Torque fluctuations during maximal voluntary knee extension efforts after stroke

Abstract

The purpose of this study of 18 ambulatory hemiparetic stroke patients was to describe the differences in torque fluctuations between sides (paretic and nonparetic) and also to determine the implications of such fluctuations on gait performance relative to other knee extension torque variables. Bilateral measurements of torque during maximal voluntary isometric knee extension efforts of about four seconds were obtained using an isokinetic dynamometer. The amplitude of the associated torque curves was measured at 0.1 second intervals and statistically manipulated to provide information about actual and percentage fluctuations. The nonparetic side displayed significantly higher actual fluctuations whereas the paretic side demonstrated significantly higher percentage fluctuations. The reliability of the torque fluctuation measurements was questionable. The correlations of the fluctuation measurements with gait performance were low, especially when compared to the significant correlations of peak and average torque with gait performance. Given the results of this study, we find little reason to focus on torque fluctuations among patients with stroke who are undergoing rehabilitation.

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