The altered time course of tension development during the initiation of fast movement in hemiplegic patients.

Abstract
The time course of tension development produced by fast isometric contraction of the quadriceps femoris muscle for knee extension was examined on eight normal subjects and 14 patients with spastic hemiparesis due to stroke. Tension lag time (TLT), the latency from the onset of EMG activities to the rise of tension, and contraction time (FTmax), the period from the rise of tension to its maximum, were longer in the patients than in the normal subjects. The prolongation of FTmax correlated with the decreased rate of tension development. The results indicated that the temporal characteristics of tension development altered in the spastic paresis, reflecting functional changes in the muscle and motor neurons.