t i o n , w e i g h t , a n d w e i g h t d i s t r i b u t i o n , singly
a n d in c o m b i n a t i o n , for d e s i g n e r s of the n e x t g e n e r a t i o n
of a b o v e - k n e e legs. W i t h the t e c h n o l o g y n o w available
to u s , this a p p e a r s to b e possible as well as practical.
Physical Therapy and Hydraulic Knee Units
Bernice Kegel R.P.T.*
W i t h o u t a t h o r o u g h u n d e r s t a n d i n g of the principles
of o p e r a t i o n a n d functional benefits e n g i n e e r e d into
the sophisticated hydraulic knee m e c h a n i s m s , the thera­
pist will b e unable to help the a m p u t e e g a i n m a x i m u m
benefits a n d to u s e the s y s t e m effectively. It is i m ­
p o r t a n t that the p r o s t h e t i s t a s c e r t a i n that t h e t h e r a p i s t
k n o w s w h a t adjustability is i n c o r p o r a t e d into the
p r o s t h e s i s . M u c h of the a d j u s t m e n t will b e d o n e
d u r i n g d y n a m i c a l i g n m e n t at t h e p r o s t h e t i c facility,
b u t modifications will n e e d to b e m a d e as the p a t i e n t
gains confidence a n d his a m b u l a t i o n p a t t e r n i m ­
proves.
A n u n d e r s t a n d i n g of the f u n d a m e n t a l differences
b e t w e e n h y d r a u l i c control a n d m e c h a n i c a l friction
will help in t r a i n i n g the a m p u t e e to take full a d v a n ­
tage of the flexibility of h y d r a u l i c m e c h a n i s m s . A m ­
p u t e e s c a n walk o v e r a w i d e r a n g e of c a d e n c e s in­
s t e a d of b e i n g limited as w i t h m e c h a n i c a l friction.
T h e r e are t w o r e a s o n s for this. First, h y d r a u l i c fric­
tion i n c r e a s e s w i t h s p e e d to just b a l a n c e t h e i n c r e a s e
in kinetic e n e r g y of the p r o s t h e s i s w h i l e m e c h a n i c a l
friction r e m a i n s essentially c o n s t a n t . T h e p r o g r a m m e d
hydraulic c h a r a c t e r i s t i c s give little frictional r e s i s t a n c e
d u r i n g initial e x t e n s i o n a n d flexion, b u t b u i l d to a
p e a k at t e r m i n a l flexion a n d e x t e n s i o n . T h i s h e l p s to
p r o v i d e a natural a p p e a r i n g gait r e g a r d l e s s of c a ­
d e n c e . T h e stability of h y d r a u l i c s y s t e m s p e r m i t s
a l i g n m e n t n e a r e r the trigger p o i n t a n d t h u s results in
less e n e r g y e x p e n d i t u r e r e q u i r e d for walking. If a p a t i e n t
h a s p r e v i o u s l y u s e d a m e c h a n i c a l k n e e , h e n e e d s to b e
r e m i n d e d that n o e x a g g e r a t e d residual l i m b m o t i o n is
n e c e s s a r y to g a i n a d e q u a t e flexion a n d e x t e n s i o n of his
hydraulic prosthesis.
F o r p u r p o s e s of b r e v i t y I will limit m y d i s c u s s i o n to
gait t r a i n i n g w i t h o n e knee u n i t — t h e M a u c h S-N-S
(Figure 1 ) . T h e M a u c h S-N-S knee unit c a n b e set to
p r o v i d e 3 functions:
1. S w i n g a n d S t a n c e p h a s e control.
2. S w i n g p h a s e control only.
3 . M a n u a l k n e e lock.
A stirrup s h a p e d lever n e a r the t o p of the p i s t o n
r o d o p e r a t e s as a selector s w i t c h . W h e n the lever is in
the d o w n p o s i t i o n , s w i n g a n d s t a n c e control are b o t h
o p e r a t i v e . This w o u l d b e the a d j u s t m e n t c h o s e n for
n o r m a l walking. T h e m a j o r a d v a n t a g e of s t a n c e c o n ­
trol is that it offers t h e p a t i e n t s t u m b l e r e c o v e r y . If
4/CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O.
F i g u r e 1. C u t a w a y d i a g r a m o f t h e M a u c h U n i t
the p r o s t h e t i c k n e e buckles, it will g i v e w a y slowly
e n o u g h that the p a t i e n t should b e able t o r e g a i n h i s
b a l a n c e before falling. W h e n t r a i n i n g a p a t i e n t w i t h a
c o n v e n t i o n a l knee u n i t , h e is t a u g h t to forcefully
c o n t r a c t his h i p e x t e n s o r s late in s w i n g p h a s e to a c ­
celerate the s h a n k f o r w a r d ( w i t h resulting t e r m i n a l
i m p a c t ) to e n s u r e e x t e n s i o n of the knee at heel strike.
A m p u t e e s w e a r i n g fluid-controlled m e c h a n i s m s n e e d
not d o this. T h e a m p u t e e should b e i n s t r u c t e d to
s w i n g his thigh f o r w a r d , d e c e l e r a t e it, a n d e n d the
m o v e m e n t with the residual limb pointing to the
p o i n t o n t h e g r o u n d w h e r e the heel should strike.
The s h a n k , a i d e d b y the built-in e x t e n s i o n b i a s will
s w i n g f o r w a r d s m o o t h l y , a n d at heel strike will be in
*Seattle, W a s h i n g t o n
Vol. 7, N o . 4
full e x t e n s i o n . W i t h the s t a n c e p h a s e c o n t r o l e n g a g e d ,
the p r o s t h e t i c k n e e will b e stable in the initial p o r t i o n
of s t a n c e p h a s e w i t h o u t forceful e x t e n s i o n of the h i p
m u s c u l a t u r e b e i n g n e c e s s a r y . T h e feature m a k e s gait
t r a i n i n g m a r k e d l y easier.
It is e x t r e m e l y i m p o r t a n t d u r i n g the e n d of s t a n c e
p h a s e o n the p r o s t h e t i c side t h a t the hip b e a h e a d of
the k n e e a n d w e i g h t o n the ball of the foot. This
h y p e r e x t e n s i o n m o m e n t is n e c e s s a r y to d i s e n g a g e the
s t a n c e p h a s e control m o m e n t a r i l y a n d allow t h e k n e e
to b e n d freely in s w i n g p h a s e . If the a m p u t e e d o e s
not exert this h y p e r e x t e n s i o n for %oth of a s e c o n d , h e
m i g h t e x p e r i e n c e difficulty in flexing the k n e e to
b e g i n s w i n g p h a s e . W h e n w a l k i n g o n soft g r o u n d , it
is e v e n m o r e i m p o r t a n t to e x e r t this h y p e r e x t e n s i o n
moment.
T h e benefits of s t a n c e control a r e also u s e d w h e n
w a l k i n g d o w n stairs a n d r a m p s i n a s t e p - o v e r - s t e p
m a n n e r . This ability to w a l k d o w n steps in a s t e p o v e r - s t e p m a n n e r r a t h e r t h a n o n e step at a t i m e o r b y
jack-knifing is o n e of the key a d v a n t a g e s of the
M a u c h k n e e unit. T h e p a t i e n t n e e d s to b e t a u g h t to
place his p r o s t h e t i c heel o n t h e lower s t e p w i t h t h e
forefoot e x t e n d i n g b e y o n d the e d g e of the step (Fig­
u r e 2 ) . H e is then told to flex his h i p f o r w a r d w h i l e
s i m u l t a n e o u s l y p u t t i n g w e i g h t o n the p r o s t h e t i c leg.
T h i s will c a u s e a controlled b e n d i n g of the p r o s t h e t i c
knee. A s the p r o s t h e t i c knee yields, the s o u n d leg is
b r o u g h t f o r w a r d a n d placed o n t h e l o w e r s t e p . If the
p a t i e n t has to w a i t for the p r o s t h e t i c k n e e to b e n d ,
t h e n s t a n c e p h a s e r e s i s t a n c e is t o o h i g h a n d should
b e r e d u c e d . This activity is p r o b a b l y the m o s t dif­
ficult to t e a c h an a m p u t e e , expecially if h e h a s u s e d a
c o n v e n t i o n a l k n e e u n i t in t h e p a s t . T h i s s a m e
t e c h n i q u e is u s e d for g o i n g d o w n r a m p s . W h e n
w a l k i n g u p steps a n d r a m p s the s a m e t e c h n i q u e s are
u s e d as in c o n v e n t i o n a l training.
W h e n sitting d o w n in a c h a i r , the patient c a n e i t h e r
u s e t h e w e i g h t b e a r i n g r e s i s t a n c e of the S-N-S u n i t to
control the rate of sitting, o r release t h e s t a n c e p h a s e
control a n d u s e the s o u n d leg to control sitting rate in
the s a m e fashion a s w i t h a c o n v e n t i o n a l k n e e unit.
H o w quickly the k n e e b e n d s u n d e r w e i g h t is de­
t e r m i n e d b y the s t a n c e a d j u s t m e n t s c r e w , w h i c h is
t u r n e d w i t h a 2 2 m m Allen w r e n c h ( F i g u r e 3 ) . T h e
a d j u s t m e n t is extremely sensitive w i t h a r a n g e of only
120 d e g r e e s . Slowest b e n d i n g a n d m a x i m u m stability
is o b t a i n e d w i t h a full clockwise a d j u s t m e n t . M o s t
patients like to start w i t h a h i g h d e g r e e of stability.
Figure 3. Allen wrench inserted into the stance adjust­
ment screw.
Figure 2. Correct placement of the prosthetic heel
Vol. 7, N o . 4
To eliminate s t a n c e p h a s e control the p a t i e n t is told
to s t a n d w i t h his p r o s t h e t i c leg b e h i n d h i s s o u n d leg.
W i t h w e i g h t o n the toe of his p r o s t h e s i s , h e pulls the
selector s w i t c h lever u p ( F i g u r e 4 ) . T h i s m o d e w o u l d
b e u s e d for bicycling a n d o t h e r activities n e e d i n g a
free s w i n g i n g leg. S w i n g r e s i s t a n c e is a d j u s t e d b y
m o v i n g the serrated c a p . T h e verticle black line u n d e r
the serrated c a p is the e x t e n s i o n r e s i s t a n c e m a r k e r .
W h e n the black line is all the w a y t o the r i g h t (4 o'clock)
e x t e n s i o n r e s i s t a n c e is lowest, a n d all t h e w a y to the left
(8 o'clock) is the m a x i m u m setting. A g o o d r e s i s t a n c e for
b e g i n n i n g walking w o u l d b e at 5 o'clock ( F i g u r e 5 ) .
T h e s a m e serrated c a p that adjusts e x t e n s i o n resis­
t a n c e also adjusts flexion r e s i s t a n c e . W h e n the " H " in
the w o r d H Y D R A U L I C is o v e r the line m a r k e r (re­
gardless of the p o s i t i o n of the line m a r k e r ) , flexion r e ­
sistance is lowest. " K " o v e r the m a r k e r i n d i c a t e s
m a x i m u m r e s i s t a n c e . A g o o d r e s i s t a n c e for b e g i n n i n g
walking is at the " D " p o s i t i o n (as s h o w n in F i g u r e 5 ) .
CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O./5
F i g u r e 4 . E l i m i n a t i n g the s t a n c e p h a s e c o n t r o l .
F i g u r e 5 . G o o d r e s i s t a n c e settings for b e g i n n i n g w a l k i n g .
To engage the knee lock, the selector switch is pulled
into u p p o s i t i o n w i t h the knee flexed a n d b e a r i n g
no w e i g h t (Figure 6 ) . T h e knee m a y n o w b e e x t e n d e d
from this flexed p o s i t i o n , b u t i n c r e a s e d flexion is n o t
possible.
A r i g h t - l e g g e d a m p u t e e m i g h t c h o o s e to lock the
prosthetic knee w h i l e driving a n d p r e s s i n g the pedal
by a f o r w a r d m o t i o n of the h i p . For s t a n d i n g at w o r k
for a n y length of t i m e o r w h i l e s t a n d i n g o n a b u s , the
a m p u t e e could b e t a u g h t to lock his k n e e .
T h e M a u c h S-N-S units h a v e also b e e n successfully
u s e d b y bilateral a m p u t e e s . T h e t w o u n i t s are likely
to b e adjusted differently b e c a u s e different residual
limb lengths call for different r e s i s t a n c e settings.
The p a t i e n t should b e t a u g h t that the h y d r a u l i c unit
m a y r e q u i r e s e r v i c i n g e v e r y o n e to t w o y e a r s . H e
should also be told that small a m o u n t s of air in the
h y d r a u l i c s y s t e m are no r e a s o n for c o n c e r n . A n a u ­
t o m a t i c selfbleeding feature will eliminate the air after
he walks a few steps, o r if h e b e n d s the knees several
t i m e s before applying the p r o s t h e s i s . T h e leg should
b e stored u p r i g h t w i t h t h e knee fully e x t e n d e d so t h a t
air does not e n t e r the hydraulic s p a c e s .
Bibliography
Kegel, B . , Byers, J . L . , " A m p u t e e ' s M a n u a l — M a u c h
S-N-S K n e e . " M e d i c P u b l i s h i n g C o . , P . O . B o x 1 6 3 6 , Bellevue, W A 9 8 0 0 9 , 1 9 7 7 .
F i g u r e 6. E n g a g i n g t h e k n e e lock.
6/CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O.
L e w i s , E . A . , " E l e m e n t s of T r a i n i n g w i t h the M a u c h
S-N-S S y s t e m for A b o v e - K n e e A m p u t e e s . " R e s e a r c h
and D e v e l o p m e n t Division, P r o s t h e t i c s a n d S e n s o r y
Vol. 7, N o . 4
Aids Service, Veterans Administration, 252 Seventh Av­
e n u e , N e w York, N e w York 1 0 0 0 1 .
Knee Prostheses, Mauch Laboratories, Inc., 3035 Dryden
Road, Dayton, Ohio 45439, January 1974.
L e w i s , E . A . a n d B e r n s t o c k , W . M . , "Clinical A p p l i c a t i o n
S t u d y of the H e n s c h k e - M a u c h M o d e l A S w i n g a n d
Stance C o n t r o l S y s t e m . " Bulletin of Prosthetics
Research
Fall, 1968.
M u r p h y , E . F . , " T h e S w i n g P h a s e of W a l k i n g w i t h
A b o v e - K n e e P r o s t h e s i s . " Bulletin of Prosthetics
Research,
S p r i n g 1964.
M a u c h , H . A . , "Stance C o n t r o l for A b o v e - K n e e Artificial
L e g s — D e s i g n C o n s i d e r a t i o n s in t h e S-N-S K n e e . " Bul­
letin of Prosthetics Research, Fall 1968.
S t a r o s , A . a n d M u r p h y , E . F . , " P r o p e r t i e s of Fluid F l o w
A p p l i e d to A b o v e K n e e P r o s t h e s e s . " Bulletin of Pros­
thetics Research, S p r i n g 1964.
Hydraulic/Pneumatic Knee Control Units
A Prosthetisf s Point of View
Charles H. Pritham, CPO*
A s M r . W i l s o n h a s d e m o n s t r a t e d , t h e use of h y d r a u l i c
a n d p n e u m a t i c control units h a d its g e n e s i s in the post
W o r l d W a r II R & D effort. T h e objective, of c o u r s e , w a s
to fit the r e t u r n i n g v e t e r a n A K a m p u t e e w i t h the best
p r o s t h e s i s t e c h n o l o g y could p r o v i d e . S u c h a m p u t e e s
w e r e y o u n g a n d physically fit, p r i m e candidates to b e n ­
efit f r o m the a d v a n t a g e s of a d v a n c e d control units. T h e
p r i m e a d v a n t a g e , usually c i t e d , is c a d e n c e r e s p o n s i v e ­
ness. A s the p a t i e n t walks at different r a t e s , the control
unit automatically adjusts to control heelrise a n d t e r m i ­
nal s w i n g i m p a c t . C o n s t a n t friction knees c a n not dupli­
cate this feature. All h y d r a u l i c a n d p n e u m a t i c units p r o ­
v i d e this feature a n d o n e , the M a u c h S-N-S, p r o v i d e s
stance p h a s e control as well. T h i s m e a n s that the u n i t
p r o v i d e s e n h a n c e d knee stability in the early p o r t i o n of
s t a n c e p h a s e to i n c r e a s e t h e p a t i e n t ' s safety.
In this m o d e , the S-N-S unit c a n b e said to function
in a fashion a n a l o g o u s to that of a c o n v e n t i o n a l safety
knee. In a n o t h e r m o d e , the function of the S-N-S c a n b e
likened to t h a t of a simple m a n u a l l y locking k n e e . T w o
o t h e r knee control u n i t s , v a r i a n t s of Kingsley's H y d r a n u m a t i c a n d U S M C ' s Dynaflex, function in a s i m i ­
lar fashion.
T h e H y d r a c a d e n c e , in a d d i t i o n to s w i n g p h a s e c o n ­
trol, also p r o v i d e s heel h e i g h t adjustability a n d toe
pick-up. Otto Bock has recently introduced a modular
knee t h a t includes a h y d r a u l i c s w i n g p h a s e control.
A s c a n b e seen t h e n , these are just a few of the
v a r i a t i o n s available to t h e p r o s t h e t i s t a n d his p a t i e n t .
T h e principle a d v a n t a g e s c l a i m e d for s u c h control units
are e n h a n c e d c o s m e s i s a n d p e r f o r m a n c e , a n d l o w e r
e n e r g y e x p e n d i t u r e . A g a i n s t these a d v a n t a g e s the dis­
a d v a n t a g e s m u s t b e w e i g h e d . Bulk, size, a n d w e i g h t of
s o m e of the units p r e c l u d e t h e i r u s e b y m a n y p a t i e n t s .
T h e c o n s i d e r a b l e e x p e n s e of m o s t , if n o t all, h y d r a u l i c
a n d p n e u m a t i c control units rules o u t o t h e r s . M o r e o v e r ,
the control units h a v e s h o w n to b e unreliable. S o m e
p a t i e n t s d e r i v e satisfactory service f r o m their units
w h i l e o t h e r p a t i e n t s u s i n g the s a m e b r a n d u n i t are c o n ­
stantly h a v i n g t h e m replaced a n d r e p a i r e d . A s m o s t of
the units n e e d to b e factory s e r v i c e d , t h e delay a n d
e x p e n s e of m a i n t a i n i n g a unit u n d e r s u c h c i r c u m s t a n c e s
c a n e n g e n d e r c o n s i d e r a b l e frustration.
Vol. 7 N o . 4
t
G i v e n these c i r c u m s t a n c e s , t h e pool of available a m ­
p u t e e s for w h o m s u c h a d v a n c e d control units are suita­
ble is a small p r o p o r t i o n of the total A K p o p u l a t i o n , a n d
m o s t closely r e s e m b l e s the p a t i e n t s for w h o m they w e r e
originally developed: y o u n g t r a u m a t i c males; i.e. vet­
e r a n s . It m u s t b e b o r n e in m i n d that this pool t o d a y
r e p r e s e n t s a less i m p o r t a n t p r o p o r t i o n of the a m p u t e e
p o p u l a t i o n t h a n it d i d s o m e 2 5 y e a r s a g o . Statistics d e m ­
o n s t r a t e that t h e m a j o r i t y of civilian a m p u t e e s in the
W e s t e r n W o r l d are geriatrics w h o lose a leg d u e to a r ­
teriosclerosis a n d are as often as not female. I n d e e d , the
v e r y a m p u t e e s w h o w e r e originally p r o v i d e d h y d r a u l i c
units b y the VA are n o t getting a n y y o u n g e r . T h e d a y will
c o m e for e a c h of t h e m w h e n they, a n d the clinic t e a m s
w h o a t t e m p t to a d d r e s s t h e i r n e e d s , m u s t m a k e a r e a p ­
praisal of their p r e s c r i p t i o n . So, the u s e of h y d r a u l i c /
p n e u m a t i c control units for a c o n s i d e r a b l e p o r t i o n of the
a m p u t e e p o p u l a t i o n c a n b e ruled out. N o t only t h a t , but
it is p o s s i b l e to b e v e r y skeptical in c o n s i d e r i n g the
suitability of s u c h units for patients for w h o m it is t h e o ­
retically ideally suited.
Y o u n g , active t r a u m a t i c a m p u t e e s a r e p r o b a b l y , chil­
d r e n a s i d e , the h a r d e s t o n their p r o s t h e s e s . G i v e n the
e x p e n s e of p u r c h a s i n g a n d maintaining such a unit, does
it m a k e s e n s e to fit an a m p u t e e w i t h o n e if h e is g o i n g to
h a v e m o r e t h a n a v e r a g e m a i n t e n a n c e p r o b l e m s ? C a n he
afford the t i m e lost from w o r k , i n t e r r u p t i o n s in h i s daily
life, a n d e x p e n s e of r e p a i r s ? G i v e n the d i s p r o p o r t i o n ­
ately rising cost of health care t o d a y , c a n s o c i e t y ? Gait
studies d e m o n s t r a t e that A K a m p u t e e s walk slower t h a n
n o r m a l subjects a n d B K a m p u t e e s b e c a u s e of i n c r e a s e d
e n e r g y e x p e n d i t u r e . If this is so, is the p r i m e a d v a n t a g e
cited for h y d r a u l i c / p n e u m a t i c u n i t s , c a d e n c e r e s p o n s e ,
relevant a n d w o r t h the additional e x p e n s e a n d p r o b ­
l e m s ? In a n o t h e r v e i n , g i v e n t h e a g i n g n a t u r e of the
population should further effort a n d m o n e y b e d e v o t e d
to d e v e l o p i n g n e w e r a n d m o r e s o p h i s t i c a t e d knee c o n ­
trol u n i t s ?
*Technical C o o r d i n a t o r
Durr-Fillauer M e d i c a l , Inc.
Chattanooga, Tennessee
Editor, C.P.O.
C L I N I C A L P R O S T H E T I C S A N D O R T H O T I C S : C . P . O . 17
In a n y e v e n t , it c a n b e said that a prosthetist in at­
t e m p t i n g to formulate a solution to his patient's p r o b ­
lems is c o n f r o n t e d w i t h a n u m b e r of q u e s t i o n s a n d a
w i d e v a r i e t y of d e v i c e s all i n t e n d e d to p e r f o r m the s a m e
function. It is also t r u e that the p r o s t h e t i s t h a s little m o r e
than p e r s o n a l e x p e r i e n c e , h e a r s a y , a n d the c o m p e t i n g
claims of t h e m a n u f a c t u r e r s to a i d h i m in m a k i n g his
decision. T h e natural t e n d e n c y o n t h e prosthetist's part
is to p r o v i d e his p a t i e n t w i t h t h e m o s t s o p h i s t i c a t e d unit
possible, for all of us g a i n c o n s i d e r a b l e satisfaction from
d o i n g so a n d from w o r k i n g w i t h s u c h u n i t s . T h e p a t i e n t
also w a n t s the best p r o s t h e s i s possible. T h e fact r e ­
m a i n s , h o w e v e r , that s u c h t e n d e n c i e s m u s t b e resisted
a n d b o t h prosthetist a n d p a t i e n t m u s t m a k e a realistic
appraisal of the situation a n d logically w e i g h t h e p r o s
and cons.
Questionnaire
The Clinical P r o s t h e t i c s a n d O r t h o t i c s — C . P . O . editorial board believes that two-way communication will aid the growth
of the profession. The Academy provides a forum, within this publication, through which practitioners can let their voices be
heard on significant issues. Please take the time to complete the questionnaire on professionalism and return to: Charles H.
Pritham, CPO, Editor, Clinical P r o s t h e t i c s a n d O r t h o t i c s , do Durr-Fillauer Medical, Inc., Orthopedic Division, 2710
Amnicola Highway, Chattanooga, TN 37406.
1. F o r w h a t p e r c e n t a g e of y o u r A K a m p u t e e s w o u l d y o u
c o n s i d e r h y d r a u l i c / p n e u m a t i c control units relevant?
0-20%
20-40%
40-60%
60-80%
80-100%
2. O f those for w h o m y o u c o n s i d e r s u c h u n i t s suitable,
w h a t p e r c e n t a g e are using t h e m ?
0-20%
20-40%
40-60%
Do y o u think further R & D is justified a n d n e c e s s a r y ?
Yes
No
N a m e the h y d r a u l i c / p n e u m a t i c control unit m o s t fre­
q u e n t l y u s e d in y o u r p r a c t i c e .
6. A d d i t i o n a l c o m m e n t s :
60- 80%
80-100%
3 . A r e y o u a n d y o u r p a t i e n t s satisfied w i t h t h e u n i t s ?
Yes
No
Results from the Questionnaire on Cervical Orthoses
T h e r e w e r e 13 r e s p o n d e n t s w h o a n s w e r e d as follows:
5. L i s t , in o r d e r of f r e q u e n c y , t h e t h r e e m o s t c o m m o n l y
u s e d cervical o r t h o s e s in y o u r p r a c t i c e .
1. Do y o u feel t h e r e exists a n e e d for further r e s e a r c h in
cervical o r t h o t i c s ?
Yes—12
No—1
Orthosis
2. D o y o u feel s u c h r e s e a r c h w o u l d affect y o u r p r a c t i c e ?
Yes—9
No—4
3 . Do y o u feel there exists a n e e d for a n o n - i n v a s i v e
halo?
Yes—9 No—2
Question—2
4. D o y o u as a n orthotist c u r r e n t l y p a r t i c i p a t e in the
application of Halo-Vests?
Yes—5
No—7
O n e r e s p o n d e n t , a p h y s i c i a n , i n d i c a t e d the q u e s ­
tion w a s n o t applicable. This s a m e i n d i v i d u a l indi­
c a t e d that the cervical o r t h o s i s he u s e d m o s t fre­
quently w a s a H a l o , followed b y t h e S . O . M . I . a n d
P h i l a d e l p h i a Collar, in that o r d e r .
8/CLINICAL PROSTHETICS A N D ORTHOTICS: C.P.O.
1.
2.
3.
4.
5.
6.
Philadelphia Collar
S.O.M.I.
Soft Collar
Halo
Four-Poster
Plastic C e r v i c a l
Orthosis
7. T h o m a s O r t h o s i s
8. D e n n i s o n T w o Poster
9. Modified F l o r i d a
Orthosis
Total
Frequency
n o . of
times
Listed Listed Listed
m e n t i o n e d 1st
2nd
3rd
10
10
6
5
3
2
1
1
1
A s always w i t h so small a s a m p l e , it is i m p o s s i b l e to
d r a w a n y m e a n i n g f u l conclusions. T h e a n s w e r s to q u e s ­
tions o n e t h r o u g h four pretty well speak for t h e m s e l v e s ;
Vol. 7, N o . 4
a l t h o u g h , c o n s i d e r i n g the n e a r u n a n i m i t y w i t h w h i c h
q u e s t i o n (1) w a s a n s w e r e d (12 o u t of 13) it is interesting
to c o n s i d e r the fact that only n i n e said yes to q u e s t i o n
(2). P r e s u m a b l y the o t h e r four r e s p o n d e n t s w e r e p r e ­
p a r e d to i g n o r e the results of a n y r e s e a r c h o r e x p e c t e d it
to confirm their p e r s o n a l e x p e r i e n c e .
In c o n s i d e r i n g q u e s t i o n n u m b e r (5) it is interesting
that the t h r e e m o s t frequently utilized o r t h o s e s w e r e
m e n t i o n e d a total of 2 6 times w h i l e all o t h e r s w e r e
m e n t i o n e d a total of 13 t i m e s . It is also w o r t h n o t i n g that
the S . O . M . I . o r t h e Philadelphia Collar w e r e first o r
s e c o n d in all three places.
It is also interesting to c o n s i d e r the a n s w e r to q u e s t i o n
n u m b e r (3) in light of the fact that s u c h o r t h o s e s as the
D e n n i s o n T w o - P o s t e r a n d the Guilford O r t h o s i s are
u s e d w i t h s u c h low f r e q u e n c y (by n u m b e r of the s a m p l e )
despite e v i d e n c e cited in the editorial as to their effec­
tiveness.
A d d i t i o n a l C o m m e n t s : The following are s a m p l e s of
o p i n i o n s a n d c o m m e n t s from the r e s p o n d e n t s .
1. I h a v e q u e s t i o n s a b o u t m a n d i b u l a r a n d articula­
tion deformities if w o r n for long p e r i o d s , also MTJ
problems.
2. I like the idea of a n o n - i n v a s i v e halo, just so it fits
m y Halo v e s t s .
3. Research should not stop in a n y field of endeavor.
4. T h e r e is a n e e d to e d u c a t e p h y s i c i a n s o n the p r o p e r
u s e a n d fitting of cervical o r t h o s e s .
5. Cervical o r t h o s e s are d i s p e n s e d m o s t frequently b y
p e o p l e o t h e r t h a n orthotists. A s a result, the pri­
v a t e p r a c t i t i o n e r s e l d o m a c q u i r e s the e x p e r t i s e
n e e d e d to initiate a p r o g r a m of c h a n g e .
The Editor
LETTERS TO THE EDITOR
After r e a d i n g t h e "Analysis of t h e Results from the
Q u e s t i o n n a i r e o n Metal v s . Plastic O r t h o s e s , " (Clinical
Prosthetics and Orthotics, Vol. 7, N o . 3 , 1 9 8 3 ) I w o u l d like
to m e n t i o n s o m e additional c o m m e n t s .
A s M a n a g e r of an o r t h o t i c s a n d p r o s t h e t i c s d e p a r t ­
m e n t , w h i c h h a s b e e n fabricating plastic o r t h o s e s exclu­
sively for the p a s t 13 y e a r s , I h a v e s o m e s t r o n g feelings
for the u s e of plastic A . F . O . ' s . W e h a v e found (as early as
1971) that w e could use plastic A . F . O . ' s on almost all
(with r a r e e x c e p t i o n s ) of o u r patients r e q u i r i n g an
A . F . O . , a n d p r o v i d e a better fitting, m o r e c o s m e t i c ,
lighter w e i g h t , a n d almost m a i n t e n a n c e free o r t h o s i s .
In r e s p o n s e to M r . D o n a l d G . S h u r r , L.P.T., M . A . w h o ,
in his Editorial entitled "Metal v s . Plastic A . F . O . — A
Therapist's V i e w , " C . P . O . Vol 7, N o . 1, 1 9 8 3 , asked if
H . R . L e h n e i s , P h . D . , C P O a n d J o h n S a r n o , M D still h a v e
the s a m e feelings a b o u t plastic A . F . O . ' s in 1983 as t h e y
did in 1 9 7 1 , let m e p r e s e n t this. After s p e a k i n g recently
( A u g u s t 1983) w i t h Dr. L e h n e i s a n d Dr. S a r n o , b o t h m e n
agree that t h e i r feelings are s t r o n g e r t o d a y for plastic
A . F . O . ' s t h a n they w e r e in 1971. T h e availability of n e w
plastics d e v e l o p m e n t a n d the a d d i t i o n of a H e m i - P . L . S .
Blank h a v e only s e r v e d to reinforce t h o s e feelings.
In Newsletter—Prosthetics
and Orthotics Clinic Vol. 4 ,
N o . 2 , 1 9 8 0 ( H . R . L e h n e i s ) , t h e r e are tables listing v a r i ­
o u s types of plastic A . F . O . ' s . Also listed are their indica­
tions for n e e d a n d c o n t r a i n d i c a t i o n s . This s h o u l d s e r v e
as an excellent g u i d e in c h o o s i n g t h e correct type of
A . F . O . for the individual patient. H o w e v e r , the c o r r e c t
type of plastic m u s t also b e chosen. Result # 4 ( C . P . O . ,
Vol. 7, N o . 3 , 1983), " M o s t Significant D i s a d v a n t a g e ,
M o s t C o m m o n l y Indicated F a c t o r s , " s h o w s as n u m b e r
o n e ( 1 ) , inability to adjust dorsiflexion/plantarflexion.
This h a s not b e e n a p r o b l e m for us. O u r P o s t e r i o r Leaf
Spring a n d H e m i - P o s t e r i o r Leaf S p r i n g Blanks are m a d e
of " O r t h o l e n " w h i c h c a n b e h a m m e r e d a n d s h a p e d in a
cold state, a n d c a n b e f o r m e d o v e r a modified cast in a
h e a t e d state. T h e cold state workability allows for a d ­
justing the p l a n t a r or dorsiflexion to a m o r e t h a n r e a s o n ­
able d e g r e e .
I believe the p i c t u r e b e c o m e s v e r y c l o u d y w h e n the
d i s c u s s i o n takes place w i t h o u t differentiating b e t w e e n
prefabricated, pre-molded, and custom molded A . F . O . ' s .
1. P r e f a b r i c a t e d . It is m y u n d e r s t a n d i n g that a
prefabricated A . F . O . is taken from the shelf a n d
w i t h m i n i m a l t i m e , effort, a n d a d j u s t m e n t , is deliv­
e r e d to the p a t i e n t .
2. P r e - M o l d e d B l a n k s . T h e p r e - m o l d e d A . F . O .
Blank r e q u i r e s m o r e labor, t i m e , a n d skill. It m u s t be
cut d o w n to a p p r o p r i a t e size, t h i n n e d out, h e a t e d
a n d m o l d e d to a properly modified p o s i t i v e cast of
the individual patient, fitted, a n d c o m p l e t e d w i t h a
strap.
3. C u s t o m M o l d e d . T h e c u s t o m m o l d e d A . F . O .
r e q u i r e s m a n y of the s a m e steps as the p r e - m o l d e d
A . F . O . w i t h the d e s i g n a n d trim line d e s i g n a t i o n as
a d d e d features to b e r e s o l v e d b y t h e orthotist for the
individual disability a n d p a t i e n t .
Vol. 7, N o . 4
CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O./9
Dear Editor,
I h a v e followed w i t h interest t h e d e b a t e of w h a t to call
a leg o r a r m that h a s h a d a p o r t i o n r e m o v e d .
I can understand some people's concern with
" s t u m p . " I c a n u n d e r s t a n d c o n c e r n w i t h e a c h alternative
s u g g e s t i o n , residual l i m b , partial l i m b , r e m n a n t l i m b . I
feel all of these are less t h a n a p p r o p r i a t e .
I h a v e , o v e r the y e a r s , always u s e d a v e r y u n i q u e
t e r m — " l e g " o r " a r m . " T h e r e m a i n i n g s e g m e n t is still
the leg o r a r m t h e p e r s o n h a s a l w a y s h a d a n d the n a m e
d o e s n o t n e e d to e x p e r i e n c e a c h a n g e d u e to a m p u t a t i o n .
W h e n I s a y " L e t m e see y o u r l e g , " the p a t i e n t i m ­
m e d i a t e l y s h o w s m e his a m p u t a t i o n rather t h a n s o u n d
limb. After all, that is w h a t he c o m e s to see m e a b o u t .
Y o u r s v e r y truly,
H.E. Thranhardt, C P O
Dear Editor,
I don't believe it is fair to l u m p all types of A . F . O . ' s
t o g e t h e r a n d g i v e t h e m a g e n e r a l c r i t i q u e , w h e t h e r it b e
g o o d o r b a d . The individual o r t h o s i s should b e j u d g e d
w i t h r e g a r d to p r o p e r type of o r t h o s i s , fit, a n d c o r r e c t
c h o i c e o f m a t e r i a l . T h e i m p r o p e r c h o i c e of m a t e r i a l c a n
in o n e c a s e b e o v e r b r a c i n g , a n d in a n o t h e r c a s e b e u n d e r b r a c i n g . T h i s c h o i c e is often critical a n d should b e
m a d e wisely.
Sincerely,
Donald Fornuff, C P
Manager
Orthotics & Prosthetics Department
Institute of Rehabilitation M e d i c i n e
N e w York University Medical Center
N e w York, N e w York
The following
Lehneis on ISPO Exec Board
and NBCs Today Show
H. Richard Lehneis, C P O , Ph.D., Immediate PastP r e s i d e n t of the A c a d e m y , w a s a m o n g the m a n y U . S .
a c a d e m i c i a n s w h o a t t e n d e d the International C o n g r e s s
of ISPO held S e p t e m b e r 5 - 9 in L o n d o n . In r e c o g n i t i o n of
his i n v o l v e m e n t in furthering the c a u s e of o r t h o t i c s a n d
prosthetics in this c o u n t r y a n d a b r o a d , Dr. L e h n e i s w a s
elected to the E x e c u t i v e B o a r d of I S P O .
D u r i n g the s a m e p e r i o d , a n i n t e r v i e w w i t h Dr. L e h ­
neis a p p e a r e d on N B C s T o d a y S h o w . A i r e d o n W e d n e s ­
day, S e p t e m b e r 7, the i n t e r v i e w focused o n m y o e l e c t r i c
p r o s t h e s e s . A s the d i r e c t o r of orthotics and p r o s t h e t i c s at
the N e w York U n i v e r s i t y Medical C e n t e r ' s Institute of
Rehabilitation M e d i c i n e , Dr. L e h n e i s is o n e of t h e lead­
ers in m y o e l e c t r i c r e s e a r c h .
is enclosed as a courtesy to the author. It is hoped that the readership will take the time to assist him in his inquiries.
The Editor
Continuing Education:
A Chance to Make a Difference
Bruce P. McClellan, CPO*
In the S u m m e r 1982 issue of C . P . O . , C h a r l e s Dankm e y e r s u b m i t t e d a v e r y timely a n d s u c c i n c t article r e ­
g a r d i n g c o n t i n u i n g e d u c a t i o n a n d the i s s u e s s u r r o u n d ­
ing it. C e r t a i n l y , c o n t i n u i n g e d u c a t i o n is a n e c e s s a r y
a n d vital c o m p o n e n t of a n y p r o g r e s s i v e p r o f e s s i o n , a n d
thus it is w i t h o u r s .
W i t h this in m i n d , m u c h h a s b e e n d o n e to create an
a t m o s p h e r e c o n d u c i v e to the p u r s u i t of quality e d u c a ­
tional seminars. T h e A c a d e m y a n d A B C , in conjunction
w i t h m a n y individuals a n d g r o u p s , h a v e in r e c e n t y e a r s
striven to u p g r a d e the profession b y initiating a n d o r ­
g a n i z i n g w o r k s h o p s a n d p r o g r a m s . T h e i m p o r t a n c e of
c o n t i n u i n g e d u c a t i o n to the field w a s u n d e r s c o r e d in
1981 w h e n the A c a d e m y m e m b e r s h i p v o t e d to m a k e t h e
existing informal s y s t e m a m a n d a t o r y o n e . Still, a t t e n ­
d a n c e in the different s e m i n a r s v a r i e s f r o m excellent to
v e r y poor. Too often, well p l a n n e d quality e d u c a t i o n a l
p r o g r a m s h a v e suffered t h r o u g h low a t t e n d a n c e o r b e e n
cancelled altogether for lack of interest. N o t only is this
d i s c o u r a g i n g to those people w h o h a v e w o r k e d to or­
g a n i z e the s e m i n a r , but it also takes a financial toll d u e to
a d v a n c e d a d v e r t i s i n g , mailing a n d b r o c h u r e costs. Still
w o r s e , t h o s e p e r s o n s w h o h a v e r e g i s t e r e d for the s e m i ­
nar lose their o p p o r t u n i t y to benefit professionally w h e n
a c o u r s e is cancelled.
The r e a s o n s b e h i n d the success o f o n e e d u c a t i o n a l
p r o g r a m a n d the failure of a n o t h e r a r e n o t a l w a y s a p p a r ­
ent. It is i m p e r a t i v e , therefore, to identify t h o s e ele­
m e n t s w h i c h a p p e a l to t h e individual p r a c t i t i o n e r s
across the c o u n t r y w h o are t h e t a r g e t e d a u d i e n c e .
In a n effort to a c c o m p l i s h this, a f o r m is h e r e w i t h
p r o v i d e d to give y o u , the p r a c t i c i n g professional, direct
influence o n the t y p e , s c o p e , a n d location of future c o n ­
tinuing education programs.
10/CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O.
The information obtained from y o u r responses will b e
u s e d in p l a n n i n g e d u c a t i o n a l f o r u m s b a s e d u p o n y o u r
r e c o m m e n d a t i o n s . In this m a n n e r , m o r e successful
s e m i n a r s should result for b o t h the s p o n s o r s a n d the
p a r t i c i p a n t s . Please take t h e initiative a n d i n d i c a t e y o u r
preferences o n the form p r o v i d e d . Y o u r i n p u t is v a l u e d
a n d will help to s t r e n g t h e n the c o n t i n u i n g e d u c a t i o n
p r o c e s s , a n d t h e r e b y i m p r o v e t h e quality of c a r e to the
communities you serve.
W h e n p l a n n i n g w o r k s h o p s a n d s e m i n a r s , it is helpful
to k n o w t h o s e topics y o u , as p r a c t i t i o n e r s , feel will b e s t
m e e t y o u r c o n t i n u i n g e d u c a t i o n n e e d s as well as the
factors influencing y o u r a t t e n d a n c e .
1. Please rank the following six factors in the o r d e r of
their i m p o r t a n c e in y o u r decision ( n u m b e r o n e b e i n g
most important).
.
topic of p r e s e n t a t i o n
institution s p o n s o r i n g
w o r k s h o p / s e m i n a r faculty
a m o u n t of r e g i s t r a t i o n fee
travel/hotel prices
g e o g r a p h i c a l location
2 . List the m o n t h ( s ) w h e n y o u prefer to a t t e n d w o r k ­
shops.
.
*Assistant Professor a n d D i r e c t o r
T h e U n i v e r s i t y of Texas
Prosthetics and Orthotics Program
T h e U n i v e r s i t y of Texas Health S c i e n c e
C e n t e r at Dallas
Dallas, Texas
Vol. 7, N o . 4
3 . B e l o w is a list of g e n e r a l p r o s t h e t i c / o r t h o t i c a r e a s .
U n d e r e a c h g e n e r a l topic is a s p a c e p r o v i d e d for
specific s u g g e s t i o n s related to t h a t t o p i c . Please r a n k
these a r e a s in o r d e r of y o u r interest from 1 - 1 2
( n u m b e r o n e b e i n g o f m o s t interest).
Below K n e e P r o s t h e t i c s
Above Knee Prosthetics
ORTHOTICS
Myoelectric C o n t r o l
Upper L i m b Orthotics
T e m p o r a r y Post A m p u t a t i o n D e v i c e s
Lower L i m b Orthotics
Endoskeletal S y s t e m s
Spinal O r t h o t i c s
Spinal C o r d Injury M a n a g e m e n t
4. Do y o u prefer topics to be ( ) specifically o r (
b r o a d l y p r e s e n t e d ? (check o n e )
)
5. Please list o t h e r specific topics of interest related to
above areas.
T h e r m a l Plastic F a b r i c a t i o n
Fracture Management
Please return completed forms to:
T h e U n i v e r s i t y of Texas P r o s t h e t i c s a n d
Orthotics Program
6 0 1 1 H a r r y H i n e s Blvd.
Suite 5 5 5
Dallas, T X 7 5 2 3 5
PROSTHETICS
U p p e r L i m b Prosthetics
Meetings and Events
Please notify the National Office immediately concerning additional meeting dates. It is important to submit meeting notices as
early as possible. In the case of Regional Meetings, it is mandatory to check with the National Office prior to confirming date to
avoid conflicts in scheduling.
1983
October 25, "Current Status of Orthotics and Prosthetics," a
symposium sponsored by the United States Members Soci­
ety of ISPO, Hyatt Regency Phoenix, Phoenix, Arizona.
October 2 5 - 2 9 , AOPA National Assembly, Hyatt Regency,
Phoenix, Arizona. Contact: AOPA National Headquarters,
703-836-7116.
November 11, "Seating and Mobility Systems," Gillette Chil­
dren's Hospital, St. Paul, Minnesota. Contact: Brett Day,
Continuing Education Dept., Gillette Children's Hospital,
200 E. University Ave., St. Paul, Minnesota 55101, 612-2912848.
November 1 2 - 1 3 , Seating Symposium, Northwestern Univer­
sity, Chicago, Illinois. Sponsored by the Academy Midwest
Chapter. Contact: Robert Picken, CP Educational Chairman,
Academy Midwest Chapter, 345 East Superior, Room 1723,
Chicago, Illinois 60611, 312-649-8006.
Vol. 7, N o . 4
November 1 5 - 1 8 (tentatively), Seventh Annual International
Rehabilitation Film Festival, New York, New York. Contact:
Rehab film, RIUSA, 1123 Broadway, New York, New York
10010.
December 9 - 1 1 , "Surgery and Rehabilitation of Complex
Problems of the Upper Limb," Sheraton Bal Harbour, Miami
Beach, Florida. Presented by the Department of Orthopae­
dics and Rehabilitation, University of Miami School of
Medicine. Contact: JoAnn Harris, Coordinating Assistant,
Department of Orthopaedics and Rehabilitation, P.O. Box
016960, University of Miami School of Medicine, Miami,
Florida 33101.
December 1 2 - 1 3 , UCLA Seminar, "Amputation Surgery Im­
mediate Post Surgical Prosthetic Techniques for Physicians/Prosthetists." Contact: Peggy Colton, Program Coor­
dinator, UCLA P.O.E.P., Rm. 22-46Rehab. Center, 1000 Vet­
eran Ave., Los Angeles, CA 90024.
CLINICAL PROSTHETICS AND ORTHOTICS: C.P.O./II
SECOND CLASS
POSTAGE PAID AT
ALEXANDRIA, VA
AND ADDITIONAL
MAILING OFFICES
Clinical Prosthetics and Orthotics . . . C.P.O,
American A c a d e m y o f Orthotists a n d Prosthetists
717 P e n d l e t o n S t . , A l e x a n d r i a , VA 2 2 3 1 4
The American Academy of Orthotists and Prosthetists
Directors
Officers
President:
Wade L. Barghausen, C P O
Columbus,
Ohio
Karl D. Fillauer, C P O
Knoxville,
Tennesse
P r e s i d e n t Elect:
Kurt Marschall, C P
Syracuse, New York
Charles W . C h i l d s , C P O
Medford,
Oregon
Vice President:
Mark J . Y a n k e , C P O
Akron, Ohio
D a v i d W. V a u g h n , C P O
Durham, North Carolina
Secretary-Treasurer:
J o h n N . Billock, C P O
Cortland, Ohio
D a v i d C. Schultz, C P O
Milwaukee,
Wisconsin
Immediate-Past
President:
H. Richard Lehneis, P h . D . , C P O
New York, New York
Executive Director
William L. McCulloch
Alexandria, Virginia
CLINICAL PROSTHETICS AND O R T H O T I C S . . . C.P.O.
A quarterly publication providing the means for interdisciplinary discussion among physicians, therapists, and
orthotics/prosthetics professionals. Contains important articles, spirited dialogue, and a sense of shared
delivery, making it a valuable publication.
Enclosed is my check for $12.00 for a 1-year subscription
(Foreign Subscription Price is $13.00.)
to Clinical Prosthetics and Orthotics, C.P.O.
Mail to:
AAOP
717 Pendleton St.
Alexandria, VA 22314
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