Physical activity in children with juvenile rheumatoid arthritis: quantification and evaluation

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.

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.

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).

There was less daily physical activity by this group of JRA patients than for healthy age- and sex-matched control subjects.