This spring I attended a breeding seminar that featured a panel discussion with prominent warmblood breeders in our region. One of the breeders in the panel challenged the prevailing philosophy of breeding specialization. These days, many breeders develop and market their horses for one discipline, typically either dressage or jumping. This panelist advocated the return to breeding "all-rounders," and she promoted her program as a successful example.
Both dressage and jumping require a superior equine athlete at the highest level of competition. In the not-too-distant-past of warmblood breeding, stallions such as Grundstein (above left) have produced horses that excelled in both disciplines. So what's the reasoning behind specialization? Well, the research suggests that while there are many commonalities in the conformation of the two types of competitors, there are also some critical differences.
Show jumping conformation traits
I'll be honest. Front end conformation has always baffled me, so this little bit of research helped my understanding of this aspect of conformation. The horse's entire foreleg should be thought of as one unit because the bones cannot move independently of one another. I'll talk mainly about the shoulder (scapula), humerus, and radius. See the picture of the gray below for reference.
For jumpers, there is no one correct configuration of the scapula, humerus, and radius. The critical conformation issue is, can the horse lift his knees high and out of the way? A successful jumper can have a shoulder that is either upright or laid back, but usually it is more the former than the latter. The scapula and humerus should be an open or steep angle (90° or greater, see photo of the bay below), and the point of shoulder -- where the humerus and scapula meet-- is fairly high up toward the neck. A long shoulder with a more upright angle offers a greater range of motion, because the scapula can rotate further backwards. This way it is easy for them to get their knees up.
The best jumpers usually have a long humerus. A long humerus generally means the horse will have a long stride and the ability to move the legs away from the rib cage, which helps make for a scopey jumper. In contrast, a more horizontal humerus or a shorter humerus will result in a shorter, choppier stride. A horizontally placed humerus also puts the leg farther under the horse, which makes it harder to get the front legs out of the way of the jump.
Note joint angles and how they fold up over a jump
The hindquarters provide the power, and the joint angles are critical in creating the upward trajectory. The point of hip to the point of buttock to the stifle should form an equilateral triangle. These are more closed angles than are seen in a dressage horse, and permit a greater coiling and release of energy. In a jumper, it is critical that the stifle be low and out of the way. The lower the stifle, the greater the scope (height and width the horse can jump), and the longer his stride will be. Hock angles for a jumper tend to be more closed. Again, this provides for more coiling and springing action. A show jumper tends to have a long neck, set fairly high, to assist with balance over the top of a fence. Their balance overall is usually level or slightly uphill.
A dressage horse needs to have a lot of forward reach from the shoulder -- out rather than up. A laid back shoulder provides the freedom to extend the forelegs. It is also desirable in dressage because it places the wither farther back, and thus puts the rider further back, over the horse's center of gravity. As with jumpers, dressage horses should have a long humerus. This increases the horse's ability to move the elbow away from the torso either toward the front or to the side, as in a half-pass. In a dressage horse, a long forearm will help to make the uphill build that is so critical to dressage. Extra length in the forearm and shorter cannon bones are advantageous for height and soundness.
Both the jumper and the dressage horse will need a high neck set. The dressage horse tends to havea shorter, more upright neck than the jumper -- the neck rises out of the withers at an angle that is close to 45 degrees. A long neck is not needed as a counterbalance (e.g., over the top of the fence), and it can actually make for a more difficult ride. While a longish neck is undeniably beautiful, it is not necessary, and horses can use a long neck to evade the aids.
The hindquarters are similar to the jumping horse overall. A critical feature for both dressage and jumping horses is to have the lumbosacral (LS) joint directly over the point of hip. This maximizes the power of the hind leg by making the most of the LS region's rotation. The LSJ is the only point of the vertebral column that allows significant amounts of flexion and extension. Dressage horses tend to have a longer femur (point of buttock to stifle) and shorter, more level ilium (point of hip to point of
buttocks) when compared to jumpers; their hip angles form a "7" where the downward stroke is the femur. They have a more open angle from ilium to femur, and while the stifle should be low, this is not as critical for the dressage horse. Dressage horses will tend to to have a straighter hock, as it will require less effort to close the joint angles and collect.
Having read all this, I understand the rationale. But there are so many other factors aside from conformation and athletic ability -- most notably temperament. I keep these things in mind, but try not to get to fixated on one aspect of an animal. Horses have a tendency to prove us and all of our theories wrong!
Functional conformation from JW Equine
Really interesting Webliography of conformation traits for eventing, show jumpers, and dressage.
Specialization for riding horses (article on jumping/dressage specialization from the KWPN)
Sport horse conformation and the breeder from The Horse Magazine
Desirable conformation traits in the dressage horse
Conformation of the dressage horse from Dressage Unlimited (clinic report)
Dressage conformation illustration
Interview with Paul Schockomole from The Horse Magazine of New Zealand
Which thoroughbred best fits my needs? from Equisearch