Strengthening the shoulders should be a critical aspect of any workout program. However, many athletes make the mistake of failing to work their entire shoulder joint.

The shoulders are made up of three main muscle groups—the deltoid, rotator cuff and upper trapezius. To develop strength and size in each of them, you must perform several different shoulder exercises that mirror the movements they perform.

You can do all of these shoulder exercises with dumbbells, which are among the most effective pieces of training equipment.

Deltoid Exercises

From the outside, the deltoid may seem like one large muscle, but it is actually comprised of three separate components:

• Anterior (front) deltoid flexes the shoulder, so perform DB Front Raises
• Lateral deltoid abducts the shoulder, so perform DB Side Raises
• Posterior deltoid extends the shoulder, so perform DB Reverse Raises

Rotator Cuff Exercises

The rotator cuff muscles typically go unnoticed when looking at the shoulder; however, these smaller muscles play a critical role in joint stability.

• Subscapularis internally rotates the arm, so perform DB Side-Lying Internal Rotations
• Supraspinatus abducts the arms, so perform DB Side Raises
• Infraspinatus externally rotates, so perform DB Side-Lying External Rotations
• Teres minor (same as above)

Upper Trapezius Exercises

The upper trapezius, the large muscle that sits on top of the shoulders, is broken into two heads that act on the neck and collarbone.

• Occipital head assists with neck extension, so perform DB Facedown Lying Neck Extensions
• Ligamentum nuchae head elevates the collarbone, so perform DB Shrugs

Sets/Reps

To strengthen and develop the muscles of the shoulder, complete a total of three sets per exercise. For the deltoid and upper traps, use the maximum amount of weight that allows you to perform six to 10 repetitions per set. For the smaller rotator cuff complex, use moderate resistance that allows you to do 12 to 15 reps per set.

For optimal performance and safety, always train larger muscles first. Begin with deltoid exercises, followed by upper trap exercises, and finally rotator cuff exercises.

References

http://www.sportsinjuryclinic.net/anatomy/human-muscles/shoulder-joint/rotator-cuff-muscles

http://www.exrx.net/Muscles/TrapeziusUpper.html