Properties of orderly recruited motor units with tripolar cuff electrode

Summary form only given, as follows. Motor units of the soleus and m. gastrocnemius muscles were recruited in order according to size with stimuli delivered by a tripolar nerve cuff electrode. One stimulus controlled the firing rate, while the second recruited the motor units, with the electrode´s center pole serving both stimuli. A series of test procedures verified that motor units were indeed recruited according to their size, that firing rate increase and motor unit recruitment were independent of each other, that a wide range of firing rate and recruitment control strategies could be implemented, and that the force fatigue profile showed resistance at low recruitment levels and progressive susceptibility as larger motor units were recruited.<>