NEW DIMENSIONS FOR
PROSTHETIC SOCKS
Martha Field, M. S.
1A l t h o u g h the basic designs a n d fitting p r o cedures for prosthetic s o c k s h a v e b e e n stand ardized f o r m a n y y e a r s ( 2 ) , K n i t - R i t e , I n c . ( 5 ) a n d o t h e r s ( 3 ) h a v e b e c o m e increasingly a w a r e that c o r r e c t fitting o f s t a n d a r d s o c k s is s o m e t i m e s c o m p l i c a t e d b y "irregular c o n tours o f the s t u m p , the presence o f skin grafts, o r the l a c k o f sensation in s o m e a r e a s " ( 4 ) . F u r t h e r m o r e , i m p r o v e d s o c k e t de signs h a v e m a d e it m o r e desirable in s o m e cases to h a v e m o r e c o n t o u r e d s o c k s rather than additional layers o f s o c k s for m o r e pad ding.
Knitting Standard Socks
Historically the c o n t o u r o r shape o f a s t a n d a r d prosthetic s o c k has been achieved b y increasing o r decreasing the stitches (wales for width, courses for l e n g t h ) . Since each w a l e is c o n t r o l l e d b y a single needle on a knitting m a c h i n e , increasing o r decreasing wales m e a n s increasing o r decreasing nee dles. T h i s c a n o n l y b e done on the side edges o f the s o c k a n d is called fashioning. A s o c k is knitted beginning at the " t o e " and widened (fashioned) o n e needle e a c h side, each r o w to a c h i e v e the desired " t o e " width (Fig. 1 ) . T h e s o c k m a y then b e knitted straight a n d widened at evenly spaced intervals often enough to achieve the necessary width de sired for the t o p . W h e n the s o c k c o m e s off
the knitting m a c h i n e , the " t o e " is the shape
of a squared-off semicircle, and the fashionings are on the sides (Fig. 2 A ) . After the s o c k has been processed, b l o c k e d , a n d fleeced, it
is soft a n d fulled, and most often the fashionings are p o s i t i o n e d in the center rather
Fig. 1. "Toe" section of sock as it comes from the knitting machine. Each stitch (wale) across the
"toe" end was made by one needle. Loops (fashionings) on the sides indicate where needles were added to increase the width of the sock. Needles
may also be deleted gradually to narrow the sock for special contours as socks for Syme's amputa tion.
than on the sides to m a k e the " t o e " rounded rather than squared-off (Fig. 2B).
Sizing S t a n d a r d S o c k s
Prosthetists usually determine " t o e " and top b y taking circumference m e a s u r e m e n t s . For s o c k s " t o e " and top are expressed in flat measurements which are equivalent to o n e
half the circumference or slightly less. T h e " t o e " width of a s o c k m a y be measured in several w a y s . O n e w a y is to measure the width two inches from the tip of the s o c k ( 6 ) .
If measures are taken at the top of the widenings, the standard " t o e " will a p p r o x i m a t e a semicircle. T h e top width of a s o c k is almost
uniformly measured at the very top of the s o c k . " T o e " and top widths are scaled to each other in seven size ranges, two for
up-Fig. 2 . Left, T h e knitted s o c k . "Toe" is s h a p e of squared-off semi-circle. Fashionings a r e on the sides. Right, S o c k r e a d y t o be delivered to the a m p u t e e . It is the s a m e size as s o c k s h o w n on the left, but has been p r o c e s s e d , blocked and fleeced. Fashionings a r e n o w in the c e n t e r of the sock a n d the "toe" h a s a r o u n d e d c o n t o u r .
Fig. 3 . T w o a m p u t e e s w e r e originally fitted in a s t a n d a r d s o c k such as the 3-ply O r i o n / L y c r a ® o n e at upper right. A m p u t e e "A" h a d a n a r r o w i n g at the distal end. A l t h o u g h the actual s t u m p c o n t o u r w a s not s y m m e t r i c a l l y n a r r o w e d , the s o c k (left) w a s m a d e s y m m e t r i c a l , and in this c a s e the s t r e t c h of the f a b r i c c o n f o r m e d t o the actual c u r v a t u r e s w i t h o u t the wrinkling that o c c u r r e d with the s t a n d a r d s o c k . W h e n a s y m m e trical configuration c a n give equal c o m f o r t , it is preferred b e c a u s e the a m p u t e e c a n then turn the sock a n d get m o r e w e a r f r o m it. A m p u t e e " B " had a n uneven side. T h e s t a n d a r d s o c k did not stretch enough to prevent w e a r in the p r o t r u d i n g a r e a . A s o c k , l o w e r right, which followed the c o n t o u r e x a c t l y g a v e superior w e a r a n d c o m f o r t .
per-limb amputees a n d five for lower-limb a m p u t e e s5. In each size range, s t a n d a r d lengths are a v a i l a b l e in increments o f two inches from 1 0 to 32 inches. P T B sizes are a separate range as are the S y m e ' s s o c k sizes which require an additional measurement across the n a r r o w e d p a r t . M e a s u r e m e n t s for all s o c k s are expressed traditionally with the length first and other m e a s u r e m e n t s in order from top to " t o e " .
Evaluating Fit
T h e ranges of sizes a v a i l a b l e and the knit c o n s t r u c t i o n of the standard s o c k does allow a g o o d fit and an adequate a m o u n t o f stretch and shaping for most, but not enough for all, a m p u t e e s . Indications that s o c k s are not fit ting c o r r e c t l y h a v e been related to wrinkling of the " t o e " caused b y irregular c o n t o u r s o f the stump (Fig. 3 A ) , inadequate w e a r from a s o c k b e c a u s e o f pulling to stretch o v e r a p r o truding area (Fig. 3 B ) , and discomfort. T h e r e are m a n y v a r i a t i o n s o f these and other ir regularities, a n y of which m a y indicate the need for a special prosthetic s o c k . S o m e special s o c k s merely require knitting a wider " t o e " called a b o x " t o e " , whereas, others m a y require much m o r e c o m p l i c a t e d pat terning to give proper fit and c o m f o r t . M a k ing s o c k s for s o m e o f these variations on a knitting m a c h i n e is extremely difficult and s o m e t i m e s impossible, but a w a y has been found to tailor a s o c k to the specific m e a surements of any amputee—in fact, even to a scale drawing o r a pinned up sample (Fig. 4 ) .
Tailoring Special Socks
T a i l o r i n g is achieved b y a seam which flat tens to the extent that it is impossible for the average wearer to feel and is less distinctive than the widenings created b y fashioning a s o c k on a knitting m a c h i n e . T h e seam is made on a modified serger. M a n y seaming yarns were tried before the specific stretch y a r n s were finally selected. T h e y a l l o w w o o l , silkoline (mercerized c o t t o n ) and O r i o n / L y c r a ® knitted fabrics to b e seamed
Fig. 4 . A t right is a scale d r a w i n g . N o m e a s u r e m e n t s w e r e needed. D r a w i n g w a s followed e x a c t ly for 1 0 0 percent w o o l a n d decreased 1 0 percent for O r i o n / L y c r a . ® Fitting s o c k w a s sent.
At left is pinned-up s a m p l e . This w a s to fit a shoulder a m p u t a t i o n and s o m e m e a s u r e m e n t s w e r e also given.
and the seam to b e stretched so that it is a b solutely flat. T h i s seam does not deteriorate in laundering. It does give a new dimension
to prosthetic s o c k s . T h e limitations of widenings and n a r r o w i n g s imposed b y the knit ting m a c h i n e do n o t h a v e to b e adhered to
a n y m o r e , and s o c k s m a y be made n o w to fit unusual shapes s m o o t h l y and snugly. T h e squared-off " t o e " c a n n o w be rounded and n a r r o w e d as gradually or abruptly as needed.
W h e n a prosthetist is ordering a special s o c k for a n e w patient, he m a y find that the fitting sock is tailored since this is a faster
process than setting up a knitting m a c h i n e for one s o c k , and results in a sock to which alterations can easily b e made if necessary. O n c e the dimensions h a v e been established, the prosthetics facility m a y specify "knitted" or "tailored" when ordering and the s o c k will b e made as closely to specifications as each m e t h o d allows (Fig. 5 ) .
A n o t h e r n e w dimension has been the tail oring and knitting o f 2 - and 3-ply O r i o n / L y c r a ® s o c k s . T h i s material w a s originally developed for fitting amputees immediately p o s t o p e r a t i v e ( l ) and is relatively new in c o n v e n t i o n a l prosthetic s o c k s . Because of its increased elasticity, it is particularly suitable to certain a m p u t a t i o n s (Fig. 6 ) , and the stretch seaming y a r n is very c o m p a t i b l e with the stretch fabric when a s o c k is tailored.
T a i l o r i n g seams were originally used o n hip-disarticulation s o c k s for the purpose o f inserting a soft, pad-like w o o l panel into a supportive, elastic, snug-fitting O r i o n / Lycra® b o d y (Fig. 7 ) . At first o n l y 2-ply O r i o n / L y c r a ® was used with 3 - and 5-ply w o o l panels. N o w 3-ply O r i o n / L y c r a ® has been developed and is especially c o m p a t i b l e with the 5-ply w o o l panel. T a i l o r i n g also allows 1 0 0 percent w o o l hip-disarticulation s o c k s to b e m a d e in widths up to 2 6 inches and with m a n y v a r i a t i o n s such as smaller waists, a tighter fit for a smaller area on o n e side of a bi-lateral and added protection down the thigh o f the contralateral leg (Fig. 8 ) .
W a s h i n g O r i o n / L y c r a ® S o c k s Hip-disarticulation s o c k s of 1 0 0 percent O r i o n / L y c r a ® b o t h 2- and 3-ply h a v e been found to be beneficial in immediate postsur gical prosthetic fittings1 and can be supplied in plastic b a g s to a c c o m m o d a t e sterilization.
T h e y are also being r e c o m m e n d e d b y prosthetists for daily w e a r b e c a u s e the superior elasticity a l l o w s for a really supportive snug
fit and the ease of laundering is especially i m p o r t a n t in this type of s o c k . M i l d deter gents and w a r m rather than hot water tem peratures are r e c o m m e n d e d — c o o l dryer or air drying—no chlorine b l e a c h — a n d the
am-Fig. 5 . A t left is p a t t e r n m a d e from m e a s u r e m e n t s supplied by prosthetist. In the c e n t e r is the tail o r e d sock sent for a fitting. A t right is knitted s o c k , requested b y the a m p u t e e , a s it l o o k e d after be ing knitted. W h e n n a r r o w i n g is s o a b r u p t , stitches must be c o n n e c t e d b y h a n d .
Fig. 6. P a t t e r n for mitt which w a s tailored in 2 -ply O r i o n / L y c r a ® . In this c a s e the elasticity of the fabric is i m p e r a t i v e .
Fig. 7. Side view showing O r i o n / L y c r a ® body seamed to w o o l panel to pad a n d p r o t e c t sensitive a r e a s .
Fig. 8 . Hip disarticulation sock (left) w a s tailored with a smaller waist and added protection for the unimpaired leg. Bilateral s o c k (right) w a s m a d e smaller o n o n e side for a snugger, wrinkle-free fit. putee will find that the elasticity is retained
for the life of the s o c k . O r i o n / L y c r a hip-disarticulation s o c k s and regular s o c k s are ordered in regular w o o l sizes but will m e a s ure up to 1 0 percent less than the same sized s o c k to assure proper fit considering the elas ticity o f the y a r as well as o f the knit. O r i o n / L y c r a ® s o c k s with the w o o l panel should be w a s h e d like a w o o l s o c k .
Main Conclusion
Prosthetists should n o w feel that all a m p u tations can be c o r r e c t l y fitted with w o o l o r O r i o n / L y c r a ® s o c k s to give c o m f o r t and p r o t e c t i o n to the a m p u t e e . T h e y should also be a w a r e that s o c k s knitted or tailored of 2-or 3-ply O r i o n / L y c r a ® y a r n s a l l o w f2-or snugger, s m o o t h e r fittings a n d easier m a i n t e n a n c e b y the a m p u t e e .
Acknowledgments
I wish to express sincere thanks a n d appre ciation to W i l l i a m B . S m i t h , Larry Pierce, a n d the entire P r o d u c t i o n D e p t . of K n i t - R i t e , Inc. for their guidance a n d c o o p e r a t i o n in
developing these new techniques and adapt ing them to the specific needs of a m p u t e e s .
Literature Cited
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