A stable, selective electrode for recording single motor-unit potentials in humans

A new application of electrode technology has enabled recording of single motor-unit potentials in human first dorsal interosseus muscle with more versatility than has been traditionally associated with this paradigm. The design, manufacture, and application are detailed for an electrode which has been used to discriminate potentials during efforts up to maximal voluntary contraction. The electrode comprises a branched, bipolar configuration which is positioned subcutaneously over the belly of the muscle. This extramuscular location maximizes stability and, with appropriate orientation of the electrode relative to the architecture of the muscle, ensures adequate selectivity of single motor-unit potentials.