Abstract
Introduction
Osteoarthritis (OA) of the hip and knee causes pain and functional limitations which lead to decreased physical activity level (1,2). Half of all male, and two thirds of all female, patients with early knee OA do not fulfill the recommendations for physical activity level (30 min/day of at least 5 days/week) (1). We tested the hypothesis that Scandinavian patients prior to total joint replacement had reduced actual physical activity and intensity levels compared with matched controls and that most patients did not fulfill the recommendations for physical activity.
Methods
Physical activity and intensity were measured during 5 consecutive days with SenseWearTM Armband (SWA; BodyMedia, Inc., Pittsburgh, PA) in 53 patients with severe knee (n = 26) or hip (n = 27) OA prior to total joint replacement (51% women, age: 68 ± 5 years, BMI: 29.8 ± 10.2) and compared with data from 15 age-matched population-based controls (53% women, age: 68 ± 5 years, BMI: 26.9 ± 3.3). Sedentary, moderate, vigorous and very vigorous intensities were equivalent to Sense Wear Armband recordings of 3 MET, >36 MET, >69 MET, >9MET, respectively. In addition, total energy expenditure, average MET, numbers of steps/day, and the combined activity of moderate, vigorous, and very vigorous activity were calculated (min/day). Unpaired students t-test was used for between group comparisons (p < 0.05).
Results
Participants wore the device for a mean ± SD of 98.5 ± 1.5% of the time. Patients spent significant less time being vigorously physically active (0.093 ± 0.082 vs. 0.156 ± 0.099 hours/day) and very vigorously active (0.015 ± 02 vs.0.028 ± 0.035 hours/day) than controls. However, no differences were observed for total energy expenditure, average MET, time spend being sedentary, and time spend being moderately physically active. The average activity of combined moderate, vigorous, and very vigorous activity for patients were 185 ± 1 min/day and 11.3% did not reach the recommended activity level. Finally, a tendency (p = 0.059) towards less steps/day was observed for patients (6778 ± 3196 vs. 8576 ± 2872 steps/day).
Conclusions
Since Scandinavian OA patients prior to joint replacement show no or little decrease in physical activity, and that the majority fulfills recommendations for physical activity an increase in actual physical activity cannot be expected from surgery. This unexpected finding needs to be confirmed.
