Foot center of pressure trajectory alteration by biomechanical manipulation of shoe design

Background: Footwear-generated biomechanical manipulations have been shown to alter lower limb kinetics. It has been suggested that this is due to altered trajectory of the foot's center of pressure (COP), conveying a shift in location of the ground reaction force and modifying moments and forces acting on proximal body segments. However, past studies have focused on qualitative association between footwear design and the COP locus. Moreover, this association was calculated via indirect analysis. The purpose of the present study was to directly examine and quantify the correlation between measured footwear biomechanical manipulation and the location of the COP trajectory during gait. Methods: A novel biomechanical device allowing flexible positioning of 2 convex-shaped elements attached to its sole was utilized. A total of 20 healthy male adults underwent direct in-shoe pressure measurements while walking with the device set at 7 mediolateral configurations. COP data were collected during gait and analyzed with respect to different stance subphases. Results: COP location significantly correlated with a shift of the elements medially or laterally. The linear model describing this correlation was found to be statistically significant. Conclusion: There was significant correlation between the plantar orientation of the shoe device configuration and the COP. Clinical Relevance: Changes in COP trajectory may be valuable in patients suffering from multiple foot disorders elevating pressure on the foot. Accurate COP control could aid in the manipulation of the forces acting on the proximal joints during gait. In addition, these findings may have implications in the field of biomechanical apparatus design and practice.