Brachial Plexus muscles

Question 1

Trapezius

Answer 1

Action: Upper scapular elevator,
Mid: scap retraction
Lower: scapular depression

Inn: CN 11

Question 2

Lattisimus Dorsi

Answer 2

A: Shoulder ext, Add, IR humerus
I: Thoracodorsal n

Question 3

Levator Scap

Answer 3

A: elevates the scap
I: dorsal scap n

Question 4

Deltoid

Answer 4

A: Ant: flexor: IR (clavicular head)
Med: Abd+ ER

I: Axillary n

Question 5

Supraspinatus

Answer 5

A: shoulder abd first 15 degrees- helps with humeral compression in glenoid
I: Suprascapular n

Question 6

Infraspinatus

Answer 6

A: shoulder ER; helps to stabilize humeral head in glenoid
I: Suprascapular n

Question 7

Teres minor

Answer 7

A: ER+ humeral compression
I: Axillary n

Question 8

Teres Major

Answer 8

A: IR

I : subscap n (lower)

Question 9

Subscapularis

Answer 9

A: IR; prevents anterior displacement of humerus
I: upper and lower subscap n

Question 10

Pectoralis Major

Answer 10

A: Shoulder IR, horiz ADD, flexor
I: medial and lateral pec n

Question 11

Biceps Brachii

Answer 11

A: Elbow flexor, supinator, shoulder flexor
I: Musculocutaneous n

Question 12

Brachialis

Answer 12

A: elbow flexor
I: musculocutaneous n (small cont from radial n)

Question 13

Corachobracialis

Answer 13

A: flexes and add arm at the shoulder
I: musculocutaneous n

Question 14

Triceps and anconeus

Answer 14

A: elbow ext (Long head extends shoulder too)
I: Radial N

Question 15

Pronator teres/quadratus

Answer 15

A: pronation, weak elbow flexor
I: Median N

Question 16

Flexor Carpi Radialis

Answer 16

A: wrist flexion, radial dev
I: Median N

Question 17

Palmaris Longus

Answer 17

A: wrist flexion
I: Median N

Question 18

Flexor carpi Ulnaris

Answer 18

A: Wrist flexion, ulnar dev
I: Ulnar N

Question 19

Flexor digitorum superficalis

Answer 19

A: Finger flexor to PIP, weak wrist, MCP and elbow flexion
I: Median n

Question 20

Flexor digitorum profundis

Answer 20

A: Flexor to DIP

I : Ulnar and Anterior interosseus branch of Median N

Question 21

Flexor Pollicus Longus

Answer 21

A: Thumb flexion
I: Median (interosseus branch)

Question 22

Supinator

Answer 22

A: supinates forearm
I: Radial N

Question 23

Brachioradialis

Answer 23

A: elbow flexor in mid pronation
I: Radial N

Question 24

Extensor Carpi radialis longus

Answer 24

A: wrist ext+ rad dev
I: Radial N

Question 25

Extensor carpi radialis brevis

Answer 25

A: wrist ext+ rad dev
I: Radial n

Question 26

Extensor digitorum

Answer 26

A: MCP and PIP ext; wrist ext when fingers ext
I: radial N (posterior interosseus)

Question 27

Extensor Digiti Minimi

Answer 27

A: Ext of 5th MCP+ IP; wrist ext when fingers ext
I: Radial N (posterior interosseus branch)

Question 28

Extensor carpi ulnaris

Answer 28

A: wrist ext and ulnar dev
I: Radial N (posterior interosseus branch)

Question 29

Extensor Indicis

Answer 29

A: extends 2nd MCP, 22 wrist ext
I: Radial n (posterior interosseus branch)

Question 30

Extensor pollicus longus

Answer 30

A: extends hallux at MCP and IP joints, can also abd hallux
I: radial n (posterior interosseus branch)

Question 31

Extensor pollicis brevis

Answer 31

A: extends hallux at MCP jt
I: Radial n (posterior interosseus branch)

Question 32

Abductor pollicis longus

Answer 32

A: thumb abd, ext, ER

I : Radial nerve (posterior interosseus branch)