Comparative kinematic analysis of the leading and trailing forelimbs of horses cantering on a turf and a synthetic surface

Abstract

SummaryReasons for performing study: The relationship between track surface properties and limb kinematics is poorly understood. Hoof orientation within the track surface has never been quantified under training conditions. Previously described kinematic and dynamic differences between leading and trailing forelimbs at the canter poorly correlate with epidemiological data regarding injuries. Objectives: To compare joint kinematics and hoof orientation in the leading and trailing forelimbs of horses cantering on turf and on a synthetic surface. Study design: Noninvasive experimental study. Methods: The right forelimb of 5 horses was equipped with markers facing the main joints while markers and a dynamometric horseshoe were placed on the hoof. The horses were filmed with 2 high-speed cameras (1000 Hz) while cantering (30 km/h). Recordings were repeated at each lead and alternated on turf and on a synthetic surface. Joint angles and angles of the hoof and limb to the track were measured from the 2-dimensional coordinates of the markers. Results: Elbow, carpus and fetlock were more maximally flexed during swing and had a larger range of motion throughout the stride in the leading forelimb. Maximal carpal extension during stance was also larger on this limb, which had a more toe-up orientation. Comparing surfaces, the limb was more oblique at landing, the range of motion of the hoof into the surface was larger, most kinematic events were delayed and fetlock and carpus extension velocities were smaller on the synthetic surface. Conclusions: The differences between limbs were more prominent than those between surfaces and the more toe-up orientation on the hoof of the leading forelimb suggests a different loading of that limb's joints and tendons. Differences between limbs may be important in the interpretation of lead changes in lame horses. While the synthetic surface appears to be less strenuous for the joints in the forelimbs, it was associated with changes in timing of the kinematic events of the stride.

A Review of Dorsal Metacarpal Disease (Bucked Shins) in the Flat Racing Horse: Prevalence, Diagnosis, Pathogenesis, and Associated Factors

“…A synthetic track creates lower hoof acceleration and GRF than turf and dirt and also alters the angle at which the hoof enters the surface. 79 Dirt surfaces are known to be the hardest and the incidence of DMD is reported as being higher in the United States where dirt is most commonly used for racing. 80 Setterbo et al 81 stated that a synthetic race surface (made of sand, rubber, and polypropylene) caused less impact and hoof shock at landing and take-off than turf and dirt, with 26 to 73% less impact and loading force than dirt.…”

“…81 However, these data came from a simulated 'trackin-a-box' experiment, where laboratory conditions and track testing devices vary. Laboratory tests cannot replicate natural hoof impact velocities accurately and studies using racehorses on the track with accelerometers/force plates are fraught with numerous confounding factors and variables, for example: 79,80 i. Age of synthetic surface Crevier-Denoix et al 79 noted that hoof angle in relation to the track on landing was larger when cantering on turf than on synthetic.…”

“…Laboratory tests cannot replicate natural hoof impact velocities accurately and studies using racehorses on the track with accelerometers/force plates are fraught with numerous confounding factors and variables, for example: 79,80 i. Age of synthetic surface Crevier-Denoix et al 79 noted that hoof angle in relation to the track on landing was larger when cantering on turf than on synthetic. 79 Hoof angles vary between forelimbs and hind-limbs, but with only a limited number of studies of fore-limb kinematics on racing surfaces, 21,79 there are insufficient data to compare hoof angle with the incidence of strain pathology on the McIII.…”

“…Age of synthetic surface Crevier-Denoix et al 79 noted that hoof angle in relation to the track on landing was larger when cantering on turf than on synthetic. 79 Hoof angles vary between forelimbs and hind-limbs, but with only a limited number of studies of fore-limb kinematics on racing surfaces, 21,79 there are insufficient data to compare hoof angle with the incidence of strain pathology on the McIII. The onset of DMD occurred after 51 fast kilometres on dirt and 138 fast kilometres on wood fibre in a study of 171 similarly-trained Thoroughbreds racehorses in a study by Moyer et al 83 However, variables regarding training regimes were not included.…”

AAEP/EVJ supplement 2013

“…Similarly, in an effort to compare the effects of different track surfaces on horses' gaits, Crevier‐Denoix et al . analysed foot and limb motion during the swing and support phases of the stride at the canter on dirt and synthetic track surfaces. They detected significant differences in foot position in the lead limb compared with the opposite limb and evidence that the synthetic surface appeared to be more forgiving than the dirt track.…”