Effectiveness of Smart-Assisted Rehabilitation Exercise Training on the Physical and Mental Health of Older Adults in Long-Term Care Facilities

"Interventions~Behavioral: Smart-assisted rehabilitation exercise system (KNEESUP) A wearable smart-assisted rehabilitation system providing personalized, progressive lower limb resistance training for elderly residents with sarcopenia in long-term care institutions. The system includes real-time monitoring, feedback, and remote adjustment by rehabilitation specialists. Unlike traditional programs, it integrates sensor technology to track knee joint angles and exercise performance, enabling precise and adaptive training.~Other: Usual care / routine physical activity Participants follow standard daily activities and rehabilitation provided by the long-term care facility, without the smart-assisted rehabilitation system."