An examination of plantar pressure measurements to identify the location of diabetic forefoot ulceration

The purpose of this study was to evaluate pressure-time parameters on the sole of the foot in order to predict sites of pathology in diabetics. Mid-gait walking steps from 36 subjects diagnosed with diabetes and ulceration to the forefoot were analyzed using the Pedar in-shoe pressure analysis system. The time that weight was loaded on the hallux and lesser digits was found to be significantly shorter on the feet with ulceration compared to those without. A combination of five pressure measure reports could significantly differentiate between the three common locations of forefoot ulcerations. The significant pressure measure reports were the pressure-time integral measured over the whole foot and pressure-time integral and peak pressure measured separately at the first and combined lesser metatarsophalangeal joint regions. A preliminary model was developed using discriminate analysis that was accurate to 72.7% in identifying the location of the subjects' ulceration. Sensitivity and specificity formulas were calculated to demonstrate the diagnostic value of the model. The model accurately identified ulceration locations to a sensitivity of 83% and a specificity of 69%. Further refinement and testing is underway to refine the model to develop a screening tool to identify the site of potential foot ulceration and to prevent it and its sequelae of lower limb ulceration in the diabetic population.