The elbow and forearm: muscle and movement

Question 1

Origin and insertions for brachialis

Answer 1

origin- distal 1/2 of humerus, insertion- tuberosity of ulna

Question 2

action and NS brachialis

Answer 2

NS- musculo-cutaneous nerve C5,6

action- main flexor at elbow joint

Question 3

Origin and insertion bicep brachii

Answer 3

short- corocoid process, long tubercle above glenoid fossa

insertion- tuberosity of radius- bicipital aponeurosis

Question 4

NS and action bicep brachii

Answer 4

NS- musculo-cutaneous nerve C5,6

action- flexion at shoulder elbow/ shoulder, supination of radio-ulnar joint

Question 5

glenoid attachments bicep and triceps brachii

Answer 5

bicep brachii- long head- supraglenoid tubercle

triceps brachii long head- infraglenoid tubercle

Question 6

brachioradialis origin and insertions

Answer 6

origin- superficial muscle, laterals side of forearm, from lateral supracondylar ridge of humerus
insertion- lateral surface of radius proximal of radial styloid process

Question 7

brachioradialis NS and action

Answer 7

NS- radial nerve C5,6
Action- flexes the elbow when forearm mid prone) works best in mid-range), returns forearm from full supination or full pronation to mid- range

Question 8

tricep brachii origin and insertions

Answer 8

origin- long= infra-glenoid tubercle, lateral= upper part of posterior surface of humerus, medial= lower part of posterior surface of humerus
insertion- posterior surface of olecranon of ulna

Question 9

NS and action tricep brachii

Answer 9

NS- radial nerve C6,7,8

Action- extends the elbow, long head also adducts and extends the shoulder

Question 10

origin and insertions of anconeus

Answer 10

origin- lateral epicondyle of humerus, insertion- olecranon and upper part of ulnar shaft

Question 11

NS and action of anconeus

Answer 11

NS- radial nerve C7,8

Action- assist extension at elbow joint

Question 12

Muscles pronating forearm

Answer 12

pronator teres, pronator quadrates, brachioradialis

Question 13

muscles supinating forearm

Answer 13

supinator, bicep brachii, brachioradialis

Question 14

Origin and insertion pronator teres

Answer 14

origin- 2 heads= medial epicondyle of humerus, coronoid process of ulna
insertion- middle lateral surface of radius

Question 15

NS and action pronator teres

Answer 15

NS- Median nerve C6,7

Action- pronation of forearm, assist elbow flexion

Question 16

Origin and insertions pronator quadratus

Answer 16

fleshy quadrangular muscle
origin- distal part of anterior surface of shaft of ulna
insertion- distal part of anterior surface of shaft of radius

Question 17

NS and action pronator quadratus

Answer 17

NS- anterior interosseous nerve C8, T1

Action- pronates forearm, stabilises bones (inferior RU junction) in weight bearing

Question 18

origin and insertion of supinator

Answer 18

origin (2 heads)- lateral epicondyle of humerus, radial collateral and annular ligaments, supinator fossa and crest of ulna
insertion- lateral posterior anterior surface of 1/3 of proximal radius

Question 19

NS and action of supinator

Answer 19

NS- radial nerve C5,6

Action- supinates forearm

Question 20

cubital fossa- lateral border

Answer 20

medial aspect of the brachioradialis

Question 21

cubital fossa- medial border

Answer 21

lateral aspect of the pronator teres

Question 22

cubital fossa- superior border

Answer 22

line drawn between the 2 epicondyles

Question 23

cubital fossa contents

Answer 23

deep branch of radial nerve between 2 heads or supinator, tendon of bicep brachii and brachialis, brachial artery- divides here into ulnar/ radial artery, median nerve