Description of an original miniature computer system capable of recording biomechanical parameters during locomotion, providing auditory signals which can be used in biofeedback locomotor learning, and triggering functional electrical stimulation of nerves and muscles at preselected moments in the locomotor cycle. The system, which is worn on the patient's back, is connected to appropriate gauges with which it is possible to measure knee angle and to record the time of heel contact with the ground. The relevant data are stored in the system memory and can be transferred to a microcassette and later displayed as a function of time on a video screen or printed on paper. The same data can be used on-line to provide a patient with a sound signal as a basis for biofeedback training. This kind of training has been successfully used to correct knee hyperextension during locomotion in hemiplegic patients. The system can also be used to trigger a stimulator and thus constitutes a valuable tool for investigations and treatments involving functional electrical stimulation. Many other applications may be developed, both in basic research and in various fields where motor training is required.