Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
J Sports Sci. 2013;31(10):1074-81. doi: 10.1080/02640414.2012.762600. Epub 2013 Jan 25.
Dynamic postural stability has been widely studied for single-leg landing, but seldom considered for double-leg landing. This study aimed to evaluate the dynamic postural stability and the influence mechanism of muscle activities during double-leg drop landing. Eight recreationally active males and eight recreationally active females participated in this study and dropped individually from three heights (0.32 m, 0.52 m, and 0.72 m). Ground reaction force was recorded to calculate the time to stabilisation. Electromyographic activities were recorded for selected lower-extremity muscles. A multivariate analysis of variance was carried out and no significant influence was found in time to stabilisation between genders or limb laterals (P > 0.05). With increasing drop height, time to stabilisation decreased significantly in two horizontal directions and the lower-extremity muscle activities were enhanced. Vertical time to stabilisation was not significantly influenced by drop height. Dynamic postural stability improved by neuromuscular change more than that required due to the increase of drop height. Double-leg landing on level ground is a stable movement, and the body would often be injured before dynamic postural stability is impaired. It is understandable to protect tissues from mechanical injuries by the sacrifice of certain dynamic postural stability in the design of protective devices or athlete training.
动态姿势稳定性已广泛研究用于单腿着地，但很少考虑用于双腿着地。本研究旨在评估双腿下落着地过程中的动态姿势稳定性和肌肉活动的影响机制。8 名休闲活跃的男性和 8 名休闲活跃的女性参与了这项研究，分别从三个高度（0.32m、0.52m 和 0.72m）跳下。记录地面反作用力以计算稳定时间。记录选定下肢肌肉的肌电图活动。进行了多元方差分析，未发现性别或肢体侧面在稳定时间上有显著影响（P＞0.05）。随着下落高度的增加，两个水平方向的稳定时间显著缩短，下肢肌肉活动增强。垂直稳定时间不受下落高度的显著影响。通过神经肌肉变化改善的动态姿势稳定性比由于下落高度增加而需要的稳定性改善更多。在水平地面上进行双腿着陆是一种稳定的运动，在动态姿势稳定性受损之前，身体通常会受伤。在设计保护装置或运动员训练时，通过牺牲一定的动态姿势稳定性来保护组织免受机械损伤是可以理解的。
