Equine heel strain and the influence of shoeing, implications for the biophysical aetiology of quarter cracks
Abstract (Summary)EQUINE EEEL STRAIN AND THE INFLUENCE OF SHOEING: IMPLICATIONS FOR THE BIOPHYSXCAL AETIOLOGY OP QUARTER CRACKS John Andrew Drake University of Guelph, 1997 Supervisor: Professor J.J.Thomason The purpose of this study was to investigate the mechanical aetiology of quarter cracks by comparing the strain patterns (Le. magnitudes and orientations at midstance, peak tension and compression, and maximum strain rates over an 18 ms interval) collected for shod and unshod hoof conditions using 4 rosette gauges attached to the lateral heel of the right forefoot. The working hypothesis of the project was that shoeing may destabilize the wall by altering the pattern of heel strain. The general pattern of heel strain was characterised by high proportions of tensile strain in the posterodistal zone and biaxial compression near to the coronary border. Numerous trends of signif icance dif ferentiate the shod and unshod responses, namely the absolute and relative magnitudes of tensile strain, the relative timing of peak events, and the strain orientations at the quarter gauge. Thus shoeing distorts heel function. For some hoof shapes imbalanced strains may progressively weaken a zone of wall (e.g. the quarter) such that microscopic flaws evolve to macroscopic proportions and cracking results. 1 wish to thank Dr. J. J. Thomason for his patience, guidance, and financial support. The tirne and efforts of Dr. J. Jofriet and Dr. M. LaFortune were also greatly appreciated. Ms. T. Rondeau-Vuk is thanked for both providing the horses and leading them through the experimental procedures during data collection. The time Dr. J. Douglas gave for numerous discussions on horse feet and the graduate process in general was greatly appreciated. Matthew Drake kindly provided the illustrations for Figures 2,3 and 4. A very special thanks is extended to W. ~ignell whose perpetual assistance in the experimental preparation, set-up, data collection and patient companionship made the project possible.
Source Type:Master's Thesis
Date of Publication:01/01/1998