Biomechanics of the Horse

“By biomechanics we mean the way that muscles move bones to produce and sustain various forms of action: as regards the horse, mainly locomotion: as regards the rider, mainly position and giving of aids.”—Hans von Blixen-Fenecke
Horse biomechanics are how horses operate physically. It varies with different conformation. Each maneuver, such as movement, trick, or exercise, has its own specific mechanic. Horse biomechanics also vary depending on how the horse is operating and carrying himself at the moment, such as inverted, stretched, sagging, or coerced. Osierlea, located in San Juan Bautista, California, offers horse training, which evaluates the progress of the horse based on three criteria:
» Improvement of the Influence - Ability and Attitude and the Understanding and Execution of the Movements (Psychology of Learning)
» Improvement of the Physique (Biomechanics)
» Improvement of the Gait (Biomechanics)

Understanding Biomechanics

Dressage is decades behind most other sports in recognizing the "basic-ness" of understanding biomechanics. We have been bogged down for decades by dogma, conventions, and misconceptions. Stephen J. Gould, of Harvard University, said, "what passes for knowledge is often dogma." This is often called "classical" in the dressage world—meaningless but catchy.

The Connection Between the Horse and the Rider

Rider biomechanics directly affect the horse's biomechanics, as the horse tries to make itself comfortable under the rider. Horse biomechanics and rider biomechanics cannot be taken in isolation. The final system is an interaction between horse and rider mechanics. To give you a better understanding, here are four helpful terms related to biomechanics:
Penny and Dream with Jane Bartle-Wilson at Osierlea
» Adduction: To move a limb toward the horse's midline.» Abduction: To move a limb away from the horse's midline.» Bend: The laterally arced position in which the horse's body appears to form a uniform curve from poll to tail. Attributes of bending include lateral flexion at the poll, stretching of the outer side of the body, lowering of the inner hip, and adduction of the inner hind and outer forelegs. Examples of faulty bending are bending only in the neck, bending only at the base of the neck, or bending toward the wrong direction.» Engagement: The bending of the joints of the grounded hind leg. Not a measure of how far forward the hind legs reach, but of how little they are on the ground after the body passes over them in the (mid) stance phase.
*Similar definitions for purity of gait, quality of gait, straightness, balance, and other commonly used terms can be found in the USDF Glossary of Judging Terms, which was written by Jeff.