Physical functions associated with health-related quality of life in older adults diagnosed with knee osteoarthritis.

[Purpose] The present study aimed to identify the physical functions associated with health-related quality of life in older adults with knee osteoarthritis. [Participants and Methods] A total of 132 participants were included in this study in two groups: the knee osteoarthritis group (n=66) and the control group (n=66). We compared the results of the Medical Outcomes Study 36-Item Short-Form Health Survey with the physical function measures related to health-related quality of life. In the knee osteoarthritis group, we examined the relationship between the degree of knee pain and health-related quality of life. [Results] The knee osteoarthritis group showed a significantly shorter one-leg standing time, lower maximum walking speed, and significantly longer time to complete the Sit-to-Stand-5 and Timed Up and Go tests than the control group. The knee osteoarthritis group had significantly lower 36-Item Short-Form Health Survey scores than the control group on seven subscales and significantly lower scores for physical component summary and role or social component summary. In the knee osteoarthritis group, physical component summary and role or social component summary were correlated with Sit-to-Stand-5, Timed Up and Go, and maximum walking speed. We observed a correlation between physical component summary and knee pain on joint loading. [Conclusion] In older adults with knee osteoarthritis, rehabilitation approaches aimed at achieving a smooth transition from sitting to standing may increase social participation and improve health-related quality of life.