Abstract—With the increasing prevalence of tenosynovitis that can be caused by repetitive use of smartphones, effective rehabilitation methods have become crucial. To address this issue, we have proposed an exergame system for softening hand wrist while playing video games using hand gestures for wrist exercises. It is known that softening thumb base is often effective for preventing tenosynovitis in addition to hand wrist. In this paper, we present an exergame system for softening thumb base by extending our previous work. We have newly designed hand gestures with a rubber band that increases exercise loads to improve the effectiveness. The gestures are recognized by a Python program using MediaPipe library. In addition, to enhance accessibility and usability, we implement a web application for this system using Node.js. To evaluate the proposal, we asked 15 persons including one tenosynovitis patient, to play four video games installed in the system, and measured the maximum thumb movement angle of each person to investigate the finger flexibility. Besides, we evaluate their engagement levels through a questionnaire with the System Usability Score (SUS). The results observe the significant improvement in the thumb base flexibility and the positive feedback on user experiences.
 
Keywords—tenosynovitis, thumb base, rubber band, Python, MediaPipe, System Usability Score (SUS), web application, Node.js


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