Objective: To measure daily physical activity in patients with juvenile rheumatoid arthritis (JRA) and in healthy controls, and to identify variables that may influence physical activity in JRA patients.
Methods: Twenty-three prepubertal children, ages 5-11 years, with mild to moderate JRA and no prior exposure to systemic glucocorticosteroids, were compared to 23 healthy children of similar age. Physical activity was measured for 3 days (minimum of one weekend day) using 3 standardized methods simultaneously. Total body movement was assessed by the Caltrac accelerometer and the University of Cincinnati Motion Sensor (UCMS). The Caltrac measured movement in the vertical plane; the UCMS measured movement of 10 degrees or more from the horizontal plane. The type and intensity of daily physical activity was measured by the 3-day activity record, which also recorded the number of hours of daily sleep. Participation and duration of involvement in organized sports was ascertained by questionnaire.
Results: The mean physical activity was significantly lower in JRA patients than in controls for the activity diary (P = 0.05). However, daily body movement measured by the Caltrac and UCMS were similar for both groups. Differences were seen in the number of hours of sleep per day (P = 0.02) and participation in strenuous activities (P < 0.01). JRA patients had significantly less participation in organized sports (P = 0.01).
Conclusion: There was less daily physical activity by this group of JRA patients than for healthy age- and sex-matched control subjects.