Power is assessed by active movement of each joint, in each direction, comparing right with left, and then adding resistance to these movements. Individual joints are considered with the musculoskeletal system.
Power can be graded from 0 to 5. Zero indicates no contraction; 1, a flicker of movement; 2, active movement with gravity excluded; 3, active muscle weakness. When assessing this power, an indication is also obtained of the control of antagonistic muscles, the smoothness and coordination of movements and whether they are limited by pain, contractures or joint abnormalities.
Initially gross movements are used to compare the limbs, such as a handshake, and flexion and extension of joints. Compare the grip on the two sides (figure 5), and active and resisted, spinal flexion and dosiflexion of the ankle (figure 6a–d).