At its most basic level, electrical stimulation is a simple and well-understood process.
Electrical pads are placed on the skin, and when a small current is applied, the muscle contracts involuntarily.
Trainers have long used the technique, which may cause a slight tingling sensation but is not painful, to build or tone athletes' muscles. Electrical stimulation is also at the heart of products touted, for example, to help people build "six-pack abs" without working out.
But the most promising application may be in physical rehabilitation, Dixon said. Specialists already use electrical stimulation to prevent unused muscle from atrophying in effect, "exercising" the muscle even though the patient has lost the ability to move it herself.
Physical therapists and some products also use electrical stimulation for purposeful movement. One commercially available walker, for example, taps preprogrammed stimulation patterns to help paralyzed people stand for brief periods of time.
Dixon said that while the current state-of-the-art shows the potential, it only applies a predetermined and relatively high voltage to a designated muscle.
That means that while the muscle may move, it can easily fatigue, becoming less responsive and sore. Also, electrically stimulated movements tend to be rough, without the degree of control and variation the subtle bends or twists that make all the difference in so much common movement that people with functioning limbs take for granted.
Dixon and his graduate students are developing methods aimed at improving that model using techniques of "adaptive learning," or giving a computer the ability to learn from a patient's actions and reactions and adjust its muscular stimulation accordingly.
One of their main tools: a standard leg lift, or leg extension, exercise machine modified with elect
|Contact: Warren Dixon|
University of Florida