Abstract
Evaluating WB status during normal knee flexion activities is important for optimizing surgical procedures and postoperative rehabilitation. This study aimed to clarify the effects of weight-bearing (WB) on in vivo knee kinematics and cruciate ligament forces in normal knees. Fluoroscopic imaging in the sagittal plane was used while volunteers performed squatting and active-assisted knee flexion. Tibiofemoral kinematics were measured using a two-dimensional/three-dimensional registration technique. Forces in the anterior cruciate ligament (anteromedial/posterolateral; aACL/pACL) and the posterior cruciate ligament (anterolateral/posteromedial; aPCL/pPCL) were analyzed. Anteroposterior translation (APT) of low contact points (LCPs) in WB and non-weight-bearing (NWB) conditions showed no anterior translation from extension to mid-flexion. The medial APT of LCPs in the NWB was more posterior than in WB. Medial stabilized articular surface and/or a surgical technique may help restore native knee kinematics across WB conditions.