Finite element analysis (FEA) as a model to predict effects of farriery on the equine hoof

Abstract

Summary A finite element (FE) hoof capsule was built as a small, symmetrical forelimb hoof on IDEAS* as a model for calculation and visualisation of stress and displacement of the equine hoof capsule. The model's loading was performed according to the suspension of the coffin bone within the hoof wall (pulling force) and over the sole and frog (compressing force) with a total of 3000 N. Restraints of the model's ground nodes and surface wall nodes were defined for simulation of 4 shoeing situations: a regular horseshoe, a horseshoe with a toe clip, a horseshoe with regular side clips and a horseshoe with a toe clip and more caudally‐placed side clips, all fixed to the hoof capsule with 3 nails on each side and each calculated in a tense and a loose nailed condition. Von Mises stresses were taken ranging from 1.22 N/mm2 in the weighthearing border of the side clip shoe fixed loosely to the capsule up to 16.67 N/mm2 in the hoof horn material surrounding the third nail. Further high stress zones were calculated in the proximal dorsal wall, the distal heel and the lateral hoof wall. Displacement values were taken showing movements of hoof wall, sole and frog according to the shoeing conditions. Maximal displacement was calculated in the hoof capsule shod with a regular horseshoe without a clip. Minimal displacement was found in the capsule with a toe clip and 2 side clips placed behind the 3rd nail. All models showed higher displacements when calculated with a loose nail fixation. Validation of the detailed features of the models is not yet possible. Finite element analysis (FEA) can be used practically to predict influences of various farrier techniques on the equine hoof in order to avoid possible harm to horses' feet in field studies.

Hoof ground interaction: when biomechanical stimuli challenge the tissues of the distal limb

“…Considerable information on the anatomical and force constraints of the distal limb has been generated through in vitro and in vivo studies on various aspects of the hoof complex, which is both rigid and flexible to support and accommodate the interaction of the hoof with the surface (Back 2001;Hinterhofer et al 2001;Roepstorff et al 2001;Olivier et al 2001;Thomason et al 2001Thomason et al , 2005. Movement of the hoof capsule during movement has been quantified by the use of strain gauges, motion analysis systems and potentiometers (Dejardin et al 1999(Dejardin et al , 2001Roepstorff et al 2001;Thomason et al 2002).…”

“…During the initial loading phase the distal phalanx pulls the dorsal hoof wall backwards and downwards, pushes the quarters outward, causing the bulbs of the heels to expand (Olivier et al 2001;Roepstorff et al 2001;Thomason et al 2002). Shoeing limits this deformation and decreases bulb expansion (Hinterhofer et al 2001;Roepstorff et al 2001). The unshod hoof can, therefore, adapt more freely to the applied load.…”

Mechanical behavior and quantitative morphology of the equine laminar junction

“…Most previous FEAs of the equine hoof have focused on the capsule (Newlyn et al, 1998;Hinterhofer et al, 2000Hinterhofer et al, , 2001; Thomason et al, 2002;McClinchey et al, 2003). In addition to testing the applicability of FEA to hooves, some of these studies have used its power to address questions of functional relevance, such as the effect of shoeing on stresses in the capsule material (Hinterhofer et al, 2000) and the effects of individual capsule shape measurements on principal strain magnitudes (McClinchey et al, 2003).…”

Sixth International Conference on Equine Locomotion

“…The finite element method (Newlyn et al 1998;Hinterhofer et al 2001) was presented to simulate mechanics of a donkey and a horse digit model. A different computational distal forelimb model was presented to investigate strains in the flexor tendons (Chan and Lawson 2008), concluding that the high repeatability of the model is an indicator for its sensitivity.…”