Activity mapping of lower leg muscles using a circumferential electrode array

The timing of muscle activity during walking and standing is crucial for the understanding of normal and pathological functioning of the human body. All muscles crossing the ankle joint are an essential part of balance control during walking or standing. However, EMG measurements concentrate typically on the large muscles and neglect the small ones. An array of EMG electrodes was proposed to measure the circumferential EMG activity of the lower leg muscles. A wavelet based method was designed to generate muscle activity maps. The findings of this study showed that: (a) the individual activity of selected small muscles crossing the ankle joint can be measured with the proposed array; (b) both timing and intensity of the muscle activity during movement can be visualized simultaneously with the proposed activity maps; and (c) the time and space resolution is suitable for the study of multiple muscle activity interplay during standing or walking. Possible applications of this technique range from gait and stability analysis to sports equipment and clinical testing.