Quality of Life, Knee Function, and Physical Activity in Japanese Elderly Women with Early-Stage Knee Osteoarthritis

Abstract

Purpose. To compare quality of life, knee function, and physical activity in 33 elderly women with or without early-stage knee osteoarthritis (OA). Methods. 33 Japanese elderly women (mean age, 66 years) with (n=18) or without (n=15) early-stage knee OA symptoms (knee pain and decreased range of motion [ROM]) were recruited. The height, weight, and body mass index, disease severity, quality of life (according to the Japanese Knee Osteoarthritis Measure [JKOM]), knee function (knee extension strength, ROM, 10-m gait time), and the amount of physical activity (net energy expenditure and step count) of the 2 groups were compared. Results. The 2 patient groups did not differ significantly with respect to mean patient age, height, and body mass index, except for weight. Regarding knee function, mean knee extension strength, ROM (extension but not flexion), and 10-m gait speed (comfortable and maximum) were significantly inferior in patients with knee OA than in controls. Regarding the mean amount of physical activity undertaken, patients with knee OA did not differ significantly from controls with respect to net energy expenditure (179 vs. 212 Kcal/day) and step count (8016 vs. 9729 steps/day). Net energy expenditure ( r = −0.65, p=0.04) and step count ( r = −0.62, p=0.02) correlated negatively with JKOM scores in patients with knee OA but not in the controls. Conclusion. In Japanese elderly women with knee OA, quality of life (JKOM scores) correlated negatively with physical activity (net energy expenditure and step count). The 2 groups undertook similar amounts of physical activity, although those with knee OA exhibited less knee extension strength. Decreased knee extension strength coupled with high levels of physical activity may exacerbate the development of knee OA.