As I know everyone gives a damn, I’m merely placing this here as a documentation for those who are in the same boat as I am and wondering about lifespans of certain mechanical parts on prosthetic limbs.
I’m a fairly active guy, have hiked mountains, climbed the apartment steps countless times with 1-2 hundred pounds in my hands at a time, ran track with it for a while (before tossing in the towel due to the weight difference of the vacuum pump being like a pendulum)… et cetera. I started using the leg seal in May/June 2008, and it started having vacuum issues about a month ago which was very vague at first. When I bent my leg while sitting down to watch television, I heard a light “hsssssss” and felt the limb raise from it’s position in the socket a touch. Of course standing up and pumping it up created pressure but the bend opened a light seam which was created over the year.
They are easy to replace, and I had 3 in stock just in case. I slapped one on and pulled it up, vacuum sealed it and everything was up to par again. I did visually locate the seal breach, which was conveniently located right by the knee gait. Basically the leg flex over time wears it out in this case.
For those who do not know how to do this, I can document my case pretty simple. For documentation I am a transtibial unilateral amputee and I use a carbon fibre socket with a gait protector. (a “gaiter”… *queues “end of joke” drums*) The best step to take is to measure how far up your leg the seal should travel, and write it down and/or memorize it. Then, remove the seal by untaping or disconnecting the seal in some way from your socket. Mine was a plastic/rubber tape which was very flexible and excellent in seal. Of course, I have the tape roll as backup. Once you untape it (or disconnect it), roll that old seal off and put it to the side to examine by eye later.
Now, take the new seal in hand. There are two sides, one is smaller than the other. The smaller side will connect with the socket, the larger on your leg. The easiest way to do it is to roll the bottom part of the seal backwards up the seal until your within 1/2 inch of the beginning of the leg connection. (you measured it, right? 😉 ) Push the gait protector down into the socket to get it out of the way, then stretch the seal around to lightly sit down onto the top by 1/2 inch. Make sure it’s even by looking at it sideways. Roll it down smoothly and make sure the seal lays parallel with the bottom of the seal. There, it’s on! Now we just need to tape it up, which is pretty straight forward. Put an even starting line right on the edge ON the seal to create a beginning surface to tape against. Then, once that line is created, keep rolling but drop down with 1/2 on the seal and 1/2 off for 1 revolution. After that, drop down another half so you’re sealing it up for 1 revolution. Cut/break the tape and flush it up to the socket (to make it look pretty) and you’re done.
All this boils down to maintenance and care of prosthetic technology as life goes on. Since they aren’t us, they break with age easier. It’s up to us to coax them to survive 😉