PECTORALIS MAJOR MUSCLE ⠀ [ANATOMY, FUNCTION & PATHOLOGY] The pectoralis major has two heads: a clavicular head coming from the medial clavicle, and a sternocostal head coming from the sternum and costal cartilages of the upper seven ribs. ⠀ It attaches distal at the lateral lip of the bicipital groove of the humerus. On its way to the humerus, it passes over the long head of the biceps brachii. ⠀ The pec major plays an important role especially if you suffer from neck or shoulder problems (Protracted/Rounded shoulders pic 3), that’s why it is very important to make sure to treat this muscle in the right way! ⠀ Especially for those who spend the majority of their day sitting, such as office workers or those who spend the majority of their day in a hunched position such as dentists, it is very important to work every day on this shoulder/neck pain culprit. Being in a poor position and using this muscle will cause an adaptive shortening and tightness already! ⠀ Pec major trigger points can lead to referred pain in the shoulder, chest or arm as you can see on the red marked zones in pic 4. ⠀ Important for therapists is to release and lengthen this muscle if your patient is suffering from rounded shoulders!