Summary of replies: Expulsion Valves...why??

Summary of replies: Expulsion Valves...why??

grantxw8

7/19/2000

My Friends,

Many thanks for the quick response to my query. Below is a summary of the
responses to date. I have removed the senders details as I did not
indicate explicitly on the original question that I would repost. All
responses are here with one exception who asked me not to include it.

I will forward any further missives I receive for further illumination:-)

Cheers,

Grant

===================

Hello,

Very interesting to read your experience, and another info. from below web
page. I am glad to share some of my personal past experiences.

I am trans tibial amp.and designed my own limb, the tightness of
socket does vary with each individual case, and so the need for a
valve that may suit some. Even slight pistoning effect can be
useful some times like myself, using just a hard socket, precisely aligned
for proper weight bearing with 3mm Foam on particular points only.

The articulating foot is very important to compensate and
reduce abrasion between socket and stump to far negligible level.
I am using an ordinary acrylic and cotton mixed socks for stump.

Some time some component just meaninglessly and weight to prosthesis
without
serving its purpose. You are right, and I support your experience.

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Grant,

 I have practiced for 27 years. I have chosen not to use expulsion valves
for
the reason you mentioned and the results you discovered.

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Grant: As a BK amputee since 1969 I use a PTB with a hard
socket, a 3X sock, and a Smith suspension. I am with you. A valve
for what? All air is expelled as you correectly note when I place my
socked stump into the socket. Never had a problem with weird
noises. Well, now and then when my sock is too loose, but in
general, no sweat.

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We have never used an expulsion valve in our BK's. Also do not use one in
our AK's if we use a suction socket (Alpha). The expulsion valve is
designed to expel air when it is trapped, as you described, and this only
happens with a traditional suction (skin on plastic) AK. I know of no one
who fabricates this way and have not seen any BK sockets with valves
except
for one from California back in 1990. Guy was 300+ pounds and was fit
just
like an AK. None since. Seems a waste of time and money. Good luck to
you.

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First - amputees are NEVER patients of prosthetists - amputees are ALWAYS
either clients or customers

there is never complete total contact at all times in a limb - unless you
stay in the postition the socket was cast which is not going to happen

the expulsion valves are used with the newer liners - ALPS etc that allow
for volume changes and changes in your position - like sitting in a quad
socket or lifting the leg/arm so the muscles are stretched, riding a
bike, any number of activities that are more involved than moving from
one seat to the next

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