A cross sectional study exploring the relationship of self-reported physical activity with function, kinesiophobia, self-efficacy and quality of life in an Asian population seeking care for knee osteoarthritis.

Background: Physical activity is a guideline-recommended first-line intervention for people with knee osteoarthritis. Physical activity levels, and its potential correlates, is underexplored in Asian populations with knee osteoarthritis.

Methods: Participants enrolled in a longitudinal study in Singapore self-reported physical activity (UCLA activity score), function (Knee Osteoarthritis Outcome Score [KOOS-12]), kinesiophobia (Brief fear of movement [BFOM]), self-efficacy (ASES-8), and quality of life (EQ-5D-5 L). One-Way ANOVA was used to test the difference in outcomes between UCLA categories, while ordinal logistic regression was used to identify the associated factors to physical activity level.

Results: Seventy-three percent of all enrolled participants (n = 311/425) reported either inactivity or low physical activity (median 4, IQR 3-5). Significant, weak, positive correlations were observed be-tween UCLA activity score and either KOOS-12 (Spearman's rho: 0.1961; p < 0.001), ASES-8 (0.1983; p = 0.004), or EQ-5D-5 L (0.2078; p < 0.001). A significant, weak, negative correlation was observed between physical activity and BFOM (-0.2183; p < 0.001). Significant differences in function between groups (moderate vs. inactive or low physical activity) were not clinically important. Participants with obesity, from the eldest age category (i.e. ≥75), or who identified as Malay or female, were less physically active than those with a healthy BMI, below the age of 54, or who identified as Chinese or male, respectively.

Conclusion: Healthcare professionals in Asia should be aware of the large proportion of people with knee osteoarthritis who are either inactive or have low physical activity levels. Screening for, and offering interventions to promote, physical activity and its correlates should be prioritised.