Reliability and limitations of the durometer and PressureStat to measure plantar foot characteristics in Native Americans with diabetes.

Neuropathy with excessive weight-bearing activity may lead to foot changes that place it at risk for ulceration. Information about instruments to measure plantar skin hardness and pressures of the foot in adult Native Americans with diabetes is presented. Skin hardness was measured at 10 sites (plantar side of the hallux, third and fifth toes, first, third, and fifth metatarsal heads, medial and lateral midfoot, heel, and the dorsal aspect between the hallux and second toe) with a durometer. The PressureStat yielded data about barefoot, static pressures. The durometer was shown to be reliable (r = .62 to .91) at all sites of the foot except at the third and fifth toe, the medial midsection of both feet, and at the third metatarsal head and between the hallux and second toe, the dorsal aspect of the left foot. With four raters, concordance was found to be acceptable at the hallux, the third toe, the first, third, and fifth metatarsal heads and the heel (W = .61 to .86) for the PressureStat. Since most diabetic foot ulcers occur at the hallux, first, third, and fifth metatarsal heads, both the PressureStat and durometer may be reliable screening tools to determine the degree of risk.