This study investigated asymmetry between lower extremities during the landing and takeoff phases of a vertical drop jump (VDJ) in adolescent athletes following anterior cruciate ligament reconstruction (ACLR) and examined if performance was affected by reducing jump height. Thirty-three athletes who underwent ACLR and were referred for 3D biomechanical assessment before returning to play (mean age 15.9, SD 1.3 years; 16/33 female; mean time since surgery 7.4, SD 1.2 months) completed the VDJ while kinematics and kinetics were collected using motion capture. Lower extremity symmetry was compared between phases using paired t-tests. Jump height was calculated to measure performance. Asymmetries in ankle inversion, ankle adduction, knee adduction, hip adduction, hip adduction moment, and hip rotation moment were observed in both phases. Asymmetry was also observed in both phases for sagittal moments and power integrals at the knee and ankle and total power integral, with the magnitude of asymmetry being smaller during takeoff for power absorption/generation. Jump height was related to power generation integrals during takeoff but not to the asymmetry of power generation. Since asymmetries are translated from landing through takeoff, rehabilitation should address both phases to decrease injury risk and maximize performance after return to play.

中文翻译：

---

在最近的前十字韧带重建后的青少年运动员中，跳跳着陆和起飞过程中的生物力学对称性

这项研究调查了前交叉韧带重建（ACLR）后青少年运动员垂直下降跳跃（VDJ）着陆和起飞阶段下肢之间的不对称性，并检查了性能是否受到降低跳跃高度的影响。三十三名接受ACLR训练的运动员在重返比赛前接受了3D生物力学评估（平均年龄15.9，SD 1.3岁； 16/33女性；平均手术时间7.4，SD 1.2个月）完成了VDJ，同时进行了运动学和动力学方面的研究。使用运动捕捉来收集。使用配对t检验比较各相之间的下肢对称性。计算跳跃高度来衡量表现。在两个阶段均观察到踝关节内翻，踝内收，膝内收，髋内收，髋内收力矩和髋旋转力矩的不对称性。在两个阶段中，矢状弯矩，膝盖和脚踝处的功率积分以及总功率积分也都观察到不对称性，在起飞过程中，不对称性的大小较小，可以吸收/产生能量。跳跃高度与起飞期间的发电积分有关，但与发电的不对称性有关。由于不对称是从着陆过渡到起飞，因此康复应解决两个阶段，以减少受伤风险并在重返比赛后发挥最大性能。