Hand and Wrist Flashcards
What are the bones of the hand?
Carpal bones (x8)
Metacarpals (x5)
Phalanges (2-3 in each digit)
What are the carpal bones called (lat to med)?
Proximal row: Scaphoid, Lunate, Triquetrum, Pisiform
Distal row: Trapezium, Trapezoid, Capitate, Hamate
(Some Lover Try Positions That They Cant Handle)
What bones articulate at the wrist?
Radius with scaphoid&lunate (radiocarpal joint)
-no participation by ulnar
What strengthens the radiocarpal joint (ant and post)?
Radiocarpal ligaments
What is the function of the distal radio-ulnar joint?
Assists proximal radio-ulnar joint in pronation and supination of the hand
What are the movements of the wrist?
- Adduction/abduction
- Flexion/extension
- Circumduction
Where are the radial and ulnar styloid processes?
On the dorsal surface of hand (lat/med)
What are the 6 extrinsic ant flexor muscles of the hand?
NB. all act on wrist joint
- FCR
- FCU
- Palmaris longus
(^^all common tendon) - Flexor digitorum superficialis (2 heads)
- Flexor pollicis longus
- Flexor digitorum profundus
Which nerves supply the extrinsic ant flexor muscles of the hand?
Median and ulnar nerves
What are the 8 extrinsic posterior extensor muscles of the hand?
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor carpi ulnaris
- Extensor digiti minimi
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
Which nerve supplies the extrinsic posterior extensor muscles of the hand?
Radial nerve
What passes through the carpal tunnel? (4)
- Flexor digitorum superificialis tendons (4)
- Flexor digitorum profundus tendons (4)
- Flexor pollicis longus tendon
- Median nerve
What are the intrinsic muscles of the hand?
- thenar muscles
- hypothenar muscles
- adductor pollicis
- lumbricals
What nerve supplies the intrinsic muscles of the hand?
Ulnar nerve
EXCEPT thenar muscles and 1st & 2nd lumbricals - MEDIAN nerve
What are the thenar muscles? (3)
- flexor pollicis brevis
- opponens pollicis
- abductor pollicis
What are the hypothenar muscles? (3)
- opponens digiti minimi
- flexor digiti minimi
- abductor digiti minimi
What is the important of opponens pollicis?
Allows opposition of thumb - grip
Why are the lumbricals called “bye bye” muscles?
Attach to flexor and extensor tendons giving them dual function;
- flexion at MCP joint
- extension at IP joint
How are thumb movements different from fingers?
Rotated 90*
- flexion = putting thumb towards palm
- abduction = moving thumb towards wrist
What are the 3 main branches of the median nerve?
- palmar cutaneous branch
- recurrent branch
- digital branch (after carpal tunnel)
What does the palmar cutaneous branch of the median nerve innervate?
Sensory supply to lateral side of palm
What does the recurrent branch of the median nerve innervate?
Motor to the thenar muscles
What does the digital branch innervate?
Motor - 1st & 2nd lumbricals
Sensory - palmar lat 3 1/2
- dorsal dist lat 3 1/2
What does the median nerve innervate altogether?
Sensory - lat 3 1/2 palmar
-dorsal dist lat 3 1/2
Motor - thenar muscles and lat 2 lumbricals
What are the medial and lateral attachments of the flexor retinaculum?
Medial - Pisiform and hook of hamate
Lateral - Scaphoid tuberosity and trapezium
What is compressed in carpal tunnel syndrome?
Median nerve
What are the symptoms of carpal tunnel syndrome? (3)
- Pins and needles in the cutaneous distribution of digital branches
- Thenar atrophy & weakness
- Inability to oppose thumb
How else is the median nerve damaged?
Lunate dislocation (FOOSH) - anterior
What are the 4 main branches of the ulnar nerve?
- Palmar branch
- Dorsal branch
- Suerficial branch
- Deep branch
Where does the ulnar nerve pass in relation to the flexor retinaculum?
Superficial to flexor retinaculum
medial to median nerve
What does the palmar branch of the ulnar nerve innervate?
Sensory - medial palm
What does the dorsal branch of the ulnar nerve innervate?
Sensory - med dorsum and med 1 1/2 digits
What does the superficial branch of the ulnar nerve innervate?
Sensory - palmar med 1 1/2 digits
Motor - palmaris brevis
What does the deep branch of the ulnar nerve innervate?
Hypothenar muscles, adductor pollicis, interossei and 4th and 5th lumbricals
What is the innervation of the ulnar nerve?
Sensory - med 1 1/2 digits
Motor - hypothenar muscles, med 2 lumbricals, 7 interossei, adductor pollicis
What is Guyon’s canal?
Tunnel superficial to medial flexor retinaculum.
What passes through Guyon’s canal?
Ulnar nerve and artery
What is ‘handlebar neuropathy’ caused by?
Compression of the ulnar nerve at the wrist
What are the 3 clinical features of handlebar neuropathy?
- sensory loss to palmer lateral 1 1/2 digits
- Motor weakness in the intrinsic muscles (except thenar eminence & lat 2 lumbricals)
- Hyperextension of MCP joints of IV & V (paralysis of lumbricals)
What does the adductor compartment consist of?
Adductor pollicis
-ulnar nerve (C8, T1)
What does the central compartment consist of?
Flexor tendons and lumbricals
Where are the dorsal interossei?
Fill 4 spaces between the 5 digits
-mid finger has 2 tendons, II&IV have 1
Where are the palmar interossei?
1st: med of metacarpal II
2nd & 3rd: lat of IV/V metacarpal
(NB. none on mid finger)
What is the function of the dorsal and palmar interossei?
DORSAL: -abduction
-contraction pulls II &IV away
PALMAR: -adduction
-contraction draws II/IV/V towards III
