Equine Lameness for the Layman. G. Robert Grisel, DVM

Referred gait abnormalities. An obligation to maintain diagonal synchrony and/or accommodate a dramatic shift in weight can cause the horse’s secondary limb to trip on occasion.

      The act of faltering usually occurs due to an event that transpires at the time of foot breakover (fig. 12.2) and/or during limb flight. Horses that experience excessive tension or pain during maximum limb extension (just before breakover) and/or pain-mediated or biomechanical restriction during flexion (limb protraction) will be predisposed to stumbling. Both of these issues are accentuated by circumstances that delay breakover of the foot and/or increase the length of the stride (an excessively long toe, for example).

       12.2 Foot Breakover

      During ambulation, the horse’s hoof works like a lever with the toe acting as the pivot point. The term breakover refers to the action of the hoof as it pivots over the toe to lift and move the limb forward.

       Muscle-Related Lameness