The muscles of the head and neck can be categorized into superficial and deep muscle groups. The large, superficial back muscles span large regions of the spine and ensure coordinated back movements. The smaller, deep back muscles connect one or two vertebrae and act to move or stabilize individual vertebrae. The spinal ligaments connect the individual vertebrae and provide joint support. The neck and tail are the most mobile regions of the horse's spine.
Dressage requires a lot of spinal movement and strength.
Jumping high fences requires rotation of the back and hind limbs for proper gait and clearance of fences. The word that causes the most confusion when chiropractic is discussed in veterinary medical circles is subluxation. The traditional veterinary definition is an incomplete or partial dislocation, less than a luxation. However, the modern chiropractic definition is the alteration of the normal dynamics, an atomical physiological relationship of contiguous articular surfaces. In other words, the loss of normal motion between two bones.