The verification and the design improvement of weight-training machines were performed. This research was carried out with computer simulation using the musculoskeletal model of the human body. The main topic of this research is the improvement of an arm-curl machine. Also the improved exercise effects were observed in this paper. The existing exercise which moves the scapula on the axis of the elbow with raised forearm is effective for only Biceps. We suggested the new concept arm-curl machine that also raises the scapula after raising the forearm to be effective for Triceps and adjacent muscles. The exercise effect to the Biceps and Triceps was verified in the partⅠ, that to the non-adjacent muscle such as Lattismus Dorsi was verified in the partⅡ of this study. The analysis with computer simulation using the musculoskeletal model could be helpful to develop improved healthcare machines with reduced price and time.

Contemporary people want to develop their bodies to enhance quality of life. Although weight-training machines have been mainly developed with this trend based on intuition and experience, this study attempted to improve and verify those products through computer simulations using the musculoskeletal model of the human body. An arm-curl machine, a weight-training machine for arm exercise, was chosen for this research and the improved exercise effects were observed. The existing exercise that moves the scapula on the axis of the elbow with raised forearm is effective for biceps but not for triceps and adjacent muscles. Thus we suggested the idea for a new concept arm-curl machine that also raises the scapula after raising the forearm. To verify the effects of this new exercise, we manufactured arm-curl linkage. The experiments found that the exercise effects of the biceps were maintained, and the exercise effects of the triceps remarkably improved. These findings verified the effects of the proposed new concept arm-curl linkage.