Quantifying the Association Between Physical Activity and Injury in Primary School–Aged Children

Abstract

BACKGROUND. Regular physical activity is strongly advocated in children, with recommendations suggesting up to several hours of daily participation. However, an unintended consequence of physical activity is exposure to the risk of injury. To date, these risks have not been quantified in primary school–aged children despite injury being a leading cause for hospitalization and death in this population. OBJECT. Our goal was to quantify the risk of injury associated with childhood physical activity both in and out of the school setting and calculate injury rates per exposure time for organized and non–organized activity outside of school. METHODS. The Childhood Injury Prevention Study prospectively followed a cohort of randomly selected Australian primary school–and preschool-aged children (4 to 12 years). Over 12 months, each injury that required first aid attention was registered with the study. Exposure to physical activity outside school hours was measured by using a parent-completed 7-day diary. The age and gender distribution of injury rates per 10 000 hours of exposure were calculated for all activity and for organized and non–organized activity occurring outside school hours. In addition, child-based injury rates were calculated for physical activity–related injuries both in and out of the school setting. RESULTS. Complete diary and injury data were available for 744 children. There were 504 injuries recorded over the study period, 396 (88.6%) of which were directly related to physical activity. Thirty-four percent of physical activity–related injuries required professional medical treatment. Analysis of injuries occurring outside of school revealed an overall injury rate of 5.7 injuries per 10000 hours of exposure to physical activity and a medically treated injury rate of 1.7 per 10000 hours. CONCLUSION. Injury rates per hours of exposure to physical activity were low in this cohort of primary school–aged children, with <2 injuries requiring medical treatment occurring for every 10000 hours of activity participation outside of school.