Slowness to develop force contributes to weakness after stroke

Objective: To examine weakness after stroke, in terms of both level and rat e of torque generation. Design: Descriptive. T tests for dependent and independent samples and Pear son's product moment correlation coefficients were performed. Setting: A rehabilitation unit. Participants: Ten stroke subjects, aged 56 to 81 years, undergoing rehabili tation. Ten neurologically normal subjects aged 55 to 78 years were the con trols. Outcome Measures: Peak isometric elbow flexor and extensor torque and time to 90% peak elbow flexor and extensor torque at 6 weeks and at 25 weeks aft er stroke. Results: At 6 weeks after stroke, subjects were only half as strong and too k two to three times longer to produce torque compared to controls (p less than or equal to .05). By 25 weeks after stroke, significant improvements i n peak torque (p less than or equal to .02) and time to 90% peak flexor tor que (p less than or equal to .05) were seen so that values were within norm al limits. Conclusion: Decreased rate of torque development compounds the problem of r educed peak torque, which may have significant implications for stroke pati ents, especially in situations where muscles are very weak or where force n eeds to be generated quickly. (C) 1999 by the American Congress of Rehabili tation Medicine and the American Academy of Physical Medicine and Rehabilit ation.