Plantar pressure distribution patterns during gait in diabetic neuropathy patients with a history of foot ulcers

OBJECTIVE: To investigate and compare the influence of a previous history of foot ulcers on plantar pressure variables during gait of patients with diabetic neuropathy. INTRODUCTION: Foot ulcers may be an indicator of worsening diabetic neuropathy. However, the behavior of plantar pressure patterns over time and during the progression of neuropathy, especially in patients who have a clinical history of foot ulcers, is still unclear. METHODS: Subjects were divided into the following groups: control group, 20 subjects; diabetic neuropathy patients without foot ulcers, 17 subjects; and diabetic neuropathy patients with at least one healed foot ulcer within the last year, 10 subjects. Plantar pressure distribution was recorded during barefoot gait using the Pedar-X system. RESULTS: Neuropathic subjects from both the diabetic neuropathy and DNU groups showed higher plantar pressure than control subjects. At midfoot, the peak pressure was significantly different among all groups: control group (139.4±76.4 kPa), diabetic neuropathy (205.3±118.6 kPa) and DNU (290.7±151.5 kPa) (p=0.008). The pressure-time integral was significantly higher in the ulcerated neuropathic groups at midfoot (CG: 37.3±11.4 kPa.s; DN: 43.3±9.1 kPa.s; DNU: 68.7±36.5 kPa.s; p=0.002) and rearfoot (CG: 83.3±21.2 kPa.s; DN: 94.9±29.4 kPa.s; DNU: 102.5±37.9 kPa.s; p=0.048). CONCLUSION: A history of foot ulcers in the clinical history of diabetic neuropathy subjects influenced plantar pressure distribution, resulting in an increased load under the midfoot and rearfoot and an increase in the variability of plantar pressure during barefoot gait. The progression of diabetic neuropathy was not found to influence plantar pressure distribution.

The evolution and biomechanics of the human foot - applied research for footwear

The onset of mankind is associated with the development from quadrupedal to bipedal locomotion, freeing our hands to use tools and thus structuring our brain towards complex intellectual capabilities. During the evolution of mankind over the span of several hundred millions years the human foot was gradually formed from the fins of early fish to an efficient load bearing structure for standing, walking, running, and jumping. The flexible foot anatomy with 26 bones, numerous ligaments and muscles allows an active adaptation of this biomechanical structure to uneven surfaces during locomotion. The human foot guarantees a stable support to the body, attenuates potentially harmful impact shocks, and provides sensory information about the contact with the ground. Early footwear was born of the necessity to provide protection when moving over rough terrain in varying weather conditions. The function of modern casual and athletic footwear is to provide comfort and protection of the body during various everyday and sports activities. Foot anatomy of men and adults. Additional body weigth in obese patients and the loss of sensory function in diabetic and neuropathic feet require special shoes to prevent pressure sores and guarantee mobility. Pressure distribuition measurement techniques are useful in analysing the mechanical behaviour of the human foot during static and dynamic loading situations in adults, children and patient groups. The understanding of foot biomechanics and the specific demands of everyday and sports activities are essential in the design of adequate footwear. Biomechanical testing of athletic footwear is necessary to inform consumers about injury preventive and performance related properties of commercially available sport shoes.