The legs of the horses on most Republican denarii with quadriga reverse are usually depicted as stick drawings with knobbed joints. It seems that the artisan who created the design felt a compulsion to get a full count of sizteen legs with all four horses in the same pose. It was not because of the Romans' lack of skill at portraying the legs of horses, as an examination of coins of the emperor Probus will show. It appears to be an artistic convention, possibly to depict strength, power, and unity.