Contributions of pain intensity, body mass index and balance to physical function in individuals with bilateral knee osteoarthritis

Abstract

Purpose To explore the contributions of pain, body mass index (BMI) and balance to physical function in individuals with bilateral knee osteoarthritis (OA). Materials and methods The cross-sectional study involved 43 individuals (32 females, 11 males) with radiograph-confirmed bilateral knee OA. Participants’ height, weight, pain intensity and balance were assessed using height metre, weighing scale, numeric pain rating scale (NPRS) and Wii balance board, respectively, while physical function was assessed using both timed up-and-go (TUG) and stair climbing tests. Data were analysed using Pearson product moment correlation and stepwise linear regression at 0.05 alpha level. Results Physical function had significant direct correlations with pain intensity (r = 0.42, p = 0.005), BMI (r = 0.36, p = 0.016), and eyes-closed balance performance (r = 0.33, p = 0.033). Pain intensity, BMI and eyes-closed balance performance jointly accounted for 42.0% (R 2 = 0.42, p = 0.011) of the variance in physical function; their relative contributions being 18.0% (R 2 = 0.18, p = 0.005), 13.0% (R 2 = 0.13, p = 0.021) and 11.0% (R 2 = 0.11, p = 0.032), respectively. Conclusion Pain, BMI and eyes-closed balance are significant predictors of physical function in individuals with bilateral knee OA. Findings suggest that reducing pain and weight may improve balance and positively impact physical function in patients with bilateral knee OA and be useful in clinical practice.