“…The original twitch interpolation technique described by Merton [3] and subsequently employed by many others [1,5,6,7,8,9,12,14,29] involved a single stimulus interpolated over voluntary contractions. Recently it has become common for 2 or more stimuli (50-100 Hz) to be employed [17,18,34,38,51] because the evoked force increments are larger and more readily detected [15,32,43,45,54,55,56,57,58] .…”