Wyle Science, Technology and Engineering Group, 1290 Hercules, Ste. 120, Houston, TX 77058, USA.
Universities Space Research Association, Houston, TX, USA.
J Biomech. 2014 Jul 18;47(10):2339-47. doi: 10.1016/j.jbiomech.2014.04.034. Epub 2014 Apr 30.
Astronauts perform treadmill exercise during long-duration space missions to counter the harmful effects of microgravity exposure upon bone, muscle, and cardiopulmonary health. When exercising in microgravity, astronauts wear a harness and bungee system that provides forces that maintain attachment to the treadmill. Typical applied forces are less than body weight. The decreased gravity-replacement force could result in differences in ground-reaction force at a given running speed when compared to those achieved in normal gravity, which could influence the adaptive response to the performed exercise. Seven astronauts (6 m/1 f) who completed approximately 6-month missions on the International Space Station (ISS) completed a preflight (1G) and multiple in-flight (0G) data collection sessions. Ground-reaction forces were measured during running at speeds of 8.0 kph and greater on an instrumented treadmill in the lab and on the ISS. Ground-reaction forces in 0G were less than in 1G for a given speed depending upon the gravity-replacement force, but did increase with increased speed and gravity-replacement force. Ground-reaction forces attained in 1G during slower running could be attained by increasing running speed and/or increasing gravity-replacement forces in 0G. Loading rates in 1G, however, could not be replicated in 0G. While current gravity-replacement force devices are limited in load delivery magnitude, we recommend increasing running speeds to increase the mechanical loads applied to the musculoskeletal system during 0G treadmill exercise, and to potentially increase exercise session efficiency.
宇航员在长时间的太空任务中进行跑步机运动，以对抗微重力暴露对骨骼、肌肉和心肺健康的有害影响。在微重力下运动时，宇航员会佩戴背带和蹦极系统，以提供维持与跑步机连接的力。典型的应用力小于体重。与在正常重力下相比，给定跑步速度下的重力替代力减小可能导致地面反作用力的差异，这可能会影响对所进行的运动的适应反应。七名宇航员（6 名男性和 1 名女性）在国际空间站（ISS）上完成了大约 6 个月的任务，完成了飞行前（1G）和多次飞行中（0G）的数据收集。在实验室和 ISS 上的仪器化跑步机上以 8.0 公里/小时及更高的速度跑步时，测量了地面反作用力。在给定速度下，0G 中的地面反作用力小于 1G，具体取决于重力替代力，但随着速度和重力替代力的增加而增加。在 1G 中以较慢速度跑步时获得的地面反作用力可以通过增加跑步速度和/或在 0G 中增加重力替代力来获得。然而，1G 中的加载率无法在 0G 中复制。虽然目前的重力替代力设备在负载输送量方面受到限制，但我们建议增加跑步速度，以增加在 0G 跑步机运动期间应用于肌肉骨骼系统的机械负荷，并可能提高运动课程的效率。
