The effect of footwear on walking biomechanics in individuals with anterior cruciate ligament reconstruction.

BACKGROUND

Gait analyses are performed following anterior cruciate ligament reconstruction (ACLR) to identify aberrant biomechanics that accelerate osteoarthritis development. However, it is unclear whether differences in participants' footwear contribute to discrepancies in findings, thus making studies incomparable.

RESEARCH QUESTION: The purpose of this study was to compare ACLR and contralateral limb walking biomechanics while individuals walked barefoot, in lab standard footwear, and in their personal footwear.

METHODS

Thirty-six individuals with primary unilateral ACLR underwent walking assessments while barefoot, in laboratory standard footwear, and in personal footwear. Peak sagittal and frontal plane knee moments and angles, and vertical ground reaction force (vGRF) and its accompanying loading rates (i.e., instantaneous and linear) were evaluated via 2 (limb) x 3 (footwear) repeated measure ANOVAs. Significant main or interaction effects were followed by Bonferroni-corrected paired t-tests.

RESULTS

The ACLR limb displayed smaller sagittal plane moments and angles, larger frontal plane moments, and smaller vGRF compared to the contralateral limb across all footwear conditions. Barefoot walking resulted in smaller frontal plane moments and vGRF but larger vGRF instantaneous loading rate than lab or personal footwear walking. Lab footwear resulted in smaller peak vGRF but larger vGRF instantaneous loading rate than personal footwear. Barefoot walking resulted in smaller vGRF linear loading rate than personal footwear. The ACLR limb displayed smaller vGRF linear loading rate while barefoot compared to the contralateral limb while barefoot and the ACLR limb while in personal footwear.

SIGNIFICANCE: Except for the vGRF linear loading rate, footwear did not differentially influence inter-limb gait biomechanics, thus studies that investigate inter-limb differences but utilize different footwear are comparable. However, the main effects of footwear suggest caution is warranted when comparing biomechanics from studies that utilize different footwear protocols.