Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, U.S.A.; Department of Orthopaedics and Rehabilitation, Vanderbilt University, Nashville, Tennessee, U.S.A.; Research Service, Veterans Administration Medical Center, Nashville, Tennessee, U.S.A.
J Electromyogr Kinesiol. 1991;1(1):49-57. doi: 10.1016/1050-6411(91)90026-2.
Anterior cruciate ligament (ACL) insufficiency and associated rotational instability of the knee joint is a potentially disabling condition. In particular, anterior-posterior laxity increases when the ACL is damaged and decreases with contraction of the hamstring musculature. Because laxity is controllable with muscle activity, comparison of muscular synergy patterns between groups of subjects with ACL-deficient and uninjured knees may identify compensatory mechanisms that could influence therapeutic procedures. All participants selected were between 18 and 40 years of age and had clinical or surgical documentation of ACL deficiency. Each subject was asked to walk and pivot with a stride time of 1 s on a 12-m walkway. The right and left foot-contact patterns and linear envelopes (LE) from the surface electromyographic (EMG) patterns of the gastrocnemius (GS), medial and lateral hamstring, rectus femoris (RF), and vastus lateralis (VL) were measured. Results from 15 subjects with uninjured knees and 12 subjects with ACL-deficient knees showed significant differences between their muscle synergy patterns. The types of differences observed depended on the stride period. All muscles within the ACL-deficient population showed some periods of abnormal activity. The differences in synergies indicate that there is a tendency for a greater net posterior force, flexor moment, and external rotation moment to be produced on the tibia during the time when most external rotation occurs to compensate for the mechanical actions of the lost ligament.
前交叉韧带（ACL）不足和膝关节相关的旋转不稳定是一种潜在的致残状况。特别是，当 ACL 受损时，前后松弛度会增加，而当腘绳肌收缩时，松弛度会减小。由于松弛度可以通过肌肉活动来控制，因此比较 ACL 缺失和未受伤膝关节的受试者群体的肌肉协同模式，可能会发现影响治疗程序的代偿机制。所有入选的受试者年龄均在 18 至 40 岁之间，且均有 ACL 缺失的临床或手术记录。要求每个受试者在 12 米的步道上以 1 秒的步幅时间行走和旋转。测量来自表面肌电图（EMG）模式的腓肠肌（GS）、内侧和外侧腘绳肌、股直肌（RF）和股外侧肌（VL）的右脚和左脚接触模式和线性包络（LE）。来自 15 名未受伤膝关节和 12 名 ACL 缺失膝关节的受试者的结果表明，他们的肌肉协同模式存在显著差异。观察到的差异类型取决于步幅周期。ACL 缺失人群中的所有肌肉在某些时期都表现出异常活动。协同作用的差异表明，在大多数发生外旋的时间，胫骨上会产生更大的净后向力、屈肌力矩和外旋力矩，以补偿丢失韧带的机械作用。
