Abstract

Females and males are at risk for ACL injuries and are shown to benefit from injury-prevention programs. An ACL injury sustained during childhood or adolescence is associated with an increase in morbidity, including early development of osteoarthritis, long term disability, and chronic pain. That the incidence of ACL injuries in children is higher in females when compared with males suggests that the pre-pubertal and pubertal period of growth and motor development may be a significant factor in injury risks related to the ACL. Unfortunately, very few studies have looked at situations that might contribute to injury and prevention of lower extremity injury in children. To determine potential injury risk, it is important to examine the activity and recruitment order of lower limb muscles to target deficiencies that can be addressed with IPPs. Female and male children participants were recruited from sports teams and organizations in Montreal, QC. Data was collected using the Noraxon DTS EMG, and a goniometer. Participants were asked to maintain balance on their non-dominant leg during unexpected perturbations in the lateral, posterior, and rotational motions as well as a combination motion that mimics an ACL injury mechanism. Our results show that differences exist between males and females 8-12 years old. For both sexes, muscle activation patterns previously identified as predisposing factors to ACL injuries were found, which suggests that injury prevention programs are of value to implement and study in this age group.