Retrospective study of hindquarter asymmetry in Standardbred Trotters and its correlation with performance

Abstract

Summary Five hundred four‐year‐old Standardbred Trotters in training were examined in a study on the correlation between conformation, soundness and racing performance. In 39 horses marked hindquarter asymmetries were observed when they were standing squarely on all four feet. The asymmetries were seen as obvious height differences between the left and right tubera sacrale. In 30 cases the left tuber sacrale was lower and in nine cases the right tuber sacrale was lower. The horses showing hindquarter asymmetry were of significantly larger body size than the 461 horses not showing the asymmetry. There was no sex difference in the incidence of hindquarter asymmetry. The asymmetric horses had significantly lower total earnings, a lower number of races per horse and less good racing records (min/km) than the remaining 461 horses. The trainers reported that the asymmetric horses often had difficulties in performing at speed. In most horses, the asymmetry had not been observed until the examination. Past clinical records of 11 of the 30 asymmetric horses were available. In only one of the 11 horses had the asymmetry been considered of clinical importance. It was concluded that the described hindquarter asymmetries are important signs indicating that there is an enhanced risk that the affected horses will not become successful Trotters.

Review of injection techniques targeting the sacroiliac region in horses

“…2003; S. Dyson, personal communication). In performance horses, SID appears to be more prevalent than is currently clinically recognised (Jeffcott 1980; Dalin et al . 1985; Dyson and Murray 2003).…”

Skeletal forelimb measurements and hoof spread in relation to asymmetry in the bilateral forelimb of horses

“…A horse's athletic capacity and ability to remain injury free are both closely linked to conformation. The effect of asymmetry deserves attention as evidence suggests that a higher degree of asymmetry is negatively correlated with performance in Standardbred trotters (Dalin 1985), Thoroughbred racehorses (Manning and Ockenden 1994) and event horses (McDonald and Dumbell 2008). Human research has identified that leg length asymmetry causes differences in loading and differing compensatory mechanisms (Goel et al 1997;White et al 2004).…”

Associations between physiotherapy findings and subsequent diagnosis of pelvic or hindlimb fracture in racing Thoroughbreds

“…They may result from chronic asymmetric muscular or ligamentous forces (Haussler 1999), abnormal morphology of the dorsal sacroiliac ligaments (Tomlinson et al. 2003) and asymmetric skeletal development (Dalin et al. 1985).…”

“…1994). Eight percent of a population of 500 racing Standardbreds had recorded height differences of >1 cm between the tubera sacrale ; however, clinical relevance of the asymmetries could not be established because past clinical records were not available for all horses (Dalin et al. 1985).…”

“…Conversely, prolonged asymmetric forces resulting from chronic pain, spasm and atrophy in the gluteal muscles may alter the morphology of the bony pelvis (Jeffcott 1982; Dalin et al. 1985; Jeffcott et al.…”