等速蹬踏运动中下肢肌力学特征的研究

Lower limb muscle mechanics during isokinetic pedaling

目的观察并分析不同速度时，下肢等速蹬踏运动时的峰力、做功和屈伸峰力比等的变化规律。方法选取健康成年人30例，采用德国产IsoMED2000型等速测试系统中的蹬踏模式（Legpress模式）对其进行测试，分别选用慢速（5cm／s）和快速（50cm／s）两种不同的速度，观察在不同速度下受试者双下肢、左下肢和右下肢的蹬踏运动，记录运动过程中峰力、做功和屈伸峰力比等力学指标。结果速度为50cm／s时，受试者左、右下肢蹬伸的峰力和做功均显著低于速度为5cm／s时，差异均有统计学意义（P〈0．05）；速度为5cm／s时，左下肢蹬伸的峰力和做功与右下肢比较，差异均有统计学意义（P〈0．05）。速度为50cm／s时，受试者左、右下肢屈曲的峰力和做功均显著低于速度为5cm／s时，差异均有统计学意义（P〈0．05）；速度为5cm／s和50cm／s时，左下肢蹬伸的峰力与右下肢同速度时比较，差异均有统计学意义（P〈0．05）。速度为50cm／s时，受试者左、右和双侧别屈伸峰力比值均显著高于5cm／s时同侧，差异均有统计学意义（P〈0．05）；速度为5cm／s和50cm／s时，右下肢屈伸峰力比值分别为（0．24±0．07）和（0．28±0．08），均显著低于左下肢同速度时的（0．28±0．07）和（O．30±0．11），差异均有统计学意义（P〈0．05）。结论不同速度时，双下肢、左下肢和右下肢蹬踏运动时的力学存在差异，在临床运动训练或康复治疗中应根据不同的目的选择不同的速度和训练模式。

Objective To document and analyze thepeak force and work during isokinetic pedaling at different linear speeds and the flexion-extension peak force ratio. Methods Thirty healthy adults were tested using the Legpress system of the IsoMED 2000 apparatus. Peak force, work and the flexion-extension peak force ratio were recorded and analyzed during isokinetic pedalingat 5 and 50 cm/s. Results The peak force applied and work clone by the lower limbs were both significantly lowerwhen pedaling at 50 cm/s than at 5 cm/s. There was no significant difference in peak force or work between the left and right legs at 50 cm/s. The peak force ratio at 50 cm/s was significantly higher than at 5 cm/s. Conclusion The mechanical characteristics of the leg muscles during isokinetic pedaling vary greatly. It is advisable to choose different linear speeds or training modes accordingly.