THE STIFFNESS OF SPASTIC MUSCLE

Abstract

Tension-time curves recorded at 30-second intervals in the calf muscle are presented for controls and cases of spastic diplegia. In the isometric state after a stretch, the decline in tension follows an exponential curve, the maximum height of which is proportional to the velocity of the initial stretch. Although the curve is uniform in shape, electromyographic activity is associated only with the first part. The height of the curve and the stretch reflex are modified by prolonged stretching, but the rheological property of muscle is also important in overall reflex postural activity.