Most fitness-conscious men are aware of the need to build shoulder strength and size. To meet these needs, shoulder presses and standing lateral raises seem to get most of the attention in a shoulder workout. This isn’t a bad thing because the anterior and middle parts of the shoulder musculature are strongly activated by these two exercises. However, the posterior deltoid is usually neglected and it becomes the weakest link in the shoulder. Without some direct attention, shoulder strength and muscle symmetry can become imbalanced and this increases the chances of eventually incurring a shoulder injury.
To achieve great shoulder structure and muscle mass, all the while avoiding sports-related or activity-induced shoulder injury, you must approach your shoulders as if they were three-sided pieces of fragile art. This can only be achieved if all three regions of the deltoid are stressed and proper exercise technique is employed during your training. Strengthening the posterior deltoid will improve your ability to pull the arm posteriorly (extension of the arm, which brings it backward). This means that strong rear deltoids will improve your back exercises, allowing you to use more resistance in rowing and pulldowns. Furthermore, strengthening the posterior deltoid will help stabilize the shoulder if it’s hit from the back or when falling on the shoulder in a contact sport.
One of the best approaches to building mass and strength in this area is through lying incline dumbbell raises. It’s not the easiest exercise to handle, but it will induce great rear shoulder activation and growth.
Although the deltoid is only one muscle, it has three separate regions and each part has a different function. The posterior fibers of the deltoid attach along the spine of the scapula (shoulder blade), which is located on the upper and posterior side of the scapula. The anterior fibers of the deltoid begin along the lateral part of the clavicle (collarbone). The medial fibers attach along the regions between the previous two muscle areas of the deltoid along the acromion (the “point” of the shoulder) of the scapula. The fibers from the deltoid muscle converge on the anterior and upper part of the humerus bone of the upper arm. The anterior fibers of the deltoid strongly flex the humerus at the shoulder (brings the humerus bone of the upper arm forward) and also produce medial (internal) rotation of the humerus at the shoulder. The medial fibers of the deltoid abduct the humerus (raising the humerus away from the side of the body). The posterior fibers of the deltoid extend the humerus by bringing it posteriorly (backward) and laterally rotate the humerus. In lateral rotation, the anterior aspects of the arm and palm of the hand are rotated away from the body. The reverse is true for medial rotation.
The rhomboids major and minor muscles are deep muscles of the back that lie medial to the scapula and are also activated by lying incline dumbbell raises. These muscles can add thickness to the upper-middle back. The rhomboid muscle fibers begin along the midline of the back at the thoracic vertebrae and attach on the medial border of the scapula (the side closest to the vertebrae). The larger rhomboid major muscle sits just below the smaller rhomboid minor muscle, but both are mechanically similar. The rhomboid major and minor muscles adduct the scapula (squeeze the shoulder blades together) and rotate the scapula upward (as when you raise your arms over your shoulders). The medial fibers of the trapezius muscle lie over the rhomboids and assist them in scapular adduction during the upward lift in lying incline dumbbell raises.
Lying Incline Dumbbell Raises
This exercise will primarily stress the posterior fibers of the deltoid and it will help to strengthen this area and help to prevent forward (anterior) displacement of the shoulder. This can be a very intense exercise that will generate a burning sensation in your posterior deltoids. Most of the intensity is generated by its direct emphasis on the posterior fibers of the deltoid. As a result, you don’t need superhuman weights to experience a deep posterior deltoid burn.
1. Select an incline bench that has no more than a 30-degree angle and lie facedown on it (or hang your head over the end of the bench if it’s short enough to do so). The bench should be high enough so when you grab a dumbbell in each hand, the bells won’t contact the floor. Your arms will be hanging toward the floor with the thumbs adjacent to each other at the beginning of the lift.
2. Your knees should remain slightly bent to reduce any lower back strain, although such strain should be minimized because you’re positioned along the incline bench. Bend your elbows just slightly, and then raise the dumbbells out to the side of your body and as high as possible. The trajectory of the dumbbells should fall slightly inferior (behind) the shoulder joint, but the dumbbells should be raised to the same height as the level of the shoulders (or higher if possible).
3. As the dumbbells approach the very top position, rotate the shoulder so that the lateral side of the hand (the side with the thumb) is pointing toward the ceiling. This movement is usually the opposite of what you would normally do for the rear deltoid fibers and it might feel strange at first. But give it a try for a few workouts before passing judgment (but with lighter weights than you might normally do until you get a better feel for the twist).
4. Hold the top position for a count of one or two, then slowly reverse the movement to the starting position.
5. Don’t pause at the bottom or between repetitions, but immediately continue upward. The posterior shoulder should be under constant tension from the beginning to the end of the exercise.
The lying incline dumbbell raise incorporates both the shoulder extension and lateral rotation functions of the posterior fibers of the deltoid. Lateral rotation doesn’t usually occur in most training schedules, and as result you can expect some post-training soreness. It’s very important to rotate your arms (humerus bone) at the shoulder joint rather than at the hand and wrist in the top portion of this movement. Simply supinating and pronating your hand involves movements in your forearm, but that will do nothing to help your posterior deltoid. Improper rotation, or rotating too quickly, could cause unnecessary pain or injury to these joints.
Don’t swing the weights upward and don’t let them drop downward. Rather, control the movement in both directions so you’ll reduce the chances of placing the shoulder joint under any inappropriate stresses or angles of pull, which might lead to an injury of the joint or shoulder cuff muscles.
Make sure you let your arms extend all the way down toward the floor at the end of each repetition. This will assist in ensuring you exercise throughout a full range of motion. The arms should initially move in a position that will stretch the posterior deltoid at the bottom of the lift (to improve its subsequent mechanical activation and contribution) because this provides a greater range of motion in which to contract over. Also, make sure you lift the weights as high as positioned (at a minimum, your arms should be parallel to the floor) and hold this for a count of two. This will ensure the greatest muscle contraction and activation of all of the fibers in the posterior deltoid.
You should always avoid explosive twisting or ballistic rotational movements at the shoulder when doing this exercise. Because the shoulder is literally being held together by its muscle attachments, it’s not wise to explode into this lift, especially during the lateral rotation part at the top of the movement. Try to go for the best exercise form to create the optimal muscle “burn” rather than the maximum weight you can hoist in a sloppy fashion.
Extremely heavy weights will impress your friends, at least for the moment, but if you’re swinging the weight up and dropping it down uncontrollably, your muscles will get very little benefit and they won’t grow. Don’t fall prey to the short-term mind games for heavy weights at all cost in the gym. On the other hand, don’t use pencil weights either. The rear deltoid is like any other muscle. It will enlarge and grow dense if you work it using good form with an all-out effort, but injury or sloppy exercise won’t accomplish those goals. It takes a little more thought and work to develop a set of massive and symmetrical shoulders as compared to muscles that have only one function, but the rewards will be worth the effort.
1. Hong T C, Kumar VP and Nather A. (2005). The posterior neuromuscular compartment of the deltoid. Plast Reconstr Surg, 1.
2. Labriola JE, Lee TQ, Debski RE and McMahon PJ. (2005). Stability and instability of the glenohumeral joint: the role of shoulder muscles. J Shoulder Elbow Surg, 14, 32S-38S.15, 1660-1664.
3. Morris AD, Kemp GJ and Frostick SP. Shoulder electromyography in multidirectional instability (2004). J Shoulder Elbow Surg, 13: 24-29.
4. Moore KL and AF Dalley. (1999) Clinically Orientated Anatomy. 4th ed. London, Baltimore: Lippincott Williams & Wilkins ISBN: 0-683-06141-0
5. Reinold MM, Wilk KE, Fleisig GS, Zheng N, Barrentine SW, Chmielewski T, Cody RC, Jameson GG and Andrews JR. Electromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises (2004). J Orthop Sports Phys Ther, 34: 385-394.
6. Wise MB, Uhl TL, Mattacola CG, Nitz AJ and Kibler WB. The effect of limb support on muscle activation during shoulder exercises (2004). J Shoulder Elbow Surg, 13: 614-620.