Investigation of tibialis anterior muscle activation patterns during walking on different terrains

Trapezoidal stimulation profile has been used for many years in clinical applications to activate the weak tibialis anterior muscle during gait for correcting foot drop. However, this stimulation profile could not well adapt to the different types of terrain, such as level ground, upstairs and downstairs. Thus an environment aware and adaptive stimulation mode would be needed to help drop foot patients walk normally in various environments. As a part of this new stimulation system, tibialis anterior (TA) muscle activation pattern during different locomotion modes were investigated in this study. Foot pressure signals from four force sensitive resistor (FSR) and TA muscle electromyogram (EMG) signal were recorded during gait from five normal subjects. Then the averaged TA muscle activation patterns for level ground, upstairs and downstairs were calculated from the EMG signals in the study, respectively. The results of the study could provide some helpful suggestions on how to design a suitable stimulation envelope for walking over different terrains.