Schilaty Nathan D, McPherson April L, Nagai Takashi, Bates Nathaniel A
Department of Neurosurgery & Brain Repair, University of South Florida Tampa Campus, Tampa, Florida, USA.
Medical Engineering, University of South Florida, Tampa, Florida, USA.
BMJ Open Sport Exerc Med. 2023 Jul 5;9(3):e001609. doi: 10.1136/bmjsem-2023-001609. eCollection 2023.
Following anterior cruciate ligament (ACL) injury, many athletes that undergo surgery and 6-9 months of rehabilitation struggle to return to sport. Evidence suggests that psychological factors contribute to this failure to return-to-sport.
Determine the motor control relationship between thigh musculature motor unit characteristics and psychological readiness to return to sport between ACL-injured and healthy controls.
A longitudinal cohort study.
Athletes longitudinally completed the ACL Return to Sport after Injury (ACL-RSI) survey and isometric strength measures with a measurement of electromyography (EMG) of the vastus lateralis, vastus medialis, biceps femoris, and semitendinosus. A score cut-off of 61 on the ACL-RSI was used to divide ACL-injured groups. EMG was decomposed to provide each identified motor unit's characteristics (amplitude, average firing rate, etc).
Data demonstrated increased average firing rate for hamstrings (p<0.001), decreased average firing rate for vastus lateralis (p<0.001) and decreased motor unit size for both the quadriceps and hamstrings at return-to-sport post-ACL reconstruction compared with sex-matched and age-matched healthy controls (p<0.001). Furthermore, there were marked differences in disparate ACL-RSI scores between ACL-injured athletes.
At return to sport, ACL-injured athletes have major alterations of thigh musculature motor control, with smaller motor units used by those with low ACL-RSI scores. This study uniquely demonstrates objective thigh muscle motor unit characteristics that coincide with subjective reports of psychological readiness. This information will be important to address psychomotor complexes of injury for future rehabilitation protocols.
前交叉韧带（ACL）损伤后，许多接受手术和6 - 9个月康复治疗的运动员在恢复运动方面仍面临困难。有证据表明，心理因素导致了这种无法恢复运动的情况。
确定ACL损伤运动员与健康对照组在大腿肌肉运动单位特征与恢复运动的心理准备之间的运动控制关系。
纵向队列研究。
运动员纵向完成ACL损伤后恢复运动（ACL-RSI）调查以及等长力量测量，并测量股外侧肌、股内侧肌、股二头肌和半腱肌的肌电图（EMG）。使用ACL-RSI得分61作为分界点来划分ACL损伤组。对EMG进行分解以提供每个识别出的运动单位的特征（幅度、平均放电频率等）。
数据显示，与性别和年龄匹配的健康对照组相比，ACL重建术后恢复运动时，腘绳肌的平均放电频率增加（p<0.001），股外侧肌的平均放电频率降低（p<0.001），股四头肌和腘绳肌的运动单位大小均减小（p<0.001）。此外，ACL损伤运动员的不同ACL-RSI得分之间存在显著差异。
恢复运动时，ACL损伤运动员的大腿肌肉运动控制有重大改变，ACL-RSI得分低的运动员使用较小的运动单位。本研究独特地展示了与心理准备主观报告相符的客观大腿肌肉运动单位特征。这些信息对于未来康复方案中解决损伤的心理运动复合体将很重要。
