Muscles Of The Anterior And Posterior Arm And Forearm Flashcards
Biceps brachii origin and insertion
O: long head- supraglenoid tubercle, short head- coracoid process
I: radial tuberosity
Biceps brachii innervation and action
Innervation: musculocutaneous nerve (C5-C7)
Action: forearm supination, elbow flexion, long head- shoulder flexion, abduction (15%)
Brachialis origin and insertion
O: distal anterior humerus
I: coronoid process of the ulna and ulnar tuberosity
Brachialis innervation and action
Innervation: musculocutaneous nerve (C5-C7)
Action: elbow flexion
Coracobrachialis origin and insertion
(Not palpable)
O: coracoid process of the scapula
I: distal medial humerus
Coracobrachialis innervation and action
Innervation: musculocutaneous nerve (C5-C7)
Action: shoulder flexion and adduction
Triceps brachii origin and insertion
O: long head- infraglenoid tubercle of the scapula, lateral head- posterior aspect of the humerus superior to the radial groove, medial head- posterior aspect of the humerus inferior to the radial groove
I: olecranon process of the ulna
Triceps brachii innervation and action
Innervation: radial nerve (C6-C8)
Action: elbow extension, long head- helps with shoulder extension
Anconeus origin and insertion
(Not palpable)
O: lateral epicondyle of the humerus
I: posterior aspect of the ulna
Anconeus innervation and action
Innervation: radial nerve (C6-C8)
Action: assists with elbow extension, helps stabilize the lateral aspect of the elbow
Brachioradialis origin and insertion
O: lateral supracondylar ridge of the humerus
I: distal lateral radius
Brachioradialis innervation and action
Innervation: radial nerve (C6-T1)
Action: elbow flexion and assisting synergistic for forearm supination
Extensor carpi radialis longus origin and insertion
O: lateral supracondylar ridge of the humerus
I: second metacarpal
Extensor carpi radialis longus innervation and action
Innervation: radial nerve (C6-T1)
Action: wrist extension and radial deviation
Extensor carpi radialis brevis origin and insertion
O: lateral epicondyle of the humerus via the common extensor tendon
I: third metacarpal
Extensor carpi radialis brevis innervation and action
Innervation: radial nerve (C6-T1)
Action: wrist extension and radial deviation
Extensor digitorum communis innervation and action
Innervation: radial nerve (C6-T1)
Action: extension of digits 2-5 at the metacarpophalangeal (MCP) joints, can also help extend wrist
Extensor digitorum communis origin and insertion
O: lateral epicondyle of the humerus via the common extensor tendon
I: extensor expansions of digits 2-5 (4 tendons to each digit, central slip goes to middle phalanx, 2 collateral bands go to distal phalanx)
Extensor digiti minimi origin and insertion
O: lateral epicondyle of the humerus via the common extensor tendon
I: extensor expansion of digit 5
Extensor digiti minimi innervation and action
Innervation: radial nerve (C6-T1)
Action: extends digit 5 at MCP joint, can also help extend wrist
Extensor carpi ulnaris origin and insertion
O: lateral epicondyle of the humerus via the common extensor tendon and the posterior border of the ulna
I: fifth metacarpal
Extensor carpi ulnaris innervation and action
Innervation: radial nerve (C6-T1)
Action: wrist extension and ulnar deviation
Supinator origin and insertion
(Not palpable)
O: lateral epicondyle of the humerus via the common extensor tendon, and proximal ulna (supinator crest)
I: proximal lateral radius
Supinator innervation and action
Innervation: radial nerve (C6-T1)
Action: forearm supination
Abductor pollicis longus origin and insertion
O: posterior surface of the radius, ulna, and interosseous membrane
I: first metacarpal
Abductor pollicis longus innervation and action
Innervation: radial nerve (C6-T1)
Action: abduction of the thumb (at the first CMC joint)
Extensor pollicis brevis origin and insertion
O: posterior surface of radius and interosseous membrane
I: proximal phalanx of digit 1
Extensor pollicis brevis innervation and action
Innervation: radial nerve (C6-T1)
Action: extension of the thumb (first MCP joint)
Extensor pollicis longus origin and insertion
O: posterior surface of the ulna and interosseous membrane
I: distal phalanx of digit 1
Extensor pollicis longus innervation and action
Innervation: radial nerve (C6-T1)
Action: extension of the thumb (MCP and interphalangeal (IP) joint of the first digit)
Extensor indicis origin and insertion
O: posterior surface of the ulna and interosseous membrane
I: extensor expansion of digit 2
Extensor indicis innervation and action
Innervation: radial nerve (C6-T1)
Action: extension of digit 2 at the second MCP joint
Carpals
Proximal row: scaphoid, lunate, triquetrum, pisiform
Distal row: trapezium, trapezoid, capitate, hamate
“Some lovers try positions that they cannot handle”
Pronator teres origin and insertion
Layer 1
O: humeral head- medial epicondyle of the humerus via the common flexor tendon, ulnar head- coronoid process of the ulna
I: middle lateral radius
Pronator teres innervation and action
Innervation: median nerve (C6-C8)
Action: forearm pronation and assisting synergist for elbow flexion
Flexor carpi radialis origin and insertion
Layer 1
O: medial epicondyle of the humerus (common flexor tendon)
I: second and third metacarpal
Flexor carpi radialis innervation and action
Innervation: median nerve (C7-T1)
Action: wrist flexion and radial deviation
Palmaris longus origin and insertion
Layer 1
O: medial epicondyle of the humerus (common flexor tendon)
I: palmar aponeurosis and flexor retinaculum
Palmaris longus innervation and action
Innervation: median nerve (C8-T1)
Action: wrist flexion
Flexor carpi ulnaris origin and insertion
Layer 1
O: humeral head- medial epicondyle of the humerus (common flexor tendon), ulnar head- posterior border of the ulna
I: pisiform bone, hook of the hamate, fifth metacarpal
Flexor carpi ulnaris innervation and action
Innervation: ulnar nerve (C7-T1)
Action: wrist flexion and ulnar deviation
Flexor digitorum superficialis origin and insertion
Layer 2
O: humeroulnar head- medial epicondyle of the humerus (common flexor tendon) and the coronoid process of the ulna, radial head- proximal one half of the radius
I: middle phalanges of digits 2 to 5
Flexor digitorum superficialis innervation and action
Innervation: median nerve (C8-T1)
Action: flexion of the proximal interphalangeal (PIP) joints of digits 2 to 5
Flexor digitorum profundus origin and insertion
Layer 3
O: proximal three fourths of the anterior surface of the ulna and interosseous membrane
I: distal phalanges of digits 2 to 5
Flexor digitorum profundus innervation and action
Innervation: tendon 1 and 2 median nerve, tendon 3 and 4 ulnar nerve (C8-T1)
Action: flexion of the distal interphalangeal (DIP) joints of digits 2 to 5
Flexor pollicis longus origin and insertion
Layer 3
O: anterior radius and interosseous membrane
I: distal phalanx of digit 1
Flexor pollicis longus innervation and action
Innervation: median nerve (C8-T1)
Action: flexion of all joints of the first digit
Pronator quadratus origin and insertion
Layer 4
O: distal 1/4 of the ulna
I: distal 1/4 of the radius
Pronator quadratus innervation and action
Innervation: median nerve (C8-T1)
Action: forearm pronation