Biomechanical Demand during 90° and 135° Cutting Manoeuvres: Implications for Anterior Cruciate Ligament Injury

Background: Anterior cruciate ligament (ACL) injuries in athletes have financial and health consequences and are considered career-threatening. The current study aimed to shed light on biomechanical differences between various change of direction (COD) manoeuvres. Understanding such differences is important, given their association with the incidence of non-contact ACL injuries. Methods: Thirty-six male recreational soccer players participated and performed 90° and 135° COD manoeuvres. For gait analysis, the Vicon system was used. The speed and shoe-surface interface were standardized in the COD manoeuvres. Paired sample t-tests were used to compare conditions. Results: A Greater peak external knee abduction moment (PEKAM) (p<0.001) and knee abduction angle at initial contact (IC) (p<0.001) in the 135° COD manoeuvre compared to the 90° COD manoeuvre were observed, highlighting the increased injury risk potential at greater COD angles. In addition, the hip sagittal plane range of motion (RoM) from IC to peak knee valgus angle was higher in the 135° COD manoeuvre than 90° COD manoeuvre (p<0.001). Conclusion: The results of the current study support the idea that ACL biomechanical risk factors are angle-dependent. A sharper cutting angle showed a higher risk of ACL injury due to the increase in the PEKAM and the knee abduction angle at initial contact. Therefore, players should be trained to reduce high PEKAM and the knee abduction angle by using different strategies.