The Pressure Relieving Capacity of Siliconepads Compared to Felted Foam to Relieve Caput Metatarsal 2 in a Population With Diabetes at High Risk of Foot Ulcerations

People with diabetes mellitus (DM) experience increased pressure under the plantar surface of the foot because of morphological, muscular and sensory abnormalities.

One third of these people have deformed feet, usually due to diabetic neuropathy, which causes localized increases in plantar pressure, particularly on the plantar side of the forefoot, where the risk of foot ulcers is high.

Custom-made therapeutic shoes and arch supports are recommended and are part of standard care for patients with foot deformities and a history of ulceration. The pressure under a human foot can be measured using a technique called Pedobarography or plantar pressure measurement, which uses insole- or platform-based pressure and force systems.

Pedobarographic measurements quantify the vertical load experienced by the foot when walking barefoot or with footwear by measuring the pressure on the plantar side. This makes it possible to identify any functional abnormalities in the structure and function of the dynamic foot. Wearing shoes with or without arch supports was reported to reduce peak pressure by 17 to 52% compared to walking barefoot. Furthermore, proof-of-principle studies have shown that reducing peak pressure on the plantar surface to less than 200 kPa (or by at least 25%) halves the risk of ulcer recurrence in people with diabetes over an 18-month period.

Felted foam therapy is, in addition to insoles and shoes, a complementary conservative treatment that facilitates this pressure relief. Felt consists of compressed wool in various thicknesses that distributes the increased pressure over a larger surface area, thereby reducing the peak pressure at a specific point. The location of the peak pressure is then relieved by the felt with a recess at this zone, whereby the pressure is distributed over the surface.