An Electrode for Recording Single Motor Unit Activity During Strong Muscle Contractions

The construction of a lightweight quadrifillar needle electrode offering four monopolar and six bipolar microelectrode combinations is described. The electrode has three useful features: 1) it can record distinct individual motor unit action potentials during strong muscle contractions, 2) the frequency response curve of the electrode can be altered to a simple functional relationship within the frequency range of myoelectric signals, and 3) the electrode minimizes the subject's discomfort.