Muscles of the Forearm & Hand Flashcards
Brachialis action
Flex the elbow
Brachialis O & I
O: Distal half of the anterior surface of the humerus
I: Tuberosity & coronoid process of the ulna
Brachialis innervation
Musculocutaneous nerve, small branch from radial, C5, C6
Brachioradialis action
1) Flex elbow
2) Assist to pronate & supinate the arm when these movements are resisted
Brachioradialis O & I
O: Proximal 2/3 of the lateral supracondylar ridge of the humerus
I: Radial styloid process
Brachioradialis innervation
Radial nerve C5, C6
Extensor carpi radialis longus & brevis actions
1) Extend the wrist
2) Radially deviate the wrist
3) Assist to flex the elbow
Extensor carpi radialis longus O & I
O: Distal 3rd of the lateral supracondylar ridge of humerus (distal to BRad origin
I: Base of second metacarpal
Extensor carpi radialis brevis O & I
O: Common extensor tendon of lateral epicondyle of the humerus
I: Base of 3rd metacarpal
ECRB Innervation
Radial nerve C6, C7, 8
ECRL Innervation
Radial nerve C5, 6, 7, 8
Extensor carpi ulnaris actions
1) Extend the wrist
2) Ulnarly deviate the wrist
Extensor carpi ulnaris O & I
O: Common extensor tendon from lateral epicondyle of the humerus
I: Base of 5th metacarpal
Extensor carpi ulnaris innervation
Radial nerve C6, C7, C8
Flexor carpi radialis action
1) Flexion of the wrist
2) Radial deviation of the wrist
Flexor carpi radialis O & I
O: Medial epicondyle of the humerus
I: Bases of 2nd & 3rd metacarpal bones
Flexor carpi radialis (FCR) innervation
Median nerve (C6-C7)
Flexor carpi ulnaris (FCU) action
1) Flexion at the wrist
2) Ulnar deviation at the wrist
Flexor carpi ulnaris O & I
O: Medial epicondyle of humerus + nearby regions of ulna & olecranon
Flexor carpi ulnaris innervation
Ulnar nerve (C8-T1)
Palmaris longus action
Flexion at the wrist
Palmaris longus O & I
O: Medial epicondyle of the humerus
I: Palmar aponeurosis & flexor retinaculum
Palmaris longus innervation
Median nerve (C6-C7)
Pronator quadratus action
Pronates the forearm
Pronator quadratus O & I
O: Distal ulna (anterior & medial)
I: Distal radius (anterolateral)
Pronator quadratus innervation
Median nerve (C8-T1)
Pronator teres action
1) Pronate forearm
2) Flex elbow
Pronator teres O & I
O: Medial epicondyle of the humerus & coronoid process of the ulna
I: Anterolateral surface of distal portion of the ulna (same as pronator quadratus)
Pronator teres innervation
Median nerve (C6-C7)
Supinator O & I
O: Lateral epicondyle of the humerus
I: Anterolateral surface of the radius, distal to the radial tuberosity
Abductor pollicis longus action
1) Abduct thumb
2) Radially deviate the wrist
Abductor pollicis longus O & I
O: Proximal dorsal surface of radial & ulna
I: Lateral margin of 1st metacarpal bone, trapezium
Abductor pollicis longus innervation
Deep radial nerve (C6-C7)
Extensor digitorum action
Extension of fingers & wrist
Extensor digitorum O & I
O: Lateral epicondyle of the humerus
I: Posterior surfaces of phallanges 2-5
Extensor digitorum innervation
Deep radial nerve (C6-C7)
Extensor pollicis brevis action
Extension of 1st CMC & MCP (not IP), radial deviation of wrist
Extensor pollicis brevis O & I
O: Shaft of radius, distal to origin of abductor pollicis longus & interosseus membrane
I: Base of proximal phalanx of the thumb
Extensor pollicis brevis innervation
Deep radial nerve (C6-C7)
Extensor pollicis longus action
Extension of all thumb joints (including IP), radial deviation of the wrist
Extensor pollicis longus (EPL) origin & insertion
O: Posterior & lateral surface of the ulna & interosseous membrane
I: Base of distal phalanx of thumb
EPL innervation
Deep radial nerve (C6-C7)
Extensor indicis action
Extension and adduction of index finger
Extensor indicis origin & insertion
O: Posterior surface of ulna & interosseous membrane
I: Posterior surface of proximal phalanx with tendon of extensor digitorum
Extensor indicis innervation
Deep radial nerve (C6-C7)
Extensor digiti minimi action
1) Extensor o f D5
2) Extension of wrist
Extensor digiti minimi O & I
O: Via extensor tendon, lateral epicondyle of humerus
I: Posterior surface of proximal phalanx of D5
Extensor digiti minimi innervation
Deep radial nerve (C6-C7)
Flexor digitorum superficialis (FDS) action
Flexion at the PIP, MCP & wrist joints
FDS O & I
O: Medial epicondyle of humerus
I: Bases of middle phalanges D2-5
FDS innervation
Median nerve (C7-T1)
FDP action
Flexion at the DIP, PIP, & wrist ( but to a lesser degree PIP & wrist)
FDP O & I
O: Medial and posterior surface of ulna, medial surface of coronoid process, interosseous membrane
I: distal phallanges of D2-5
Flexor pollicis longus action
Flexion of all thumb joints
Flexor pollicis longus O & I
O: Anterior shaft of radius
I: Interosseous membrane
FPL innervation
Median nerve (C8-T1)
