Racial differences in gait mechanics.
The effect of race has rarely been investigated in biomechanics studies despite racial health disparities in the incidence of musculoskeletal injuries and disease, hindering both treatment and assessment of rehabilitation. The purpose of this study was to test the hypothesis that racial differences in gait mechanics exist between African Americans (AA) and white Americans (WA). Ninety-two participants (18-30 years old) were recruited with equal numbers in each racial group and sex. Self-selected walking speed was measured for each participant. 3D motion capture and force plate data were recorded during 7 walking trials at regular and fast set speeds. Step length, step width, peak vertical ground reaction force, peak hip extension, peak knee flexion, and peak ankle plantarflexion were computed for all trials at both set speeds. Multivariate and post-hoc univariate ANOVA models were fit to determine main and interaction effects of sex and race (SPSS V26, α = 0.05). Self-selected walking speed was slower in AA (p = 0.004, ƞp2 = 0.088). No significant interactions between race and sex were identified. Males took longer steps (regular: p < 0.001, ƞp2 = 0.288, fast: p < 0.001, ƞp2 = 0.193) and had larger peak knee flexion (regular: p = 0.007, ƞp2 = 0.081, fast: p < 0.001, ƞp2 = 0.188) and ankle plantarflexion angles (regular: p = 0.050, ƞp2 = 0.044, fast: p = 0.049, ƞp2 = 0.044). Peak ankle plantarflexion angle (regular: p = 0.012, ƞp2 = 0.071, fast: p < 0.001, ƞp2 = 0.137) and peak hip extension angle during fast walking (p = 0.007, ƞp2 = 0.083) were smaller in AA. Equivalency in gait measures between racial groups should not be assumed. Racially diverse study samples should be prioritized in the development of future research and individualized treatment protocols.