METHODS

OVERVIEW A 20-mm Neurocuff ™ with 8 sets of tripolar electrodes placed inside longitudinal chambers separated by insulating ridges [1] was implanted on the left sciaticnerve of 3 cats. Epimysial bipolar EMG electrodes were sutured onto 8 calf muscles. During the next 3-12 mo, force and EMG recruitment properties produced by Neurocuff stimulation were tested under anaesthesia using a 3D force/torque sensor. We found that: 1) Every major muscle supplied by the sciatic nerve can be activated through at least 1 of 8 stimulation channels. 2) Individual Neurocuff channels typically recruit functionally synergistic muscle groups. 3) Single channels produce substantial forces and force recruitment can be well controlled. 4) Forces produced by simultaneous activation of 2 channels sum linearly and predictably, with only modest overlap of axon pools activated by nearby channels