Training-induced changes in the pattern of triceps to biceps activation during reaching tasks after chronic and severe stroke
OBJECTIVE To examine weakness after stroke, in terms of both level and rate of torque generation. DESIGN Descriptive. T tests for dependent and independent samples and Pearson's product moment correlation coefficients were performed. SETTING A rehabilitation unit. PARTICIPANTS Ten stroke subjects, aged 56 to 81 years, undergoing rehabilitation. Ten neurologically normal subjects aged 55 to 78 years were the controls. 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 after stroke. RESULTS At 6 weeks after stroke, subjects were only half as strong and took two to three times longer to produce torque compared to controls (p < or = .05). By 25 weeks after stroke, significant improvements in peak torque (p < or = .02) and time to 90% peak flexor torque (p < or = .05) were seen so that values were within normal limits. CONCLUSION Decreased rate of torque development compounds the problem of reduced peak torque, which may have significant implications for stroke patients, especially in situations where muscles are very weak or where force needs to be generated quickly.