Comparisons of humans to horses logically can start with the anatomy. We stand upright; horses stand prone on their four limbs. What we call our knees are the stifles of horses, and our heels or ankles are horses’ hocks. Our foot is their cannon bone, and from the fetlocks to the ground are our fingers and toes. Our fingernail is their hoof, and our nail growth generates from the cuticle, their hoof from the coronary band. The hoof is the weight-bearing structure so susceptible to laminitis (founder). Humans don’t founder, although a diabetic’s loss of blood supply to the legs has some comparable pathology.

The forelimb is complex in the horse, with the head and neck being a crane-like structure that causes 60% of a horse’s body weight distribution to the forelimbs. Therefore, impact is greatest on the front legs (except when pushing off from behind).

Skeletal anatomy of a horse

Equine skeletal anatomy

What we really call the horse’s knee is our wrist. From our wrist to the first knuckle is their single cannon bone, with the splints along the side being remnants of our other palm bones. Again, each finger is analogous to the horse’s single fetlock and hoof. Our hands and feet are well endowed with muscle. Contrary, the forelimbs and hind limbs of the horse are essentially devoid of muscle below their so-called knees and hocks, with the tendons and ligaments being a “spring loading” system of recoil that adds to their efficiency of movement.

Because we stand upright and they are prone, this creates the forelimb concussion issue for the horse, but also loads the spring.

Horses don’t have clavicles (collarbones), so the front limbs are held to the body by soft tissue alone (musc