Influence of gender on the myoelectric signal of thigh muscles

The surface electromyographic (sEMG) signal is commonly utilized as principal input information to the controller of robotic systems, such as exoskeleton robots. It has been shown that sEMG signals could vary from subject to subject, and that gender is one of the factors influencing this variation. Thus, the goal of this study is to detect possible gender-related alteration in the sEMG activity of principal thigh muscles, rectus femoris (RF), biceps femoris (BF) and vastus lateralis (VL), during gait at natural speed and cadence. The statistical analysis of sEMG signals, performed in seven male (M-group) and seven female (F-group) age-matched adults, showed clear gender-related differences, in terms of frequency of occurrence, in the behavior of VL, and no relevant differences in the behavior of RF and BF. This suggests a propensity of females for a more complex recruitment of the muscles during gait, performed mainly by muscles involved in the motion of the lower leg joints. The novel informations on gender-related differences provided here suggest considering a separate approach for males and females, in providing electromyographic signals as input information to the controller of exoskeleton robot.