Wearing thick-soled shoes increases the magnitude of peroneus longus muscle activity required to resist an unanticipated foot inversion, elevating the risk of an ankle sprain, according to research from the University of Dundee in Scotland.
Investigators used electromyography to assess peroneus longus activity in 38 healthy participants standing on a platform designed to invert from 0° to 20° without warning. Participants were tested while barefoot and while wearing shoes with soles of varying thicknesses, up to 5 cm.
Peroneus longus activity during the resulting eversion response was significantly greater in magnitude for all shoe conditions compared to barefoot, and increased with shoe sole thickness. The muscle also responded earlier during the shod conditions than the barefoot conditions. The findings were published in the December issue of Foot & Ankle Surgery.
The authors suggested their results may have injury-risk implications for patients who wear thick-soled shoes to correct a limb-length discrepancy as well as those partial to wearing platform shoes or other thick-soled fashion footwear.
Source: Ramanathan AK, Parish EJ, Arnold GP, et al. The influence of shoe sole’s varying thickness on lower limb muscle activity. Foot Ankle Surg 2011;17(4):218-223.