Upper extremity innervation and action

Question 1

Biceps

Answer 1

Innervation: C5-C6
Musculocutaneous nerve
Action: Powerful flexor of forearm at elbow
Suppinator of forearm
Accessory flexor of arm at glenohumeral joint

Question 2

Brachialis

Answer 2

Innervation: C5-C6
Musculocutaneous nerve
Contribution of radial nerve to lateral part of
muscle
Action: Powerful flexor of forearm at elbow

Question 3

Triceps

Answer 3

Innervation: C6-C7-C8
Radial nerve
Action: Extension of forearm at elbow
Long head: accessory adductor and extension of
arm at GH joint

Question 4

Brachioradialis

Answer 4

Innervation: C5-C6
Radial nerve
Action: Accessory flexor of elbow when forearm is mid-pronated

Question 5

Suppinator

Answer 5

Innervation: C6-C7
Posterior interosseous nerve
Action: Suppination

Question 6

Pronator teres

Answer 6

Innervation: C6-C7
Median nerve
Action: Pronation

Question 7

Wrist flexors

Answer 7

Innervation: C6-C7
Action: wrist flexion

Question 8

Wrist extensors

Answer 8

Innervation: C6-C7-C8
Action: wrist extension