Leonardo Luiz Barretti Secchi

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

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.

Dinamometria isocinética de tronco em nadadores de diferentes estilos

Objective: To compare the effect of asymmetric and symmetric swimming strokes on muscle activity of the trunk flexor and extensor muscles. Methods: Fourteen elite speed swimmers, specialists in one of four swimming styles, all without any history of spinal cord injury, were divided in two groups: 1) asymmetric group, consisting of five athletes specializing in the freestyle stroke and three in the backstroke; and 2) symmetric group, consisting of four athletes specializing in the butterfly stroke and three in the breaststroke. All the swimmers were assessed using a Cybex 6000 isokinetic dynamometer. Results: The acceleration time for the trunk flexor group at a speed of 120 o per second was greater in the symmetric group (p=0.054). The power of the extensor group at speeds of 90 o and 120 o per second was greater in the asymmetric than in symmetric group (p=0.053 and 0.052), respectively. There was no significant statistical difference for any of the other variables assessed. Conclusion: The asymmetric strokes (crawl and backstroke) provided a more efficient muscular response (recruitment) in the trunk flexor muscles, which may be due to the constant maintenance of isometric contraction of the abdominal muscles.