Lower limb kinematics differ at the time of foot contact between successful and unsuccessful single limb landings following anterior cruciate ligament reconstruction

Abstract Objectives To investigate differences in lower extremity kinematics at initial ground contact between successful and unsuccessful single limb landings following anterior cruciate ligament (ACL) reconstruction. Design Observational study. Setting Controlled laboratory environment. Participants 22 male participants (aged 17–40 years) who had undergone unilateral ACL reconstruction attended a single test session. Main outcome measures Within-subjects comparisons was performed for pelvis, hip, knee and ankle kinematics using paired t-tests. Results When unsuccessful at landing on the ACL reconstructed limb, participants had significantly increased knee flexion (P = 0.04) and reduced ankle plantarflexion (P = 0.03) compared to their successful landings. In contrast, when unsuccessful at landing on the unaffected limb, participants had significantly increased pelvic contralateral hitch (P  Conclusion Body position at the time of initial contact was different for landings that were successful compared to landings that were unsuccessful. These differences were limb-specific: altered position in sagittal plane preceded unsuccessful landings on the reconstructed limb whereas altered position in the coronal plane body position that preceded unsuccessful landings on the unaffected limb. These findings suggest that limb specific landing strategies may be required to improve athletes’ performance following ACL reconstruction. Level of evidence IV.