Design of a Cable Driven Wearable Fitness Device for Upper Limb Exercise

To provide an alternative to conventional large-scale fitness equipment, we previously developed a soft passive wearable device for upper limb resistance exercises that utilized elastic exercise bands. However, the user was required to manually adjust the level of strength. In this paper, we introduce a novel wearable fitness device for upper limb exercise that constitutes cable-driven actuation to control the resistance profiles. Our proposed device allows for the generation of isotonic force trajectories, similar to those produced during dumbbell lifting, utilizing custom cable-driven actuators. The cable path of the device was determined based on the results of user testing aimed at optimizing muscle stimulation levels. In addition, linear resonant actuators were installed at customized haptic handles and upper arm modules to enhance proprioceptive sensitivity and exercise efficacy. The immersive 'exer-tainment' user display interface was also redesigned to increase user motivation. The efficacy of our device was assessed by comparing the surface electromyography (sEMG) activities of upper limb muscles during chest press and triceps extension exercises performed with our device versus those using traditional weight training machines and rubber bands. It was found that our device could effectively strengthen during arm exercise, such as triceps extension.