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Preventing Rotator Cuff Injuries With Rotational Dumbbell Raises |
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Written by Stephen E. Alway, PhD, FACSM
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Monday, 23 April 2007 |
A shoulder injury is among the lowest points of any bodybuilder's career. This is the nagging deep burning pain just does not want to go away, no matter how much ice you apply or how many painkillers you consume. Shoulder injury, and especially pain arising from a rotator cuff injury, affects almost all your upper body work. It certainly prevents you from loading heavy plates on a squat bar or leg press unit. Recovery from rotator cuff injury sometimes requires surgical repair and almost always requires an extensive layoff. So why is this seemingly small area so vulnerable to injury, and what can be done to prevent a layoff?
The shoulder joint (glenohumeral joint) is an unstable, complex joint. It represents the first link in a mechanical chain of levers that extends from the thorax to the fingers. Every movement of your arm involves the shoulder in some fashion or another. Even back or chest work can involve variable amounts of lateral and medial rotation of the humerus at the shoulder joint, which involves your rotator cuff. Your shoulders are particularly vulnerable when you're struggling to finish the last reps in a heavy set. However, injury can occur even during light warm-up sets when the weight is light and when exercise form can be a little sloppy.
Structure and Function
The glenohumeral joint consists of a nearly circular humeral head (like a little ball) that sits in a very small indentation (socket) in the scapular bone (shoulder blade) called the glenoid fossa. The ball is too big to fit in this socket joint and this creates a very unstable joint. Nevertheless, this instability permits the large degree of movement that is possible at the shoulder. The shoulder relies on soft tissue ligaments and tendons of the rotator cuff to provide significant support for the joint. The rotator cuff muscles also stabilize the joint and largely prevent dislocations from occurring.
A tendon sheath covers the tendons of the rotator cuff to reduce the friction of the tendons sliding over the bony segments of the shoulder. Tissue that is not tendon, but is likely to receive a lot of friction during movement, is protected by a kind of sac called a bursa. The bursas are generally filled with a soft substance and they are well lubricated for smooth movement. The subacromial bursa is such a structure. This bursa reduces the friction that would otherwise occur as the tendon of the supraspinous muscle passes under and rubs against the acromion (the lateral point of the scapula). The subacromial bursa can be irritated and it can become inflamed if a small bone spur develops, or if there is excessive friction during joint movement.
Musculature
Four scapular muscles (subscapularis, supraspinatus, infraspinatus, and teres minor) form the rotator cuff muscles. All except the supraspinatus are rotators of the humerus bone at the shoulder joint. The infraspinatus muscle fills most of the infraspinatus fossa and it attaches between this fossa and the greater tubercle of the humerus bone. The teres minor muscle attaches between the superior (upper) part of the lateral border of the scapula and the greater tubercle of the humerus. Both the infraspinatus and teres minor muscles rotate the humerus laterally at the shoulder joint and help stabilize the shoulder joint by keeping the head of the humerus in the glenoid fossa. The supraspinatus muscle is a rounded muscle that lies in the supraspinatus fossa (a hollowed out area on the superior or top part of the posterior side of the scapula). It begins near the medial side of the scapula (close to the vertebrae and the center of the body) and runs over to the superior part of the head of the humerus. It lies deep to the trapezius muscle and part of it is deep to the coracromial arch and the acromion. The deltoid muscle covers the tendon of the supraspinatus.
Along with the lateral fibers of the deltoid, the supraspinatus acts to abduct the humerus. Abduction is the act of raising the arm out to the side of the body, so the hand moves in a lateral movement upward. The supraspinatus muscle is most active between positions in which the arm is vertical and parallel to the floor. The other important function is to hold the head of the humerus in the glenoid cavity of the scapula. It's really the only muscle of the rotator cuff that does not have a rotational function. Unlike the other muscles of the rotator cuff, the subscapularis muscle lives exclusively on the front or anterior side of the scapula. It crosses the anterior part of the shoulder joint and inserts on the humerus. This muscle is a strong medial rotator of the humerus. It also holds the humeral head in the glenoid cavity.
Rotational Dumbbell Raise (Horizontal to Vertical)
The rotational dumbbell raise is a version of the dumbbell lateral raise, but it emphasizes loading the rotator cuff muscles. This exercise cannot be adequately performed with a barbell, although in some cases, cables will substitute for dumbbells.
1. Put two dumbbells on the floor and close to your feet, which should be about shoulder-width apart. Take an overhand grip (pronated hand) position on each dumbbell and lift them from the floor. If a mirror is available, stand in front of it because you will find the mechanics of the movement easier to control with constant visual feedback.
2. Stand vertical with a dumbbell in each hand beside your thighs. Bend your elbows slightly and lock them in this position. With your palms facing the floor, raise the dumbbells up and to the sides (abduction of the shoulder) as if you were doing a lateral dumbbell raise. The first part of the lift pauses for a count of one with the dumbbells out to the sides and at shoulder level.
3. The second part of the exercise is a rotational component. From the paused position (with arms parallel to the floor), lift the weight upward so the dumbbells move from shoulder level to just short of being directly over your head/shoulder. Rotate your shoulders so that as you are lifting the weight, your arms will move from a position with the palms facing the floor to one where the thumbs point toward the ceiling as you approach the top of the lift. The top position ends with the dumbbells in a position that's the same as when you complete a dumbbell press.
4. Once you're at the top position, lower the weight down to the "paused" position where your arms, the dumbbells and your shoulders are all in the same horizontal line. Rotate the dumbbells slowly in a medial direction as you are lowering the weight to this position so the palms face the floor. Again, pause for a count of one; then repeat the lift upward to the top as you rotate the shoulders laterally.
Important Tips
The supraspinatus muscles will be most strongly activated as your arms are abducted and the weight is lifted upward. They will continue to fire and act as stabilizers of the shoulder during the lift from shoulder level to the final overhead position (the second half of the exercise). Although the infraspinatus will be activated throughout the time when the dumbbells are lifted from your waist to the highest position, this muscle will be particularly active as you add the lateral rotation of the shoulder to the upper part of the lift. The infraspinatus and supraspinatus muscles will be recruited during the controlled descent of the exercise. Make all of the rotational movements slowly and in a very controlled manner.
There is no need to use gut-busting tonnage in this exercise. Your goal should be to do 12-15 repetitions in a set. The focus of the exercise is to strengthen the rotator cuff muscles and tendons, thereby preventing and not causing injury. Therefore, you must be careful that the rotation is smooth and not explosive, sloppy or extremely heavy. To make sure this remains a rotator cuff exercise, you can lock your wrists to ensure that the rotational movements are not made from the wrist and hands, but rather from the shoulders. Do not twist too far at the top, or you may lose your balance and your grip on the dumbbells. It's probably obvious, but you should carefully lower the weight from the top position, since this unraveling at the shoulder should also be done with control. If you find you are flexing your elbows during the initial part of the lift or using an exaggerated body movement to get the weight up, lower the resistance of the dumbbells.
Although we frequently take our healthy shoulders for granted, it only takes a small injury to appreciate how much they are involved in everything we do. The application of the rotation dumbbell raises for a few months, then once a week thereafter, will help minimize the chances that you'll obtain rotator cuff injuries and be forced to endure a long layoff. After all, it's pretty hard to climb to the top of the bodybuilding ladder with injury-induced layoffs. But then, any climbing will be too painful with a rotator cuff injury. Thus, injury prevention is worth a little investment of time and sweat if you are at all serious about your bodybuilding success.
References
Basmajian, J.V. Recent advances in the functional anatomy of the upper limb. Am. J. Phys. Med. 48:165, 1969.
Basmajian, J.V., and C.J. Deluca. Muscles Alive. 5th Edition. Baltimore, Williams and Wilkins, pp. 220-224, 1985.
Burke WS, Vangsness CT and Powers CM. Strengthening the supraspinatus: a clinical and biomechanical review. Clin Orthop 292-298, 2002.
Codine P. Bernard PL. Pocholle M. Benaim C. Brun V. Influence of sports discipline on shoulder rotator cuff balance. Medicine & Science in Sports & Exercise. 29(11):1400-5, 1997
Desmeules F, Cote CH and Fremont P. Therapeutic exercise and orthopedic manual therapy for impingement syndrome: a systematic review. Clin J Sport Med 13: 176-182, 2003.
Hirano M, Ide J and Takagi K. Acromial shapes and extension of rotator cuff tears: magnetic resonance imaging evaluation. J Shoulder Elbow Surg 11: 576-578, 2002.
Kibler WB, McMullen J and Uhl T. Shoulder rehabilitation strategies, guidelines, and practice. Orthop Clin North Am 32: 527-538, 2001.
Kuechle DK. Newman SR. Itoi E. Morrey BF. An KN. Shoulder muscle moment arms during horizontal flexion and elevation. J. Shoulder & Elbow Surgery. 6(5):429-39, 1997.
Moncrief SA, Lau JD, Gale JR and Scott SA. Effect of rotator cuff exercise on humeral rotationtorque in healthy individuals. J Strength Cond Res 16: 262-270, 2002.
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