The center of gravity is a theoretical point in the horse's body around which the mass of the horse is equally distributed. At a standstill, the center of gravity is the point of intersection of a vertical line dropped from the highest point of the withers and a line from the point of the shoulder to the point of the buttock. This usually is a spot behind the elbow and about two thirds the distance down from the topline of the back.

   Although the center of gravity remains relatively constant when a well-balanced horse moves, most horses must learn to rebalance their weight (and that of the rider and tack) when ridden. In order to simply pick up a front foot to step forward, the horse must shift his weight rearward. How much the weight must shift to the hindquarters depends on the horse's conformation, the position of the rider, the gait, the degree of collection, and the style of the performance. The more a horse collects, the more he steps under his center of gravity with his hind limbs.

   If the forehand is proportionately larger than the hindquarters, especially if it is associated with a downhill topline, the horse's center of gravity tends to be forward. This causes the horse to travel heavy on his front feet, setting the stage for increased concussion, stress, and lameness. When the forehand and hindquarters are balanced and the withers are level with or higher than the level of the croup, the horse's center of gravity is located more rearward. Such a horse can carry more weight with his hindquarters, thus move in balance and exhibit a lighter, freer motion with his forehand than the horse with withers lower than the croup.

   When evaluating yearlings, you need to take into consideration the growth spurts they have which make them have an uneven topline temporarily. However, be suspicious of a two-year-old that shows an extreme downhill configuration. Even if a horse's topline is level, if he has an excessively heavily muscled forehand in comparison to his hindquarters, he is probably going to travel heavy on the forehand and have difficulty moving forward freely.

  A balanced horse has approximately equal ratio between his front "leg" and his depth of body. The "leg" (lower limb length) is measured from the chest floor to the ground. It should be equal to the distance from the chest floor to the top of the withers. Proportionately shorter lower limbs are associated with a choppy stride.

   The horse's height or overall limb length is measured from the point of withers to the ground. It should be equal to the length of the horse's body which is measured from the point of the shoulder to the point of buttock. A horse with a body a great deal longer than its height often experiences difficulty in synchronization and coordination of movement. A horse with limbs proportionately longer than the body may be predisposed to forging, over-reaching and other gait defects.

   When viewing a horse overall, the right side of the horse should be symmetric to the left side. Asymmetry from left to right can lead to stiffness in one direction, difficulty bending or performing maneuvers to one side, or even lameness from left to right imbalance.

   Although horses with imperfect balance have become great performers, in general a balanced horse has an easier time performing and a better chance of staying sound.