Abstract
Context: Gait biomechanics and daily steps are important aspects of knee-joint loading that change after anterior cruciate ligament reconstruction (ACLR). Understanding their relationship during the first 6 months post-ACLR could help clinicians develop comprehensive rehabilitation interventions that promote optimal joint loading after injury, thereby improving long-term knee-joint health. Objectives: To compare biomechanical gait waveforms throughout stance at early time points post-ACLR in individuals with different daily step behaviors at 6 months post-ACLR and to examine how these gait waveforms compare with those of uninjured controls. Design: Case-control study. Setting: Laboratory. Patients or Other Participants: A total of 32 individuals with primary ACLR assigned to the low-step group (LSG; n = 13) or the high-step group (HSG; n = 19) based on their average daily steps at 6 months post-ACLR and 32 uninjured matched controls. Main Outcome Measure(s): Gait biomechanics were collected at 2, 4, and 6 months post-ACLR for the ACLR groups and at a single session for the control group. Knee-adduction moment, knee-extension moment (KEM), and knee-flexion angle (KFA) waveforms were calculated during gait stance and then compared via functional waveform analyses. Mean differences and corresponding 95% CIs between groups were reported. Results: Primary results demonstrated less KFA (1%–45% versus 79%–92% of stance) and greater KEM (65%–93% of stance) at 2 months and greater knee-adduction moment (14%–20% versus 68%–92% of stance) at 4 months post-ACLR for the HSG compared with the LSG. Knee-adduction moment, KEM, and KFA waveforms differed across various proportions of stance at all time points between the step and control groups. Conclusions: Differences in gait biomechanics were present at 2 and 4 months post-ACLR between step groups, with the LSG demonstrating an overall more flexed knee and more profound stepwise underloading throughout stance than the HSG. The results indicate a relation between early gait biomechanics and later daily step behaviors post-ACLR.

This publication has 48 references indexed in Scilit: