Parameters for analysis of walking foot pressures at different levels of diabetic neuropathy and detection of plantar ulcers at early stages

Abstract

In this paper, studies are performed on a large number of diabetic patients belonging to different levels of planar sensation loss, using foot pressure parameters, i.e., normalized peak pressure (NPP), pressure contact ratio (PCR) and their gradients, which include effects of the weight of the subject, velocity of walking and duration of high pressures in all the foot sole areas. The foot areas of the diabetic subjects are scanned in ten specified areas using Semmes-Weinstein nylon monofilaments to quantify the different levels of sensation loss in diabetic neuropathy. A statistical study of the mean maximum values of these parameters, in different plantar areas of the feet of diabetic neuropathic subjects (in different levels of sensation loss), indicateds distinguishing trends. Good correlations are found between the quantified levels of sensation loss and foot pressure parameters in the areas where there is high incidence of plantar ulcers. The study shows that plantar ulcers could at an early stage (level) of sensation loss and also confirms that specially designed footwear helps in reducing foot pressure parameters of diabetic neuropathic feet and thereby could prevent plantar ulcer. The NPP and PCR transforms calculated on-line (using specially developed software) help the clinician to quickly determine the heavily-loaded foot areas that could be the sites of ulceration in the early level of plantar sensation loss and to take necessary action to prevent further damage to the foot sole.