Hand & Forearm Flashcards
Carpal Bones
Proximal Row (lateral to medial) Scaphoid Lunate Triquetrum Pisiform (a sesamoid bone, formed within the tendon of the flexor carpi ulnaris)
Distal Row (lateral to medial) Trapezium Trapezoid Capitate Hamate (has a projection on its palmar surface, known as the ‘hook of hamate’
Thenar Muscles
Opponens Pollicis
Abductor Pollicis Brevis
Flexor Pollicis Brevis
Hypothenar muscles
Opponens Digiti Minimi
Abductor Digiti Minimi
Flexor Digiti Minimi Brevis
Intrinsic muscles of the hand
Lumbricals
Palmar & Dorsal Interossei
Palmaris Brevis
Adductor Pollicis
Opponens Pollicis
Origin: tubercle of trapezium
Insertion: lateral margin of 1st metacarpal
Innervation: median nerve (recurrent branch/thenar branch)
Function: opposes the thumb
Abductor Pollicis Brevis
Origin: tubercles of scaphoid & trapezium & flexor retinaculum
Insertion: lateral side of proximal phalanx of thumb
Innervation: recurrent branch of median n.
Function: Abducts the thumb
Flexor pollicis Brevis
Origin: tubercle of trapezium/flexor retinaclulm
Insertion: base of proximal phalanx of thumb
Innervation: recurrent branch of median n.
Function: Flex MCPJ of thumb
Opponens digits minimi
Origin: hook of hamate & flexor retinaculum
Insertion: medial margin of 5th MTC
Innervation: Ulnar nerve
Function: rotates 5th MTC towards palm, producing opposition
Abductor digiti minimi
Origin: pisiform and tendon of FCU
Insertion: base of proximal phalanx of 5th
Innervation: ulnar nerve
Function: abducts little finger
Flexor digiti minimi brevis
Origin: hook of hamate and flexor retinaculum
Insertion: base of proximal phalanx of little finger
Innervation: ulnar
Function: flexes MCPJ 5th
Lumbricals
4 lumbricals associated with each finger
Origin: tendon of FDP, pass dorsally and laterally around each finger
Insertion: extensor hood
Innervation: lateral 2 - median. medial 2 - ulnar
Function: flexion at MCPJ and extension of IPJs
Dorsal Interossei
4 dorsal interossei muscles
Origin: lateral and medial surface of MTCs
Insertion: extensor hood and proximal phalanx of each finger
Innervation: ulnar n
Function: abduct fingers at MCPJ
Palmar interossei
3 palmar interossei Origin: medial or lateral surface of MTC Insertion: extensor hood and proximal phalanx Innervation: ulnar nerve Function: adducts the fingers at MCP
Palmaris brevis
Origin: palmar aponeurosis and flexor retinaculum
Insertion: terms of skin and medial margin of hand
Innervation: ulnar n.
Function: wrinkles skin of hypothenar eminence, deepens curvature of hand (improving grip)
Adductor Pollicis
Origin: 1st head - 3rd MTC. 2nd head - capitiate, 2nd and 3rd MTC
Insertion: proximal phalanx of thumb
Innervation: ulnar n.
Function: Adductor of the thumb
Borders of the carpal tunnel
Deep carpal arch
- Lateral border: scaphoid and trapezium tubercles
- medial: hook of hamate and pisiform
Flexor retinaculum: Roof
Contents of Carpal tunnel
9 tendons:
- 4 tendons of Flexor digitorum profundus
- 4 tendons of flexor digitorum superficial
- flexor polices longus
Median nerve
Extensor compartments of the wrist
6 compartments:
- Extensor pollicis brevis/Abductor pollicis longus
- Extensor carpi radialis brevis/extensor carpi radialis longus
- Extensor pollicis longus
- extensor digitorum/extensor indices
- Extensor digiti minimi
- Extensor carpi ulnaris
Borders of the anatomic snuffbox
Ulnar: tendon of extensor pollicis longus
Radial: tendons of extensor policic brevis and abductor pollicis longus
Proximal border: styloid process of radius
Floor: carpal bones: scaphoid & trapezium
Roof: skin
Contents of the anatomic snuffbox
Radial artery
Superficial branch of radial nerve
Cephalic vein
Borders of Ulnar (Guyon’s) canal
Medial (ulnar) - pisiform, flexor carpi ulnaris tendon, abductor digiti minimi muscle
Lateral (radial) - hook of hamate
Roof - palmar carpal ligament
Floor - flexor retinaculum, pisohamate ligament, hypothenar muscles
Contents of Ulnar (Guyon’s) canal
Ulnar nerve
Ulnar artery
Venase comitantes of ulnar artery
Lymphatic vessels
3 layers of muscles in anterior compartment of forearm
Superficial
Intermediate
Deep
Muscles in the superficial layer of anterior forearm
Pronator teres Flexor carpi radialis Palmaris longus Flexor carpi ulnaris (Pass, fail, pass, fail)
Muscles in intermediate layer of anterior forearm
Flexor digitorum superficialis
Muscles in deep layer of anterior forearm
Flexor pollicis longus
Flexor digitorum profundus
Pronator quadratus
Pronator teres
Origin: medial epicondyle, coronoid process of ulnar
Insertion: laterally on mid-shaft of radius
Innervation: median n.
Function: pronation of forearm
Flexor carpi radialis
Origin: medial epicondyle
Insertion: base of 2nd and 3rd MTC
Innervation: median n.
Function: flexion and radial deviation of wrist (abduction)
Palmaris longus
Absent in 15% Origin: medial epicondyle Insertion: flexor retinaculum Innervation: median n. Function: flexion of wrist
Flexor carpi ulnaris
Origin: medial epicondyle, olecranon of ulna
Insertion: pisiform bone, hook of hamate, base of 5th
Innervation: ulnar n.
Function: flexion and ulnar deviation (adduction) of wrist
Flexor digitorum superficialis
2 heads. median n. & ulnar art. run between them.
Origin: medial epicondyle, radius. Splits into 4 tendons at wrist. Travels through carpal tunnel.
Insertion: middle phalanx of 4 fingers
Innervation: median n.
Function: flexes MCPJs, PIPJs and wrist
Flexor digitorum profundus
Origin: ulna and interosseous membrane. Splits into 4 tendons at wrist. Passes through carpal tunnel.
Insertion: distal phalanx of 4 fingers
Innervation: medial 2: ulnar. lateral 2: median
Function: flexion at DIPJs, MCPJs and wrist
Flexor pollicis longus
Origin: anterior surface of radius and interosseous membrane
Insertion: distal phalanx of thumb
Innervation: median nerve (ant interosseous branch)
Function: flexes IPJ and MCPJ of thumb
Pronator quadratus
Origin: ant. surface of ulna
Insertion: ant. surface of radius
Innervation: median nerve (ant. interosseous)
Function: pronates forearm
Layers of the posterior compartment of the forearm
Superficial
Deep
Superficial muscles in the posterior forearm
Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carp ulnaris Anconeus
Deep muscles of the posterior forearm
Supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor indicis
Brachioradialis
Origin: proximal aspect of lateral supracondylar ridge of humerus
Insertion: distal end of radius
Innervation: radial nerve
Function: flexes elbow
Extensor carpi radialis longus
Origin: supracondylar ridge
Insertion: 2rd & 3rd MTC
Innervation: radial n.
Function: extends and abducts wrist
Extensor carpi radialis brevis
Origin: lateral epicondyle
Insertion: 2rd & 3rd MTC
Innervation: radial n.
Function: extends and abducts the wrist
Extensor digitorum communis
Origin: lateral epicondyle. tendon splits into 4 at distal forearm
Insertion: extensor hood of each finger
Innervation: Radial n. (deep branch)
Function: extension of MCPJs and IPJs
Extensor digiti minimi
Origin: lateral epicondyle
Insertion: extensor hood of little finger
Innervation: radial n. (deep branch)
Function: Extends little finger and extension of wrist
Extensor carpi ulnaris
Origin: lateral epicondyle
Insertion: base of 5th MTC
Innervation: radial n. (deep branch)
Function: extension and adduction of wrist
Anconeus
Origin: lateral epicondyle
Insertion: posterior and lateral olecranon
Innervation: radial nerve
Function: extends and stabilises elbow joint. Abducts ulnar during pronation of forearm
Supinator
Origin: lateral epicondyle, posterior surface of ulna
Insertion: posterior surface of radius
Innervation: radial nerve (deep branch)
Function: supinates forearm
Abductor Pollicis longus
Origin: interosseous membrane and post. surface of radius
Insertion: lateral side off base of 1st MTC
Innervation: radial n. (post. interosseous branch)
Function: abducts the thumb
Lateral border of anatomic snuffbox
Extensor pollicis brevis
Origin: post. surface of radius and interosseous membrane
Insertion: base of proximal phalanx of thumb
Innervation: radial n. (post. interosseous branch)
Function: extends MCPJs and CMCJs of thumb
Lateral border of anatomic snuffbox
Extensor Pollicis longus
Origin: post. surface of ulnar and interosseous membrane
Insertion: distal phalanx of thumb
Innervation: radial n. (post. interosseous branch)
Function: extends IPJ/MCPJ/CMCJ of thumb
Medial border or anatomical snuffbox
Extensor indicis proprius
Origin: posterior surface of ulna and interosseous membrane
Insertion: extensor hood of index finger
Innervation: radial n. (post. interosseous branch)
Function: extends index finger
Borders of cubital fossa
Lateral - medial border of brachioradialis
Medial - lateral border of pronator trees
Superior - horizontal line between epicondyles of humerus
Roof - bicipital apnoeurosis, fascia
Floor - brachial (proximal), supinator (distal)
Content of cubital fossa
(Lateral to medial) Radial nerve Biceps tendon Brachial artery (branches into ulnar/radial at apex) Median nerve
Borders of ulnar (cubital) tunnel
Medial - medial epicondyle
Lateral - olecranon
Floor - elbow joint capsule and medial collateral ligament of elbow
Roof - ligament spanning medial epicondyle and olecranon (cubital tunnel retinaculum/arcuate ligament of Osborne)
Content of the ulnar (cubital) tunnel
Ulnar nerve
