Over much of the past year, through this series I have presented the building blocks of information needed to understand the structure of the forelimb reciprocating apparatus in horses. Starting from collagen and elastin at the molecular level and working through all the various connective tissues structured by those two molecules, you have had the opportunity to learn equine anatomy and terminology as enrolled university zoology, pre-medicine or pre-veterinary majors would.

Writing this installment in our Equine Reciprocating Limb series, I could not help but hear the lyrics to Bob Dylan’s “Subterranean Homesick Blues” running through my head — especially the punch line: “The pump don’t work ’cause the vandals took the handles.” That very aptly sums up one of my main points: if anatomical parts aren’t connected, reciprocation does not happen.

Most, if not all, farriers are already familiar with the chain of bones that forms the equine forelimb: scapula, humerus, radius-ulna, carpal bones, cannon bones and splints, pastern bones and coffin bone. Added to this list are the three pseudo-bones called sesamoids, which lie behind the ankle and coffin joints.

The periosteum, thin but tough connective tissue that enwraps all true bones, was the focus of the third installment of this series, “Equine Reciprocating Systems: Connecting Tendon to Bone.” Knowledge of the periosteum creates a good starting point for learning the structure of joints.

In the fourth in this series, Dr. Deb Bennett illustrates the relationship between the horse’s forelimb and the body.

The forelimb reciprocating apparatus of the horse is a unique and important biomechanical system that every farrier must understand before good decisions concerning hoof trim and appliances can be made. Detailed study of tissue types is the first step, but we also have to be careful of our choice of terminology.

In the first installment of this series on the anatomy and function of the forelimb reciprocating apparatus in horses (September/October 2019 American Farriers Journal), I discussed the many differences between white vs. yellow ligament tissue. In this installment, we focus on the relationships between muscles, the tendons of muscles, and yellow ligaments.

The specialized and fascinating anatomy and function of the reciprocating systems, which aid locomotion in horses, is crucially important for farriers. I want to begin by clearing up some confusions about anatomical terminology, as well as make clear my approach to teaching horse anatomy.