The pectoralis minor muscle is a triangular-shaped, thin muscle. The pectoralis minor muscle is located directly beneath the pectoralis major muscle. This muscle is present on the upper chest. It comes from the area next to the costochondral junction on the ends of the third to fifth ribs.

The medial pectoral nerve supplies the pectoralis minor muscle with sensory information. The pectoralis minor muscle serves to stabilize the scapula. Furthermore, the pectoralis minor muscle improves shoulder elasticity and stability. 

In this article, we will examine the anatomy, purpose, and significance of the pectoralis minor muscle. And highlighting the reasons for its importance. 

Anatomy of Pectoralis Minor Muscle

The pectoralis minor is a small, triangular muscle. The pectoralis minor muscle is located on the upper part of the chest. It arises from the third and fifth ribs close to their costal cartilages. Furthermore, it grows upward and inserts into the scapula's coracoid junction (shoulder blade). The pectoralis minor is small in structure, but it plays an important role in various shoulder girdle movements.

Origin

The base of the pectoralis minor muscle originates from the third, fourth, and fifth ribs close to their costal cartilage. 

Insertion

The top of the triangle is inserted into the coracoid process of the scapula's upper surface and medial border.

Innervation

The muscle receives motor signals from the medial pectoral nerve. The lateral pectoral nerve's "ansa pectoralis" is a communicating branch that innervates the pectoralis minor muscle. It is typically located anterior to the first segment of the axillary artery. As a consequence, the spinal roots of C5–T1 supply the pectoralis minor.

Blood Supply To Pectoralis Minor Muscle

The nerve and atrial supply to the pectoralis minor muscle come from different sources. The medial pectoral nerves (C8, T1) are its primary source of nerve supply. The "ansa pectoralis," a communicating branch of the lateral pectoral nerve, may also innervate it.  Furthermore, the pectoralis minor muscle receives blood supply from the thoracoacromial artery. 

Supplying Branches to Pectoralis Minor: 

• The superior thoracic artery is a branch of the axillary artery's first segment artery, gives rise to the branches which nourish the pectoral and deltoid muscles

• Superior thoracic artery, a branch of the first segment of the axillary artery.

• The lateral thoracic artery.

Function Of The Pectoralis Minor

The pectoralis minor muscle plays a crucial role in the mobility and stability of the shoulder joint. The pectoralis minor serves the following main purposes:

Sustaining the Scapula: The pectoralis minor helps to keep the scapula stable. The coracoid process serves as the attachment point, securing it to the thoracic wall. Moreover, the effective movement of the upper limb depends on its stabilization.

Scapula Extension: The contraction of pectoralis minor causes the scapula to be pulled downward and forward. Protraction is the movement required for actions such as punching and pushing.

Downward Scapula Rotation: The pectoralis minor helps rotate the scapula downward. Likewise, lower the arm from an elevated position.

Protraction: Protraction of the scapula involves moving it anteriorly and laterally against the ribcage. It works in conjunction with the anterior serratus muscles. Yet this motion is crucial for extending the arm forward.

Significance for Shoulder Wellness

The pectoralis minor is essential for maintaining general shoulder health.  The pectoralis minor muscle works in the correction of posture and many more. Here is a list of a few of the reasons.

1. Repositioning Your Shoulders: A tightened pectoralis minor muscle causes a rounded shoulder. This may result in several musculoskeletal problems. Likewise, there is discomfort in the upper back and neck.

2. Avoiding Impingement of the Shoulder: The space between the shoulder blade and the rotator cuff tendons is known as the subacromial space. The pectoralis minor muscle preserves subacromial space. Shoulder impingement syndrome occurs when these tendons become compressed. Furthermore, the condition may worsen if the pectoralis minor is dysfunctional.

3. Athletic Performance: A strong and flexible pectoralis minor benefits athletes. And particularly those who participate in sports that require repetitive upper-body movements. Such as swimming, baseball, and tennis. Pectoralis minor ensures proper shoulder mechanics. Besides, it lowers the risk of injury.

Pectoralis Minor: A Stretch and Strengthening Exercise

It is important to include stretches and strengthening exercises in your routine. To sustain the health of the pectoralis minor muscle.

Stretching Activities:

For the health of pectoralis minor, some of the stretching activities are followed for pectoralis minor health.

• Doorway Stretch: Place your forearm against the doorframe and your arm at a 90-degree bend while standing in a doorway.  Stretch your chest and front shoulders gently as you take a single stride forward.

• Stretch With a Foam Roller: Lie down on a foam roller along your spine, positioned length-wise. Lean your arms out to the sides to open up your shoulders and chest.

Strengthening Activities:

Some of the strengthening activities are followed for pectoralis minor health.

• Push-Ups: This traditional exercise works the pectoralis minor as well as the pectoralis major.

• Scapular Protraction: Engage in exercises that target protracting (drawing forward) the shoulder blades. By using a cable machine or resistance band.

The Significance of Physiotherapy

Pectoralis muscle dysfunction results in major health issues. Long-term bent positions are the cause of this. This can result in pain or restriction in neck movements. Moreover, there is stiffness and pain in the upper back. Furthermore, there is a higher risk of rotator cuff disorders.

A tightened or shortened pectoralis muscle restricts the rotation of the shoulder joint. This is done by limiting scapular joint movement. Furthermore, it also prevents the glenoid cavity from attaining its specific orientation. Physiotherapy plays a vital role in avoiding pectoralis minor muscle dysfunctions.

Conclusion

The maintenance of the shoulder's stability, mobility, and overall health depends on the pectoralis minor muscle. Using appropriate stretches and strengthening exercises can help prevent posture-related issues. In addition, it enhances athletic performance. You can increase the functionality and general health of your upper body. As a consequence, by paying attention to this tiny but powerful muscle.