Shoulder Muscles Anatomy-Functionality and Exercises

Shoulder Muscles

Shoulders are part of the upper body and are considered as a sign of power. Three bones are involved in the formation of the shoulder: the scapula, the clavicle and the humerus. Shoulders are closely related to the movement of the arms, the back, the chest etc.

The major Muscles of the shoulder

The muscles that make up the anatomy of the shoulder are: teres major, teres minor, deltoid, supraspinatus, infraspinatus and subscapularis muscle which exert their action to the joint of the shoulder.

The deltoid muscle is a strong muscle of the shoulder, providing its round shape and covering the joint. The name deltoid comes from the round shape which looks like an inverted Greek capital Δ letter. For descriptive reasons the deltoid muscle divides into 3 parts: the anterior, middle and the posterior, which act separately or as a whole and participate in all the movements of the arm.

Supraspinatus and Infraspinatus mucle, belong to the group of circumpenate muscles. Supraspinatus has a conic shape. Its tendon is covered by the deltoid muscle.

Infraspinatus muscle. It looks like a triange. One of its characteristics is the intramuscular tendon that is found in the middle of the muscle belly.

Teres major muscle is a wide square muscle that comes from the rear surface of the down angle of the scapula.

Teres minor: It is an elongated muscle that separates from the Infraspinatus muscle with intra-muscle diaphragms.

The Functionality of Each Muscle group

The deltoid: All parts of the deltoid have an abduction role. Additionally the anterior deltoid has a flexing role and works as an internal rotator of the arm. On the other hand, posterior deltoid has an external rotation role.

Teres major muscle pulls on and turns to the inside the arm. It participates in its own extension and stabilizes the head of the arm in the glenoid cavity during the abduction of the arm.

Supraspinatus major action is the abduction of the arm.

The infraspinatus muscle externally rotates the arm and stabilizes the glenohumeral joint.

Teres minor like the infraspinatus externally rotates the arm. In addition it contributes to the horizontal abduction.

Subscapularis muscle's action is the internal rotation of the humerus.

Shoulder Muscles

Exercises that Target the Shoulder Muscles

There are a number of exercises for shoulder training, but the most common involve the use of dumbbells and barbell. Here are some of the basic shoulder exercises that don't need any special gym equipment:

Bent-Over Rear Deltoid Raise

This is an exercise focusing on the rear deltoids. It can be performed seated or standing. Seated alternative doesn't stress the lower back. In addition you can perform it using one arm at a time or both hands simultaneously. Using both hands is usually preferred when using heavier dumbbells.

When performed seated, you have to sit on the end of the bench keeping the legs together. Then bend at the waist and slowly pick up the dumbbells. You have to keep your torso forward and lift the dumbbells straight sideways in order to bring the arms parallel to the floor. While lifting you exhale and when you reach the top of the lift, you slowly lower the dumbbells in order to get to the starting position. This exercise is good while getting lean and helps you define the shoulders, so I recommend 4 sets of 8-12 reps.

Seated Barbell Shoulder Press

This is one of the best exercises for your shoulders development. You have to find a bench with back support in a barbell press station. The barbell should be at a height above the head. You grip the barbell just outside the shoulder width, palms facing forward. Then take out the bar of the rack and in a strong motion, lift the bar straight up over the head to the position of elbow lockout. Afterwards you lower the bar at your upper chest and then lift again to the position of elbow lockout. This is a muscle builder exercise, so you don't need to do more than 3-4 sets of 6-10 reps. Just keep in mind to add weight in order to get maximum results!

Dumbbell Lateral Raise

I call it a "must do" exercise for all serious weight lifters. Some people prefer doing an alternative exercise using gym machines but the "old school" body-builders would agree with my suggestion to use dumbbells. This exercise helps you improve your middle deltoids. While standing up and holding a dumbbell with each hand, palms facing each other, you raise the dumbbells to the sides in order to almost reach a parallel to the ground position and then you lower hands back down along the same path, after a short pause on the top of the motion. You don't need to use heavy weights in order to avoid cheating and injuries. The ideal number of sets for this exercise is 3-4 sets of 8-10 reps.

Front Dumbbell Raise

This exercise improves mainly the front part of the shoulder. It is one of the shoulder isolation exercises. For this exercise you need a dumbbell for each hand. Firstly, stand with a straight torso. You have to grip the dumbbells in front of your thighs and the palms of the hand facing your thighs. You lift one dumbbell at a time. You lift the dumbbell until the arm is almost parallel to the ground and when you reach this position you squeeze for a second and then lower the hand to the starting position and continue with the other hand. Doing this exercise in a slow tempo helps you focus more on the shoulder and results to better isolation of the muscle. Four sets of 10-12 reps are enough for this isolation exercise.

No matter how hard you train, shoulders training must be part of your weekly program. Shoulders are involved in a wide range of movements and should be treated as a major body part. They are one of the most often injured body parts that’ s why you should try to execute the exercises properly, without cheating or using very heavy weights. A number of 3-4 exercises are enough for a total shoulder program. If you are not in to lifting weights there are a number of good body weight shoulder exercises include in this article.