Is there a dose-response of medial wedge insoles on lower limb biomechanics in people with pronated feet during walking and running?

Abstract

Background: Although the effects of medial wedge insoles on lower limb biomechanics have been investigated, information about the effects of different magnitudes of medial posting is still lacking.
Research question: What are the dose-response effects of medial wedge insoles with postings varying between 0°, 3°, 6°, and 9° of inclination on the lower limb biomechanics during walking and running in individuals with pronated feet?
Methods: Sixteen participants with an FPI ≥ 6 were recruited. Four arch-supported insole conditions with varying degrees of medial heel wedge were tested (0, 3, 6, and 9). A 3D motion analysis system with force plates was used to obtain the kinetics and kinematics of walking and running at self-selected speeds. To compare the ankle, knee, and hip angles and moments among conditions, a time series analysis was performed using Statistical Parametric Mapping (SPM).
Results: A reduction in ankle eversion angle was observed during walking for all insoles. For running, the 6º and 9º insoles decreased the ankle eversion angle during early stance and increased this angle during the propulsive phase. A decrease in ankle eversion moment was observed in walking and running for 6º and 9º insoles. An increase in knee adduction moment occurred in walking and running for all insoles. For hip, the 6º and 9º insoles showed, during walking, a decrease in hip adduction angle and an increase in hip adduction and external rotation moments. For most variables, statistical differences were found for a greater period across the stance phase as the medial wedge increased, except for ankle eversion moment and hip external rotation moment during walking.
Significance: The biomechanical effects over the time series for many of the parameters increased with the addition of insole inclination, showing a dose-response effect of medial wedge insoles on the lower limb biomechanics during walking and running in adults with excessive foot pronation.