The Effect of a Modified Perturbation Training on Muscle Activation Pattern and Function in ACL Deficient Patients

A lesion of the anterior cruciate ligament (ACL) is a major trauma of the knee. Neuromuscular control is believed to be a critical factor in dynamic knee stability in ACL deficient (ACLD) patients. Neuromuscular training programs (in particular perturbation training) are increasingly integrated into clinical practice for ACL lesion rehabilitation. The purpose of this study was to investigate the effect of the modified perturbation training on neuromuscular control system and functional improvement in ACLD.Subjects and 10 professional male athletes with an average of 6.7±3.19 months after their unilateral ACL rupture participated in this study. Surface Electromyographic (EMG) data were recorded during a cross hop task, from the rectus femoris, vastus medialis, medial head of the gastrocnemius, biceps femoris and gluteus maximus muscles. Muscle activation patterns before and after 10 sessions of perturbation training were compared. Treatment outcome was determined from scores of questionnaires and functional tests. Scores of IKDC subjective questionnaire and functional tests were significantly improved (P<0.05). Muscle activation patterns were modified. The significant earlier onset and late peak of the rectus femoris resulted in the longer duration from onset-to-peak activity in both of the involved and non involved limbs (P<0.05). Perturbation training has a central effect that modifies neuromuscular control system through the change in feed-forward control for ACL deficient patients. Rectus femoris activation is not harmful to ACL and causes a protective effect. Optimum activity of this muscle is important for ACL injury prevention and rehabilitation.