Extensors

Question 1

Deltoid (post fibres)

Answer 1

Origin- spine of scapula
Insertion- mid shaft of humerus; deltoid tuberosity

Innervation- Axillary C5-6

Question 2

Teres Major

Answer 2

Origin- inf angle of scapula
Insertion- med lip of intertubercular groove

Innervation- Lower Scapular C5-6

Question 3

Latissimus Dorsi

Answer 3

Origins- via thoracolumbar fascia from spinous recesses T6-12 and all lumbar and sacral vertebrae
- iliac crest
- lower 4 ribs and inf angle of scapula
Insertion- floor of intertubercular groove (rotates 90deg again)

Innervation Thoracodorsal C6-8

Question 4

Pectoralis Major (sternocostal head)

Answer 4

Origin- med 1/2 ant border of clavicle, ant surface of sternum, ant surface of upper 6 costal cartilages and rib6
Insertion- lat lip of intertubercondylar groove via laminated tendon (almost 90deg rotation)

Innervation- Med/Lat Pectoral C5-8

Question 5

Triceps Brachii (long head)

-assists

Answer 5

Origin- infra-glenoid tubercle
Insertion- post surface of olecranon of ulna

Innervation- Radial C6-8