Shoulder Myology

Question 1

Muscles attaching upper limb to the vertebral column

Answer 1

Trapezius
Latissimus dorsi
Rhomboid major
Rhomboid minor
Levator scapulae

Question 2

Trapezius

Answer 2

Originates: medial 1/3 nuchal line on occipital bone
External occipital protuberance
Ligamentum nuchae
C7-T12 SP/ supraspinous ligaments

Inserts: upper- posterior border of lateral 1/3 clavicle
Middle- medial margin acromion / superior lip crest of scapula spine
Lower- tubercle of of medial spine of scapula

Actions: upper- elevation, Cx spine extn (bi), side-flex (uni)
Middle- retraction Lower- depression

Spinal accessory nerve C2,3,4

Question 3

Latissimus Dorsi

Answer 3

Origins: posterior surface of thoracolumbar fascia
T7-S5 SP/ intervening supraspinous ligs
Posterior surface outer iliac crest/ outer ribs 9-12
Inferior angle of scapula

Inserts: floor of intertubercular groove on humerus

Extends, adducts, medially rotates shoulder

Thoracodorsal nerve C6,7,8

Question 4

Rhomboid minor

Answer 4

Originates: C7-T1 Sp
Lower ligamentum nuchae/supraspinous ligaments

Inserts: upper medial border of scapula

Retracts/medially rotates scapula
Dorsal scapular nerve C5

Question 5

Rhomboid Major

Answer 5

Originates: T2-5 SP/ intervening supraspinous ligaments

Inserts: lower medial border of scapula (base/inferior angle)

Retracts/medially rotates scapula
Dorsal scapula nerve C5

Question 6

Levator scapulae

Answer 6

Origin: TP C1-4
Insertion: upper medial border of scapula
Actions: elevates, retracts, medially rotates scapula
Innervation: dorsal scapula nerve C5

Question 7

Muscles attaching upper limb to thoracic wall

Answer 7

Serratus anterior
Pectoralis major
Pectoralis minor
Subclavius

Question 8

Serratus anterior

Answer 8

Originates: outer ribs 1-9/ intercostal fascia

Inserts: outer surface of ribs 3-5/ intercostal fascia

Protracts, laterally rotates scapula

Long thoracic nerve C8,T1

Question 9

Pectoralis minor

Answer 9

Originates: coracoid process

Inserts: outer surface ribs 3-5/ intercostal fascia

Protracts, medially rotates scapula
Medial pectoral nerve C8,T1

Question 10

Subclavius

Answer 10

Originates: 1st rib

Inserts: inferior clavicle

Stabilises clavicle
Nerve to subclavius C5,6

Question 11

Pectoralis major

Answer 11

Originates: medial anterior border of clavicle
Anterior sternum
Anterior surface upper 6th rib/costal cartilage

Inserts: via laminated tendon into lateral intertuberular groove
Clavicle head- inferior to intertubercular groove on humerus

Flexes, medially rotates, adducts arm at shoulder

Medial pectoral nerve- C8-T1, lateral pectoral nerve- C5,6,7

Question 12

Muscles connecting upper limb to the scapula

Answer 12

Teres major
Coracobrachialis
Deltoid

Question 13

Teres major

Answer 13

Originates: lower 2/3 lateral border of scapula/ inferior angle

Inserts: medial lip of intertubercular groove

Adducts, medially rotates arm at shoulder
Lower subscapular nerve C6,7

Question 14

Coracobracialis

Answer 14

Originates: apex of coracoid process

Inserts: medial shaft of humerus

Adducts/flexes arm at shoulder
Musculocutaneus nerve C6,7

Question 15

Deltoid

Answer 15

Originates: anterior- anterior border lateral 1/3 clavicle
Middle- outer margins of acromion
Posterior- lower border of spine of scapula

Inserts: deltoid tuberosity on humerus

Abducts arm, anterior fibres flex/med rotate
Posterior fibre extend/lat rotate

Axillary nerve C5,6