Step width modification to change rearfoot eversion and medial longitudinal arch angle during walking and running in individuals with pronated feet

Background: Individuals with pronated feet often experience altered foot biomechanics, leading to increased risk of lower limb injuries. Step width modification has been proposed as a potential intervention to improve foot alignment during gait. Research question: Does modifying step width influence rearfoot eversion and medial longitudinal arch angle (MLAA) in individuals with pronated feet during walking and running? Methods: Twenty individuals with pronated feet underwent analysis during walking and running on treadmill, maintaining increased or decreased step width using real-time visual feedback. Three-dimensional motion analysis measured rearfoot eversion and MLAA during the stance phase of gait. Results: Wide step width significantly reduced peak rearfoot eversion during waking (mean difference - with normal step width - (MD) = 3.6 degrees, p < 0.001) and running (MD = 4.4 degrees, p < 0.001), time to peak rearfoot eversion during walking (MD = 16.6 p < 0.001) and running (MD = 13.8 degrees, p = 0.014), rearfoot eversion at touch down (TD) during walking (MD = 1.3 degrees, p = 0.004), rearfoot eversion excursion during running (MD = 4.3 degrees, p < 0.001), and peak MLAA during walking (MD = 2.9 degrees, p = 0.006) and MLAA excursion during running (MD = 4.8 degrees, p = 0.004). By contrast, during running, narrow condition significantly increased peak rearfoot eversion (MD = 3.4 degrees, p < 0.001). During walking, time to peak rearfoot eversion (MD = 16.1, p < 0.001), rearfoot eversion at TD (MD = 1.4 degrees, p = 0.008), rearfoot eversion excursion (MD = 5.9 degrees, p < 0.001), and peak MLAA (MD = 3.4 degrees, p < 0.001) were significantly increased. Significance: This study highlights the potential of step width modification as a simple yet effective intervention to improve foot biomechanics in pronated feet individuals during walking and running. Further research could lead to the development of personalized strategies for pronated feet individuals.