Research Institute for Sport and Exercise Sciences, Faculty of Science, Liverpool John Moores University, Liverpool, UK.
J Biomech. 2012 Sep 21;45(14):2444-9. doi: 10.1016/j.jbiomech.2012.06.029. Epub 2012 Jul 25.
Side cutting involves mechanical loading of the knee which has been associated with anterior cruciate ligament injury risk. Despite a fast growing body of research, the relationship between loading mechanisms and running speed is still unclear. The aim of this study was to investigate how running speed determines a likely trade-off between task achievement and actual mechanical loading.
Fourteen female participants (mean age=20.6±0.7yr, height=1.66±0.05m, mass=57.5±6.9kg) performed 45° side cutting manoeuvres at 2, 3, 4 and 5ms(-1) approach speeds. Three dimensional motion and ground reaction forces were recorded to calculate whole body centre of mass (CoM) velocity and lower limb kinematics and kinetics, focusing on knee flexion angle at touch-down and peak knee valgus loading during weight acceptance. One-way repeated measures ANOVA and one-dimensional statistical parametric mapping were used to identify significant speed effects on task achievement and mechanical loading.
Analysis of CoM velocities revealed that side cutting manoeuvres at higher running speeds matched the task requirements to a lesser extent. Despite a gradual increase of anterior-posterior deceleration and medio-lateral acceleration with running speed, knee loading mechanisms only reached meaningful levels from a 4ms(-1) running speed.
Our results confirmed a trade-off between task achievement and actual mechanical loading. This identified a need for standardisation of reporting running speeds. Taking into account also safety considerations, standardisation of a 4ms(-1) running speed is proposed for female athletes.
侧切动作涉及膝关节的力学加载，这与前交叉韧带损伤风险有关。尽管研究越来越多，但加载机制与跑步速度之间的关系仍不清楚。本研究旨在探讨跑步速度如何决定在任务完成和实际机械加载之间可能存在的权衡。
14 名女性参与者（平均年龄 20.6±0.7 岁，身高 1.66±0.05m，体重 57.5±6.9kg）以 2、3、4 和 5ms(-1)的接近速度进行 45°侧切动作。记录三维运动和地面反作用力，以计算身体重心（CoM）速度和下肢运动学和动力学，重点关注触地时的膝关节屈曲角度和承重时的最大膝关节外翻加载。使用单向重复测量方差分析和一维统计参数映射来确定速度对任务完成和机械加载的显著影响。
CoM 速度分析表明，较高跑步速度下的侧切动作在较小程度上符合任务要求。尽管随着跑步速度的增加，前后减速和内外加速逐渐增加，但膝关节加载机制仅在 4ms(-1)的跑步速度下才达到有意义的水平。
我们的结果证实了任务完成和实际机械加载之间存在权衡。这就需要对报告的跑步速度进行标准化。考虑到安全因素，建议女性运动员的标准跑步速度为 4ms(-1)。
