Effects of metatarsal domes on plantar pressures in older people with a history of forefoot pain

Abstract

Background Forefoot pads such as metatarsal domes are commonly used in clinical practice for the treatment of pressure-related forefoot pain, however evidence for their effects is inconsistent. This study aimed to evaluate the effects on plantar pressures of metatarsal domes in different positions relative to the metatarsal heads. Methods Participants in this study included 36 community-dwelling adults aged 65 or older with a history of forefoot pain. Standardised footwear was used and plantar pressures were measured using the pedar (R)-X in-shoe plantar pressure measurement system. Peak pressure, maximum force and contact area were analysed using an anatomically-based masking protocol that included three forefoot mask sub-areas (proximal to, beneath, and distal to the metatarsal heads). Data were collected for two different types of prefabricated metatarsal domes of different densities (Emsold metatarsal dome and Langer PPT metatarsal pad) in three different positions relative to the metatarsal heads. Seven conditions were tested in this study: (i) control (no pad) condition, (ii) Emsold metatarsal dome positioned 5 mm proximal to the metatarsal heads, (iii) Emsold metatarsal dome positioned in-line with the metatarsal heads, (iv), Emsold metatarsal dome positioned 5 mm distal to the metatarsal heads, (v) Langer PPT metatarsal pad positioned 5 mm proximal to the metatarsal heads, (vi) Langer PPT metatarsal pad positioned in-line with the metatarsal heads, and (vii) Langer PPT metatarsal pad positioned 5 mm distal to the metatarsal heads. Results When analysed with the mask that was distal to the metatarsal heads, where the plantar pressure readings were at their highest, all metatarsal dome conditions led to significant reductions in plantar pressure at the forefoot compared to the control (no pad) condition (F-3.9,F- 135.6 = 8.125, p < 0.001). The reductions in plantar pressure were in the order of 45-60 kPa. Both the Emsold metatarsal dome and the Langer PPT metatarsal pad, when positioned proximal to the metatarsal heads, managed to achieve this without adversely increasing plantar pressure proximally where the pad was positioned, however the Emsold metatarsal dome was most effective. Conclusions Metatarsal domes reduce plantar pressure in the forefoot in older people with a history of forefoot pain. All metatarsal dome conditions significantly reduced peak pressure in the forefoot, however metatarsal domes that were positioned 5 mm proximal to the metatarsal heads provided the best balance of reducing plantar pressure distal to the metatarsal heads, where the pressure is at its greatest, but not adversely increasing plantar pressure proximally, where the bulk of the pad is positioned. In this proximal position, the Emsold metatarsal dome was more effective than the Langer PPT metatarsal pad and we cautiously recommend this forefoot pad for alleviating forefoot pressure in older people with forefoot pain.