Vubcent,

This is a subject that's interested me for some time, since I'm a below-knee (BK) amputee myself.

People have approached me with this sort of problem repeatedly, and I tell them I can't imagine a way, at least with present battery technology, to improve on the entirely passive sorts of BK prostheses that are being produced today, except by improving the criteria for "fit" and suspension (the way in which it's attached).

Over the years, the prosthetist's craft has been reduced from a fine art, which is still applied to the business of alignment of a prosthesis so that it integrates into the ergonomics of the wearer's physiology, to the basic function of a plumber, selecting parts off-the-shelf and either succeeding or failing in his task with those often inappropriate but available "parts."

I've had a number of "articulated" and semi-articulated ankles and various "high-tech" foot designs, and still believe that the contributions that microelectronics could make would demand the addition of too much in terms of battery and motor weight.

Without that extra weight, there'd be no real facility to assist in the user's walking, standing, etc, beyond what the currently popular "energy-storing" foot assemblies provide.

What did you have in mind with respect to that?

When you say lower limb, I assume you're referring to the entire leg, where there's some lattitude as to weight limits, but it's got to be considered, that AK amputees have less muscle to work with than BK's. The consequence is that, so far, anyway, adding weight to the prosthesis works out badly for the lower back, since that's what has to operate the hip that slings the prosthesis about.

You refer to hydraulics ... how do you plan to power them? Where will the weight be borne?

RE