A two-channel method for sampling, averaging and quantifying motor unit potentials

A method is described for sampling and averaging individual motor unit potentials (MUPs), which is based on an averaging technique using a special EMG electrode. The needle has two separate electrode surfaces, a conventional coaxial electrode at the tip and a single-fiber electrode opposite the bevel of the tip. With this method it is possible to extract individual MUPs even from interference activity during a moderate or even high muscular effort. The averaging of MPUs gives a good signal-to-noise ratio, which makes the quantification of MPUs precise. Late components are easily identified. Additionally during the collection of MPUs information of single-fiber characteristics (jitter, blocking and fiber density) is also acquired.