School of Kinesiology, Shanghai University of Sport, Shanghai 200438, China.
Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai 200438, China.
J Healthc Eng. 2017;2017:5690519. doi: 10.1155/2017/5690519. Epub 2017 Jul 12.
The purpose of the study was to determine the effects of fatigue on the impact forces and sagittal plane kinematics of the lower extremities in a drop landing task. 15 male collegiate athletes were recruited. Five successful trials of a drop landing task were obtained during prefatigue and postfatigue in two fatigue protocols (constant speed running fatigue protocol [R-FP] and shuttle running + vertical jumping fatigue protocol [SV-FP]). Duration time, maximal heart rate, and RPE of each protocol were measured separately. Kinematic measures of the hip, knee, and ankle joints at different times coupled with peak impact force and loading rate were acquired. Our results showed a more flexed landing posture due to an increase in hip and knee flexion angles in the postfatigue condition. However, no differences in peak impact force and loading rate were found between pre- and postfatigue conditions. The changes were similar between protocols, but the SV-FP showed a significantly shorter exercise duration time than the R-FP. Fatigued athletes in this study demonstrated altered motor control strategies during a drop landing task, which may be an intentional or unintentional protective strategy for preventing themselves from potential ACL injury.
本研究旨在确定疲劳对下落着地任务中下肢冲击力量和矢状面运动学的影响。招募了 15 名男性大学生运动员。在两种疲劳方案（匀速跑步疲劳方案[R-FP]和穿梭跑+垂直跳疲劳方案[SV-FP]）中，在疲劳前和疲劳后分别获得了 5 次成功的下落着地任务试验。分别测量了每个方案的持续时间、最大心率和 RPE。获得了不同时间髋关节、膝关节和踝关节的运动学测量值以及峰值冲击力量和加载率。我们的结果表明，由于疲劳后髋关节和膝关节弯曲角度增加，导致着陆姿势更加弯曲。然而，在疲劳前和疲劳后条件下，峰值冲击力量和加载率没有差异。两种方案的变化相似，但 SV-FP 的运动持续时间明显短于 R-FP。本研究中的疲劳运动员在下落着地任务中表现出改变的运动控制策略，这可能是一种有意或无意的保护策略，以防止自己受到 ACL 损伤的潜在风险。
