Posterolateral shear stress increases with heel height and could play a key role in high-heeled shoe-related foot disorders, according to a study in the June issue of the Journal of Biomechanics.
Investigators from Hong Kong Polytechnic University used in-shoe triaxial force transducers to investigate the interface between a high-heeled shoe and the plantar aspect of the foot in 10 female volunteers. As heel height increased from 30 mm to 70 mm, peak pressure and shear stress shifted from the lateral to the medial forefoot during standing and walking.
Heel height had a greater influence on peak shear than peak pressure; peak shear increased up to 119% during walking, about five times that of peak pressure. Increasing heel height raised peak posterolateral shear over the hallux at midstance; peak pressure at push-off decreased.
The authors concluded that increased posterolateral shear could contribute to hallux deformity and other foot disorders related to high-heeled shoes, and that plantar shear stresses may be of particular importance with high heels’ inclined supporting surface.