Anatomy Of Shoulder And Elbow

Question 1

What are the bones of the pectoral girdle and upper extremity, and their surface features?

Answer 1

Pectoral girdle: scapula and clavicle

Upper extremity/limb: clavicle, scapula, humerus, radius, ulna, wrist bones, metacarpals, phalanges

Question 2

What is the structure and function of the joints of the upper extremity?

Answer 2

Shoulder

• synovial ball and socket
• allows arm to rotate, giving strength and range of motion

Elbow

• synovial hinge joint
• allows for flexion and extension of forearm relative to upper arm and allows rotation of forearm and wrist

Wrist

• synovial condyloid
• optimises functions of the hand

Question 3

What muscles position the limb?

Answer 3

Shoulder muscles eg pectoralis minor, serratus anterior, rhomboids, trapezius, pectoralis major, intrinsic shoulder muscles (rotator cuff muscles)

Question 4

What muscles help to stabilise the shoulder joint?

Answer 4

Short scapular muscles: supraspinatus, infraspinatus, teres minor, teres major, subscapularis

Question 5

What muscles move the arm and shoulder?

Answer 5

Muscles of the arm:

• supination of forearm, flexion of forearm: Biceps brachii
• extension of forearm: Triceps
• flexion of elbow: brachialis
• coracobrachialis
• pronation of forearm: pronator teres and quadratus

Muscles of the shoulder:

• abduction: deltoid
• adduction: pectoralis major
• elevation, depression, retraction: trapezius
• protraction: serratus anterior