Shoulder Muscles

Question 1

Deltoid

Answer 1

Artery - posterior circumflex humeral

Nerve - axillary

Origin - lateral third of clavicle, acromion, spine of scapula

Insertion - deltoid tuberosity of humerus

Action - abducts arm

Question 2

Supraspinatus

Answer 2

Artery - suprascapular

Nerve - suprascapular

Origin - supraspinous fossa of scapula

Insertion - greater tubercle of humerus

Action - initiates abduction of arm

Question 3

Infraspinatus

Answer 3

Artery - Circumflex scapular, suprascapular

Nerve - suprascapular

Origin - infraspinous fossa of scapula

Insertion - greater tubercle of humerus

Action - external rotation

Question 4

Teres minor

Answer 4

Artery - circumflex scapular, posterior circumflex humeral

Nerve - axillary

Origin - upper portion of lateral border of scapula

Insertion - greater tubercle of humerus

Action - external rotation

Question 5

Subscapularis

Answer 5

Artery - subscapular

Nerve - upper and lower subscapular

Origin - subscapular fossa

Insertion - lesser tubercle of humerus

Action - internal rotation

Question 6

Teres major

Answer 6

Artery - circumflex scapular, subscapular

Nerve - lower subscapular

Origin - dorsal surface of inferior angle of scapula

Insertion - intertubercular groove of humerus

Action - adduction, internal rotation

Question 7

Trapezius

Answer 7

Artery - transverse cervical

Nerve - spinal accessory

Origin - external occipital protuberance, ligamentum nuchae, spinous processes of C7-T12

Insertion - lateral 1/3 of clavicle, acromion, spine of scapula

Action - elevates, retracts and rotates scapula

Question 8

Levator scapulae

Answer 8

Artery - transverse cervical

Nerve - dorsal scapular, cervical plexus C3-C4

Origin - transverse processes of C1-C4

Insertion - medial part of superior border of scapula

Action - elevates scapula

Question 9

Rhomboid minor

Answer 9

Artery - dorsal scapular

Nerve - dorsal scapular

Origin - ligamentum nuchae, spinous processes of C7 and T1

Insertion - medial margin of scapula

Action - retract and rotate scapula

Question 10

Rhomboid major

Answer 10

Artery - dorsal scapular

Nerve - dorsal scapular

Origin - spinous processes of C7 and T1

Insertion - medial margin of scapula

Action - retract and rotate shoulder

Question 11

Lattissimus dorsi

Answer 11

Artery - thoracodorsal

Nerve - thoracodorsal

Origin - spines of T7-T12, thoracolumbar fascia, iliac crest, ribs 9-12

Insertion - intertubercular groove of humerus

Question 12

Serratus Anterior

Answer 12

Artery - lateral thoracic

Nerve - long thoracic

Origin - 1st and 2nd ribs

Insertion - costal surface of scapula

Action - protract and rotate scapula