For lower extremity amputees, traditionally, the amount of function they can expect depends on the level, or how high, their amputation is. Those with below-knee amputations can expect good function, sometimes so good that others will accuse them of having an unfair advantage in competitive activities (as we have previously reported, not true). As one moves higher up to an above knee amputation, things become slightly more complicated. The energy expenditure of ambulating with an above knee prosthetic is typically 60-70% greater than normal. In addition, while advanced and functional, the prostheses available still leave something to be desired in that they their gait is not entirely normal, and going up and down stairs can be very exhausting for the user.
To address some of these issues, engineers at Vanderbilt University have been spending the past 7 years working on a “bionic” above knee prosthesis that has a powered knee and ankle and a microprocessor to coordinate their function. The ultra-light powered device lets amputees walk 25% faster, and uses 30-40% less energy than traditional devices. It is also designed to make sitting, standing, and going up/down stairs and ramps much easier. The device weighs approximately 9 pounds and operates for 3 days on a single battery charge. The prosthetic even incorporates an “anti-stumble” feature which will assist the amputee in regaining balance if it senses the user is about to fall.
Press release: New ‘bionic’ leg gives amputees a natural gait …