Impact of Race, gait speed and arch height on plantar loading

Diabetes is a leading cause for death in the United States, with African Americans (AA) being twice as likely to die from diabetes than White Americans (WA). AA are twice as likely to experience diabetes-related foot amputation due to foot ulcers, which are most often caused by high plantar pressure. While it is known that arch height, sex, family history of diabetes, Body Mass Index (BMI), age, and gait speed can impact plantar loading, there is a need to test the hypothesis that race in combination with the previously mentioned variables are significant predictors of plantar loading. To answer this question, plantar loading data was collected from 107 participants using an EMED pressure-measurement system (Novel Electronics, Inc, St Paul, MN, USA). Each participant walked barefoot at a self-selected walking pace ten times. Contact area, maximum force, and were force-time integral collected for each step on the pressure plate. A multiple linear regression was used to test if race, age, Arch Height Index (AHI), gait speed, sex assigned at birth, family history of diabetes, and BMI significantly predicted plantar loading. Race, age, AHI, gait speed, sex, and BMI were considered significant predictor variables for plantar loading. Most importantly, race was a significant predictor of maximum force in the hallux (β = 6.46, p < 0.001), rearfoot (β = -6.36, p < 0.001), and lateral midfoot (β = -2.72, p < 0.001), and the force-time integral in the hallux (β = 2.37, p < 0.001), rearfoot (β = -2.14, p < 0.001), and lateral midfoot (β = -0.65, p < 0.001). These findings could help with understanding why AA are more likely to develop diabetic foot ulcers than WA.