PECTORALIS MAJOR

• Origin

Clavicle, sternum, and costal cartilages of upper ribs

• Insertion

Greater tubercle and intertubercular sulcus of humerus

• Agonist(s)

- Anterior fibers: clavicular head - Upper fibers of serratus anterior, sternocostal head - Pectoralis minor; Sternocostal fibers - Upper fibers of serratus anterior

• Antagonist(s)

- Posterior fibers: Latissimus dorsi, teres major, and posterior fibers of deltoid

• Function

Adducts and medially rotates arm; clavicular head: flexes arm; sternocostal head: extends flexed arm

TRIGGER POINT(S)

• Location

Trigger points can be found along the length of the muscle, particularly in the sternal and clavicular portions.

• Pain Referral Pattern

Pain may refer to the anterior chest, shoulder, and arm.

It can cause aching, burning, or sharp pain along the chest wall, and may contribute to discomfort or restricted movement in the shoulder and arm.

• Potential Causes

▫ Overuse or repetitive activities involving the chest and shoulder, such as weightlifting, push-ups, or sports activities.

▫ Poor posture, especially slouching or rounded shoulders.

▫ Muscle imbalances between the pectoralis major and other shoulder muscles.

▫ Trauma or injury to the chest or shoulder area.

• Prevention Tips

▫ Use proper techniques and form during chest and shoulder exercises to avoid overloading the pectoralis major.

▫ Incorporate regular stretching and strengthening exercises for the chest and shoulder muscles.

▫ Ensure proper warm-up and cooldown routines before and after exercise.

▫ Maintain good posture and ergonomics during daily activities.

▫ Ensure balanced strength training to avoid muscle imbalances.