School of Exercise and Rehabilitation Sciences, College of Health and Human Services, The University of Toledo, 2801 W. Bancroft St., HH 2505E, Mail Stop 119, Toledo, OH, 43606, USA.
Department of Kinesiology, College of Agriculture, Health and Natural Resources, University of Connecticut, Storrs, CT, USA.
Sports Med. 2021 Aug;51(8):1751-1769. doi: 10.1007/s40279-021-01433-w. Epub 2021 Feb 20.
Hamstrings neuromuscular function is a crucial component of functional movement, and changes after anterior cruciate ligament (ACL) injury contribute to risk factors for secondary injury and long-term sequelae. To effectively treat muscular impairments, an accurate understanding of hamstrings neuromuscular function in patients with ACL reconstruction (ACLR) is needed.
A systematic review and meta-analysis were undertaken to describe and quantify hamstrings neuromuscular function in individuals with ACLR compared to controls.
We searched PubMed, Web of Science, SPORTDiscus, CINAHL, and EBSCOhost databases in October of 2020 for studies evaluating the difference between hamstrings electromyography (EMG) between individuals with ACLR and controls. Two independent reviewers assessed each paper for inclusion and quality. Means and standard deviations were extracted from each included study to allow random-effect size (ES) meta-analysis calculations for comparison of results.
Thirty-four studies were included for final review. From these, 5 categories of neuromuscular outcomes were identified, and studies were grouped accordingly: (1) muscle activation levels (EMG amplitude), (2) co-activation, (3) onset timing, (4) electromechanical delay, and (5) time-to-peak activity. Moderate to strong evidence indicates that individuals with ACLR demonstrate higher hamstrings EMG amplitude (normalized to % maximum voluntary isometric contraction) and hamstrings-to-quadriceps co-activation during gait and stair ambulation compared to controls. In addition, there was moderate evidence of longer electromechanical delay during knee flexion and greater hamstrings-to-quadriceps co-activation during knee extension compared to controls.
Greater hamstrings EMG amplitude and co-activation during gait and ambulation tasks and longer electromechanical delay of the hamstrings in individuals with ACLR align with clinical impairments following ACLR and have implications for re-injury risk and long-term joint health, thus warranting attention in rehabilitation.
腘绳肌神经肌肉功能是功能性运动的一个关键组成部分，而前交叉韧带（ACL）损伤后的变化是导致二次损伤和长期后遗症的危险因素。为了有效地治疗肌肉损伤，需要对 ACL 重建（ACLR）患者的腘绳肌神经肌肉功能有准确的了解。
进行系统评价和荟萃分析，以描述和量化 ACLR 患者与对照组相比的腘绳肌神经肌肉功能。
我们于 2020 年 10 月在 PubMed、Web of Science、SPORTDiscus、CINAHL 和 EBSCOhost 数据库中搜索评估 ACLR 患者和对照组之间腘绳肌肌电图（EMG）差异的研究。两名独立的审查员评估了每篇论文的纳入和质量。从每个纳入的研究中提取均值和标准差，以允许进行随机效应大小（ES）荟萃分析计算，以比较结果。
共有 34 项研究被纳入最终综述。从这些研究中，确定了 5 类神经肌肉结果，并相应地将研究分组：（1）肌肉激活水平（EMG 幅度），（2）共激活，（3）起始时间，（4）机电延迟，和（5）达到峰值活动时间。有中等至强证据表明，与对照组相比，ACLR 患者在步态和上下楼梯时表现出更高的腘绳肌 EMG 幅度（相对于最大随意等长收缩的百分比）和腘绳肌-股四头肌共激活。此外，在膝关节屈曲时存在中等程度的证据表明机电延迟较长，在膝关节伸展时腘绳肌-股四头肌共激活较大。
ACLR 患者在步态和活动任务中腘绳肌 EMG 幅度和共激活增加，以及 ACLR 后腘绳肌的机电延迟延长，与 ACLR 后的临床损伤一致，对再损伤风险和长期关节健康有影响，因此在康复中值得关注。
