The role of skin hardness, thickness, and sensory loss on standing foot power in the development of plantar ulcers in patients with diabetes mellitus--a preliminary study

Abstract

This article presents the results of a study on patients with diabetic neuropathy to find the relationships between the foot pressures characterized by power ratio (PR), foot sole hardness (Shore values), and foot sole soft tissue thickness. The results showed that the increase in PR values for diabetic patients in the upper sensation loss levels (S = 7.5 to 10 g) compared to the corresponding increase in lower sensation loss (S=3 to 4.5 g)were of the order of 5 times in the lateral heel and big toe, respectively, and 4 times in the first metatarsal head regions. The increase in PR values for diabetic patients in the upper Shore value regions (30 to 40) compared to the corresponding increase in lower Shore value regions (20 to 30) were of the order of 3.4 times in lateral heel and 2.4, 2.0, and 2.3 times in the first, second, and lateral metatarsal head regions, respectively. At sites contiguous to frank ulcers for foot sole hardness (Shore values of 50) at sensation level > 10 g PR was as high as 59, and foot sole thickness values were also greater than the corresponding normal values. The study shows all measured parameters may play a part in the development of plantar ulcers.