Dynamic Foot Pressure and Other Studies as Diagnostic and Management Aids in Diabetic Neuropathy

Abstract

The pressures and loads under the feet during walking have been compared in three groups of 41 patients each, using a microprocessor-controlled optical system. Group A consisted of patients with diabetic neuropathy, group B of non-neuropathic diabetic patients, and group C of nondiabetic controls. Thirteen patients in group A had a history of neuropathic foot ulceration. Other investigations in the diabetic patients included motor conduction velocity (MCV) in the median and peroneal nerves, vibration perception threshold (VPT) in the great toes, the valsalva response (VR), skin resistance (SR), and the ankle pressure index (API). Fifty-one percent of neuropathic feet had abnormally high pressures underneath the metatarsal heads compared with 17% of the diabetic controls and 7% of nondiabetic subjects. All those feet with previous ulceration had abnormally high pressures at the ulcer sites. Of the other investigations, the VPT correlated most significantly with the presence of foot ulceration. In addition, a low median and peroneal nerve MCV, an abnormal VR, a high API, and the absence of sweating all correlated with the presence of foot ulceration. We therefore conclude that simple bedside investigations, such as measurement of the VPT alone, may be useful in identifying those patients at risk of foot ulceration. Foot pressure studies may then be used in such patients as a predictive and management aid by determining specific areas under the foot that are prone to ulceration.

The diabetic foot: from art to science. The 18th Camillo Golgi lecture

“…After our initial confirmation that plantar ulcers invariably occurred at sites of high pressure [35], we demonstrated that foot pressure abnormalities occur early in the natural history of neuropathy [51]. In a longitudinal study it was confirmed that sites of peak pressure change over time, an observation with important implications for orthotists [52].…”

“…The association between both somatic and autonomic neuropathy and foot ulceration has been recognised for many years [35]. It is only in the last decade that prospective follow-up studies have confirmed this causative role of somatic neuropathy [12,18,19].…”

Metatarsal Length does not Correlate with Maximal Peak Pressure and Maximal Force

“…The most increased pressure measurement in one defined region represented the maximal peak pressure. According to previous studies, maximal peak pressure directly correlates with the risk for developing mechanicalinduced forefoot complaints [2,16]. Maximal force was the most increased force in one defined anatomic region (F = p/A).…”

An in-shoe laser Doppler sensor for assessing plantar blood flow in the diabetic foot

“…There is also considerable evidence that abnormal plantar pressures occur in the diabetic foot (Boulton et al 1983, Stess et al 1997. Plantar ulcers do not normally occur in the absence of pressure and a reduction in pressure is the normal pre-requisite for healing (Cavanagh and Ulbrecht 1994).…”

“…By considering the findings from several clinical studies, Cavanagh and Ulbrecht (1992) have suggested several factors that may affect the pressure thresholds for plantar tissue breakdown: variation between different plantar sites; adequacy of the vascular supply, and tissue perfusion; glycosylation of the tissues; the presence of scar tissue; the duration for which pressure is applied rather than peak pressure. Boulton et al (1983) first concluded plantar pressure in the diabetic could increase with time. This is supported by the findings of Veves et al (1992) who measured plantar pressure in three subject types over a thirty-month period.…”