Ears forward and eyes fixed, the horse concludes his gallop in front of the fence. He gathers himself and leaps gracefully into the air, clearing the obstacle with ease and landing on the other side of the obstacle to gallop on to the next challenge. In competition, the hunter and jumper repeat this action over a course of fences, the difficulty of which at the upper levels can almost exceed the limits of the human mind. While hunters and jumpers compete individually over fences in their respective disciplines, the basis of their competitions is vastly different.
Hunters in the United States jump in a ring or hunt field, in a round that lasts less than two minutes. They are judged subjectively on form--how they jump fences that resemble those a hunter would encounter cross country. Judges must penalize the hunter for certain "faults," including refusals, knocking down rails, and style.
The jumper faces more demanding, colorful obstacles set at "technical" distances. The course asks horse and rider to clear every obstacle within a specific time frame.
Both hunters and jumpers jump two basic types of fences: the vertical and the spread. The horse must calculate height and breadth in his approach, so he can leap in an arc appropriate to the fence's dimensions. A vertical fence requires a tighter, higher arc, while a flatter arc clears a wide spread.
Worldwide, jumping is a sport popular with spectators. A crowd of 30,000 watched jumping at the 1996 Olympics; the Aachen, Germany, Festival of Equestrian Sport, considered the world's top show, attracts 200,000 spectators over six days. Generous sponsors boost jumper prize money for major events, and horses can earn thousands of dollars or even a new Volvo or Mercedes, for owners and riders. In the United States, the Grand Prix is the highest level, with more jumping efforts, longer distances, and more combinations of jumps placed fewer strides apart.
American Horse Shows Association (AHSA) rules apply to most U.S. shows, with smaller organizations adopting the national rules. The rules of the Federation Equestre Internationale (FEI) govern international show jumping events worldwide.
Selection For Jumping
Any horse can jump. Superior jumpers--animals which jump the course powerfully and cleanly--are of the sport horse type. Germany's Hanoverian stud book boasts the world's top jumpers, as reported in the current world breeding rankings of the World Breeding Championships for Sport Horses.
German breeders rely on Hanoverian breeding stock, which have proven themselves through generations of champions. Stallions are selected, trained, and tested for their performance ability. The breed is known for courageous jumpers.
In decades past, U.S. riders have relied on the American Thoroughbred. Daniel Flynn, VMD, noted that of his equine clients, about half the top show hunters now include European sport horse lines in their ancestry.
"We have bred the Thoroughbred to race," said Flynn, who practices at Georgetown Equine Hospital in Charlottesville, Va. "In my opinion, over the years they've had less and less ability to jump. Even if a Thoroughbred may be an exceptional individual (at jumping), he does not transmit that ability (to the next generation). The warmblood can transmit that ability from generation to generation."
Another prominent veterinarian, Richard Mitchell, DVM, practices at Fairfield Equine Associates in Monroe, Conn. He said, "The most outstanding jumpers I took care of in my life were mostly Thoroughbreds, such as Albany, For the Moment, and Gem Twist. The vast majority now are European imports."
Both jumpers and hunters still demonstrate the influence of Thoroughbred blood, which French, German, and Dutch breeders infuse to improve refinement and speed. These horses are built to gallop with long strides in a smooth, fluid movement.
The ideal jump is an extension of the galloping stride. The horse can "use himself" over a fence, which means he is able to coordinate his muscles to sustain and control forward movement. He ascends, floats over the obstacle, and lands.
The hunter should flow across the ground and jump in a perfect arc, clearing the fence by six to 10 inches. A clever jumper, faced with high, wide obstacles, knows exactly how high to leap to clear the top rail. In either discipline, the horse needs scope, to take off at a safe distance from the fence.
"The jumping horse differs from the running horse or the trotting horse," explained Mitchell. "He has to not only gallop across the ground, but at some point his conformation has to be adapted to some degree to be able to change some force vectors--so he is able to catapult himself up. Jumping requires some unique anatomical features."
Hind leg activity is transmitted forward, so the horse covers ground at the gallop and thrusts his body over the obstacle. He propels himself with his front end, changing the direction of energy by shifting his weight forward. He drops his neck and lightens the croup so he can flex and spring from both hind legs. He raises the forehand while his hind legs extend to project him over the jump.
At a meeting of the American Horse Council, Marvin Beeman, DVM, discussed the jumper's relationship of form to function. He analyzed the Olympic horse, Calypso, in the takeoff: "Look at the pressure on his hind legs--the angle of his stifle, the length of his tibia, the length of his cannon bone as a lever. Does it not make sense that a shorter cannon bone is more applicable to a horse that is going to propel himself?"
In flight, the horse folds his forelegs so his forearms are parallel with his underline. He bends at stifle and hock to carry his hind legs over the fence.
To land, his legs extend so one forefoot touches the ground ahead of the other, signaling the lead the horse will resume. In the subsequent galloping stride, he rebalances his weight to resume the gait.
Beeman explained, "As he lands over the fence, look at the pounds per square inch of energy that the horse has to accept on his front limb. When you assess conformation, look at those things that accept the greatest amount of pressure."
Along with physical ability, the jumper has to want to jump. The activity requires a bold attitude--lazy horses don't jump carefully or consistently. The hunter must express confidence, while a jumper adds the quality of aggressiveness. Both types must respond amenably to the rider's cues and never refuse to jump.
Conformation on the Line
"We like a horse with good balance, a lot of depth to his body," said Flynn. "We like a horse with good bone, and we use the term flat--the bone is more elongated from front to back. The flat-boned horse is generally one with desirable muscle mass."
The horse with substance shows the ideals of a strong chest, sufficient tendon behind the cannon bone, an elegant neck, and powerful muscle mass in the hindquarter.
Mitchell described a good jumper as showing "a fairly high wither and long scapula, with a fairly low angle. The shoulder is long and sloping, not upright and straight, which gives the horse the ability to plant the front end. He has the strength to spring off like a cat would jump up in the air."
He said that the hunter should not be too broad in the chest, which can affect the quality of movement. "You want the horse to be deep in the chest from withers to the heart girth, but not necessarily thick from side to side. In the motion behind, a mild stifle angle allows the hunter to propel himself across the ground and to step underneath himself, without too much angulation. A lot of angulation tends to make the hunter move a bit high behind."
Muscle development affects the horse's ability to lift the forearm to a horizontal angle, and to fold the front legs over the obstacle. A horse that "hangs" over a fence is more likely to hit the top rail.
Dutch sport horse authority Gert van der Veen explained how the jumper benefits from a relaxed back over fences. He said: "Most horses resist through a taut back. A cooperative back is the center of the horse. You don't want a straight back, which isn't supple. You need a back that curves. An absolutely straight topline lacks the power to carry weight."
Hunter judges prefer the flexible, rounded back over the fence, rather than a horse that jumps "flat." A hollowed back is considered poor form.
Strong, supple muscles propel the jumper in the takeoff. The horse benefits from a long hip with good stifle angulation. Mitchell said, "I like to see a greater distance from the top of the croup to the point of the buttocks, or from the tubera sacrale to the tubera ischii. A long hip gives the horse a bigger gluteal muscle, and that can provide for more power."
He added, "I find that the really good jumpers tend to be a little higher through the croup and withers. They're not quite as smooth and pleasing to the eye as the hunter."
Hunter fanciers have preferred the horse with a straighter hind leg. Mitchell described this as a horse with a straighter, more vertical stifle, which can limit the power of the horse's takeoff. "The horse needs angulation at that point so he has something to straighten there muscularly, and then to give him the spring. I like to see a jumper have a fairly marked angle to his stifle, from his femur to his tibia, then a fairly straight angle down through the hock joint itself down to the cannon bone." He added that the forward sloping femur forms a smaller angle between the tibia and femur and gives the horse more power. A plumb line dropped from the point of the buttock can run along the back of the cannon bone to the ground.
In the takeoff, the horse rocks back on his hocks, and strong hocks contribute to his ability to spring. Horsemen debate the pros and cons of the sickle hocked structure, with some claiming that this can improve power in the hind end. However, a conformation that is both sickle hocked and cow hocked can lead to problems in the hock and stifle.
Flynn described an ideal gaskin as long and powerful. "We like a lot of distance through the gaskin, viewed from the side. You want a nice blending down back to the point of the hock, out of the thigh and down through the gaskin."
The jumper relies on sound forelegs. Landing stresses the limb, so the foreleg must be well positioned to endure weight-bearing. The suspensory ligaments and deep and superficial flexors absorb the load. Mitchell recommended a pastern angle of 50 to 52 degrees, which approximates the angle of the shoulder.
European authorities have performed scientific studies on conformation. A French study reported that good jumpers showed a wide chest and pelvis, greater heart girth, a longer pelvis, and a forward sloping femur. A Swedish study, reported by M. Holmstrom, noted no jumper less than 160 centimeters tall at the withers. The jumpers tended to have longer necks than dressage horses. Jumpers also had smaller fetlock angles in the forelimbs than other horses in the study. Holmstrom wrote, "There is a positive relationship between conformation and jumping ability, mainly due to width of the front cannon at the middle, length of the hind phalanx, and angle of the stifle and hock joints."
Demands of Jumping
AHSA hunter classes are judged on performance and soundness. After the horses jump the course, the judge calls ribbon contenders back in order of preference. Each must jog for soundness, with the rider leading the horse.
Only serviceably sound horses can win ribbons. This is defined as not showing any lameness, broken wind, or blindness. Because hunters don't confront as difficult a course, structure deviations might not affect their soundness as dramatically as it would with jumpers.
Jumpers aren't jogged after performing. FEI rules require each competitor to be presented to the ground jury prior to the show. These judges agree whether to accept each animal as fit to compete.
Top Grand Prix jumpers might tend to have long backs, combined with a broad, strong loin. "These horses have a good spring to the ribcage," said Flynn. "There's a lot of depth and power. Through the lower back, they have the power to sustain or prevent themselves from being injured through the back."
He noted that a weaker long back is associated with weakness through the hind end, and back pain. A stronger structure shows muscle mass going from the back's long muscles into the loin and down into the croup and gaskin.
Mitchell said that the long-backed jumper can have more problems, especially as he ages and gravity affects the back's structure. "I like to see a horse stand over a lot of ground, but it needs to be in proportion to the rest of his body."
The "jumper's bump" is formed by the tubera sacrale, and one side of the sacroiliac joint can rise higher than the other. Flynn said, "When you see one side higher than the other, it means that there is some subluxation of the sacroiliac on that side. This can be rather prominent in some horses, and many times that horse is deficient through the length of the croup. He loses some of that long power of the muscles." Pressure of collection and extension affects the muscles' strength and stresses the sacroiliac ligaments.
Back pain and croup pain are common, along with pain in the stifle. Flynn said, "These are areas that are exerted and sometimes over-exerted. The horse that twists his hind end over a fence--this pain would occur as a primary injury."
Like other equine athletes, hunters and jumpers show the highest incidence of lameness in the front feet. Mitchell prefers to see a forefoot with the heel's weight-bearing surface back underneath the cannon bone, when viewed from the side. He named the underrun heel with a long toe as the greatest cause of foot and leg problems that he sees in jumpers.
Fixing this condition can be difficult, because of the horse's conformational adaptation, growth of tissue, and the way he adjusts movement. Mitchell named the Olympic jumper Albany as an example: "I struggled with his feet for years. He was a racehorse and came off the track with a grossly underrun heel and long toe. We never could change it. We dealt with it through an egg bar shoe that was fully fitted and a minimum toe." During this horse's career, he suffered from crushed heels and heel bruises. Such heels can be caused through trimming.
In regard to other structures of the forelegs, Mitchell said, "An extremely long, sloping pastern in the jumper will predispose him to a variety of problems. The most common are suspensory and tendon problems. The long pastern is probably too flexible. And the horse with an extremely short, stubby pastern puts too much concussion on his feet--coffin joints in particular."
The suspensory apparatus in forelimbs is a frequent area of soft tissue injury. Flynn said, "You want sufficient bone and tendon under the knee. The horse should show a lot of tendon there, because the tendon goes together with the suspensory apparatus.
"An ideal conformation structure includes a short cannon bone. You minimize the risk of injury with a shorter distance from knee to fetlock. The horse with a longer cannon bone not only doesn't have as much length of forearm and musculature to give him power and speed, but it's also a weakness from the standpoint of structure."
Flynn added that front foot lameness can relate to stasis in the foot. The trainer or rider schools the horse over fences, then returns him to the stall to stand. Instead of moving around to recover circulation to the foot, the horse rests after putting pressure on hard and soft tissues. "I use the term foot syndrome. I relate it to circulation to the foot--it is related to trauma and the pressures from high jumping."
He noted that the horse which is lame in the front feet can incur a secondary injury in the hind end by pushing into his forehand. "The forehand is not free, and it creates pain through the hind end, especially through the hocks. The horse goes lame in the back end, and you learn where the primary problem is--in my opinion, it's always in the front feet."
An important injury area of any horse which jumps is the soft tissue of the poll and cervical spine, said Flynn. The jumper uses his neck for balance in takeoff, flight, and landing, and pain in the poll can affect the spine through the croup. "The head and neck exert a tremendous amount of pressure. We actually do have subluxation that is readily palpable of the atlantor occipital joint."
The good jumper withstands the sport's demands and performs amazing feats to clear fences. His scope of motion inspires awe at the beauty and grace of the equine athlete in flight.
About the Author
Award-winning writer Charlene Strickland lives in Bosque Farms, N.M. She has published 8 books and over 600 magazine articles, and is a member of the International Alliance of Equestrian Journalists.
POLL: Radiographs for Hoof Care