Injury risk during different physical activity behaviours in children: a systematic review with bias assessment.

INTRODUCTION The current focus on a physically active lifestyle in children puts children at increased physical activity-related injury risk. OBJECTIVE To summarise, in a systematic review, the evidence for the injury risk of several physical activity behaviours in 6- to 12-year-old children. METHODS An electronic search was performed in three databases (Embase, PubMed and SPORTDiscus). Inclusion criteria were: age 6-12 years; report on injuries related to overall physical activity, active commuting, unorganised leisure time physical activity, physical education and/or organised sports; incidence rates expressed as injuries per hours of physical activity; and published after January 1st 2000. Risk of bias was assessed for all studies included. RESULTS Eight studies were included. The risk of bias assessment resulted in two studies with a score that was higher than 75 %; risk bias of those two studies was considered low. The medically treated, injury incidence rate was reported to be between 0.15 and 0.27 injuries per 1,000 h of physical activity. The absolute number of injuries related to unorganised leisure time physical activity was higher than the absolute number of injuries reported in organised sports. The respective injury incidence rate expressed per 1,000 h exposure was, however, generally lower during unorganised leisure time than during organised sports. Reported injury incidence rates related to active commuting were comparable to those for unorganised leisure time physical activity. Conflicting injury incidence rates were reported for physical education. Subgroup analysis suggested that girls and children with low habitual levels of physical activity are at increased injury risk. A limitation of the review is that no standard bias assessment was available for this specific context. CONCLUSIONS Children are at an inherent injury risk while participating in physical activities. Most injury prevention efforts have focussed on the sports setting, but our results suggest that many children sustain an injury during unorganised leisure time physical activities.