Dynamic plantar pressure measurement in 49 patients with diabetic neuropathy with or without foot ulcers

Abstract

Summary We compared plantar pressures under selected areas of the foot in 49 diabetic patients with neuropathy using the F-scan system — in their own shoe (with and without an insole), in a jogging shoe (with and without an insole) and in an extra depth orthopaedic shoe with a small metatarsal bar. Patients with current or previous plantar ulcers ( n =30) were compared to those with no such history ( n =19). There was very little decrease in plantar pressure between the patients' shoes and the jogging shoes, although non-ulcer patients put more weight on the lateral toes and more on the medial side after adjustments. In most cases the orthopaedic shoe increased pressure under the forefoot significantly. Large standard deviations between patients made comparisons between groups impossible. Integrated peak pressure values were not often significantly different from peak pressure values alone, suggesting some compensation of pressure by time. Standard extra depth shoes did not give the reduction of pressure anticipated. Close attention must be paid to the location of the bar. The reliability of the F-scan system allows for variation of up to 30% between different measurements, and calibration is difficult in these patients; this limits its use in scientific studies. The accuracy is adequate for visual appraisals of changes in pressure.