According to the National Strength and Conditioning Association, or NSCA, when the entire range of motion is covered during resistance training, the impact of the exercise is maximized and flexibility can be maintained or improved. Specifically, training the rear deltoids can help maintain shoulder stability and prevent injuries.
Every muscle in the body has a particular function depending on its origin and its insertion point. A deltoid is a multi-pennated muscle used to move the arm through its full range of motion. The rear division of the deltoid muscle originates at the scapula or shoulder blade and inserts into the back of the humerus. Since the rear deltoid is on the back of the body, it is activated during a pulling motion.
According to Frederic Delavier, author of "Strength Training Anatomy," a standard pushup mainly targets the pectoralis major, triceps brachii and anterior deltoids. This push motion does not activate the shoulder extensors, which includes the posterior deltoids. Understanding that any pushup would not target the rear deltoids, a different motion is needed for effective training. These include exercises such as bent-over rows, one-arm dumbbell rows, seated rows, and bent-over lateral raises.
This movement contracts the major muscles in the back, including the rear deltoids. To perform this exercise, start with your legs slightly bent and grasp a barbell with an overhand grip shoulder-width apart. Keep your back straight while you lean forward at a 45-degree angle, so that the bar is hanging at knee level. Inhale as you pull the barbell up toward your chest, then return to the initial position and exhale.
This exercise also targets the back muscles and shoulder extensors. Sit facing the machine and rest your feet on the foot pad. With your torso bent forward, inhale and bring the handle toward your chest. Keep your back straight and pull your elbows back as far as possible. Exhale at the end of the movement and return the weight slowly to the initial position.
Bent-Over Lateral Raises
Bent-over lateral raises are one of the few movements that mainly targets the rear deltoids. Stand with your legs slightly apart, knees bent and lean forward at the waist. Keeping your back straight, grasp a dumbbell in each hand with your elbows slightly bent. Inhale and raise your arms horizontally, exhale and return the weight to starting position.