Letafatkar Amir, Rajabi Reza, Minoonejad Hooman, Rabiei Pouya
Department of Biomechanics and Sports injuries, Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran.
Department of Health and Sports Medicine, Faculty of Physical Education and Sport Sciences, University of Tehran, Tehran, Iran.
Int J Sports Phys Ther. 2019 Apr;14(2):214-227.
Deficits in dynamic neuromuscular control of the knee may contribute to the higher incidence of the anterior cruciate ligament (ACL), specifically in female athletes. Little is known about the effects of preventive training programs on muscle onset time and activation during functional tasks.
The purpose of this study was to evaluate the efficacy of perturbation-enhanced neuromuscular training on hamstring and quadriceps onset time and activation, and knee flexion angle in female athletes with quadriceps dominance (QD) deficit during a tuck-jump (TJ) task.
Quasi-experimental study.
Thirty-one collegiate female athletes with neuromuscular quadriceps dominance deficit randomly divided into experimental (n=16) and control (n=15) group. The experimental group performed a six-week perturbation training (18 sessions). Electromyograhic (EMG) assessment of quadriceps and hamstring activation and knee flexion angles during a TJ task were completed at baseline and after six weeks.
A significant decrease in the preparatory(p=0.003) and reactive (p=0.013) quadriceps-hamstring (Q/H) co-activation ratio was found in the experimental group. Perturbation training markedly decreased latency in medial hamstring (MH) (p=0.001), vastus medialis (VM) (p=0.004) and lateral hamstring (LH) (p=0.031), while latency increased for rectus femoris (RF) (p=0.001) and vastus lateralis (VL) (p=0.023) during a TJ task. The experimental group had average increases of 41.1%, 40.8%, and 39.5% in initial knee flexion, peak knee flexion and knee flexion displacement angle during the TJ task, respectively.
Increased preparatory VM and MH activities and decreased Q/H co-activation ratio, decreased VM and MH latency represent preprogrammed motor strategies learned during the perturbation training. This observed neuromuscular adaptation during TJ task could potentially reduce the risk for non-contact ACL injury.
膝关节动态神经肌肉控制缺陷可能导致前交叉韧带（ACL）损伤发生率较高，尤其是在女性运动员中。关于预防性训练计划对功能任务期间肌肉起始时间和激活的影响知之甚少。
本研究的目的是评估扰动增强神经肌肉训练对在收腹跳（TJ）任务中股四头肌占优势（QD）缺陷的女性运动员腘绳肌和股四头肌起始时间、激活以及膝关节屈曲角度的效果。
准实验研究。
31名有神经肌肉股四头肌占优势缺陷的大学女运动员随机分为实验组（n = 16）和对照组（n = 15）。实验组进行为期六周的扰动训练（18节）。在基线和六周后完成对TJ任务期间股四头肌和腘绳肌激活以及膝关节屈曲角度的肌电图（EMG）评估。
实验组中，准备期（p = 0.003）和反应期（p = 0.013）股四头肌 - 腘绳肌（Q/H）共同激活比率显著降低。在TJ任务期间，扰动训练显著缩短了内侧腘绳肌（MH）（p = 0.001）、股内侧肌（VM）（p = 0.004）和外侧腘绳肌（LH）（p = 0.031）的潜伏期，而股直肌（RF）（p = 0.001）和股外侧肌（VL）（p = 0.023）的潜伏期增加。实验组在TJ任务期间初始膝关节屈曲、峰值膝关节屈曲和膝关节屈曲位移角度分别平均增加了41.1%、40.8%和39.5%。
增加准备期VM和MH活动以及降低Q/H共同激活比率、缩短VM和MH潜伏期代表了在扰动训练期间学到的预先设定的运动策略。在TJ任务期间观察到的这种神经肌肉适应可能会潜在降低非接触性ACL损伤的风险。
2级。
