Hi folks,
Greetings from sunny Queensland. I have a question which may just show my
ignorance or it may be an “emperors new clothes” scenario. This is: what
is the purpose of expulsion valves?
Don’t get me wrong. I know the suggested purpose ie to expel air but just
what air needs to be expelled? For example, in a trans tibial prosthesis
using some sort of gel liner interface and a suspension sleeve if the
socket fits correctly then pushing the stump into the socket will expel
any air present (assuming the presence of some sort of wick/sock/cloth
cover) and the application of the sleeve will seal the system. I started
making these types of socket about 18 months – 2 years ago and have found
all types of valves I tried to be worse than useless. Patients returned
time after time with the prosthesis pistoning and making noises all of
which vanished when the valves were sealed. Now I make these sockets and
save manufacturing time, the cost of the valve and the patients patience
and blushes by not using any valve.
Am I missing something or does anyone else make these “suction” type
sockets without the valves? I look forward to hearing your opinions.
Grant Crosthwaite BSc(Hons) SRPros/Orth MBAPO
Artificial Limbs and Appliances Pty Ltd
33 Jeays St
Bowen Hills
Brisbane 4006
Australia
email: ala.bne@bigpond.com
