At the initiation of breakover, the heels begin to unload as tensile forces in the deep digital flexor tendon overwhelm the extending moment of the center of pressure. The center of mass passes over the foot as the limb retracts under the body. The heels lift off at 80% of the stance phase.
- A horse’s movement and breakover are evaluated on a straight line, but horses spend significant time moving sideways, as opposed to directly from point A to point B.
- Toe length is critically important to breakover. Moving breakover back by removing too much toe undermines the structural integrity of the horn, which can lead to further lengthening, bending at the toe and blowing out the quarters.
- Before making adjustments that can influence breakover, consider the horse’s conformation, foot morphology, age and pathologies.
Life would be simpler if the definition of breakover, as it relates to horses, is as unambiguous as Merriam-Webster’s entry of breakover, as it relates to publishing. The dictionary describes breakover as, “the portion of a newspaper or magazine story continued on another page.” This leaves little room for interpretation.
Wikipedia’s mechanical description is closer. It defines breakover in that context as “the maximum possible supplementary angle that a vehicle, with at least one forward wheel and one rear wheel, can drive over without the apex of that angle touching any point of the vehicle other than the wheels.”
At its core, the mechanical definition emphasizes angles and the interplay between where…