RESUMEN
BACKGROUND: Metatarsal pads are frequently prescribed for patients with metatarsalgia to reduce pain under the distal metatarsal heads. Several studies showed reduced pain and reduced plantar pressure just distal to the metatarsal pad. However, only part of the pain reduction could be explained by the decrease in plantar pressure under the forefoot. Therefore, an alternative hypothesis is proposed that pain relief is related to a widening of the foot and the creation of extra space between the metatarsal heads. This study focused on the effect of a metatarsal pad on the geometry of the forefoot by studying forefoot width and the height of the second metatarsal head. METHODS: Using a motion analysis system, 16 primary metatarsalgia feet and 12 control feet were measured when walking with and without a metatarsal pad. RESULTS: A significant mean increase of 0.60 mm in forefoot width during the stance phase was found when a metatarsal pad was worn. During midstance, the mean increase in forefoot width was 0.74 mm. In addition, walking with a metatarsal pad revealed an increase in the height of the second metatarsal head (mean, 0.62 mm). No differences were found between patients and controls. CONCLUSIONS: The combination of increased forefoot width and the height of the second metatarsal head produced by the metatarsal pad results in an increase in space between the metatarsal heads. This extra space could play a role in pain reduction produced by a metatarsal pad.