Center of Gravity
The most exciting biomechanical idea current in the latter half of the 19th century was the discovery of the “center of gravity” (CG). An invisible, infinitely small point, the CG is nevertheless real: it is the point at which a body fundamentally responds to a gravitational field. The CG is the point about which a horse’s body can be suspended without tilting.
The horse’s weight is distributed over its haunches and forehand. Because of the heavy head and neck, the horse carries a greater amount of weight on its forehand. When in motion, the horse uses its head and neck to influence its balance.
One of the key elements of cowboy dressage is improving the horse’s balance. By teaching the horse to carry more weight of the forehand with its haunches, the forehand lightens and makes the horse more agile and balanced.
The sling muscles are extremely important to the self-carriage of the horse. The goal in our training is to teach the horse to use its sling muscles throughout the workout. With time, these muscles get stronger and the persistent elevation allows the horse to push and hold its hind legs under the center of gravity through its motion to be even more pronounced and uphill.
The ‘sling muscles’ consist primarily of the serratus ventralis thoracis muscle assisted by the pectoral muscles. Contraction of these sling muscles lift the trunk and withers between the shoulder blades, raising the withers to the same height or higher than the croup.
The average horse carries 55 percent of its weight on its front legs and 45 percent on its hind legs.
On the 1st beat the horse is carrying is weight on the outside hind leg. On the 2nd beat the horse is carrying is weight on the inside hind leg and the outside front leg. On the 3rd beat the horse is carrying is weight on the inside front leg.
The horse must learn to move in an uphill balance by pushing upwards with its forelimbs. The hind legs can then function as they should by carrying more weight and by providing pushing power. The heavy chest needs to be up and out of the way for the hind legs to push.
If the horse doesn’t have the strength in his front legs to lift the body up, or if he lacks the confidence in his hindquarters to support and lift, he will try to speed up or lower his neck and lean on the reins.
Gustav Steinbrecht says “that the resistance you feel in the bridle usually finds its support in one of the horse’s legs”. In many cases it’s a hind leg, in others it’s a front leg. The horse can only brace and lean on the bit as long as this leg is on the ground. He uses the ground against the rider. When you ask him to pick this leg up, he has to redistribute his weight to the other side of the body. Otherwise, he would fall down.
There is a distinct correlation between the rider’s posture and the horse’s posture as they train together. If the rider’s core muscles are not engaged, then the horse’s core muscles also will not be engaged. Even though the horse has a distinct advantage in having four legs, a rider must learn to hold his or her own posture in order for the horse to engage its own core strength, which is necessary for it to hold its frame up.
A horse’s self-carriage is achieved through controlled tension of the muscle groups. There is a muscle ring that wraps around deep inside the horse through its back and abdominal muscles which allow it to maintain roundness of its back. The abdominal muscles encase the abdomen from the pelvis to the ribcage to the sternum. Contraction of these muscles and the back muscles allow the horse to be supple and loose to free its legs to push and carry all of its weight.
Most riders think that only the hind legs need development and push. More accurately, the push from the hind legs has to be supported by the upward push of the front legs. So pushing power of the hind legs must be harnessed by the elevation of the forehand so the horse can perform with controlled power in an uphill balance.
The balanced rider will be sitting over the center of gravity of the horse (gold circle). The red circle shows the position of the center of gravity in an untrained horse and will move further back to the gold circle after correct training
