Thoracolumbar movement in sound horses trotting in straight lines in hand and on the lunge and the relationship with hind limb symmetry or asymmetry.

The research highlights that movement in circles puts more strain on the hind limb gait and thoracolumbar movement of horses than movement in straight lines, implying potential issues for sound horses required frequently to move in circles.

Overview of Research Study

• The aim of the study was to evaluate the impact of different movements, specifically straight line movement versus circular motion, on the thoracolumbar kinematics (the movement of the jointed structures in the horse’s back) of horses that were deemed sound or non-lame. This was further correlated to the symmetry or asymmetry of the horse’s hind limb gait.
• The research involved collecting sensor data from landmarks on 14 non-lame horses that were trotting in straight lines and lunges on both reins. The landmarks included spots like the withers, T13 and T18, L3, tubera sacrale, and left and right tubera coxae.

Major Findings

• Data indicated that the term ‘dorsoventral movement’ refers to a motion pattern, which bore a resemblance to two oscillations per stride in a sinusoidal pattern. This suggested that dorsoventral movement is characterized by up and down motion.
• There were observable differences in the thoracolumbar movements of horses moving in straight lines and circles. Notably, circular motion induced greater dorsoventral movement asymmetry and a more significant amplitude of this movement at the T13 point.
• Likewise, greater range of motion (ROM) in flexion-extension, lateral bending, and lateral motion were induced when the horses moved in circles than in straight lines.
• The study also established that moving in circles created a movement pattern that resembled an inside hindlimb lameness which was significantly associated with the increased asymmetry of dorsoventral movement induced by the circular movement.

Implications of the Findings

• These findings suggest that circular movement can influence the gait of sound horses, potentially causing changes that resemble those seen in lame horses. Therefore, caution might be necessary when frequently working horses in circular patterns.
• The findings underline the complexity of equine locomotion and hold implications for diagnosing lameness or irregularities in gait, making it crucial to take the horse’s typical movement patterns into account.