Racial differences in gait mechanics associated with knee osteoarthritis

Background and aims: This study examines racial differences in gait mechanics in persons with knee osteoarthritis and the influence of anthropometrics, educational level, radiographic disease severity (rOA), and self-report measures of pain and disability on racial differences in gait. Methods: One hundred seventy five (64 black and 111 white) adults with radiographie knee OA were tested. 3-D kinematic and kinetic data were collected while subjects walked at two self-selected speeds (normal and fast). Anthropometrie data, radiographie level of OA, and self-report measures of pain and disability were also collected. Gait patterns were compared across groups and within groups. Results: Black and white subjects did not differ significantly in radiographie OA. However, blacks walked significantly more slowly when asked to walk fast. At the normal speed, blacks had a smaller knee range of motion and loading rate than whites. Blacks also took longer to reach their peak maximum ground reaction force than whites. Within black subjects variations in gait mechanics were primarily explained by BMI, rOA, self-reported psychological disability, and pain self-efficacy. In white subjects, variations in gait mechanics were primarily explained by weight, age, velocity, psychological disability, and self-efficacy. Conclusions: Blacks in this study had a pattern of gait mechanics generally associated with high levels of osteoarthritis, though they did not differ significantly in rOA from whites. The variability in gait patterns exhibited by blacks was most strongly related to variance in walking speed, anthropometries, and perceived physical ability. Taken together, these results suggest that race is an important factor that must be considered in the treatment and study of osteoarthritis.