As an amputee having a short stump, a major requirement for my prosthetic leg is low weight of the prosthetic knee joint.
My new prosthetic knee, the Very Good Knee – Short Transfemoral (VGK-S), is specifically designed for above knee amputees having a short stump (as well as hip disarticulation amputees). Previously, I had to choose between acceptable weight OR advanced functionality. The Very Good Knee – Short Transfemoral gives me both, and that has been another major improvement for my quality of life.
The major innovation of this prosthetic knee is the high centre of gravity, having the hydraulic above the knee axis, unlike all other prosthetic knee joints on the market. Why? Because the manufacturers have a One Size Fits All strategy. For the majority of above knee amputees, there is no room ABOVE the knee axis because of the length of the stump, and for those above knee amputees having a longer stump weight is not so much a problem. But the shorter the stump is, the more the weight of the prosthesis -and in particular of the prosthetic knee- does become a problem.
Image you hold a hammer at the distant end of the handle. Now imagine you hold that same hammer at the hammerhead. It will feel MUCH lighter. This is the concept of the Very Good Knee – Short Transfemoral: By placing the hydraulic unit close to the body, there is a high centre of gravity resulting in a low moment of inertia – that is what an above knee amputee feels when wearing a prosthetic leg.
The Very Good Knee – Short Transfemoral has the same functions as the traditional Very Good Knee – Go!, as described in my comparison of prosthetic knee joints. Very important for me: This prosthetic knee is waterproof. See the video.
The key to a good prosthetic leg is proper fit of the prosthetic socket. Which depends first and foremost on the expertise of your prosthetist. Therefore it is difficult to say if your prosthetic socket fit is good or if you could have a better one. I have seen many prosthetists and more than once I had to change my prosthetist because the prosthetic socket I got was uncomfortable or even painful.
The prosthetic socket I am demonstrating in this video is unconventional because I hold this socket purely with muscle contraction in my residual limb. I do not need a silicone liner or a donning aid (to pull the stump skin into the socket). This might not work for all above knee amputees. However, the precise fitting of this socket is a demonstration of what is possible even with a short stump. This should give hope to amputees who are struggling with their current prosthetic leg. See my video to understand why this above-knee prosthetic socket is exceptional.
I give credit to my prosthetist Alexander Schwarz from Schwarz Prosthetics in Hamburg, Germany, who was patient enough to try out unconventional ways and whose expertise as a specialist for above knee prosthetic sockets is unparalleled. For me as an above knee amputee a prosthetic socket that is both functional and comfortable is a major factor for my quality of life!
In the following video I am testing my socket on difficult terrain, requiring a maximum of stability in the socket. See how it works, even with a short stump: