
The shoulder is unequivocally the most complex joint in the upper body. It utilized in virtually every movement, and there is a profusion of muscles connecting to and controlling the joint. To that end, there are a surfeit of shoulder exercises you can perform, each targeting a specific section of the deltoids, rhomboids and trapezius.
When most people think of the shoulder muscles, they are thinking of the deltoids—the large, ball-shaped group of muscles above the biceps and triceps. The most basic lift, which will target the full range of shoulder muscles, is the basic shoulder press. However, by slightly augmenting the lift, you can achieve an even more comprehensive workout. This variation is dubbed the Arnold Press, in recognition of its originator, Arnold Schwarzenegger. Begin with a dumbbell in each hand. Raise the weights to shoulder level and begin with your palms facing you. As you raise the weight above your head, twist your wrists 180-degrees, and perform the opposite motion to bring the weights back to the starting position.