Muscle coordination following rupture of the anterior cruciate ligament: Electromyographic studies of 14 patients

Abstract

In an electromyographic (EMG) study, the coordination in muscles acting on the knee joint was assessed in 14 patients with an arthroscopically verified complete rupture of the anterior cruciate ligament and in 16 controls. EMG and heel-contact signals were recorded while walking on a treadmill at walking gradients from 0 to 25 percent. There was an earlier onset of EMG bursts in the patients, especially in the lateral hamstrings and medial gastrocnemius; and the duration of EMG bursts also tended to be prolonged in the patients. Normalized root mean squares of amplitudes, which correlate with muscle tension, were higher in the gastrocnemius in the patients. EMG profiles, outlining the averaged muscle activity throughout the gait cycle, showed a displacement of peak activity in the hamstrings from the late swing phase into the stance phase, with increasing gradients in both the patients and the controls. Our study indicates that the gastrocnemius muscle contributes to functional stability in the anterior cruciate ligament deficient knee, and more attention should be paid to this muscle.

Prehabilitation: The Void in the Management of Anterior Cruciate Ligament Injuries—A Clinical Review

“…ACL injured patients eventually develop a greater extensor torque at the hip and a reduced extensor torque at the knee during the stance phases of walking and running [29][30][31][32]. These observations have been supported by increased electromyographic (EMG) activity in the hamstrings and reduced EMG activity in the quadriceps in ACL-deficient patients during the gait cycle [33][34][35][36][37][38][39]. These adaptations are advantageous to individuals with both ACL deficiency and ACLR because they reduce anterior displacement of the tibia relative to the femur and therefore reduce stress on the knee joint while also enabling individuals to perform complex knee movements [29-31, 38, 40].…”

Hamstring extensibility and transverse plane knee control relationship in athletic women

“…These studies have shown evidence of a synergistic ACL and hamstring muscle group relationship [6,8,31,32], particularly when the knee is flexed ≥ 25° [27]. To enhance hamstring capability for providing dynamic control of this motion couple (thereby protecting the ACL), various authors have emphasized the importance of increased hamstring strength [6,24,36], reactivity [6,8,18,20,24,26,31,32,36], and increased passive [3] or active [4,5,19] stiffness.…”

Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport

“…45,139 While it is difficult to draw unequivocal conclusions from the conflicting evidence following surgical reconstruction of the torn ACL, it appears that eccentric hamstring strength is impaired after ACL reconstruction. 105,108,123 As well, quadriceps weakness following ACL reconstruction is also variable 105,108 and somewhat dependent on the numerous rehabilitation and testing protocols used, making it difficult to draw any consensus from the literature. Clearly, however, eccentric muscle dysfunction does exist around unstable (and painful 141 ) joints, and therefore must be reversed.…”