Ashley Griffin, University of Kentucky
As one muscle in the body increases, total muscle mass increases. Muscling is visually appraised in the:
Heavy-muscled horses have greater circumference of forearm, gaskin, and width of hindquarter than light-muscled horses.
Today, the horse industry accepts muscling that is long, clean, and well-defined. The degree and amount of muscling will be determined by the breed.
For example, Arabian horses will not have as much quantity, bulge, ripple, and definition to the muscle structure as stock horse breeds.