Motricity Index for Motor Impairment After Stroke

The Motricity Index is a quick way to put a number on how weak a limb is after a stroke. Rather than testing every muscle, it tests one movement at each of three joints per limb — and treats those as standing in for overall strength.

For the arm: pinch grip, elbow flexion, shoulder abduction. For the leg: ankle dorsiflexion, knee extension, hip flexion. Each is graded on a six-level scale from no movement to normal power, but the levels are converted to weighted scores rather than counted evenly — 0, 9, 14, 19, 25, 33 — because the effort to move up a grade is not the same at every step. The three scores are summed, plus one point, giving 0 to 100 per limb.

Licensing Notes: The scale is reproduced without restriction across clinical resources and trial protocols. Equipment is a 2.5 cm cube for the pinch grip test.

Learn More: A known limitation: ceiling effects have been reported, so the index is less useful once a person approaches normal strength. All tests are administered sitting.