Three-dimensional CT observation of position and movability of the scapula in the horse using carcasses of Falabella.

This study analyzes the positioning and motion of the scapula in horses using CT scanning and image analysis on the carcass of a Falabella, one of the smallest horse breeds. The results indicate morphological changes in the scapula that adapt to varying body weights among the horse breeds, providing insights into horse locomotion.

Understanding the Objective & Methodology

• The research aimed to examine the scapula’s (shoulder blade’s) position and movability in horses. Since typical horses are too large for comprehensive CT scanning and image analysis, the study utilized a carcass from a Falabella breed, one of the smallest horses.
• The scientists deployed three-dimensional CT scanning to observe the entire skeletal system in the thoracic (chest) part of the Falabella horse.
• They then used this data to create three-dimensional images and simulation to further understand the position and movement of scapula.

Analyzing the Findings

• These images show that the scapula slides towards the head (cranially) and the lower part of the scapula (ventral part) rotates towards the back of the head (dorso-cranially) when the shoulder joint is in its most forward (cranial) position.
• The angle of this three-dimensional rotation was found to be roughly 10 degrees.
• The scapula’s comparative osteology (study of bone structure) between the Falabella and a larger draft horse revealed that the infraspinous fossa, a cavity on the scapula, was larger towards the tail (caudal) in the larger horse, while the Falabella had a narrower infraspinous fossa.

Implications of the Study

• The difference in the size of the infraspinous fossa between the Falabella and the larger draft horse is speculated to be an adaptation to various body weights among different horse breeds.
• These findings indicate that the use of CT scanning and simulation on smaller horse breeds like the Falabella can shed light on bigger horse breeds’ bone movements during various locomotions such as walking and running.
• Further, this study could be a foundation for external and functional-morphological motion analysis in horses, which could eventually have implications in horse health, performance, and veterinary sciences.