Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Santiago, Chile.
Clinica Santa Maria, Santiago, Chile.
Sports Biomech. 2024 May;23(5):670-681. doi: 10.1080/14763141.2021.1884284. Epub 2021 Mar 5.
During running, the mechanical energy of the centre of mass of the body (COM) oscillates throughout the step like a spring-mass system, where part of its mechanical energy is stored during negative phases to be released during the following positive phases. This storage-release of energy improves muscle-tendon efficiency, which is related to lower-limb stiffness. This study explores the effect of sports background on the bouncing mechanism, by examining differences in stiffness and step spatiotemporal parameters between swimmers and football athletes. All athletes performed three consecutive running bouts on an instrumented treadmill at three different speeds (3.9, 4.4 and 5.0 m·s). The ground reaction forces were recorded. Vertical stiffness and step spatiotemporal parameters were analysed and compared using a two-way ANOVA. Vertical stiffness of football players was on average 21.0 ± 1.1% higher than swimmers. The modification of step spatiotemporal parameters also suggests a more elastic rebound by increasing the stretch of tendons relative to muscle within muscle-tendon units in football players. Compared to swimmers, they (1) decrease the effective contact time by 9.7 ± 2.4% and (2) decrease the duration of the push by 15.0 ± 6.4%, suggesting that background training adaptations influence spring-mass behaviour during running.
在跑步过程中，身体质心（COM）的机械能像一个弹簧质量系统一样在整个步幅中振荡，其中部分机械能在负相期间存储，以便在下一个正相期间释放。这种能量的存储和释放可以提高肌肉肌腱的效率，这与下肢刚度有关。本研究通过检查游泳运动员和足球运动员之间的刚度和步幅时空参数的差异，探讨了运动背景对反弹机制的影响。所有运动员在装有仪器的跑步机上以三种不同速度（3.9、4.4 和 5.0 m·s）连续进行三次跑步。记录地面反作用力。使用双向方差分析分析和比较垂直刚度和步幅时空参数。足球运动员的垂直刚度平均比游泳运动员高 21.0 ± 1.1%。步幅时空参数的改变也表明，足球运动员的肌肉肌腱单位中的肌腱相对于肌肉的拉伸增加，从而产生更有弹性的反弹。与游泳运动员相比，足球运动员（1）将有效接触时间减少 9.7 ± 2.4%，（2）将推蹬时间减少 15.0 ± 6.4%，这表明背景训练适应会影响跑步过程中的弹簧质量行为。
