Muscles of the forearm Flashcards
Learn the actions, attachments, and innervation
Brachialis attachments
Distal half of anterior surface of humerus
Ulnar tuberosity and anterior coronoid process
Brachialis action
Elbow (humeroulnar) flexion
Brachialis innervation
Musculocutaneous C5-7
Flexor carpi ulnaris attachments
Common flexor tendon from medial epicondyle of humerus and posterior 2/3 of proximal ulna
Inserts at pisiform, hook of hamate, and base of the fifth met
Note that the ulnar nerve travels along this line
Flexor carpi ulnaris actions
Wrist flexion
Wrist ulnar deviation (adduction)
Assists humeroulnar flexion
Flexor carpi ulnaris innervation
Ulnar nerve C7/8, T1
Attachments of palmaris longus
Common flexor tendon from medial humeral epicondyle
Inserts at palmar aponeurosis and flexor retinaculum
Note, good landmark for median nerve
Actions of palmaris longus
Primary: gripping w palm
Secondary: wrist flexion humeroulnar flexion
Innervation of palmaris longus
Median nerve C5-T1
Attachments of flexor carpi radialis
Common flexor tendon at medial epicondyle
Base of 2nd and 3rd Mets
Note that radial nerve follows
Actions of FCR
Radial deviation (abduction)
wrist flexion
elbow flexion
assists pronation
Innervation of FCR
Median nerve C5-T1
Attachments of pronator teres
medial epicondyle of humerus and medial aspect of coronoid process
Middle 1/3 of lateral surface of radius
Actions of pronator teres
Pronation
Weak elbow flexion
Innervation of pronator teres
Median nerve C5-T1
Attachments of the flexor digitorum superficialis
Common flexor tendon, medial aspect of coronoid process, ulnar collateral ligament
Oblique line of radius
Insertions: middle phalanges of digits 2-5, note that there is a bifurcation near insertion for FDP to pass through
Note that median nerve passes between two heads
Actions of FDS
PIP, MIP and wrist flexion
Secondary: elbow flexion
Innervation of flexor digitorum superficialis
Median nerve C5-T1
Attachments of flexor digitorum profundus
Proximal 3/4s of medial anterior ulna, middle of anterior aspect of interosseus membrane
Insertion: palmar aspect of DIPs of digits 2-5, passing through bifurcation of FDS
Actions of FDP
Flexion at DIPs, MIPs, and PIPs of 2-5 and wrist flexion
Innervation of FDP
Digits 4/5 ulnar nerve C7-T1
Digits 2/3 median nerve C5-T1
Attachments of Flexor pollicis longus
Anterior aspect of radius distal to oblique line down to pronator quadratus
Interosseus membrane on radial half
(note that FPL has its own tendinous sheath separate from flexor digitori)
Inserts at base of distal phalanx of pollux
Actions of flexor pollicis longus
Flexion of pollux at IP and MCP
Wrist flexion
Innervation of flexor pollicis longus
Median nerve C5-T1
Attachments of pronator quadratus
Distal anterior medial 1/4 of ulna to distal anterior lateral radius (wraps borders of anterior forearm)
Actions of pronator quadratus
Pronation (slow strong)
Holds radius and ulna together
Innervation of pronator quadratus
Median nerve C5-T1
Attachments of brachioradialis
Lateral supracondylar ridge of humerus to styloid of radius
Actions of brachioradialis
Elbow flexion (most effective in mid pronation (handshake position)) Assists pronation and suppination
Innervation of brachioradialis
Radial nerve C5-T1
Attachments of extensor carpi radialis longus and brevis
Lateral supracondylar ridge of humerus
Insertions:
Dorsum of base of the 2nd met (longus)
Dorsum of base of 3rd met (brevis)
Actions of extensor carpi radialis longus and brevis
Wrist extension, abduction
Assists elbow flexion
Innervation of extensor carpi radialis longus and brevis
Radial nerve C5-T1
Attachments of Extensor digitorum
Common extensor tendon from lateral epicondyle
Middle and distal phalanges of digits 2-5 w bifurcation at PIP for lumbricals
Actions of extensor digitorum
Extension at DIPS/PIPS/MTPs of 2-5
Wrist extension
Assists elbow extension
Innervation of extensor digitorum
Radial nerve C5-T1
Extensor digiti minimi (part of ED but different sheath) attachments
Lateral epicondyle of humerus
Dorsal aspect of middle and distal fifth digit
Extensor digiti minimi action
Extension of fifth digit
Assists wrist and elbow flexion
Innervation of extensor digiti minimi
Radial nerve C5-T1
Attachments of extensor carpi ulnaris
Common extensor tendon at lateral epicondyle
Dorsum of base of fifth
Actions of extensor carpi ulnaris
Wrist extension
Ulnar deviation (adduction)
assists elbow extension
Innervation of extensor carpi ulnaris
Radial nerve C5-T1
Attachments of anconeus
Lateral epicondyle of humerus
lateral olecranon process and lateral proximal shaft of ulna (crosses over head of radius)
Actions of anconeus
Elbow extension
Stabilizes head of radius
Innervation of anconeus
Radial nerve C5-T1
Attachments of supinator
Lateral epicondyle, supinator crest, radial collateral lig, annular lig
Envelops the neck and proximal
shaft of the radius
Lateral proximal radial shaft
Actions of supinator
Supination
Innervation of supinator
Deep branch radial nerve C5-T1
Components of the anatomical snuffbox
Radial artery
Scaphoid
Trapezium
Cubital fossa
Depression between pronator teres and brachioradialis
Also bordered by radial nerve, ulnar nerve and radial artery
Borders of the anatomical snuffbox
Tendon of extensor pollicis longus
Abductor pollicis longus
Styloid process of the radius