A healthy 50-year-old white man presented with a long-standing painful plantar callus over the second metatarsal head that required podiatry treatment to remove the callus. After removal of the callus the area was often painful and it required the use of felt padding to offload plantar pressure before orthoses were prescribed for long-term treatment of the condition.
Felt padding has been used for a long time as a material for redistribution of foot pressure from various parts of the plantar surface of the foot, although there is little published research on the effect of felt on plantar pressure. According to Nube
et al. [
1], the purpose of felt padding is to deflect pressure away from a particular area of the foot. They demonstrated that plantar pressure can be reduced in people with diabetes by the application of felt padding that is adhered to the foot. They argued that foot ulceration in diabetes is precipitated and perpetuated by many factors, chiefly peripheral neuropathy and biomechanical abnormalities but offloading of plantar pressure is a key element in the management of diabetes-related neuropathic foot ulcers. The technique principally involves the adherence of felt or felted-foam to the sole of the foot, with an aperture cut into the material which corresponds with the ulcer location. Varying thicknesses of felt and methods of adhesion are used. Holmes and Timmerman [
2] used a pedobaragraph to assess the effect of a simple metatarsal pad on pressures transmitted to metatarsal heads by measuring dynamic pressure for 100 participants with and without metatarsal pads. They concluded that, when properly positioned, metatarsal pads can be an inexpensive and effective means of reducing plantar pressure. Hayda
et al. [
3] reported similar findings; they measured plantar pressures within the shoes of 10 volunteers with normal asymptomatic feet. Test conditions included large foam, large felt and small felt situated at three different positions. They concluded that metatarsal pads can effectively decrease plantar pressure in the shoe. A study by Zimny
et al. [
4] evaluated the effects of felted foam on wound healing in diabetes-related foot ulcers compared with a standard method of plantar pressure relief. All patients received identical standard ulcer wound care including debridement and daily careful monitoring of the ulcer. In a randomized trial, the patients received pressure relief in the ulcerated area either with felted foam dressing or with a pressure-relief half-shoe (Thanner, Hoechstaedt, Germany). Zimny
et al. [
4] demonstrated that a dressing of 0.635cm thick rubber foam combined with a 0.158cm layer of felt appeared to be as effective as conventional plantar ulcer treatment using the pressure-relief half-shoe. They postulated that it may be a useful alternative in treating neuropathic foot ulceration, especially in patients who are unable to avoid weight-bearing. Paton
et al. [
5] studied the effect of 7mm semi-compressed felt plantar cover padding, with a U shape cutout to the second metatarsal head, on forefoot peak pressure (PP) and forefoot pressure-time integral (PTI). Both feet of 10 healthy individuals were studied. A F-scan in-shoe pressure analysis system compared the dynamic measurements for each individual, with and without felt plantar cover padding. Related sample
t-tests were conducted to analyze significant differences between test conditions. The PP and PTI at the center of the 'U' decreased by a mean of 25% and 29% respectively. The PP and PTI at the periphery of the 'U' increased by a mean of 44% and 58%, 24.178kPa/second. Exactly what is determined as high peak plantar pressure in causing foot ulcers is debatable but Armstrong
et al. [
6] found that peak plantar pressure was, as expected, significantly higher for patients with ulcers compared to controls: 83.1 +/− 24.7 N/cm
2 (range, 10 to 125) versus 62.7 +/− 24.4 N/cm
2 (range, 7.3 to 113),
p < .001. The ulcer group was clearly skewed toward a higher prevalence of elevated peak plantar forefoot pressure compared with the control group. They concluded that, while there is no optimal cut-point for clearly screening patients for risk of foot ulceration, the higher the PP, the higher the commensurate risk. It can therefore be deduced from the literature that felt padding can play an important role in the management of patients’ foot health but more research is required in this area as there is a variety of types and thicknesses of felt available.