ACL injury mechanisms & offaxis neuromuscular diagnosis & training

描述（申请人提供）：前交叉韧带是体育相关活动中最常见的膝关节韧带损伤，尤其是在旋转运动中。前交叉韧带损伤机制，包括导致女运动员的发生率比男运动员高2-9倍的因素，仍然不是很清楚。考虑到离轴膝关节运动（胫骨旋转和外翻/内翻）相当有限，而且离轴特性可能存在性别差异，ACL损伤通常与过度的离轴负荷有关。目的：探讨男女非接触性前交叉韧带损伤的离轴神经力学和解剖学特征，并在诊断的基础上进行干预训练，以改善神经肌肉对危险、潜在伤害性离轴运动的控制。假设1：女性在胫骨内外旋和外翻、内翻时的稳定性、刚度和强度较男性低，关节松弛度较大，本体感觉敏感度较男性低。具体目标1：使用定制的膝关节设备进行离轴评估和一种新型的枢轴滑动椭圆机，对女性和男性的膝关节离轴神经力学特性进行训练前诊断。还将进行临床/功能检查。假设2：在胫骨外旋转和外翻负荷下，女性比男性更容易发生前交叉韧带撞击，其特征是受试者特异性FE撞击模型。具体目的2：利用三维FE前交叉韧带撞击模型确定个体在胫骨外旋转和外翻时前交叉韧带撞击外侧切迹壁的易感性。假设3：基于诊断在旋转滑动椭圆运动机上进行特定科目训练，可改善离轴神经肌肉控制。具体目标3：在训练前诊断的基础上，开展针对受试者的旋转滑动椭圆训练，改善离轴神经肌肉控制。具体目标4：确定训练引起的神经力学和功能变化。研究设计设置：离轴神经力学特性将由个体受试者确定。我们将据此实施干预计划。设置：神经力学评估的研究实验室，训练/评估的学校体育馆。参与者：来自当地高中和青少年运动队的60名男女运动员。干预措施：使用新型旋转滑动椭圆机训练离轴神经肌肉控制。每周进行3次40分钟的训练，持续6周。结果指标：胫骨旋转（旋转）和外翻/内翻时的稳定性、肌肉力量、僵硬度、松弛度、本体感觉和反应时间、功能活动和前交叉韧带损伤的发生率。公共卫生相关性：拟议的研究将对个体女性和男性受试者的内外旋转和外翻/内翻的离轴神经力学特性进行特定的诊断，并使用新型枢轴滑动椭圆机根据诊断进行受试者特定的离轴神经肌肉控制干预训练。

DESCRIPTION (provided by applicant): ACL is the most commonly injured knee ligament in sports-related activities, especially in pivoting sports. ACL injury mechanisms, including factors contributing to the 2-9 times higher incident rate in female athletes than their male counterparts, are still not very clear. Considering off-axis knee motions (tibial rotation and valgus/varus) are rather limited and there may be gender differences in off-axis properties, ACL injuries are often associated with excessive off-axis loadings. Objectives: To investigate off-axis neuromechanical and anatomical properties of noncontact ACL injuries in men and women, and to conduct intervention training based on the diagnosis to improve neuromuscular control of risky, potentially injurious off-axis movements. Hypothesis 1: Females have lower stability, stiffness and strength, greater joint laxity, and less sensitive proprioception in external and internal tibial rotations and in valgus and varus than males. Specific Aim 1: To perform a pre-training diagnosis of knee off-axis neuromechanical properties in females and males using custom knee devices for off-axis evaluations and a novel pivoting-sliding elliptical machine. Clinical/functional measures will also be conducted. Hypothesis 2: Females are more likely to have ACL impingement than males under external tibial rotation and valgus loading, characterized by a subject-specific FE impingement modeling. Specific Aim 2: To determine the susceptibility of ACL impingement against the lateral notch wall during external tibial rotation and valgus in individuals using a 3-D FE ACL-impingement model. Hypothesis 3: Subject-specific training on a pivoting-sliding elliptical exercise machine based on the diagnosis improves off-axis neuromuscular control. Specific Aim 3: To conduct subject-specific pivoting-sliding elliptical training and improve off-axis neuromuscular control, based on the pre-training diagnosis. Specific Aim 4: To determine training-induced neuromechanical and functional changes. Study Design Setting: Off-axis neuromechanical properties will be determined for individual subjects. An intervention program will be conducted accordingly. Setting: A research lab for neuromechanical evaluations, and school gym for training/evaluation. Participants: 60 female and 60 male athletes from local high school and youth sports teams. Interventions: Training off-axis neuromuscular control using a novel pivoting-sliding elliptical machine. Training will be done in three 40-minute training session per week for 6 weeks. Outcome Measures: Stability, muscle strength, stiffness, laxity, proprioception, and reaction time in tibial rotation (pivoting) and in valgus/varus, functional activities, and incidence of ACL injuries. PUBLIC HEALTH RELEVANCE: The proposed studies will conduct subject-specific diagnosis on off-axis neuromechanical properties in internal and external rotations and in valgus/varus in individual female and male subjects, and perform subject-specific intervention training of off-axis neuromuscular control based on the diagnosis, using a novel pivoting-sliding elliptical machine.