Manual stretch: Effect on finger movement control and force control in stroke subjects with spastic extrinsic finger flexor muscles

This study evaluated the effects of manual stretch of extrinsic finger flexor muscles on finger extension movement control and force control in 16 spastic hemiparetic subjects. These subjects were randomly divided into a control group and an experimental group. A group of able-bodied subjects also participated. A joint-movement tracking test (JMTT) quantified control of active finger extension movement at the metacarpophalangeal joint of the index finger within the available range of active movement, and a force tracking test (FTT) quantified control of isometric finger extension force at the same joint within the subject's available force range. Electromyographic activity was monitored in the extensor digitorum and flexor digitorum superficialis muscles during both tracking tests. Manual stretch was applied to the extrinsic finger flexor muscles of the experimental group between the pretest and posttest tracking tests. The JMTT performances of both control (p < .025) and experimental (p <.05) groups were significantly subnormal on the pretest as were FTT performances of controls (p < .01) and study subjects (p < .03). The JMTT improvement on posttest was significantly greater (p < .05) in subjects than in controls. However, the change in FTT performance was not significantly different between the two groups. Manual stretch treatment, properly applied to extrinsic finger flexor muscles, is an effective method of temporarily improving the control of finger extension movement in spastic hemiparetic subjects.