The integrated function of muscles and tendons during locomotion
The integrated function of muscles and tendons during locomotion
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DOI：
10.1016/s1095-6433(02)00244-1
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发表时间：
2002-12-01
影响因子：
2.3
通讯作者：
Roberts, TJ
中科院分区：
文献类型：
--
作者：
Roberts, TJ
肌腱和肌肉收缩元件在运动过程中的机械作用通常被独立考虑，但在功能上它们是紧密结合的。肌腱可以增强各种运动活动的肌肉性能，因为肌肉肌腱单位缩短和延长的速度在机械上不利于肌纤维单独发挥作用。在需要很少的净机械功率输出的活动中，例如稳定速度跑步，肌腱通过储存和恢复身体机械能的循环变化来减少肌肉做功。肌腱的拉伸和反冲不仅减少了肌肉做功，而且还允许肌肉纤维几乎等长地运行，其中，由于力-速度关系，骨骼肌纤维产生很高的力。肌腱中的弹性能量存储和恢复也可能提供一个关键机制，使个体肌肉能够改变其机械功能，从稳定速度跑步期间的等长力产生器到在加速或上坡跑等高功率活动期间主动缩短功率产生器。对火鸡肌肉收缩和肢体动力学研究的证据表明，在跑步加速过程中，功直接从肌肉转移到肌腱，因为步伐早期的肌腱拉伸是由肌肉缩短提供动力的。储存在肌腱中的能量随后被释放，以帮助身体能量的增加。这些肌腱长度的变化重新分配肌肉力量，使收缩元件能够以相对恒定的速度和功率输出缩短，而与关节的屈曲/伸展模式无关。肌腱弹性能量存储和恢复通过将肌纤维缩短模式与身体运动模式脱钩来扩展肌肉的功能范围。 (C) 2002 Elsevier Science Inc. 保留所有权利。
The mechanical roles of tendon and muscle contractile elements during locomotion are often considered independently, but functionally they are tightly integrated. Tendons can enhance muscle performance for a wide range of locomotor activities because muscle-tendon units shorten and lengthen at velocities that would be mechanically unfavorable for muscle fibers functioning alone. During activities that require little net mechanical power output, such as steady-speed running, tendons reduce muscular work by storing and recovering cyclic changes in the mechanical energy of the body. Tendon stretch and recoil not only reduces muscular work, but also allows muscle fibers to operate nearly isometrically, where, due to the force-velocity relation, skeletal muscle fibers develop high forces. Elastic energy storage and recovery in tendons may also provide a key mechanism to enable individual muscles to alter their mechanical function, from isometric force-producers during steady speed running to actively shortening power-producers during high-power activities like acceleration or uphill running. Evidence from studies of muscle contraction and limb dynamics in turkeys suggests that during running accelerations work is transferred directly from muscle to tendon as tendon stretch early in the step is powered by muscle shortening. The energy stored in the tendon is later released to help power the increase in energy of the body. These tendon length changes redistribute muscle power, enabling contractile elements to shorten at relatively constant velocities and power outputs, independent of the pattern of flexion/extension at a joint. Tendon elastic energy storage and recovery extends the functional range of muscles by uncoupling the pattern of muscle fiber shortening from the pattern of movement of the body. (C) 2002 Elsevier Science Inc. All rights reserved.