Elbow Muscles

Question 1

Biceps brachii (flexor)

Answer 1

-Origin: short head (coracoid process of scapular)
Long head (supraglenoid tubercle of scapular)

-insertion: radial tuberosity of the radius.

Action: elbow and shoulder flexion, forearm supination

-innervation: musculocutaneus nerve (c5-c6)

Question 2

Brachialis (flexor)

Answer 2

-original: anterior surface of the distal half of the humerus

-insertion: coronoid process and tuberosity of the ulnar

-Action: elbow flexion (most effective in elbow pronation)

-innervation: musculocutaneous nerve (c5-c6)

Question 3

Brachioradialis (flexor)

Answer 3

-Origin: lateral supracondylar ridge of humerus

-insertion: styloid process of radius

-action: elbow flexion (neutral between supination and pronation)

Innervation: radial nerve (c5-c6)

Question 4

Pronator teres (flexor)

Answer 4

-origin: medial epicondyle of the humerus and coronoid process of the ulnar.

-insertion: lateral surface of radius

-action: elbow flexion, forearm pronation

-innervation: median nerve (c6-c7)

Question 5

Triceps brachii (extensor)

Answer 5

-origin: (long head) infraglenoid tubercle of scapular.
-(lateral head) posterior surface of the humerus above radial groove.
-(medial head) posterior surface of the humerus below radial groove

-Insertion: olecranon process of the ulnar

-action: main elbow extensor. Long head also assists in shoulder extension.

-innervation: radial nerve (c6-c8)

Question 6

Anconeus (extensor)

Answer 6

-origin: lateral epicondyle of humerus

-insertion: lateral surface of the olecranon and upper posterior surface of the ulnar

-action: assists in elbow extension. Stabilises the elbow joint

-innervation: radial nerve (c7-c8)