[Effect of sports training in angular compartment of the lower limbs in children footballers aged 11 to 12 years old].

Anterior Cruciate Ligament (ACL) injury is an important cause of days lost in athletes. Most ACL injuries are non-contact and are associated with biomechanical risk factors that increase tension in the ACL: increased knee valgus (KV) and hip flexion (HF) and decreased flexion of knee (KF). Muscle around the knee contributes to knee stability, so fatigue produced by exercise could alter knee balance, increasing LCA tension. The aim of the study is to determine the angular behavior before and after a physical load for CF, RR and RV in children born in 2002-2003. A non-randomized clinical trial was conducted. The sample consisted of 50 students from soccer schools born between 2002 and 2003. The angular behavior of CF, RR and VR was compared, before and after performing standardized training. The angular behavior was measured by performing the DJ test with data obtained by inertial sensors. After exercise, the 3 variables increased, but only HF reached significant difference. Other important finding was the difference found in KV between the dominant leg and the support limb, at both times: rest and post exercise. It was concluded that the angular behavior of CF increases significantly in both limbs post-exercise and that preventive measures should be applied for the management of valgus in the supporting limb.