(Medical Research Council of the UK. Aids to the investigation of perifpheral nerve injuries. Memorandum n. 45. London, Pendragon House, 1976, pp 6-7)

As far as possible, the action of each muscle should be observed separately.

0. No contraction
1. Flicker or trace of contraction
2. Active movement, with gravity eliminated
3. Active movement against gravity
4. Active movement against gravity and resistance
5. Normal power