Sevrez Violaine, Rao Guillaume, Berton Eric, Bootsma Reinoud J
UMR 7287 ISM Marey, Aix-Marseille Université, Marseille Cedex 9, France.
J Appl Biomech. 2012 Feb;28(1):57-62. doi: 10.1123/jab.28.1.57. Epub 2011 Oct 4.
Five elite gymnasts performed giant circles on the high bar under different conditions of loading (without and with 6-kg loads attached to the shoulders, waist or ankles). Comparing the gymnasts' kinematic pattern of movement with that of a triple-pendulum moving under the sole influence of nonmuscular forces revealed qualitative similarities, including the adoption of an arched position during the downswing and a piked position during the upswing. The structuring role of nonmuscular forces in the organization of movement was further reinforced by the results of an inverse dynamics analysis, assessing the contributions of gravitational, inertial and muscular components to the net joint torques. Adding loads at the level of the shoulders, waist or ankles systematically influenced movement kinematics and net joint torques. However, with the loads attached at the level of the shoulders or waist, the load-induced changes in gravitational and inertial torques provided the required increase in net joint torque, thereby allowing the muscular torques to remain unchanged. With the loads attached at the level of the ankles, this was no longer the case and the gymnasts increased the muscular torques at the shoulder and hip joints. Together, these results demonstrate that expert gymnasts skillfully exploit the operative nonmuscular forces, employing muscle force only in the capacity of complementary forces needed to perform the task.
五名优秀体操运动员在不同负荷条件下（肩部、腰部或脚踝不附加负荷以及附加6公斤负荷）在单杠上进行大回环动作。将体操运动员的运动学模式与仅在非肌肉力影响下运动的三摆锤的运动学模式进行比较，发现了定性的相似之处，包括下摆时采用拱形姿势和上摆时采用屈体姿势。通过逆动力学分析结果进一步强化了非肌肉力在运动组织中的构建作用，该分析评估了重力、惯性和肌肉成分对净关节扭矩的贡献。在肩部、腰部或脚踝处添加负荷会系统地影响运动学和净关节扭矩。然而，当负荷附加在肩部或腰部时，负荷引起的重力和惯性扭矩变化提供了所需的净关节扭矩增加，从而使肌肉扭矩保持不变。当负荷附加在脚踝处时，情况就不再如此，体操运动员增加了肩部和髋关节的肌肉扭矩。总之，这些结果表明，优秀的体操运动员巧妙地利用了有效的非肌肉力，仅在执行任务所需的补充力的能力范围内使用肌肉力。
