The effect of concentrating periods of physical activity on the risk of injury in organized sports in a pediatric population.

BACKGROUND

The trend in pediatric sport organizations is to regroup activities into tournaments. Sports-related injuries in children are a public concern.

OBJECTIVE

To evaluate the association between sport injuries and consolidation of physical activity in children.

DESIGN

A case-crossover study.

SETTING

The emergency department of a tertiary care hospital for approximately 1 year in 2006.

PARTICIPANTS

Eligible participants had to be between 8 to 16 years of age, presenting to the emergency department for an acute injury that occurred during a timed organized sport event.

ASSESSMENT OF RISK FACTORS

A standardized questionnaire was used to evaluate the number of hours of organized physical activity, which was defined as a supervised exercise leading to competitions. The number of hours of activity was compared between case periods (48 hours and 7 days) and control periods of same length.

MAIN OUTCOME MEASUREMENTS

An injury was defined as any acute problem with organic tissue that occurred during a sport.

RESULTS

On average, participants performed 136 minutes of organized sport activity in the 48 hours preceding the injury for a mean difference of 8 +/- 18 min. They also performed 356 minutes of organized sports in the 7 days prior the injury. This represented an increase of 40 +/- 31 minutes compared to the control periods.

CONCLUSIONS

More injuries were observed if the athletes had increased the concentration of activity in the 7 days prior. Although small, this difference reflected a minor clinical effect. In our study, we failed to disclose an association for the period of 48 hours.