Differences in equine spinal kinematics between straight line and circle in trot

Area of Science:

• Equine biomechanics
• Animal locomotion
• Equine sports science

Background:

• Circular movements are integral to horse training and dressage.
• Horses exhibit natural asymmetry in limb loading during circular motion.
• Scientific data on equine spinal and neck lateral bending during circles is lacking.

Purpose of the Study:

• To scientifically investigate and quantify lateral bending of the horse's thoracolumbar spine and neck.
• To compare spinal and neck movements of horses trotting on circles versus straight lines.
• To analyze the range of motion (ROM) in lateral bending during circular locomotion.

Main Methods:

• Twelve horses were analyzed using optical motion capture at 100 Hz.
• Horses were measured while trotting on straight paths and left/right circles without a rider.
• Markers were placed along the spine to record movement data.

Main Results:

• Horses showed increased lateral bending towards the inside of the circle for both the thoracolumbar back and neck.
• Lateral bending ROM increased on circles compared to straight-line trotting.
• Individual variations were observed, but horses maintained consistent movement patterns.

Conclusions:

• The study provides the first scientific evidence of increased lateral bending in horses on circles.
• Observed differences in back movement were subtle, but may be amplified by associated muscle and limb dynamics.
• Findings contribute to a better understanding of equine biomechanics in curved-path locomotion.