Comparing the effect of short foot exercise and toe curl exercise on plantar pressure during single-leg standing in individuals with flatfoot: A randomized controlled trial.

BACKGROUND

Controlling flatfoot biomechanics is crucial in preventing lower limb musculoskeletal injuries. Short foot exercise (SFE) and toe curl exercise (TCE) are interventions for flatfoot; however, their effects on foot biomechanics remain inconsistent. We aimed to compare the impact of SFE and TCE on plantar pressure during single-leg standing (SLS) in individuals with flatfoot.

METHODS

This randomized controlled trial recruited 34 participants with flatfoot (Foot Posture Index-6 > 7). Participants were randomly assigned to SFE or TCE groups and completed 8 weeks of exercise. Plantar pressure during SLS was assessed pre- and post-intervention using a plantar pressure sensor. The foot was divided into eight regions: heel, midfoot, medial, central, lateral metatarsophalangeal joint (MTPJ), hallux, second toe, and 3rd-5th toes. Peak plantar pressure and contact area were analyzed using intention-to-treat (ITT) and per-protocol (PP) analysis.

FINDINGS: In the ITT analysis, SFE significantly increased peak plantar pressure in the medial MTPJ (p = 0.016), hallux (p < 0.001), and second toe (p = 0.004), while reducing midfoot pressure (p = 0.0012). TCE significantly increased the heel pressure (p < 0.001). The PP analysis showed similar trends, with additional increases in the lateral MTPJ pressure (p = 0.032) and contact areas of the 3rd-5th toes (p = 0.008) in the SFE group.

INTERPRETATION: SFE increased the medial and lateral MTPJ, hallux, and toe pressure while reducing midfoot pressure. TCE increased the heel pressure. These findings suggest that SFE improves the midfoot, medial and lateral MTPJ, and toe pressure in individuals with flatfoot.

CLINICAL TRIAL REGISTRATION NUMBER: UMIN000049963.