EMG analysis, or electromyographical analysis, is a method of analyze the firing motoneurons within the muscle fiber, and is useful for determining things like rate coding, % maximal voluntary isometric contraction (MVIC) etc. Unfortunately, most EMG analysis, even IEMG (integrated via computer) generally uses only suface analysis, giving an inaccurate representation of what may be happening deep within the tissue.
True EMG analysis requires probes to be inserted, and for some strange reason, it is hard to find volunteers for this sort of study.