"Master Knees 2" is an artificial intelligence application designed for people with knee problems in the community, integrating exercise, games, and treatment. An online game in which physical therapists become game designers and create exercise prescriptions based on the elderly's mobility, thereby helping players establish exercise habits, detecting and tracking their exercise performance in real time, and recording relevant data and posture skeleton diagrams for exercise performance analysis. . Players can compete with other players online to increase interaction and fun.