Shoulder Girdle Anatomy: Bones, Muscles, and Nerve Supply

What bones are involved in the kinetic chain of the upper limb?

The sternum, clavicle, scapula, and humerus.

What are the two major joints of the shoulder girdle?

The glenohumeral joint and the scapulothoracic joint.

What type of joint is the glenohumeral joint?

A shallow ball and socket joint with 3 degrees of freedom.

Which muscles are considered anterior axio-appendicular muscles?

Pectoralis major, pectoralis minor, and serratus anterior.

What is the primary action of the pectoralis major?

To adduct and internally rotate the humerus.

Where does the pectoralis minor attach?

Proximally to ribs 3-5 and distally to the coracoid process.

What is the function of the serratus anterior?

To stabilize the scapula against the thoracic wall and act as a prime mover for protraction.

What are the key posterior axio-appendicular muscles?

Trapezius, latissimus dorsi, levator scapula, rhomboid major, and rhomboid minor.

What is the primary action of the trapezius?

To elevate and depress the scapula.

What is the function of the latissimus dorsi?

To adduct, extend, and internally rotate the glenohumeral joint, as well as depress the scapula.

Which muscles retract and elevate the scapula?

Levator scapulae and rhomboids.

what muscles in rotator cuff

subscapularis, supraspinatus, infraspinatus, and teres minor.

What are the three distinct actions of the deltoid muscle?

Flexion (anterior), abduction (middle), and extension (posterior).

What is the role of the rotator cuff muscles?

To dynamically stabilize the head of the humerus in the glenoid fossa.

What is the location of the teres major muscle?

Adjacent to the distal fibers of the latissimus dorsi in the posterior shoulder.

What is the brachial plexus and its significance?

A network of nerves from C5-T1 that supplies different parts of the upper limb.

What are the three major nerves that emerge from the brachial plexus?

Median nerve, radial nerve, and ulnar nerve.

What is the primary action of the median nerve?

To control movements in the forearm and hand.

What is the primary action of the radial nerve?

To extend the arm and forearm.

What is the primary action of the ulnar nerve?

To control fine movements of the hand.

Which bony landmarks should be visualized in relation to the shoulder girdle?

Acromion process, coracoid process, spine of scapula, medial border and inferior angle of the scapula, glenoid fossa, and tubercles.

What is the significance of the scapulothoracic joint?

It is not a true joint but is crucial for shoulder movement controlled by muscles.

What are the proximal attachments of the pectoralis major?

Clavicle, sternum, and costal cartilages.