[Forefoot relief with shoe inserts : Effects of different construction strategies].

BACKGROUND: Shoe inserts and shoe modifications are used to reduce plantar peak pressure. The effects of different shoe inserts and shoe construction strategies for relief of the forefoot have not yet been sufficiently evaluated.

PURPOSE: The aim of this study was to analyze the effects of shoe inserts and shoe construction strategies (e.g. metatarsal pad, forefoot cushioning and control) and shoe modifications (e.g. flexible or stiff) on the peak plantar pressure in the forefoot region.

MATERIAL AND METHODS: In this study 15 healthy subjects were recruited. Plantar pressure distribution was measured using an in-shoe system during walking (3.5km∙h-1 ) on a treadmill and the average plantar peak pressure (kPa) in the forefoot was calculated. The statistics for testing the hypothesis were carried out using 2‑factorial ANOVA with repeat measurements (factors: shoe, insert; α = 0.05).

RESULTS: The metatarsal pad and forefoot cushioning led to a reduction of peak pressure, which was statistically significant compared to the control condition (p = 0.009). No differences were observed between both shoe inserts (p > 0.05). A comparison between stiff and flexible shoes revealed a statistically significant pressure reduction in favor of stiff shoes (p = 0.0001). The metatarsal pad led to a peak pressure increase in the midfoot of 12% and by 21% compared to control and forefoot cushioning, respectively.

DISCUSSION: A peak pressure reduction in the forefoot can be achieved with a metatarsal pad or with cushioning; however, the metatarsal pad resulted in a subsequent increase in midfoot pressure. Moreover, shoe construction is crucial because a stiff shoe contributes to a better peak pressure reduction compared to a flexible shoe. Prospective clinical studies should be carried out to prove whether this results in beneficial effects for patients with metatarsalgia.