The following scale, originally developed by The Medical Research Council of the United Kingdom, is now used universally: 0: No visible muscle contraction 1: Visible muscle contraction with no or trace movement 2: Limb movement, but not against gravity 3: Movement against gravity but not resistance 4: Movement against at least some resistance supplied by the examiner 5: Full strength The difficulty with this and similar scales is the large range in strength possible between grades 4 and 5.