The Effect of Perturbation Training on Timing of Hamstring and Quadriceps Electromyography Activation in Active Subjects with Neuromuscular Dominance Quadriceps Deficit

How and when muscles are activated influences knee's ability to absorb and disperse forces and thereby preventing ACL injuries. The aim of this study was to investigate the effect of six weeks of perturbation training on timing of quadriceps and hamstring activation in active subjects with neuromuscular dominance quadriceps deficit. For this purpose, 53 active students (26 subjects in control group and 27 subjects in experimental group) with neuromuscular dominance quadriceps deficit were selected. Hurd et al. modified perturbation training were applied for experimental group for six weeks (18 sessions). EMG data of quadriceps and hamstring (during single limb drop-landing task) were assessed in pretest and after six weeks of training. For statistical data analysis, the analysis of variance with repeated measures, paired and independent sample t tests, one-way analysis of variance (ANOVA) and Tukey post hoc tests were used (significance level of 0.95% and α≤0.05) with SPSS version 18.0. Perturbation training used in this study significantly decreased the timing of rectus femoris and vastus lateralis whereas it increased the timing of vastus medialis,medial and lateral hamstring [there were sex differences]. Earlier hamstring activation is considered as a positive adaptation after perturbation training. Finally, because the neuromuscular dominance quadriceps deficit is considered as one of the most important mechanisms of ACL non-contact injuries in athletes and the effect of perturbation training in eliminating this problem was indicated in this study, so coaches are recommended to use perturbation trainings in order to eliminate this defect.