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“If you don’t understand locomotion, you shouldn’t be shoeing horses”.
— H AY D N P R I C E

Hock Displacement
Lateral Extension Shoes to Support the Hind Limb in Sport Horses By Fran Jurga with Haydn Price and Mark Johnson

W

orking on behalf of the British Equestrian Federation to monitor horses that may represent Great Britain at the 2004 Olympic Games,farrier

Haydn Price Dip WCF and British Equestrian Federation team veterinarian John McEwen BVMS have collaborated with biomechanics expert Mark Johnson to develop a system to evaluate and periodically re-evaluate potential team horses. (See related story.) Johnson accompanied Price to America for a demonstration at Rood and Riddle Equine Hospital in Lexington, Kentucky in June 2004.
Theinformation collected by the British system can overcome some of the subjectivity and shortfalls in information when practicing veterinarians and farriers assess the gait of individual horses. Kinematic information such as stride length, breakover distance, and carpal/tarsal/fetlock flexion can now be measured and reported for evaluation of individual horses, wherever they are located. “If you don’tunderstand locomotion, you shouldn’t be shoeing horses,” Price always reminds his audience. Price uses pre- and post-shoeing video gait analysis—often viewing a horse’s footfalls frame by frame by frame—to monitor minor adjustments made in the shoeing of the British team horses. The British system uses three cameras and sophisticated software. While there is strict protocol to follow, it is a more“on-the-job” system than Dr Hilary Clayton’s carefully controlled system (see related article on hock research), since it is portable and is used for determining therapeutic options. It can however, monitor knee action, hock displacement, and stride length, as well as other parameters desired by the testers. Price also likes to informally videotape the horses on the surface where they will be working,to see how his oftenminute shoeing adjustments function for performance. A real concern in the shoeing of dressage horses is that the horse should “float” over the surface, and not sink too deeply into soft footing. Expert shoeing modifications and shoe designs can keep the horse from expending excess energy, stressing joints, tendons, and ligaments, or looking like he is laboring to a judge. Ofprime importance to Price is “hock displacement”, since the hock seems to be displaced laterally toward the end of a stride; in America, this might be called a “wobbly” or “floppy” hocks. Remedying this condition is critical in the maintenance of sound jumping and dressage horses. Farriers working on sport horses
At recent seminars sponsored by the International League for the Protection of Horsesin England and Rood and Riddle Equine Hospital in Kentucky, horses are walked on a runway and taped from different angles by multiple digital video cameras. Data is graphed by motion analysis software and a readout traces stride length, straightness of movement, or other characteristics of the horse relevant to performance. Taping before and after shoeing graphically shows the effects of shoemodifications on sport horses.

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HOOFCARE

&

LAMENESS

Issue No.78

LEARN MORE AT www.hoofcare.com

LEARN MORE AT www.hoofcare.com

Issue No.78 H O O F C A R E & L A M E N E S S

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are continually battling the deterioration of gaits and performance attributed to weakness or degeneration of the hocks or conformational weaknesses such as sickle hocks. When horses areidentified as being at high risk for hock lameness, Price employs what looks like a radical device, a winged hind shoe. An arching extension of steel bursts from the heel quarter to the heel, often an inch of so in width at its widest point. The radius of the extension is modified to help stability and there is no ground contact under the outer edge of the extension. “We’re not trying to stop the hock...