Muscular activity analysis of haptic-based resistance training machine compared with dumbbell training

Abstract

A haptic-based resistance training machine was developed to incorporate a biomechanical feature for resistance training, offering a customized exercise for each individual user. It can generate a variable resistance profile that is proportional to the maximum strength curve of the user in order to fully stress the agonistic muscle throughout the entire range of motion. In this study, muscular activity was examined with this variable resistance scheme and compared with conventional dumbbell training. Elbow flexion known as biceps curl was selected as a template exercise for clinical evaluation. Thirteen subjects participated in this experiment. The individual strength curve was measured using the haptic-based resistance training machine and the resistance torque exerted upon the elbow joint was analyzed. The muscle activation was obtained through surface electromyography. The pattern of the resistance torque varied between individuals, while that of the dumbbell was fixed regardless of the user. This made a significant difference in the muscle activation. In the mid-section of motion, the haptic-based resistance machine exhibited significantly higher activation than the dumbbell. In the beginning and the end of a repetition, no differences were observed between the machine and the dumbbell. The results indicated that the customized training by the machine stimulated muscle movement more effectively over the range of motion.