Equine Conformation - Conformation of The Pasterns

Conformation of The Pasterns

The angle of the pasterns is best at a moderate slope (about 50 degrees) and moderate length.

Pasterns Long and Sloping

• The pasterns are long (more than 3/4 length of cannon) relative to rest of leg.
• This defect affects long-distance and speed sports
• Long pasterns have been favored because they can diffuse impact, giving a more comfortable ride. However, excess length puts extreme tension on the tendons and ligaments of the back of the leg, predisposing the horse to a bowed tendon or suspensory ligament injury. The suspensory is strained because fetlock is unable to straighten as horse loads the limb with weight.
• The pasterns are weak and unable to stabilize fetlock drop, so the horse is predisposed to ankle injuries, espescially in speed events where the sesamoids are under extreme pressure from the pull of the suspensory. This can cause sesamoid fractures & breakdown injuries.
• May be associated with high or low ringbone. Increased drop of fetlock causes more stress on pastern and coffin joints, setting up conditions for arthritis.
• There is a delay time to get the feet off the ground to accelerate, and thus long pasterns make the horse poor for speed events.
• The horse is best for pleasuring riding, equitation, and dressage

Pasterns Short and Upright

• A horse's pasterns are short if they are less than 1/2 length of cannon. The pasterns are upright if they are angled more toward the vertical. A long, upright pastern has the same performance consequences as short and upright.
• Most commonly seen in Quarter Horses, Paints, and Warmbloods
• The horse is capable of rapid acceleration, but is restricted to a short stride. They excel in sprint sports. The short stride is a result of both a short pastern and upright shoulder, creating a short, choppy stride with minimal elasticity and limited speed.
• Short pasterns have less shock-absorption, leading to more a jarring ride and amplified stress on the lower leg. The concussion is felt over the navicular apparatus, so the horse is more at risk for navicular disease, high or low ringbone, and sidebone. Also windpuffs and windgalls occur from chronic irritation within fetlock or flexor tendon sheath.
• The horse has reduced mechanical efficiency for lifting and breaking over the toe, so it may trip or stumble.
• The horse is best for sprint sports like Quarter Horse racing, barrel racing, roping, reining, and cutting