Modification of Knee Flexion Angle Has Patient-Specific Effects on Anterior Cruciate Ligament Injury Risk Factors During Jump Landing
Modification of Knee Flexion Angle Has Patient-Specific Effects on Anterior Cruciate Ligament Injury Risk Factors During Jump Landing
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DOI：
10.1177/0363546516634000
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发表时间：
2016-06-01
影响因子：
4.8
通讯作者：
Andriacchi, Thomas P.
中科院分区：
文献类型：
--
作者：
Favre, Julien;Clancy, Caitlin;Andriacchi, Thomas P.
背景资料：前交叉韧带（ACL）损伤的发生率可以通过使用干预计划来降低，这些干预计划侧重于在跳跃着陆期间增加膝关节屈曲角度，从而减少ACL的应变。目的：研究旨在改变落地时膝关节屈曲角度的干预训练是否会导致与ACL损伤风险相关的其他已知指标的继发性变化，并检查以下时间点：研究设计：对照实验室研究。方法：共有39名健康的娱乐运动员在装有仪器的步态实验室中进行排球跳块任务。参与者首先完成跳跃，没有对他们正常的着陆技术进行任何修改。然后，他们被给予口头指导，以轻轻地着陆，并在着陆过程中增加他们的膝关节屈曲角度。使用光电运动捕捉系统测量修改前后的下半身运动学和动力学。改良后的膝关节屈曲角在初始接触时从11.2度显著增加到15.2度，在最大屈曲时从67.8度增加到100.7度，初始接触和最大屈曲之间的时间从177.4毫秒增加到399.4毫秒。屈曲改良显著降低了垂直地面反作用力（243.1 - 187.8%BW），同时降低了最大屈曲力矩。有趣的是，屈曲修改只影响了外展角和外展力矩的一组参与者降落在一个初始内收位置修改前，并没有显着的效果降落在一个外展position.Conclusion：增加膝关节屈曲角度跳着陆过程中可能是一种有效的干预措施，以改善膝关节生物力学的风险因素与ACL损伤。然而，事实上，屈曲修改只影响关键的风险因素，（外展角和外展力矩）表明，预防ACL损伤的干预措施的选择应考虑患者的具体特征。临床相关性：这项研究有助于阐明增加膝关节屈曲角度如何影响下半身生物力学，并为需要引入患者-预防ACL损伤的具体策略。
Background: The incidence of anterior cruciate ligament (ACL) injuries may be decreased through the use of intervention programs that focus on increasing the knee flexion angle during jump landing, which decreases strain on the ACL.Purpose: To investigate whether intervention training designed to change the knee flexion angle during landing causes secondary changes in other known measures associated with the risk of ACL injuries and to examine the time points when these secondary measures change.Study Design: Controlled laboratory study.Methods: A total of 39 healthy recreational athletes performed a volleyball block jump task in an instrumented gait laboratory. The participants first completed the jumps without any modification to their normal landing technique. They were then given oral instruction to land softly and to increase their knee flexion angle during landing. Lower body kinematics and kinetics were measured before and after the modification using an optoelectronic motion capture system.Results: The knee flexion angle after the modification significantly increased from 11.2 degrees to 15.2 degrees at initial contact and from 67.8 degrees to 100.7 degrees at maximum flexion, and the time between initial contact and maximum flexion increased from 177.4 to 399.4 milliseconds. The flexion modification produced a substantial reduction in vertical ground-reaction force (243.1 to 187.8 %BW) with a concomitant reduction in the maximum flexion moment. Interestingly, the flexion modification only affected the abduction angle and abduction moment for the group of participants that landed in an initial adducted position before the modification and had no significant effect on the group that landed in an abducted position.Conclusion: Increasing the knee flexion angle during jump landing may be an effective intervention to improve knee biomechanical risk factors associated with an ACL injury. However, the fact that the flexion modification only influenced critical risk factors (the abduction angle and abduction moment) in participants who initially landed in an adducted position suggests that the selection of interventions to prevent ACL injuries should account for patient-specific characteristics.Clinical Relevance: The study helps elucidate how increasing the knee flexion angle affects lower body biomechanics and provided evidence for the need to introduce patient-specific strategies for preventing ACL injuries.