Foot bearing pressure in patients with unilateral diabetic foot ulcers

Foot ulceration due to neuropathy is a serious cause of morbidity in diabetes. Ulceration usually occurs at the part of the foot subjected to excessive mechanical pressure. A more generalized increase in pressure under the feet has also been shown to be a feature of many patients with diabetic neuropathy. In this study the electrodynogram was used to measure the pressure at seven positions under each foot. The maximum vertical foot bearing pressure was found to be higher in 11 diabetic patients with previously healed unilateral foot ulcers (10.6 +/- 5.9 kg cm-2) than in 11 diabetic patients who did not have such a history (4.2 +/- 1.3 kg cm-2). However there was no difference in pressure between the foot with previous ulceration and the contralateral foot (9.7 +/- 6.8 kg cm-2, 11.6 +/- 7.9 kg cm-2). Vertical foot bearing pressure was decreased by an average of 18% by wearing shoes padded with a Professional Protective Technology insole and the decrease was greater in patients with higher foot pressure. These results showed that increased vertical foot pressure is an important, but not the only, factor in determining the occurrence of foot ulcer.