FRONTAL PLANE LANDING MECHANICS AND GLUTEUS MEDIUS MUSCLE ACTIVITY IN INDIVIDUALS RETURNED TO SPORT POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Abstract

Knee injuries, particularly to the anterior cruciate ligament (ACL), are common and can negatively impact joint health. These injuries often occur during high-impact movements, such as landing from a jump. While jump landings are used in rehabilitation and return-to-sport protocols, current assessments lack sensitivity in identifying individuals at risk. This thesis investigated differences in peak frontal plane projection angle (FPPA) and gluteus medius (GMed) activity during single-leg landings, as well as the relationship between FPPA, GMed activity, and hip abductor strength. Twenty-five individuals post-ACL reconstruction (ACLR) and 25 asymptomatic controls performed single-leg drop landings and maximal voluntary isometric contractions. No significant differences in peak FPPA were found between groups, but the affected limb in the ACLR group showed greater FPPA than the unaffected limb. No group differences were observed in GMed activity. However, lower GMed activity and hip abductor strength were significantly associated with greater FPPA.