Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut
Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut
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DOI：
10.1177/2325967116639578
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发表时间：
2016-04-01
影响因子：
2.6
通讯作者：
Norcross, Marc F.
中科院分区：
文献类型：
--
作者：
Cronin, Baker;Johnson, Samuel T.;Norcross, Marc F.
背景资料：髋关节外展肌和伸肌力量与前交叉韧带损伤风险相关的额面髋关节和膝关节运动之间的关系是不明确的。然而，以前对这些关系的研究评估了相对低水平的运动任务和峰值扭矩，而不是时间关键的力量测量，如扭矩发展率（RTD）。假设：具有更大髋关节外展和伸展RTD的女性在单腿跳跃切割任务中表现出更少的额状面髋关节和膝关节运动。四十娱乐活跃的女性进行最大的等长收缩和单腿跳切。根据记录的扭矩数据，计算从扭矩开始到开始后200 ms的髋关节伸展和外展RTD。三维运动分析被用来量化额面髋关节和膝关节运动学在运动任务。对于每个RTD的措施，跳切生物力学进行了比较参与者之间的最高（高）和最低（低）RTD tertiles.Results：额状面髋关节和膝关节的运动学没有显着差异，确定之间的高，低髋关节外展RTD组。然而，高髋关节伸展RTD组的髋关节内收较低（高，3.8 ° 3.0 °;低，6.5 ° 3.0 °; P = 0.019）和膝外翻（高，-2.5度+/- 2.3度;低，-4.4度+/- 3.2度; P = 0.046）跳切期间的位移。在髋关节处于相对外展和屈曲位置时进行切割等运动时，臀中肌控制髋关节内收的能力可能会受到影响。然而，臀大肌，作为髋关节外展肌的功能，可能会在控制髋关节内收和膝关节外翻运动在这些类型的tasks.Clinical Relevance中发挥关键作用：训练，特别强调增加爆发力的髋关节伸肌可能是一种手段，通过它来提高额面髋关节和膝关节控制在高风险的演习，如切割。
Background: The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD).Hypothesis: Females with greater hip abduction and extension RTD would exhibit lesser frontal plane hip and knee motion during a single-leg jump-cutting task.Study Design: Descriptive laboratory study.Methods: Forty recreationally active females performed maximal isometric contractions and single-leg jump-cuts. From recorded torque data, hip extension and abduction RTD was calculated from torque onset to 200 ms after onset. Three-dimensional motion analysis was used to quantify frontal plane hip and knee kinematics during the movement task. For each RTD measure, jump-cut biomechanics were compared between participants in the highest (high) and lowest (low) RTD tertiles.Results: No differences in frontal plane hip and knee kinematics were identified between high and low hip abduction RTD groups. However, those in the high hip extension RTD group exhibited lower hip adduction (high, 3.8 degrees 3.0 degrees; low, 6.5 degrees 3.0 degrees; P = .019) and knee valgus (high, -2.5 degrees +/- 2.3 degrees; low, -4.4 degrees +/- 3.2 degrees; P = .046) displacements during the jump-cut.Conclusion: In movements such as cutting that are performed with the hip in a relatively abducted and flexed position, the ability of the gluteus medius to control hip adduction may be compromised. However, the gluteus maximus, functioning as a hip abductor, may take on a pivotal role in controlling hip adduction and knee valgus motion during these types of tasks.Clinical Relevance: Training with a specific emphasis on increasing explosive strength of the hip extensors may be a means through which to improve frontal plane hip and knee control during high-risk maneuvers such as cutting.