Factors contributing to racial differences in gait mechanics differ by sex.

BACKGROUND

Racial differences in gait mechanics have been recently reported, but we don't know what factors may drive differences in gait and whether these factors are innate or modifiable. The answers to those questions will inform both basic research and clinical interventions and outcomes.

RESEARCH QUESTION

Do anthropometric, strength, and health status measures explain racial differences in gait between African Americans (AA) and white Americans (WA)?

METHODS

Venous blood samples, anthropometric measures, lower extremity strength, and an assessment of health status were collected from 92 participants (18-30 years old) as part of an Institutional Review Board-approved study. 3D motion capture and force plate data were recorded during 7 walking trials at set regular (1.35 m/s) and fast (1.6 m/s) speeds. Racial differences in gait were identified at both speeds. Correlations between anthropometric, strength, and health status independent variables and outcome measures were computed after stratifying data by sex. Stepwise linear regression models evaluated whether the inclusion of anthropometric, strength, and health status independent variables explained racial effects.

RESULTS

In males, no racial differences in gait were explained by independent variables. Q-angle and ankle dorsiflexion strength accounted for racial differences in self-selected walking speed in females. Racial differences in ankle plantarflexion angle were explained by ankle plantarflexion strength differences.

SIGNIFICANCE

Factors that explain racial differences in gait in females were both innate and modifiable. These data make clear that it is important to include racially diverse normative gait databases in research studies. These results also identify potential intervention targets aimed at reducing racial health disparities.