Objective: To describe the association between knee and hip radiographic osteoarthritis (ROA), a measure of knee pain, stiffness and functional ability and objectively measured physiological falls risk predictors.
Methods: Cross-sectional, population-based study of 850 randomly selected men and women aged 50-80 years (mean 62.5, SD 7.4). Falls risk (Z score) was determined objectively with the short form Physiological Profile Assessment (PPA). Two observers assessed knee and hip ROA using the Altman atlas. Pain, stiffness and functional ability were assessed using the Western Ontario McMasters Osteoarthritis index (WOMAC).
Results: Overall, the study population was at a mild risk of falling. In multivariable analysis, the WOMAC function and pain score were significantly associated with reaction time, balance, proprioception, knee extension strength, and edge contrast sensitivity. Stiffness was associated with knee extension strength and edge contrast sensitivity. Males had a dose response association between the global WOMAC score and falls risk (r=0.17, P<0.001). Those who reported a global WOMAC score of 50 and above had a higher risk of falling compared to those with a score below 50 (Z score: 0.53 vs 0.14, P<0.001). Hip joint space narrowing (JSN) was significantly associated with knee extension strength (r=-0.10, P=0.003), however, no other significant associations were observed between ROA and falls risk predictors.
Conclusion: Self-reported functional ability and pain, and to a lesser extent, stiffness (but not knee and hip ROA), have a modest but independent association with physiological predictors of falls risk.