Trulsson Anna, Miller Michael, Gummesson Christina, Garwicz Martin
Department of Health Sciences, Physiotherapy, Lund University, Lund, Sweden.
Department of Pain Rehabilitation, Skåne University Hospital, Lund, Sweden.
BMJ Open Sport Exerc Med. 2017 Jan 3;2(1):e000131. doi: 10.1136/bmjsem-2016-000131. eCollection 2016.
Little is known about factors contributing to the altered movement patterns observed in many individuals with anterior cruciate ligament (ACL) injury. We addressed whether altered muscular activity is such a factor.
16 participants with unilateral, non-reconstructed ACL rupture were scored for altered movement patterns according to Test for Substitution Patterns (TSP), which includes the single-leg squat (SLS). Surface electromyography (SEMG), was recorded in the lower extremities at initiation of weight-transfer from double-leg to single-leg stance (eyes closed), simulating the initiation of an SLS. Normalised SEMG amplitudes 200-300 ms after weight-transfer initiation were compared between injured and non-injured sides, and correlated to the TSP scores for the SLS. Peak absolute SEMG amplitudes during 5 TSP test movements were also compared between sides.
At weight-transfer initiation, muscle activity was lower in the tibialis anterior, gastrocnemius and peroneus longus muscles on the injured side. Low muscle activity correlated moderately to worse TSP scores for the SLS for the gluteus medius (r=-0.56, p=0.03), and gastrocnemius muscles (r=-0.56, p=0.02). Median peak absolute amplitude during TSP movements was lower in the quadriceps, gastrocnemius and peroneus longus muscles on the injured side.
The altered patterns of muscle activity at weight-transfer initiation, correlations between lower activity at movement initiation and altered movement patterns during SLS and the altered peak amplitudes during TSP movements together indicate alterations in sensorimotor control that may contribute to the observed altered movement patterns. Future studies will determine if exercises targeting muscle activity initiation should complement customary ACL injury rehabilitation.
对于导致许多前交叉韧带（ACL）损伤患者出现运动模式改变的因素，我们了解甚少。我们研究了肌肉活动改变是否是其中一个因素。
16名单侧、未重建ACL断裂的参与者根据替代模式测试（TSP）对运动模式改变进行评分，该测试包括单腿深蹲（SLS）。在从双腿站立到单腿站立（闭眼）的重量转移开始时，记录下肢的表面肌电图（SEMG），模拟SLS的起始动作。比较受伤侧和未受伤侧在重量转移开始后200 - 300毫秒的标准化SEMG振幅，并将其与SLS的TSP评分相关联。还比较了两侧在5次TSP测试动作期间的峰值绝对SEMG振幅。
在重量转移开始时，受伤侧的胫骨前肌、腓肠肌和腓骨长肌的肌肉活动较低。肌肉活动低与臀中肌（r = -0.56，p = 0.03）和腓肠肌（r = -0.56，p = 0.02）的SLS的TSP评分较差中度相关。受伤侧的股四头肌、腓肠肌和腓骨长肌在TSP动作期间的中位峰值绝对振幅较低。
重量转移开始时肌肉活动模式的改变、运动开始时较低活动与SLS期间运动模式改变之间的相关性以及TSP动作期间峰值振幅的改变共同表明感觉运动控制的改变，这可能导致观察到的运动模式改变。未来的研究将确定针对肌肉活动起始的锻炼是否应补充常规的ACL损伤康复。
