Effect of rocker-sole footwear on knee joint biomechanics while walking in people with ACL-reconstructed knees: a cross-sectional biomechanical study

Abstract

Background: Reinjury has occurred at a high rate after anterior cruciate ligament (ACL) reconstruction. Low knee flexion angles and high peak posterior ground reaction forces in landing tasks increase ACL loading. Some studies reported that rocker-sole shoes increased knee flexion angle in the early stance phase of the gait. The aim of this study was to investigate the biomechanics of walking with a custom-made heel-to-toe rocker shoe design, with special attention to the sagittal knee joint kinematics of patients after ACL reconstruction. Methods: This study examined 10 male participants with ACL-reconstruction participants. Three-dimensional gait analysis was performed under two conditions of level walking that were tested in random order using either modified footwear adapted with a heel-to-toe rocker sole or baseline footwear with a flat sole. The knee flexion angle at initial foot contact with the ground, average knee flexion angle from heel strike to 25 stance phase, and first peak knee flexion angle were compared across footwear conditions. Results: Walking with the heel-to-toe rocker shoes increased the knee flexion angle at the early stance phase of the gait cycle when compared with the baseline footwear. Conclusions: Rocker-shoe intervention was found to have potential as a rehabilitation tool to modify gait patterns in the sagittal plane of people with ACL-reconstructed knees and may protect against high reinjury rates. Further research is required to evaluate whether prolonged wear of rocker-sole shoes can modify lower extremity biomechanics of participants who have undergone ACL reconstruction.