Forearm

Question 1

What fascia envelopes the forearm?

Answer 1

Antebrachial fascia

Question 2

Posterior and lateral muscles are innervated by what nerve? Anterior and Medial?

Answer 2

1. Radial nerve

2. Median Nerve

Question 3

What are the different actions of the wrist - condyloid joint?(5)

Answer 3

1. Flexion
2. Extension
3. Abduction
4. Adduction
5. Circumduction

Question 4

Supination and pronation occurs at what joint?

Answer 4

Radioulnar

• extension and flexion at the elbow

Question 5

The metacarpals are what kind of joint?

Answer 5

Condyloid - circumduction occurs

interphalangeal = hinge joint –> flexion/extension

Question 6

What are the two main supinators?

Answer 6

Biceps Brachii and Supinator muscle

Question 7

What are the actions, innervations, and originate of the anterior compartment of the forearm?

Answer 7

Flexion and Median Nerve (all EXCEPT ulnar half of flexor digitorum profundus and flexor carpi ulnaris – ulnar N.)

Originate at medial epicondyle (via common flexor tendon)

Question 8

What two muscles rotate the radius on the ulna from the anterior compartment of the forearm?

Answer 8

1. Pronator teres (assists elbow flexion as well)

2. Pronator Quadratus

Question 9

What muscles flex the hand at the wrist and insert onto palmar aponeurosis/metacarpals?

Answer 9

1. Palmaris Longus - tense the palm, flex wrist
2. Flexor Carpi Radialis - ABDuction, flex wrist
3. Flexor Carpi Ulnaris - ADDuction, flex wrist

Question 10

What muscles flex the hand at the wrist and DIGITS and insert onto phalanges?

Answer 10

1. Flexor digitorum superficialis - flex MCP, PIP
2. Flexor Digitorum Profundus - flex DIP*
3. Flexor Pollicis Longus - flex thumb

Question 11

What are the actions, innervations, and origin of the POSTERIOR compartment of the forearm?

Answer 11

A: Extension, rotate radius on ulna (supinator)
N: Radial Nerve*
Origin: Common extensor attachment of LATERAL epicondyle

Question 12

What muscle rotates the radius on the ulna from the POSTERIOR compartment of the forearm?

Answer 12

Supinator

Question 13

What muscles EXTEND the hand at the wrist and insert onto metacarpals 2,3, or 5?

Answer 13

1. Extensor Carpi Radialis Longus - abduct*
2. Extensor Carpi Radialis Brevis - abduct
3. Extensor Carpi Ulnaris - ADDucts

*all extend

Question 14

What muscles EXTEND the hand at the wrist and DIGITS and insert onto phalanges? Where do they insert?

Answer 14

Insert onto the extensor expansion hood

1. extensor digitorum – 2 to 5
2. extensor indicis - extend digit 2
3. extensor digiti minimi - extends digit 5 (pinky)

Question 15

What muscles EXTEND the thumb? Where do they insert?

Answer 15

1. Abductor Pollicis Longus - base of 1st Metacarpal –> extend and abduct
2. Extensor Pollicis Brevis - base of proximal phalanx (extend PIP)
3. Extensor Pollicis Longus - base of distal phalanx (extends the DIP)

Question 16

What muscle is also part of the posterior compartment and serves to flex the elbow and guide us to find the extensor muscles?

Answer 16

Brachioradialis!

• flexes the elbow when pronated
• *RADIAL NERVE**

Question 17

What forms the snuff box?

Answer 17

1. Abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus
2. Contains Radial ARTERY
3. Superficial Radial NERVE
4. Scaphoid bone

Question 18

What nerve runs between flexor digitorum superficial is and flexor digitorum profundus?

Answer 18

Median nerve

Question 19

All the triceps insert onto_________

Answer 19

Olecrenon Fossa (back of arm)

Question 20

What nerve lies between the medial and lateral heads of the triceps?

Answer 20

Radial Nerve

Question 21

What nerve travels by the funny bone?

Answer 21

Ulnar Nerve

Question 22

Once the radial nerve hits the supinator it is called:

Answer 22

Posterior Interosseus Nerve

Median is the Anterior Interosseus Nerve

Question 23

Muscles that attach to the Radius always abduct or adduct?

Answer 23

Abduct

Question 24

What nerve supplies the cutaneous innervations for the lateral aspect of the forearm?

Answer 24

Lateral Antebrachial Cutaneous (Musculocutaneous)

Medial Antebrachial Cutaneous is the Medial aspect of the arm (arises from the medial chord of the brachial plexus)

Question 25

Pronator Teres Muscle

Answer 25

O: Medial Epicondyle I: Radius A: Pronation of forearm, assist with elbow flexion N: Median Nerve

Question 26

Flexor Carpi Radialis

Answer 26

``` O: Medial Epicondyle I: base of 2nd metacarpal A: flexion and ABDuction wrist N: Median N. B: Radial Artery ```

Question 27

Flexor Carpi Ulnaris

Answer 27

O: medial epicondyle I: pisiform bone, hook of hamate, 5th metacarpal A: Flexion and ADDuction hand at wrist N: Ulnar N.

Question 28

Palmaris Longus

Answer 28

O: Medial Epicondyle I: Flexor Retinaculum and Palmar Aponeurosis A: Flexion of wrist, tenses palm* N: Medial N. * not everyone has this

Question 29

Flexor Digitorum Superficialis

Answer 29

O: Medial Epicondyle I: Bodies of middle phalanges (PIP) of medial 4 digits A: Flexion of PIP and MCP, (assist) flex hand at wrist N: Median N.

Question 30

Flexor Digitorum Profundus

Answer 30

O: Medial Epicondyle I: DIP of medial 4 digits A: Flexion of DIP, assist flexion hand at wrist N: Median N. , Ulnar N for the Ulnar 1/2

Question 31

Pronator Quadratus

Answer 31

O: Distal 1/4 of anterior Ulna I: Distal 1/4 of anterior Radius A: Pronation of forearm N: Median N. (anterior interosseus)

Question 32

Flexor Pollicis Longus

Answer 32

O: Surface of radius and interosseus membrane I: DIP of thumb A: Flexes phalanges of thumb N: Median N.

Question 33

Extensor Carpi Radialis Longus

Answer 33

O: lateral supracondylar ridge of humerus I: base of 2nd metacarpal A: Extends and ABDucts hand at wrist N: Radial

Question 34

Extensor Carpi Radialis Brevis

Answer 34

O: lateral epicondyle of humerus I: base of 3rd metacarpal A: Extends and ABDucts hand at wrist N: Radial N.

Question 35

Brachioradialis

Answer 35

O: 2/3 of lateral supracondyle ridge of humerus I: Radius A: weak flexion of forearm when PRONATED* N: Radial N.

Question 36

Extensor Carpi Ulnaris

Answer 36

O: Lateral epicondyle of humerus I: Dorsal base of 5th Metacarpal A: Extension and ADDuction N: Radial N. ** (posterior interosseus, not ulnar)

Question 37

Extensor Digiti Minimi

Answer 37

O: Lateral Epicondyle I: Extensor Expansion Hood of 5th Metacarpal* A: Extension of 5th digit N: Radial Nerve (posterior I = deep radial)

Question 38

Extensor Digitorum

Answer 38

O: Lateral Epicondyle I: extensor expansion of medial 4 digits A: extension of medial 4 digits (assist in wrist extension) N: Radial N. (posterior interosseus)

Question 39

Abductor Pollicis Longus

Answer 39

O: posterior surface of ulna,radius, and interosseus membrane I: base of 1st METACARPAL A: abduction/ extension of the thumb and carpometacarpal joint N: Radial N. (posterior interosseus)

Question 40

Extensor Pollicis Brevis

Answer 40

O: Posterior surface of radius + interosseus membrane I: base of PROXIMAL Phalanx of thumb A: extension of PIP of thumb at carpometacarpal joint N: Radial N. (posterior interosseus)

Question 41

Extensor Pollicis Longus

Answer 41

O: Posterior surface of middle third of ulna, interosseus membrane I: base of DISTAL phalanx of thumb A: Extension of Distal phalanx N: Radial N. (posterior interosseus)

Question 42

Extensor Indicis

Answer 42

O: Posterior surface of ulna, interosseus membrane (close to extensor pollicis longus) I: Extensor Expansion of 2nd digit (pointer finger) A: Extension of 2nd digit, assist extension of hand at wrist N: Radial Nerve (posterior interosseus)