Q: I’ve recently started taking dressage lessons and have been told by my instructor to “bend” my horse around my inside leg in corners and on circles. Is this even physically possible? A horse’s back seems extremely rigid to me. His neck I can bend—but his back? Any insight would be greatly appreciated. Name withheld by request

A: In horses, the majority of lateral (side to side) bending of the spine does occur within the neck region. However, when you carefully watch how a horse uses his body to bite at a fly near his flank or to reach a carrot placed near his stifle, you will notice that he does have some ability to laterally bend his back.

In fact, the horse’s trunk (the region from the base of the neck to the beginning of the tail) has about 50 percent of the range of motion in lateral bending that is present in the neck region. This is opposite to people, where our trunk (or torso) actually has more flexibility in lateral bending than our neck does.

Research has shown that horses use their backs differently during various gaits. They tend to have more pronounced lateral bending of the back at a walk and a relatively stiff back while trotting. During the canter and gallop, flexion-extension (up-and-down movement) is the primary spinal motion noted, which occurs mainly at the junction of the back and the pelvis (at the lumbosacral junction).

Since most ridden exercise is done in a straight line or on a large circle, most horses do not fully demonstrate their ability to laterally bend their backs. However, flying lead changes or half-pass/shoulder-in movements do require a high level of coordination and trunk flexibility. Horses used for barrel racing also need to laterally bend their backs to get around barrels quickly and efficiently.

A horse’s back is designed so that lateral bending occurs mostly within the saddle region: from the seventh to 18th thoracic vertebrae. A well-fitting saddle is designed to support and not interfere with or restrict spinal or forelimb movements. But since the majority of saddles are made to be relatively stiffer than a horse’s back, riders may not be able to sense lateral bending of a horse’s back underneath the tack. Most Western saddles in particular provide a limited sensation of lateral bending since the saddles are heavier and cover a relatively larger area of the horse’s back than an English saddle does. The use of a bareback pad or treeless saddle would afford the best opportunity for a rider to sense lateral bending of the horse’s back.

Many dressage instructors ask students to “bend” the horse’s back around the inside leg while turning corners or circles. However, this may be more of a conceptual teaching aid used to help riders visualize the requested movement than a clearly observable physical phenomenon or distinct perception sensed by most riders.

For a horse to physically bend around a rider’s leg, the rider must guide the head and neck in one direction with her hands and reins and push the saddle and underlying horse’s back in the opposite direction with her inside leg. The goal is to create a smooth, uniform curvature of the horse’s neck and back with the rider’s inside leg placed at the middle of the induced lateral bending. Horses who lack appropriate trunk flexibility will bend their necks in the direction of the circle or turn but will not be able to laterally bend their backs in a similar manner, which produces the condition termed “falling out on the hindquarters.”

To improve a horse’s ability to bend laterally, try riding serpentines at a walk. This exercise requires constant changes in aids by the rider and alternating lateral bending by the horse. A horse with restricted or asymmetrical left-right lateral bending of the trunk may benefit from routine stretching exercises that promote flexibility and allow him to readily touch his nose to his stifle. Most human contortionists would be challenged to perform a similar bout of flexibility—touching the nose to the hipbone.

Kevin Haussler, DVM, DC, PhD
Colorado State University
Fort Collins, Colorado