Natural rigaidity of the horse’s backbone.

The research article discusses the functional anatomy of a horse’s thoracolumbar (TL) spine, highlighting its relative rigidity and its implications on the horse’s athletic performance. The study used post-mortem specimens from thoroughbreds to gauge the TL spine’s range of movement, and discusses potential causes and treatments of common back ailments in horses.

Understanding the Thoracolumbar Spine in Horses

The first part of the study details the functional anatomy of the horse’s thoracolumbar (TL) spine, more commonly known as the area from the horse’s mid-back to its lumbar region. Specifically, the paper examines how the structural features of the equine back contribute to its relative inflexibility.

• The morphological characteristics of the equine back, which hint towards its inflexibility, are described and this notion is corroborated by various experimental studies.
• In order to determine the range of movement, fresh post-mortem specimens from five Thoroughbreds were used. Measurements were taken from the mid-thoracic to the cranial lumbar region (T10-L2).

Range of Motion in the Horse’s Back

The researchers found that:

• On maximum ventroflexion (downward bending), the individual spinous processes could be moved by an average of 1.1-6.0 mm.
• On dorsiflexion (upwards bending), the average movement was 0.8-3.8 mm.
• The total flexibility of the back was approximately 53.1 mm.

They further noted that there was little to no lateral or rotational movement in the horse’s spine past the midpoint of their back.

Common Back Troubles in Horses

The authors then discuss common causes of back problems in horses. They focus particularly on vertebral subluxation, a condition that is often treated by chiropractic manipulation.

• They argue that this condition might be misnamed from an anatomical perspective, as it might largely be due to a muscular imbalance leading to spastic scoliosis (a type of spinal curvature caused by muscle spasms).
• The paper doesn’t refute the existence of these conditions, but instead suggests a reinterpretation based on the anatomical evidence presented.