Application of functional electrical stimulation to the paralyzed extremities

This paper describes restoration of motor function in patients with paralyzed extremities due to upper motor neuron disorders by functional electrical stimulation (FES). Percutaneously indwelling intramuscular electrodes were implanted into the muscles of the paralyzed upper and lower extremities to be controlled by FES. Stimulation patterns for extremity FES were created from electromyography (EMG) during motion in healthy subjects. By using a percutaneous FES system, all of the joint movement in the extremities could be controlled as long as severe lower motor neuron damage did not exist. In the paralyzed upper extremity, motor function of not only the hand but also the wrist, elbow, and shoulder could be restored with well-coordinated manner by EMG-based stimulation data and utilized for vocational tasks in the hemiplegic and quadriplegic patients. Continuous bias stimulation to the paralyzed muscle in combination with volitional contraction of its antagonistic muscles provided the patient with more volitional and natural control of the upper extremity. Restoration of locomotive movement in the paraplegics at around T-8 level was also achieved by FES under the usage of a walker.