Habitual physical inactivity risks activity-related injuries in children
MedWire News: Children who do not take part in regular physical exercise are more likely to sustain injuries when they do engage in activities than their peers who exercise more frequently, study results show.
The findings are of special importance, say the researchers, because these vulnerable children are the target audience for physical education (PE) promotion and therefore efforts should also focus on injury prevention.
Compared with adults, the risk for children for injury resulting from participation in sports and free play is low. Nevertheless, these injuries pose a substantial individual socioeconomic burden.
"More importantly, children may lose their enthusiasm for healthy activities and sports through negative associations with injury," Evert Verhagen (VU University Medical Center, Amsterdam, the Netherlands) and colleagues comment in the British Journal of Sports Medicine.
In order to inform preventive measures, there is need for an injury epidemiology describing the burden and etiology of injuries.
The researchers therefore conducted a prospective cohort study in 995 children aged 9-12 years, recording injuries occurring during either PE class, leisure time physical activity (PA), or sports that caused the child to at least stop the current activity.
Individual weekly exposure was estimated from baseline and follow-up questionnaires. Potential risk factors considered in the study were gender, age, socioeconomic status, ethnicity, habitual level of PA, body mass index, and motor fitness.
During the school year, a total of 119 injuries were reported by 104 children, resulting in an overall injury incidence density (IID) of 0.48 per 1000 hours of exposure.
In terms of the different modalities of activity, incidence was lowest for leisure time PA (IID=0.39), followed by PE (IID=0.50), and sports (IID=0.66).
Multivariate regression analysis revealed that overall injuries were predicted by gender, age, and weekly exposure.
Specifically, girls were at higher risk for any injury than boys (hazard ratio [HR]=1.60) and injury risk increased as age increased to 12 years (relative to 9 years; HR=2.62).
Most notably, injury risk significantly declined with an increase in weekly exposure with the most active quartile of children having the lowest injury risk (HR=0.03).
For specific activity modalities, sports-related injuries were significantly increased with age (12 years relative to 9 years; HR=7.17). For leisure time PA, none of the variables were significant risk factors for injury.
Discussing the findings, Verhagen et al note that the gender findings contradict what is generally reported in the literature.
"Even though this study is the first to find these gender differences in such a pronounced way, Sorensen et al previously indicated that gender differences in injury risks 'cross over' between ages 12 and 14 years… presumably due to the growth spurt appearing earlier in girls."
In conclusion, they comment: "Our results indicate that the prevention of PA-related injuries should be an essential part of PA promotion in youth."
By Andrew Czyzewski