power grading

Last reviewed 01/2018

Muscle strength is assessed by gauging the examiner's ability to overcome the patient's full voluntary muscle resistance. Normal power is dependent on the patient's age, sex and build. The power grading scheme is:

  • 0 - complete paralysis
  • 1 - flicker of contraction possible
  • 2 - movement is possible when gravity is excluded
  • 3 - movement is possible against gravity
  • 4 - movement is possible against gravity + some resistance
  • 5 - normal power

If any weakness is detected then the examiner must note the pattern. For example, in an upper motor neurone lesion there may be weakness in the upper limb of shoulder abduction, elbow extension and wrist extension; and a weakness in the lower limb of hip flexion, dorsiflexion and foot eversion.