The stability of the shoulder is provided through these four muscles rather than by bony structure. These muscles are responsible for positioning and holding the head of the humerus (the long bone of the upper arm) into the shoulder joint. If the head of the humerus is not positioned correctly, it hits the overlying bone, the acromion, pinching the tendons and the bursa (a sack-like, fluid-filled cushion in the joint) causing pain and inflammation. When the head of the humerus is correctly positioned, the larger muscles that move and position the arm can work efficiently and properly.
Because the stability of the shoulder is provided by soft tissues such as the ligaments and muscles, the shoulder has great ability to position the arm and hand in a wide arc of motion for activity. However, the shoulder is also at greater risk for muscular sprains and strains than a joint that derives its stability from bone (such as the elbow).
Even though the muscles of a healthy shoulder work in well-balanced synergy, the muscles that rotate the shoulder inward (internal rotators) are naturally stronger than those that rotate the shoulder outward (external rotators). However, it is the external rotators that are essential for proper positioning of the humeral head into the shoulder joint.
When the muscles of the rotator cuff are in balance, shoulder movement is pain-free. When the muscles are out of balance, the risk for injury, pain and inflammation increases. The rounded shoulder posture that often develops from computer and desk work can lead to muscular imbalance. A large percentage of those who experience hand and elbow pain also have shoulder pain.
To prevent rotator cuff injuries, it is important to do the following:
- Stretch the Internal Rotators
- Lie on your right side with your right arm at shoulder height, elbow bent 90 degrees. Using your other arm, gently rotate your shoulder inward bringing your hand towards the mat by your hip. Hold for 20 seconds. Repeat 2-3 times. Switch sides and stretch the left side.
- Picture of a Posterior Capsule Stretch from The Journal of the American Academy of Orthopaedic Surgeons
- Picture A – Use a pillow to support the neck in a neutral position and stretch the shoulder gently, not aggressively.
- Stretch the Chest
- Standing by a door, rest your right forearm along the door frame with the elbow at shoulder height or slightly below. Keeping the forearm on the door frame, slowly turn your body away from your arm until you feel a gentle stretch across the chest and into the front of the shoulder. If you feel a pinch in the back, take a small step forward until you feel the stretch in the chest instead. Hold for 20 seconds. Repeat 2-3 times. Switch sides and stretch the left side.
- Picture of Doorway Stretch for the Chest (Pectoralis) from PhysioTherapyExercises.com
Strengthen the External Rotators- Lie on your right side with your left elbow tucked into your side and bent at a 90 degree angle, hand towards the mat. Rotate your shoulder outward bringing the hand up towards the ceiling. Keep the elbow bent at the 90 degree angle and the elbow tucked in at the side. Hold at the end range for 3-5 seconds then relax the shoulder rotation and bring the hand back towards the mat. Repeat 8-12 times. Switch sides and strengthen the right side.
- Picture of External Rotator Strengthening Exercise from PhysioTherapyExercises.com
Focus on Posture- Avoiding the rounded shoulder posture will help keep the head of the humerus in proper position.
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- Being aware of correct ergonomic positioning while working at your desk or on your computer will help avoid the rounded shoulder posture.
- See these related articles for more information.
Information for this article was taken from The Seven Minute Rotator Cuff Solution: A Complete Program to Prevent and Rehabilitate Rotator Cuff Injuries by Joseph Horrigan, D.C. & Jerry Robinson.
Also available from Amazon.com
The Frozen Shoulder Workbook by Claire Davies & Treat Your Own Rotator Cuff by Jim Johnson, P.T.
Additional Products Helpful for Relieving Shoulder Pain
Marji Hajic is an Occupational Therapist and a Certified Hand Therapist practicing in Santa Barbara, California. For more information on hand and upper extremity injuries, prevention and recovery, visit Hand Health Resources.