Understanding Your Horses Back
Did you know that horses have around 56 vertebrae which form a supporting framework for the neck, back and tail? There are 7 cervical (neck), 18 thoracic (withers and saddle region), 6 lumbar (loin region), 5 sacral (croup region) and about 20 caudal (tail region) vertebrae. The degree of movement varies greatly in different regions.
Consider the degree of range of motion in flexion and extension of the following joints;
90 degrees the atlantaoccipital joint which is between the skull and the first cervical vertebrae
15-35 degrees in the remaining cervical vertabrae
10 degrees in the first interthoracic joint, just in front of the withers
1 degee in joint at withers
3-4 degrees in joints under the saddle
30 degrees of motion in lumbosacral joint, between the last lumbar vertebra and the fused sacral vertebrae
This image demonstrates RJ/Hidalgo rounding his back, activating his abdominal muscles as he extends his back extends. Studies prove that the movements between the vertabrae are created by the forces of locomotion and are controlled by the horse’s back muscles. Thus, the back muscles do not cause the spine to round and hollow, the forces of locomotion do. The back muscles control the amount of rounding and flexing.
These findings are fascinating, allowing us to better understand our horses ability to move while training. You can find more information from Hilary Clayton at her web site www.cvm.msu.edu/dressage