Abstract：
BACKGROUND: Individuals with a recent anterior cruciate ligament reconstruction may demonstrate an altered movement strategy for protecting the knee and maintaining stability. Altered knee movement might lead to abnormal intra-articular load, potentially contributing to early knee osteoarthritis onset. A protective strategy may be particularly evident during active tasks that induce a pivot-shift manoeuvre, such as a step-down and cross-over task. In this study, we investigated whether knee joint mechanics and muscle activity differed between participants early (∼3 months) following reconstruction (n = 35) to uninjured controls (n = 35) during a step-down and cross-over task with a 45° change-of-direction.
METHODS: We used motion capture, force plates and surface electromyography to compare time-normalised curves of sagittal and transverse-plane knee mechanics and muscle activity during the cross-over phase between groups using functional t-tests. We also compared knee mechanics between sides within the injured group and compared discrete outcomes describing the cross-over phase between groups.
RESULTS: Compared to controls, the injured participants had greater knee flexion angle and moment, lower internal rotation moment, more preparatory foot rotation of the pivoting leg, a smaller cross-over angle, and a longer cross-over phase for both the injured and uninjured sides. The injured leg also had greater biceps femoris and vastus medialis muscle activity compared to controls and different knee mechanics than the uninjured leg.
CONCLUSIONS: Individuals with anterior cruciate ligament reconstruction showed a knee-stabilising and pivot-shift avoidance strategy for both legs early in rehabilitation. These results may reflect an altered motor representation and motivate considerations early in rehabilitation.
METHODS: We used motion capture, force plates and surface electromyography to compare time-normalised curves of sagittal and transverse-plane knee mechanics and muscle activity during the cross-over phase between groups using functional t-tests. We also compared knee mechanics between sides within the injured group and compared discrete outcomes describing the cross-over phase between groups.
RESULTS: Compared to controls, the injured participants had greater knee flexion angle and moment, lower internal rotation moment, more preparatory foot rotation of the pivoting leg, a smaller cross-over angle, and a longer cross-over phase for both the injured and uninjured sides. The injured leg also had greater biceps femoris and vastus medialis muscle activity compared to controls and different knee mechanics than the uninjured leg.
CONCLUSIONS: Individuals with anterior cruciate ligament reconstruction showed a knee-stabilising and pivot-shift avoidance strategy for both legs early in rehabilitation. These results may reflect an altered motor representation and motivate considerations early in rehabilitation.
摘要：
背景：最近前交叉韧带重建的个体可能表现出改变的运动策略以保护膝关节和维持稳定性。膝关节运动改变可能导致关节内负荷异常，可能导致早期膝骨关节炎发病。在主动任务期间，保护策略可能特别明显，这些任务会引起枢轴移位操作，比如一个递阶和跨接任务。在这项研究中,我们调查了在45°方向改变的步降和跨接任务期间,重建后(n=35)和未受伤对照组(n=35)的早期参与者之间的膝关节力学和肌肉活动是否存在差异.
方法：我们使用动作捕捉，力板和表面肌电图，使用功能t检验比较两组间交叉阶段矢状面和横向面膝关节力学和肌肉活动的时间归一化曲线。我们还比较了受伤组中两侧的膝关节力学，并比较了描述组间交叉阶段的离散结果。
结果：与对照组相比，受伤的参与者有更大的膝关节屈曲角度和力矩，较低的内部旋转力矩，枢转腿的更多准备脚旋转，一个较小的交叉角,以及受伤和未受伤双方的更长的交叉阶段。与对照组相比，受伤的腿的股二头肌和股内侧肌活动也更大，并且与未受伤的腿相比，膝盖力学也不同。
结论：前交叉韧带重建术的患者在康复早期表现出双腿的膝关节稳定和枢轴移位避免策略。这些结果可能反映了运动表现的改变，并激发了康复早期的考虑。
方法：我们使用动作捕捉，力板和表面肌电图，使用功能t检验比较两组间交叉阶段矢状面和横向面膝关节力学和肌肉活动的时间归一化曲线。我们还比较了受伤组中两侧的膝关节力学，并比较了描述组间交叉阶段的离散结果。
结果：与对照组相比，受伤的参与者有更大的膝关节屈曲角度和力矩，较低的内部旋转力矩，枢转腿的更多准备脚旋转，一个较小的交叉角,以及受伤和未受伤双方的更长的交叉阶段。与对照组相比，受伤的腿的股二头肌和股内侧肌活动也更大，并且与未受伤的腿相比，膝盖力学也不同。
结论：前交叉韧带重建术的患者在康复早期表现出双腿的膝关节稳定和枢轴移位避免策略。这些结果可能反映了运动表现的改变，并激发了康复早期的考虑。
