The serratus anterior is a group of muscles connected to the rib cage that help stabilize the shoulder blades. If this muscle is poorly developed due to poor development or instability, the shoulder blade will wing out, or appear to protrude from the back. Additionally, the muscles surrounding the rotator cuff and scapula will tighten in attempt to stabilize the rotator cuff and scapula. The result will be pain and stiffness in the area in addition to on going damage to the joints.



The serratus anterior is as a band of muscles attached to each of the eight upper ribs on the side of the chest and from there, they wrap around the chest to attach to the shoulder blade also known as the scapula at the medial border.

This muscle is responsible for the protraction, or moving forward, of the shoulder blade that produces forward movement to stabilize our arm when we reach forward. It is also responsible for the upward movement of our shoulder blade to stabilize our arm when we reach upward. It is largely responsible for our ability to move our arms above shoulder level and for the ability to rotate our arms while above the shoulder level.

The serratus anterior is supported and stimulated to action by the long thoracic nerve that originates with the brachial plexus. This nerve is especially susceptible to injury during surgery or infection to the area. The types of surgery that may affect the nerve process of the thoracic nerve may include lymph node clearance, back surgery near the area, broken ribs, or other types of injury that may occur in that area. If the brachial nerve is damaged, or the muscle is weak, often a winged scapula is the result.

What Is Involved In A Winged Scapula

Although it is considered normal posture in children, in adults a winged scapula is a sign of muscle weakness and trouble. When the shoulder blade protrudes from the back, especially when not in use, it is a definite sign of a weak serratus anterior. This condition may also be accompanied by a protracted shoulder girdle. Complete flexation or rotation of the shoulder may be restricted because the winged scapula causes a forward tilt of the shoulder joint. Additionally, the rhomboids may be weak and the pectoralis minor may be shortened.

The rhomboids are two diamond shaped muscles on either side of the spine directly beneath the trapezius that connects to the spine at the T2 and T5 vertebra and also connects at the medial border of the scapula along with another stabilizer tendon called the supraspinous.

The pectoralis minor, located directly behind the pectoralis major, is a triangular shaped muscle near the uppermost part of the chest and connects to the third, fourth, and fifth ribs and two other sets of muscles called the intercostalis. The pectoralis minor pass over the shoulder and also connect along the upper medial border of the scapula.

The risk of shoulder injury compounds with weakness of the supraspinitus, external shoulder rotation inflexibility, and the shortening of the pectoralis minor or weak rhomboids.

Exercises That Harm Or Heal

There are some exercises that should be avoided or that may cause injury or pain if performed while the serratus anterior and its supporting muscle are weak. These include the shoulder press; pull overs, pull downs, bench press, chest press, dumbbell flies, and other lat exercises.

You should, however, attempt to strengthen the serratus anterior and lengthen the pectoralis minor. Exercises that can aid you in doing so should include shoulder raises, cable rows, lever rows, pectoralis minor stretches, wall lat stretches, door way modified stretches, wall shoulder girdle stretch, doorway subscapularis stretch, and the breast stroke when swimming.

Avoid stretches and exercises that protract the shoulder, holding your shoulder in a protracted position, and any daily movements, including during sleep, that cause the shoulder to protract, or move outward.

To check for a weak serratus anterior or a winged scapula condition, stand facing a wall and place both your hands on the wall with arms outstretched. If your shoulder blade swings out to the sides and are clearly, extremely visible then you have a weak serratus anterior.

It is important to note that just a weak muscle may not be all that is at stake here. The thoracic nerve may be affected, either through injury or infection, both current and past occurrences. Therefore it is important to be diagnosed by a specialist before obtaining or affecting treatments.