Tight muscles
Latissimus dorsi+
Latissimus dorsi
Muscle dictionary
- Functions
- Extends; adducts; and medially rotates the arm
- Origin
- Lower thoracic vertebrae, thoracolumbar fascia, iliac crest, and lower ribs
- Insertion
- Floor of the intertubercular sulcus of the humerus
Pectoralis major+
Pectoralis major
Muscle dictionary
- Functions
- Adducts and medially rotates the arm; the clavicular fibers assist shoulder flexion
- Origin
- Medial clavicle, sternum, and costal cartilages of the upper ribs
- Insertion
- Lateral lip of the intertubercular sulcus of the humerus
Pectoralis minor+
Pectoralis minor
Muscle dictionary- Functions
- Draws the scapula anteriorly and inferiorly against the thoracic wall; contributing to scapular downward rotation; and may assist forced inspiration when the scapula is fixed
- Origin
- Ribs three to five
- Insertion
- Coracoid process of the scapula
Weakened muscles
Lower trapezius+
Lower trapezius
Muscle dictionary
- Functions
- The lower fibers assist scapular depression and upward rotation and contribute to posterior tilt during arm elevation
- Origin
- Lower thoracic spinous processes
- Insertion
- Medial end of the scapular spine
Middle trapezius+
Middle trapezius
Muscle dictionary
- Functions
- Retracts the scapula and assists scapular control during reaching and pulling
- Origin
- Spinous processes and supraspinous ligaments of the upper thoracic vertebrae
- Insertion
- Acromion and superior lip of the scapular spine
Rhomboid major+
Rhomboid major
Muscle dictionary
- Functions
- Retracts and downwardly rotates the scapula and helps hold it against the thoracic wall
- Origin
- Spinous processes of the upper thoracic vertebrae
- Insertion
- Medial border of the scapula from the scapular spine to the inferior angle
Rhomboid minor+
Rhomboid minor
Muscle dictionary
- Functions
- Retracts and downwardly rotates the scapula and helps secure it to the thoracic wall
- Origin
- Ligamentum nuchae and spinous processes of the seventh cervical and first thoracic vertebrae
- Insertion
- Medial end of the scapular spine
