Orderly stimulation of skeletal muscle motor units with tripolar nerve cuff electrode

An electrical nerve stimulation technique, using a single tripolar electrode, was shown to be capable of recruiting motor units according to their size, while allowing simultaneous but independent control of firing rate in the active units. Test paradigms consisting of established fundamental physiological concepts of soleus-gastrocnemius architecture, motor units conduction velocity, firing rate behavior of motor units of different sizes, and their susceptibility to fatigue were used to validate the technique and demonstrate its utility as a basic and applied research tool.