Purpose: This 3-year prospective study assessed risk factors for noncontact anterior cruciate ligament (ACL) injuries in female Japanese high school basketball players. Players suffering noncontact ACL injuries were assumed to demonstrate poorer hip abductor, knee flexor, and knee extensor muscle strength, as well as static balance, than those without injuries.
Methods: One hundred and ninety-five new female high school basketball players underwent baseline examinations for various parameters during their first year of high school. After the baseline data were collected, all ACL injuries occurring over the subsequent 3 years were recorded. The assessment parameters between the noncontact ACL injury group and the control group were compared.
Results: Of the 195 players, 24 were excluded due to pre-existing injuries present during the initial examination, quitting the basketball club during the follow-up period, or missing data. The remaining 171 players were observed for 3 years; unilateral noncontact ACL injuries were occurred in 12 players. Significantly lower general joint laxity and greater hip abductor strength were observed in the ACL injury group than in the control group. Body mass index (BMI) and hip abductor strength were significantly greater in the ACL injury group than in the control group, based on logistic regression analysis.
Conclusions: Greater BMI and hip abductor muscle strength were independent risk factors for noncontact ACL injuries in female Japanese high school basketball players. Although performing complete screens may be difficult, attention should be given to ACL injuries, particularly in highly competitive players with strong muscles.
Level of evidence: III.
Keywords: Anterior cruciate ligament injury; Body mass index; Female; Hip abduction muscle; Japanese high school basketball players; Noncontact.