Search Results (2)

Knee post-traumatic osteoarthritis (PTOA) often develops in younger populations following anterior cruciate ligament (ACL) rupture, accounting for 12% of all symptomatic osteoarthritis (OA). The current literature implicates gait asymmetry in late-stage knee OA progression; however, early-knee PTOA development involvement is ill defined. This study explored gait asymmetry involvement in early-stage knee PTOA following ACL ruptures. Gait asymmetry, measured as asymmetry in duty factor (relative contact time), and joint loading data were collected, using infrared-camera motion capture and Kistler force plates for participants exhibiting either historical ACL ruptures (ACL+; n = 4) or no previous joint trauma (ACL−; n = 11). Joint loading measures included external knee adduction moment (EKAM) and external knee flexion moment (KFM), early (peak 1; EKAMp1 and KFMp1) and late (peak 2; EKAMp2 and KFMp2), stance peaks (Nm/kg), and respective time integrals (Nm·ms/kg; iEKAMp1, iEKAMp2, iKFMp1, and iKFMp2). ACL+ exhibited greater asymmetrical duty factor (78% difference) and greater joint load differences: EKAMp1 (26%), EKAMp2 (49%), KFMp1 (37%), iKFMp1 (44%), and iKFMp2 (60%). Significant relationships were found between duty factor asymmetry and both KFMp2 (R² = 0.665) and iKFMp2 (R² = 0.504). These preliminary data suggest gait asymmetry-induced joint loading may contribute to knee PTOA progression, but further research with increased sample sizes and the quantitative assessment of cartilage status is required. Full article

We investigated the effects of hindfoot and forefoot eversion on the knee’s positional and rotational displacement, plantar pressure, and foot discomfort in a standing posture, beyond the traditional focus on external knee adduction moments (EKAM) in lateral wedge insoles. Twenty-six healthy participants underwent hindfoot eversion from 0 to 10 degrees in 2-degree increments, and forefoot eversion from 0 degrees to the hindfoot eversion angle in 2-degree increments in a standing posture. At each eversion angle, the knee’s medial displacement, EKAM’s moment arm decrease, plantar pressure changes, and foot discomfort were obtained and compared across varying angles. Both hindfoot-only and entire-foot eversion led to significant medial knee displacement and the EKAM’s moment arm decrease, with more pronounced effects in entire-foot eversion. At each hindfoot eversion angle, increasing forefoot eversion resulted in significant medial knee displacement and EKAM’s moment arm decrease. Lower leg rotations were not significantly affected in hindfoot-only eversion but displayed significant medial tilting and internal rotation in entire-foot eversion at specific combinations. Varying eversion angles significantly influenced the forefoot pressure, with heel pressure remaining unaffected. Notably, the lateral forefoot pressure increased significantly as the forefoot eversion angle increased, particularly at higher hindfoot eversion angles. Foot discomfort increased significantly with higher eversion angles, particularly in entire-foot eversion, and also increased significantly as the forefoot eversion angle increased at higher hindfoot eversion angles. Insole configurations incorporating 6–10 degrees of hindfoot eversion and 40–60% forefoot eversion of the hindfoot angle may offer optimized biomechanical support for knee osteoarthritis patients. Full article