Hoof wall function in horses and donkeys: Experimental alteration of surface strain

Surface strains recorded from multiple rosette gauges at different sites on the left forehooves of horses and donkeys during walks at 1.8 m/s are discussed. The strain pattern of the wall was manipulated by adding 12 mm cleat wedges to the heels of the horseshoes. Principal strains were repeatable for each gauge site and cleat situation on an individual. Substantial inter-individual variation existed. Peak principal strains were always in compression. Under normal circumstances (no cleats attached) peak strains were on the order of 1000-3000 με, depending on gauge site. Biaxial compression dominated in the wall, but the degree of horizontal compression was reduced by altering the mediolateral balance of the foot. The strain pattern of the hoof wall correlates well with the complex fiber orientation of the wall material and appears to result from well coordinated distortion of different regions of the structure