The impact of callosities on the magnitude and duration of plantar pressure in patients with diabetes mellitus. A callus may cause 18,600 kilograms of excess plantar pressure per day.

The importance of high peak plantar pressure (PP) in the development of foot ulcer is well known. However, few studies have analyzed the real impact of callosities on plantar pressure and ulcer formation.The plantar pressure (PP) in patients with diabetes mellitus was studied in three groups, of a total number of 33 type 2 diabetic patients, without neuropathy or peripheral vascular disease: subjects with callus (A) (n = 10), subjects without callus (B) (n = 10), and a separate group of patients with callus which was submitted to callus removal (C) (n = 13). The plantar pressure (PP) parameters were measured by FSR 174 sensors and computer analyses were performed by LabView.Both maximum peak PP and duration of PP are significantly higher in patients with callus (peak PP: 314 +/- 52 kPa vs 128 +/- 16 kPa, p < 0.005; duration of PP: 621 +/- 27 ms vs 505 +/- 27 ms, p < 0.05). The intervention group C before and after callus removal showed an identical trend. Callus removal has decreased the peak PP by 58% (p < 0.001) and duration of PP has been decreased by 150 milliseconds by step (p < 0.05).This study has shown the deleterious role of callus and assuming that an average person walks about 10,000 steps a day, a callus may cause 18,600 kg of excess plantar pressure per day. In addition, this study has proven the importance of early and regular removal of hyperkeratotic tissue. Even more aggressive removal could be recommended in patients with neuropathy and peripheral vascular disease.