The Effect of Functional Fatigue on Pattern and Onset of Electromyography Activation of Selective Lumbo-Pelvic and Peroneal Muscles in Elite Female Taekwondo Athletes

Fatigue causes afferent feedback disorder, muscle timing disorder and injury in organs. In this study, the effect of a functional fatigue protocol on pattern and onset of electromyography activity of selective lumbo-pelvic and peroneal muscles. 13 healthy female taekwondo athletes (mean age 20.92±1.25 years, weight 53.69±4.17 kg, height 166.92±5.00 m and activity experience 7.92±1.75 years) took part voluntary in this study. Firstly, the onset of EMG activity of erector spinae, quadratus lumborum, gluteus medius and peroneus lunges muscles was recorded during single leg jump-landing. Then, subjects participated in the fatigue protocol and EMG activity of muscles was recorded again. The analysis of variance showed significant differences in onset of muscle activity in pretest and posttest (P≤0.0005), but this pattern showed no significant differences in pretest and posttest. Paired t test showed a faster onset of each four muscles after fatigue; that was significant in quadratus lumborum, gluteus medius and peroneus lunges. But it was not significant in erector spine. As a result, central nervous system is more sensitive in fatigue condition when it predicts more injury risk and employs muscles sooner so that it can protect joints in high-risk conditions. So it attempts to recall motor strategies to prevent probable injuries sooner.