Physical inactivity is the key risk factor for disability and many other health issues. Evidences have shown that being physically active can reduce the risk of disability in older adults with arthritis. However, available evidences did not particularly evaluate inactive adults. Song J et al. assessed the link between changes in physical activity with disability among initially inactive adults with or at high risk of knee osteoarthritis.

Inactive individuals were recognized at baseline according to the US Department of Health and Human Services classification (no [zero] 10-minute session of moderate-to-vigorous [MV] activity over 1 week) from objective accelerometer monitoring. After two years, physical activity change status was reported as: (1) met federal physical activity guidelines (≥150 MV minutes/week acquired in bouts ≥10 minutes), (2) insufficiently increased activity (some but <150 MV bout minutes/week), or (3) remained dormant. The disability at baseline and after 2 years was analyzed by Late Life Disability Instrument limitation and frequency scores. Multiple regression estimated the relationship of physical activity change status with baseline-to-2-year changes in disability scores altering for socioeconomics, health factors, and baseline disability score.

The increased physical activity exhibited a graded relationship with ameliorated disability scores in Late Life Disability Instrument limitation (p<0.001) and frequency scores (P=0.027). The greatest reduction even insufficiently increased physical activity was concerned with the reduced disability while increasing MV activity to guideline levels.

Therefore, it can be concluded that increasing MV physical activity can reduce the disability among inactive adults with or at high risk of knee osteoarthritis, even when guidelines are not met.