This is a great exercise that I do along with front and side laterals to hit the muscles of my shoulders. The rear deltoid that is being stressed here is the weakest of the deltoid muscles and this exercise will really make a difference in strengthening the rear deltoid and therefore help widen your shoulders.
Position: A standing position with the feet a comfortable distance apart, the trunk bent forward at the hips and parallel with the floor. The arms are extended toward the floor with the elbows straight and a dumbbell held in each hand.
Action: From this position, keeping the elbows locked and the trunk parallel to the floor, the arms are raised straight out to the sides until they are level with the upper back. The arms must not come back as they are raised, but must go straight out to the sides. This position is held for a moment, then the arms are lowered to the starting position.
Breathing: Inhale as the arms are raised out to the sides and exhale as they are lowered.
Starting Resistance: Some women can start with 5 lbs. in each hand but most will find the 7½ lbs. to be better. Most men can start comfortably with 5 lbs. in each hand.
Progression: Begin with 7 counts, adding 1 count each week until 15 have been performed for three periods, then add 1¼ lbs. to each and begin again at 7 counts.
Goal: This is a “leverage movement” and all should work up to a resistance of 7½ to 15 lbs. in each hand for 15 counts. Most women will find 10 lbs. a reasonable goal and most men 15 lbs.
Results: This movement is particularly good to pull the shoulder blades back, and to strengthen and develop the muscles of the upper back. This has a little more direct effect upon the rhomboid muscles that hold the shoulder blades back than has the rowing exercise.
Comments: This is a very difficult motion if done correctly. There is a strong tendency to swing the weights out to the sides, but they must be pulled up, not swung.
This movement, too, is very effective in improving the “round shouldered” condition.