Fig. 3

Average EMG activity (%MVC) of measured muscles during one gait cycle. a Average sEMG activity of rectus femoris during one gait cycle. b Average sEMG activity of biceps femoris during one gait cycle. c Average sEMG activity of tibialis anterior during one gait cycle. d Average sEMG activity of medial gastrocnemius during one gait cycle. FG free gait without robot assistance, RAG-Z robot-assisted gait with zero torque, RAG robot-assisted gait, sEMG surface electromyography, MVC maximum voluntary contraction