The effects of motor learning on clinical isokinetic performance of postmenopausal women

Abstract

Objective: To analyze the effects of motor learning on knee extension-flexion isokinetic performance during clinical isokinetic evaluation of postmenopausal women.

Methods: One-hundred and twenty postmenopausal women (60.3±3.2 years; BMI=27.6±4.7 kg/m(2)) without knee pain or injury and that never underwent isokinetic testing, were submitted to two bilateral knee extension-flexion (concentric-concentric) isokinetic evaluation (5 repetitions) at 60°/s (Biodex™ Multi-Joint System 3 dynamometer). The tests were first performed in the dominant leg, with a 1-min recovery between them, and after a standardized warm-up that included 3 submaximal isokinetic repetitions. The same procedure was repeated in the non-dominant leg. Peak torque (PTQ) was adjusted for body weight (PTQ/BW), total work (TW), coefficient of variation (CV) and agonist/antagonist (agon/antag) ratio was compared between tests.

Results: Subjects showed greater levels (P<0.001) of PTQ, PTQ/BW and TW, and lower CV levels (P<0.01) in test 2 of both legs. Agon/antag ratio did not change significantly between tests.

Conclusions: PTQ, PTQ/BW, TW and CV improved in the second knee extension flexion isokinetic testing of postmenopausal women. The results suggests that performing two tests, even with a short period of recovery between them, could be considered for reducing motor learning effects on clinical isokinetic evaluation of knee joint in postmenopausal women.