Multivariable Logistic Regression Models of X-Ray Thoracic Spinous Process Osseous Changes Findings and Body Measurement Factors Associated With Defined Over-riding of the Dorsal Spinous in Riding Horses.

Authors: Takeyama Tetsuya, Sasaki Naoki

Journal: Journal of equine veterinary science

DOI: 10.1016/j.jevs.2021.103839 PubMed: 34923073Log in to save

Summary

# Editorial Summary Thoracic spinous process pathology in ridden horses develops from chronic compression loads, yet the relationship between radiographic changes and individual conformation remains poorly characterised. Takeyama and Sasaki examined 55 sports horses, using a muscle hardness tester to quantify dorsal back musculature (multifidus, longissimus and latissimus dorsi) alongside radiographic assessment and morphometric measurements to identify associations with spinous process pathology. Horses exhibiting greater muscle hardness—particularly those with longer distances from the 13th thoracic vertebra to the sacro-lumbar junction—showed significantly elevated rates of spinous process osteosclerosis on imaging. The findings suggest that conformation permitting increased dorsal-ventral spinal mobility may predispose horses to compensatory muscular hardening and consequent osseous changes, indicating that individual anatomical variation warrants consideration when assessing back pain risk and designing loading programmes for ridden horses.

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Practical Takeaways

•Back muscle hardness correlates with spinous process pathology—horses with harder back muscles show osteosclerotic changes that may indicate chronic riding-induced compression
•Conformation matters: longer distances from mid-thorax to lumbosacral junction may predispose to both muscle hardening and spinous process changes under saddle
•Objective muscle hardness measurement could help identify at-risk horses early and inform saddle fit, workload management, and conditioning protocols

Key Findings

•Horses with longer distance from T13 to the sacral-lumbar junction (L5) demonstrated higher back muscle hardness (n=55)
•High back muscle hardness was significantly associated with spinous process osteosclerosis in riding horses
•Muscle hardness tester proved effective for quantifying hardness of multifidus, longissimi, and latissimi muscles
•39 of 55 horses exhibited high muscle hardness with associated osseous changes compared to 16 with low muscle hardness

Conditions Studied

thoracic spinous process osseous changesspinous process osteosclerosisriding-induced back compressiondorsal spinous process over-riding

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