Prevention Programs: Hip Angle Behaviour in Landing after Drop Jump in Children

Background: The Anterior Cruciate Ligament (ACL) injury is uncommon, but constitutes an important percentage of the lesions requiring more than 8 weeks of recovery in sports. Most ACL injuries do not require external contact and are associated with biomechanical risk factors that stress this ligament ACL: like an increase in knee valgus an- gle (KV) and hip flexion (HF) and a decreased in knee flexion (KF). The ACL requires muscle cooperation to resist the load; however, when there is fatigue, the protective capacity of the musculature would decrease.

Objectives: The objective of the study is to analyze the angular behavior before and after a physical load for HF in children of 14-15 years old

Hypothesis: The physical load applied in a single training session is enough to change some biomechanical risk factors of ACL injury.

Study Design: Experimental study.

Level of Evidence: 2b.

Methods: The sample consisted of 50 students from different soccer schools between 14-15 years old. We analyzed the hip angular behavior of hip flexion before and after a training session. The angles where obtained from inertioal sensor while the students performed a Drop Jump test from a 30 centimeters drawer.

Results: Statistically significant differences were found in the differences between pre physical load HF / post-load HF (p = 0.00053), right pre physical load HF / right post- load HF (p = 0.0086) and left post- load (p = 0.0248206).

Conclusions: It was concluded that the angular behavior of HF increases significantly in both post-training limbs, after performing a physical load.

Clinical Relevance: This study analyzed the importance of using prevention injury programs since early stages, and give importance to the eccentric role of hamstring, gluteus and core exercises.