Hand and Wrist Flashcards
Describe the superficial palm
Proximally :
- Flexor retinaculum
- Palmar aponeurosis
- Fibrous digital sheaths
- Thenar eminence
- Hypothernar eminence
- Dupuytren’s contracture
What is the palmar aponeurosis ?
Has deep attachments - 3rd and 5th metacarpals
Palmar longus and brevis
Function of the palmar aponeurosis
Anchor your skin to deeper tissues
Helps with grip
Where are fibrous digital sheaths found ?
Over each digit on the palmar side
What is Dupuytren’s contracture ?
When you get a contraction in the palmar aponeurosis, affects the 3rd digit.
Pulls the 3rd digit down
State the palmar spaces
Thenar space
Midpalmar space continuous with forearm
Long flexor tendons
Common flexor synovial sheath wrist –> mid palm
Flexor policis longus; separate sheath –> distal phalynx
Synovial sheaths for each digit
Digiti mini sheath; continuous to the palm
Where are fibrous sheaths found ?
Superficial to the synovial sheaths
Function of the fibrous sheaths
Pulleys:
Annular over bone
Cruciform near the joints
“Osseofibrous” tunnel
In order to allow the deeper tendon (flexor digitorum profundus) to get to the deeper phalynx what happens ?
Tendon of Flexor digitorum superficialis splits to allow flexor digitorum profundus through distally.
What does the median nerve supply on the anterior hand ?
Supplies :
- Palm of hand laterally
- The lateral 3 + 1/2 digits
What does the median nerve supply on the posterior hand ?
Supplies :
- Distal ends of the lateral 3 + 1/2 digits
- (nail beds)
Describe the palmar cutaneous branch of the median nerve
Supplies skin of the palm
Doesn’t pass through the carpal tunnel like the rest of the median nerve.
Emerges before the carpal tunnel
In carpal tunnel syndrome, why won’t you get pain in the palm of the hand ?
As the palmar cutaneous branch of the median nerve emerges before the carpal tunnel.
What does the radial nerve supply on the anterior hand ?
Supplies :
- Area of anatomical snuffbox
- Lower thumb
What does the radial nerve supply on the posterior hand ?
Supplies :
- Lateral dorsum of the hand
What does the ulnar nerve supply on the anterior hand ?
Supplies :
- Medial border of the hand
- Medial 1 + 1/2 digits
What does the ulnar nerve supply on the posterior hand ?
Supplies :
- Medial aspect of the dorsal of the hand
- Fingertips of 1 + 1/2 digits
If you want to test for sensation from the medial nerve, where should you press
Tip of index finger
If you want to test for sensation from the ulnar nerve, where should you press
Tip of little finger
OR
Medial border of the hand
If you want to test for sensation from the radial nerve, where should you press
Over the dorsal webspace
Where do palmar nerves lie ?
Neuromuscular structures lie superficially
Common digital arteries and nerves run together
Where does the ulnar nerve and artery emerge ?
Through Gyon’s canal.
The Ulnar artery into the palm of the hand, forming superficial palmar arch.
What does the recurrent branch of the median nerve supply ?
Supplies :
- Thenar muscles of the hand
Name the thenar muscles
Abductor Pollicis Brevis
Opponens Pollicis
Flexor Pollicis Brevis
Adductor Pollicis
Where are the thenar muscles found ?
At the base of the thumb
What supplied the abductor pollicis brevis ?
Recurrent median
Describe flexor pollicis brevis
2 heads :
Superficial (supplied by the recurrent median nerve)
[Deep (supplied by the deep ulnar nerve) T1]–> not required
Describe opponens pollicis
Supplied by :
- The recurrent branch of the median nerve C8
Allows grip and tool use (opposition of the thumb)
Function of opponens pollicis
Opposition of the thumb
Describe the adductor pollicis muscle
Deep branch of ulnar (T1)
2 heads :
- Transverse
- Oblique
What are the deep thenar muscles ?
Flexor Pollicis Brevis
Opponens pollicis
Name the hypothenar muscles
Abductor digiti minimi
Opponens digiti minimi
Flexor digiti minimi brevis
What are the hypothenar muscles supplied by ?
The deep branch of the ulnar nerve
What is found in the extensor hood ?
Extensor expansion
Extensor digitorum tendon
Describe the origin of the lumbrical muscles
Radial side of the flexor digitorum profundus tendon.
Lateral 2 - unipennate
Medial 2 - bipennate
State the insertion of the lumbrical muscles
Extensor expansion
State the action of the lumbrical muscles
(Exam type Q)
Flex metacarpal phalangeal joint and extend interphalangeal joint
Flex MCP AND extend IP
State the innervation of the lumbrical muscles
Medial 2 : deep ulnar
Lateral 2 : median
Where are interossei muscles found ?
Found between the bones
(particularly metacarpals)
What innervates interossei muscles ?
Deep ulnar nerve (C8, T1)
What are the 2 groups of interossei ?
Dorsal (4) DAB
Palmar (3) PAD
Function of the dorsal interossei
Abduct digits
Bipennate
DAB
Function of palmar interossei
Adduct digits
Unipennate
PAD
Action of interossei
Can act together with each other, and lumbricals
What are the muscles of the hand innervated by ?
The ulnar nerve (C8, T1)
EXCEPT :
L - Lumbricals (lat 2)
O - Opponens Pollicis
A - Abductor Pollicis Brevis
F - Flexor Pollicis Brevis
State the origin of dorsal interossei
Metacarpals
State the insertion of dorsal interossei
Base of proximal phalynx and extensor hood
Describe dorsal interossei
1st and 5th digits have their own intrinsic abductors
Describe palmar interossei
No adduction at middle finger
State the origin of the palmar interossei
Adductor side of metacarpal
State the insertion of the palmar interossei
Proximal phalynx and extensor hood
Describe ulnar nerve injury
Claw hand - Ulnar paradox
- Determined by Froment’s sign
What muscles lose innervation in an ulnar nerve injury
Median 2 lumbricals
All interossei
1/2 FDP (flexor digitorum profundus)
Describe claw hand
Extension @ metacarpal phalangeal joint
Flexion @ interphalangeal joint
Describe the ulnar paradox
Distal injury appears worse
FDP action
Describe the test for carpal tunnel syndrome
Phalens test
What is carpal tunnel syndrome ?
Compression of the carpal tunnel
Weakness of thenar muscles
Describe median nerve injury
Hand of benediction
Ape hand
What muscles are affected by median nerve injury ?
Lateral 2 lumbricals
FDS and 1/2 FDP
Thenar muscles
Describe the hand of benediction
Inability to form a fist
Describe ape hand
Loss of opposition
Anterior interosseous nerve damage
FDP
Flexor Pollicis Longus
