High risk the saddle will slip sideways. The horse's barrel becomes wider and rounder the farther back it goes, and the withers also become lower before blending into the back altogether, leaving nothing to prevent the saddle from sliding. Pressure on the horse's loins, which is not only uncomfortable for the animal, but may cause damage to the spinal column, particularly the lumbar vertebrae, which are not supported by the ribs. Pinching and pain in the loins and hips. Lack of balance by the rider in the saddle, as the rider will be perpetually behind the motion of the horse. Misbehavior by the horse due to discomfort. The pommel of the saddle will drop downwards, making the rider 'slide downhill' in the saddle and increasing the risk of a fall over the shoulder. Fitting the horse A saddle must be measured for width, length, and front arch height (clearance over the withers). In ideal circumstances, the saddle is tried on the horse prior to purchase, or is purchased with a return option if it does not fit. When saddle shopping, or if having a saddle custom-made, one method of sizing the horse is known as a "wither tracing." To create this, an artist's flexicurve or a piece of coat hanger wire is placed up over the withers about two inches behind the horse's shoulder blade, then shaped to fit across the withers. The shape is then traced onto heavy paper or cardboard. An average horse can be fitted with just this measurement by comparing the angle of the wither tracing to the angle of the piping at the front arch of the saddle. However, horses with an unusual shape are measured in three locations, the second measurement approximately two inches behind the first one, and the last measurement nine inches behind the withers. Often for accurate measurements, a professional saddle fitter may need to be consulted. Tree width The tree width, which dictates the width of the saddle and height of the gullet, is one of the most important factors when fitting the saddle, and can be tested easily by looking at the sweat pattern on the animal's back after work. A tree that is too narrow is more of a threat than one too wide, as it pushes the points of the saddle tree into the horse's back. This will often result in a hollowing if it persists for