How to Measure the Shoulder Angle on a Horse

A horse's conformation, or its proportionate dimensions, is often a good indicator of his athletic abilities and talents. The shoulder angle on a horse is commonly measured as an indicator of the scope of the horse's gait and smoothness. The angle of the shoulder, combined with the rest of the animal's conformation, may be evaluated or judged during competition.

  1. Basics of Shoulder Measurements

    • A horse's shoulder can be measured in several different ways, with each measurement having different positive and negative attributes. For a better understanding of your horse's shoulder conformation, you will need to measure the slope of the shoulder, the angle of the shoulder and the length of the humerus. The humerus is the length of leg that spans between the shoulder and the elbow. Depending on the measurement of the various aspects of the shoulder, a horse may be considered a good prospect for specific riding disciplines and a poor prospect for others.

    Measuring Shoulder Angle

    • You measure the angle of your horse's shoulder by using a protractor to take the
      measurement of the joint between the scapula and the humerus. The scapula is the line between the wither and the shoulder. The humerus runs between the shoulder and the elbow. The joint exists where the two meet. A 90 degree angle is considered a fairly normal shoulder. A shoulder angle that measures less than 90 degrees is considered to be closed and may restrict the amount of movement possible if the slope of the shoulder is more upright than normal. A shoulder angle that is more than 90 degrees is an open shoulder that may allow the horse freer and more fluid movement.

    Shoulder Slope

    • Shoulder slope is often used in connection with the shoulder angle to evaluate the likelihood that a horse has good movement and gait under saddle. The slope is measured by drawing a straight line between the wither and the shoulder, then measuring that line against the horizon. Most horses have a shoulder slope that is between 45 degrees and 55 degrees. A slope of less than 45 degrees is considered to indicate an laid-back conformation of the shoulder. A slope of more than 55 degrees is considered upright. Horses with an upright shoulder often have short strides and choppy gaits, so an upright shoulder is not considered a desirable attribute.

    Humerus Length

    • A long humerus is thought to add more scope to a gait, improving the reach, arc and ability to perform smooth lateral movements. Humerus length is measured in percentages based on the length of the shoulder blade. For example, if the humerus is at least 50 percent as long as the shoulder blade or longer, the horse is thought to have a long humerus and therefore will likely have better gait and athletic abilities.