Surface Electromyography: A New Indicator of Fatigue Level

Abstract

AbstractProlonged high intensity physical activity induces fatigue at the central and peripheral system, and inadequate recovery process lead to the emergence of maladaptation symptoms. Usually in tracking fatigue level, lactate test, heart rate and self-evaluation questionnaire are utilized. Surface EMG is known as one of the electrophysiological techniques, which physiological information of human body can be extracted from sEMG signals. This paper proposes a new indicator known as surface electromyography (EMG) to track fatigue level with the existence of maladaptation symptoms muscle soreness, unexplained lethargy and performance reduction. An experiment has been conducted on twenty participants to investigate the behavior of surface EMG during five days of intensive training that was based on Bruce Protocol treadmill test. The intension was to induce maladaptation signs on biceps femoris (BF), rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM). Results demonstrate that ΔFmed of BF, RF, VL and VM tend to decrease under normal fatigue condition, and increase under fatigue with maladaptation signs (P < 0.05) for RF and VL. Thus, this study successfully demonstrated that inception of maladaptation signs can be observed based on surface EMG.KeywordsSurface electromyographyFatigue levelMaladaptation