Myology of the Forearm and Hand Flashcards
What are the four superficial flexors
Pronator teres
Palmaris longus
Flexor carpi radialis
Flexor carpi ulnaris
What is the common origin of the superficial flexors
Medial, epicondyle of humerus
Pronator teres details
Also originates at the coronoid process of the ulna
I: Lateral mid shaft radius
Palmaris longus
I: Palmar aponeurosis and flexor retinaculum (May not be present, evolution)
Flexor carpi radialis
I: Bases of metacarpal 2+3
F: Lateral deviation of wrist
Flexor carpi ulnaris
Also originates at the olecranon process
I: Pisiform and hamate, base of metacarpal 5
F: Medial deviation of wrist
What is the intermediate flexor
Flexor digitorum superficialis
Flexor digitorum superficialis details
O: Humerus medial epicondyle and adjacent anterior surfaces of radius and ulna
I: Mid-lateral surfaces of middle phalanges 2-5
F: Gives rise to 4 tendons that pass through the carpal tunnel in two pairs, one superficial to the other
What are the three deep flexors
Flexor digitorum profundus, flexor policis longus and pronator quadratus
Flexor digitorum profundus
O: Medial/posterior ulna, medial coronoid process, interosseous membrane
I: Base of distal phalanges 2-5
Gives rise to 4 tendons that pass through the carpal tunnel side by side. These tendons pass through the v shapes formed by flexor digitorum superficialis
Flexor policis longus
O: Anterior shaft of radius and interosseous membrane
I: Base of distal phalanx of thumb
F: Flexion of thumb
Pronator quadratus
O: Anterior and distal surfaces of distal ulna
I: Anterolateral surface of distal portion of radius
What forms the walls of the carpal tunnels
Medial: Pisiform and hamate
Lateral: Trapezium and scaphoid tubercle
Floor: Other carpal bones
Roof: Flexor retinaculum
Name the six superficial extensors
Brachioradialis Extensor carpiulnaris Extensor digitorum Extensor digit minimi Extensor carpi radialis longus Extensor carpi radialis brevis
Brachioradialis
O: Lateral supracondylar ridge of distal humerus
I: Styloid process of radius
F: Flexor of the elbow
Extensor carpiulnaris
O: Lateral epicondyle of humerus
I: Base of 5th metacarpal
F: Extension and medial deviation
Extensor digitorum
O: Lateral epicondyle of humerus
I: 4 tendons into extensor expansions and distal phalanges of 2-5
Extensor digit minimi
O: Lateral epicondyle of humerus
I: Posterior proximal phalanx of little finger (digit 5)
Extensor carpiradialis longus
O: Lateral supracondylar ridge of humerus
I: Base of metacarpal 2
This is a long tendon that runs superficial
Extensor carpi radialis brevis
O: lateral epicondyle of humerus
I: Base of metacarpal 3
This is a short tendon that runs deeper
What are the five deep extensors
Supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor indicis
Supinator
O: Lateral epicondyle of humerus and proximal ulna
I: Proximal radius
F: Acts to supinate; when hand is pronated, wraps around radius with lengthened fibres. Shortening the fibres (concentric) reverses this and draws the hand back to supination.
Abductor pollicis longus
O: Dorsal shaft of radius and ulna
I: Lateral MCI (and trapezium)
Extensor pollicis longus
O: Dorsal shaft of radius/ulna and interosseous membrane
I: Base of distal phalanx of thumb
Extensor pollicis brevis
O: Dorsal shaft of radius/ulna and interosseous membrane
I: Base of proximal phalanx of thumb
Extensor indicis
O: Posterior of distal ulna and interosseous membrane
I: Extensor expansion of index finger
Digit extensors information
O: Tendon of flexor digitorum profundus
I: Lateral edge of extensor expansion on 1st phalynx of 2-5
F: Flexion of metacarpophalangeal joints and extension of interphalangeal joints.
What are the two types of interossei
Palmar and dorsal
Details of palmar interossei
O: Side of metacarpals facing digit 3
I: Extensor expansion of first phalanx on same side
Details of dorsal interossei
O: Sides of metacarpals
I: Extensor expansion over first phalanx of 2-4, on both sides of #3, but opposite sides of other digits
