Shoeing was originally intended to protect the feet of horses against excessive wear. However, farriers currently also try to optimize performance by use of shoeing methods and application of specific shoes. In addition, shoeing techniques are often used during the rehabilitation process for lame horses. Farriery is still a craft based primarily on empiric observations, rather than science-based information. This is not because of a lack of interest; however, it has proven extremely difficult to measure effects of shoeing interventions because of the speed with which events happen and the subtlety of the changes induced by typical shoeing practices. Studies on the effects of special shoes, such as rocker1 and rolled-toed2 shoes, or specific shoeing techniques, such as natural balance,3 were unable to provide scientific evidence for the effects these shoes were presumed to have on locomotion of horses. However, to optimize shoeing for modern equine athletes and to improve therapeutic shoeing interventions, it is essential to know how horses compensate for the changes induced with shoeing.
The effects of an 8-week shoeing interval have been studied.4,5 Changes in hoof morphology attributable to hoof growth and wear during this shoeing interval were a decrease of 3.3° in hoof angle of the forefeet and a decrease of 3.2° in the hoof angle of the hind feet. Length of the dorsal hoof wall increased by 1.4 cm and 1.5 cm, respectively.4 On mere geometric analysis, these changes in hoof morphology should lead to a shift of the CoP at midstance in a palmar or plantar direction to maintain equilibrium. This indeed was the case but to a smaller extent than calculated, which indicated a compensatory mechanism.4 In a follow-up study5 that used a subgroup of the same cohort of horses and focused on changes in joint moments in standing horses, it was reported that horses at the end of the shoeing interval had a more broken or backward alignment of the distal segments of the limbs, especially for the distal interphalangeal joint but not for the proximal interphalangeal joint, which suggested compensation through the adaptation of angles between the distal segments of the limbs.
Relationships between hoof angles and limb angulation have been the subjects of other studies. In standing horses, artificially induced changes achieved by the use of heel and toe wedges resulted in linear relationships between hoof angle changes and alterations in angulation of the distal portions of the limbs.6–8 Furthermore, a change of 10° in the hoof angle can cause an increase in the time between heel lift and toe off (ie, breakover duration), but other stride characteristics (eg, stance time and step length) remain unaltered.9,10 However, all of these studies focused on artificially induced changes, achieved primarily by the use of wedges, and investigators often evaluated only acute effects. The reports do not yield information about how horses compensate for typical hoof growth and the ensuing changes in hoof morphology during a typical shoeing interval in which changes are subtle and develop over a prolonged period.
In the study reported here, we tested the hypothesis that horses maintained their specific neuromuscular pattern of movement and therefore compensated for changes induced by typical hoof growth by subtle changes in angular motion patterns, rather than by changes in linear or temporal stride characteristics. To minimize variation, kinematic measurements were obtained from the same population of horses and for identical circumstances as those in the aforementioned studies.4,5
Center of pressure
Proximal hoof angle
Horses for the study were provided by Dr. Leendert-Jan Hofland and Jan Van Kooten.
Mustad shoe, 22/8 lb, Mustad Hoofcare SA, Bulle, Switzerland.
RsFootscan scientific version, RSscan International, Olen, Belgiun.
Kistler force plate type Z4852/c, 600 × 900 mm, Kistler Corp, Winterthur, Switzerland.
Proreflex, Qualisys AB, Sävedalen, Sweden.
SPSS, version 10.0, SPSS Inc, Chicago, Ill.
Willemen MA, Savelberg HHCM & Jacobs MWH, et al. The biomechanical effects of rocker-toed shoes in sound horses. Vet Q 1996;18(suppl 2):S75–S78.
Clayton HM, Sigafoos R, Curle RD. Effects of three shoe types on the duration of breakover in sound trotting horses. J Equine Vet Sci 1990;11:129–132.
Eliashar E, McGuigan MP & Rogers KA, et al. A comparison of three horseshoeing styles on the kinetics of breakover in sound horses. Equine Vet J 2002;34:184–190.
van Heel MCV, Moleman M & Barneveld A, et al. Changes in location of centre of pressure and hoof-unrollment pattern in relation to an 8-week shoeing interval in the horse. Equine Vet J 2005;37:536–540.
Moleman M, van Heel MCV & van Weeren PR, et al. Hoof growth between two shoeing sessions leads to a substantial increase of the moment on the distal, but not on the proximal interphalangeal joint. Equine Vet J 2006;in press.
Bushe BA, Turner TA & Poulos PW, et al. The effect of hoof angle on coffin, pastern and fetlock joint angles, in Proceedings. Annu Meet Am Assoc Equine Pract 1987;33:729–737.
Crevier-Denoix N, Roosen C & Dardillat C, et al. Effects of heel and toe elevation upon three digital joint angles in the standing horse. Equine Vet J Suppl 2001;33:74–78.
Clayton HM. The effect of an acute hoof wall angulation on the stride kinematics of trotting horses. Equine Vet J Suppl 1990;9:86–90.
Clayton HM. The effect of an acute angulation of the hind hooves on diagonal synchrony of trotting horses. Equine Vet J Suppl 1990;9:91–94.
van Heel MCV, Barneveld A & van Weeren PR, et al. Dynamic pressure measurements for the detailed study of hoof balance: the effect of trimming. Equine Vet J 2004;36:778–782.
Clayton HM, Schamhardt HC. Measurement techniques for gait analysis. In: Back W, Clayton HM, eds. Equine locomotion. London: WB Saunders Co, 2001;55–76.
Back W, van den Bogert AJ & van Weeren PR, et al. Quantification of the locomotion of Dutch Warmblood foals. Acta Anat (Basel) 1993;146:141–147.
Willemen MA, Savelberg HHCM, Barneveld A. The effect of toe weights on linear and temporal stride characteristics of Standardbred trotters. Vet Q 1994;16(suppl 2):S97–S100.
Willemen MA, Savelberg HHCM, Barneveld A. The improvement of the gait quality of sound trotting warmblood horses by normal shoeing and its effects on the load on the lower limb. Livest Prod Sci 1997;52:145–153.
van Weeren PR, van den Bogert AJ, Barneveld A. A quantitative analysis of skin displacement in the trotting horse. Equine Vet J Suppl 1990;9:101–109.