Forefoot and rearfoot plantar pressures in diabetic patients: Correlation to foot ulceration

In the setting of diabetes mellitus, high plantar foot pressures are an important risk factor and can predict foot ulceration. Most studies have used measurements of peak plantar pressures under the whole foot. The purpose of this study was to evaluate forefoot and rearfoot plantar pressures separately in diabetic patients and examine their validity in predicting foot ulceration. A total of 90 patients were enrolled in a prospective study and were followed up for a mean period of 36 months. All the patients underwent a complete medical history and lower extremity evaluation for neuropathy, vascular status, vibration perception threshold (VPT), joint mobility, and foot pressures. The peak foot pressures under the rearfoot and forefoot were evaluated using the F-scan mot system with patients ambulating without footwear. Significant correlations were Found between forefoot peak pressures and age, height, neuropathy disability score (NDS), vibration perception threshold (VPT), and force applied on the ground during walking. In contrast, reverse correlations were found between rearfoot peak pressures and measurements of neuropathic severity. Binary regression analysis showed a higher risk of foot ulceration in patients with high forefoot pressures (OR 1.15, CI 1.04-1.28, p=0.005), while no association was found for rearfoot pressures (OR 0.99, CI 0.96-1.03, p=NS). We conclude that peak foot pressure measurements of the forefoot but not the rearfoot correlate with neuropathy measurements and con also predict foot ulceration over 36 months. Measurement of forefoot peak pressures rather than the whole foot may therefore be more useful in identifying at-risk patients.