Auditory sEMG biofeedback for reducing muscle co‐contraction during pedaling

Muscle co‐contraction between the agonist and antagonist muscles often causes low energy efficiency or movement disturbances. Surface electromyography biofeedback (sEMG‐BF) has been used to train muscle activation or relaxation but it is unknown whether sEMG‐BF reduces muscle co‐contraction. We hypothesized that auditory sEMG‐BF improves muscle co‐contraction. Our purpose was to investigate whether auditory sEMG‐BF is effective in improving muscle co‐contraction. Thirteen participants pedaled on a road bike using four different auditory sEMG‐BF conditions. We measured the surface electromyography at the lower limb muscles. The vastus lateralis (VL) and the semitendinosus (ST) activities were individually transformed into different beep sounds. Four feedback conditions were no‐feedback, VL feedback, ST feedback, and both VL and ST feedback. We compared the co‐contraction index (COI) of the knee extensor‐flexor muscles and the hip flexor‐extensor muscles among the conditions. There were no significant differences in COIs among the conditions (p = 0.83 for the COI of the knee extensor‐flexor; p = 0.32 for the COI of the hip flexor‐extensor). To improve the muscle co‐contraction by sEMG‐BF, it may be necessary to convert muscle activation into a muscle co‐contraction. We concluded that individual sEMG‐BF does not immediately improve muscle co‐contraction during pedaling.