1. Upper Limb, part II Cubital fossa, Forearm, and Hand

2. Objectives: Bones and joints of the upper limb
Fascial compartments of arm, forearm and hand
Special areas of upper limb - cubital fossa, wrist, carpal tunnel, anatomical snuffbox
Arteries and veins of upper limb
Nerves innervating upper limb
Inside wrist: Carpal tunnel, anatomical snuffbox

3. humerus
ulna
radius
carpal bones
metacarpal bones
phalanges {

4. Radiolulnar joints
Radius and ulnar articulate via synovial joints at 2 positions.
- name: radiolulnar joint (proximal and distal)
Supination: Summoning
Pronation: Engagement ring show off pose
Interosseous membrane
- Keeps bones together and from rubbing against each other

5. Which carpal bone is the most commonly fractured? scaphoid
Wrist (radiocarpal joint)
Intercarpal joints
Carpometacarpal and
intermetacarpal joints
Carpometacarpal joint
of the thumb
Metacarpophalangeal joints
Interphalangeal joints
Responsible for wrist rotation
Knuckles
8 short bones in the carpal. Know which bones are located in the proximal row (closer to forearm) and in the distal row
5 metacarpal bones (long bones).
Must know names of the joints.
1. Only one bone articulates directly to the wrist (radialcarpal joint, aka the “wrist joint”): radius
2. Joints between the radiocarpal joint and the rest of the hand: intercarpal joint.
3. The intercarpal joints, carpometacarpal and intermetacarpal joint are responsible for the rotation of the wrist
4. Metacarpophalangeal joints are the knuckles
Interphalangeal joints
Most commonly fractured carpal bone? Scaphoid
Why is the scaphoid the most commonly fractured carpal bone?
- due to palming a floor after a fall

6. Proximal row of carpals (from lateral to medial): 1. scaphoid bone S
Carpal bones:
Proximal row of carpals
(from lateral to medial):
1. scaphoid bone S
2. lunate bone L
3. triquetrum bone T
4. pisiform bone P
Distal row of carpals
(from lateral to medial):
1. trapezium bone T
2. trapezoid bone T
3. capitate bone C
4. hamate bone H
Some Lovers Take Positions / That They Can’t Handle
Proximal row of carpals (Lateral to medial):
-Scaphoid
Lunate
Triquestrum
Pisiform
Distal Row (lateral to medial)
Trapezium
trapezoid
capitate
hamate

7. the anatomical position*
Hand movements
Flexion - Extension
Abduction - Adduction
*Be sure to reference
the anatomical position*

8. Compartmentalization = Functionally related groups of muscles are enclosed within compartments defined by thick layers of deep fascia and intermuscular septa that attach to the bone. Compartments contain muscles sharing a common function (action) and a common innervation.
What covers the muscles superficially? Fascia
What is the common link between muscles in a compartment?
- Common function and innervation

9. } } anterior FLEXORS biceps brachii, ARM coracobrachialis
compartment
anterior
FLEXORS }
biceps brachii,
coracobrachialis
brachialis
musculocutaneous n.
brachial a.
EXTENSORS }
Compartment
- flexors of elbow or forearm
- innervated via muscularcutaneous (lateral cord)
- Blood via brachial artery
Extensor
- Innervated by radial artery (posterior cord)
radial n.
triceps brachii
profunda brachii a.
posterior

10. } } FLEXORS anterior median and ulnar nn. flexors, pronators,
FOREARM
compartment
FLEXORS
anterior }
median and
ulnar nn.
flexors,
pronators,
palmaris longus
ulnar and
radial aa.
brachioradialis
radial n.
EXTENSORS
radial a. }
Brachioradialis does not match any group (really weird)
- starts somewhere in the humerus and goes the radius
- functionally, it’s a flexor
- innervated like an extensor
- Flexes when half prone
extensors,
supinator,
abductor
radial n.
posterior interosseus a.
posterior

11. Superficial group (5): Deep group (3): Three functional groups:
Forearm muscles - anterior/flexor-pronator compartment
Three functional groups:
1. Muscles which pronate the forearm and hand
*pronator teres
*pronator quadratus
2. Muscles that flex the hand
*flexor carpi radialis/abduct
*flexor carpi ulnaris/adduct
*palmaris longus
3. Muscles that flex the digits
*flexor digitorum superficialis (FDS)
*flexor digitorum profundus (FDP)
*flexor pollicis longus
Superficial group (5):
*pronator teres
*flexor carpi ulnaris
*flexor carpi radialis
*palmaris longus
*flexor digitorum spf. (FDS)
Deep group (3):
.: pronator quadratus
.: flexor digitorum prof. (FDP)
.: flexor pollicis longus
Pronators:
- main function: pronate forearm and wrist
Group 2
main function: flex the hand
one on radial side (flexi carpi radialis muscle)
one on ulnar side (flexi carpi ulnaris)
Group 3 flexes the digits
superficialis  muscle goes to medial pharynges. Just flexes base of index finger (ends in middle)
FDP: flexes upper part of index finger
FPL
Way to remember:
- flex digits, flex hand, rotate wrist
- alternatively, can be placed into two groups: superficial or deep groups
Flexor carpi ulnaris and medial half of FDS are innervated by ulnar nerve
First two lumbricals, thenar muscles and … are innervated by the median nerve

12. Palmaris longus muscle Flexor digitum superficialis
Teres: round
5 superficial muscles
Pronator teres
Flexor carpi radiales
Flexor carpi ulnaris
Palmaris longus muscle
Flexor digitum superficialis
Medial epicondyle is the place where 5 muscles attach (Note that these are the 5 superficial wrist muscles)
- pronator teres
- flexor carpi radiales
- flexor carpi ulnaris
- palmaris longus muscle
- flexor digitum superficialis
Ulnar side
- neurovascular bundle like ulnar nerve
Medial nerve is in the middle, but it’s not superficial. Must get between muscle

13. Flexor carpi ulnaris Flexor digitorum superficialis Palmaris longus
What’s the missing superficial wrist muscle?
Pronator teres
Tendon of flexor
carpi radialis
Radial artery

14. Forearm muscles - posterior/extensor-supinator compartment
Three functional groups:
1. Muscles that extend the hand
*extensor carpi radialis longus/abduct
*extensor carpi radialis brevis/abduct
*extensor carpi ulnaris/adduct
2. Muscles that extend the digits
*extensor digitorum
*extensor digiti minimi
*extensor indicis
3. Muscles that extend the thumb
*extensor pollicis longus EPL
*extensor pollicis brevis EPB
*abductor pollicis longus ABL/abduct
Superficial group:
*extensor carpi radialis brevis
extensor carpi radialis longus *extensor carpi ulnaris
*extensor digitorum
*extensor digiti minimi
brachioradialis
Deep group:
supinator
EPL
EPB
APL
extensor indicis
Both flexor and extensor on ulnar side do adduction
Both flexor and extensor on radial side do abduction
Superficial posterior muscles attach to the medial condyle
Superficial anterior muscles attach to the lateral condyle

16. 5 1 3 2 4
Lateral epicondyle 8 7 6
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Abductor policis longus
Extensor pollicis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris

17. Cubital fossa - borders and contents
Borders: (4; it’s a “cube)
* medially - pronator teres m.
* laterally – brachioradialis m.
* the roof – deep fascia, subcutaneous tissue, and skin
* the floor – supinator m. laterally and brachialis m. medially.
Contents from medial to lateral side: (5)
* median n.
* bifurcation of the brachial a.
* (deep) accompanying veins of the arteries
* tendon of biceps brachii m.
* radial n. and its branches (within the floor of the fossa)
Picture is where the “cubital fossa” is
Superficially, in the subcutaneous tissue overlying the fossa:
*median cubital vein (connects cephalic vein to basilar vein)
*medial and lateral antebrachial (forearm) cutaneous nerves

18. Don’t spend too much time finding this stuff

19. Structure most medially: median nerve
Adjacent to that is the brachial artery
Splits into radial and ulnar, radial goes further?

20. Tendon of biceps brachii
Superficial branch
of radial nerve
Brachial artery
Tendon of biceps brachii
Biceps brachii
Brachioradialis
Median nerve
Anatomical section of cuboidal fossa
Medial epicondyle
Pronator teres

21. Muscles of the hand – 4 compartments
1. Thenar compartment:
* abductor pollicis brevis
* flexor pollicis brevis median n. – recurrent branch
* opponens pollicis
2. Adductor compartment:
* adductor pollicis ulnar n. – deep branch,
3. Hypothenar compartment:
* abductor digiti minimi
* flexor digiti minimi ulnar n. – deep branch
* opponens digiti minimi
4. Central compartment:
* lumbricals : st and 2nd median n. – digital branches
3rd and 4th ulnar n. – deep branch
* interossei- 3 PAD and 4 DAB ulnar n. – deep branch
Thenar: a raised fleshy area on the palm of the hand near the base of the thumb
Thenar compartment: short muscles
Note that median nerve does only a few things in the hand. It’s primarily the ulnar nerve that controls the hand.

22. { Palmar aponeurosis Hypothenar fascia Flexor pollicis brevis
Palmar aponeurosis is all about protection
Hypothenar fascia
Flexor pollicis brevis
Abductor pollicis brevis
Palmaris brevis
Thenar fascia

23. Abductor pollicis brevis
1st lumbrical
1st dorsal interosseous
Superficial palmar branch
Adductor pollicis
Abductor digiti minimi
Flexor pollicis brevis
Palmaris brevis
Abductor pollicis brevis
Ulnar artery
Pisiform bone
Superficial branch of radial artery
Radial artery

24. Short muscles of the Hand
Flexor digitor profundis
Palmar muscles adduct
Abduct the digits
(4 DAB)
Adduct the digits
(3 PAD)
Flex the digits at the metacarpophalangeal joints
and extend the interphalangeal joints.

25. Abductor: Dorsal interossei muscles
Lumbricals:
.: What do they do?
They flex the digits at the metacarpophalangeal joints and extend the interphalangeal joints
Abductor: Dorsal interossei muscles
How many are there? 4
Hence, 4 DAB
Adductor: Palmar interossei
How many are there? 3
Hence, 3 PAD
Metacarpophalangeal joints are the knuckle joints

27. Carpal tunnel
4 tendons of flexor digitorum profundus
4 tendons of flexor digitorum superficialis tendons
1 flexor pollicis longus tendon
Carpal tunnel is the space between the carpal bones and the flexor retinaculum. The flexor retinaculum (transverse carpal ligament) is a thick connective tissue ligament that bridges the space between the medial and lateral side of carpal arch.

28. Structures that pass anterior to the flexor retinaculum (from medial to lateral side):
* ulnar n.
* ulnar a.
*tendon of palmaris longus m.
Structures that pass beneath to the flexor retinaculum - pass the carpal tunnel (from medial to lateral side):
* tendons of flexor digitorum superficialis and profundus
*median n.
*tendon of flexor pollicis longus m.

29. Anatomical snuffbox (visible, when the thumb is fully extended):
Anteriorly (laterally) bounded by 2 muscles:
extensor pollicis brevis (EPB)
abductor pollicis longus (APL)
Posteriorly (medially) bounded by 1 muscle:
extensor pollicis longus (EPL)
The radial artery lies in the floor of the snuff box.
That depression formed when you extend your thumb all the way back

30. Anatomical snuffbox
EPB
APL
EPL

31. BRACHIAL A
(ANTERIOR COMPARTMENT)
ARTERIAL ARCHES
(HAND)
ULNAR A
RADIAL A
CUBITAL FOSSA
DEEP BRACHIAL A. = profunda brachi
(POSTERIOR COMPARTMENT)
INTEROSSEOUS AA
(ANTERIOR AND POSTERIOR
COMPARTMENTS)
AXILLARY A.
(SHOULDER REGION)
Axillary artery is a continuation of the subclavian
The axillary artery turns into the profunda brachi and the brachial artery. The brachial artery is the more anterior of the two.
The brachial artery
Highly vascular because of compression when flexing or extending the arm in so many different directions
Which artery in the forearm is often used to palpate an arterial pulse? Radial artery (remember the thumb point)

32. Superficial palmar arch is formed mainly by the ULNAR ARTERY
Deep palmar arch is formed mainly by the
RADIAL ARTERY

33. Where is the common place for venipuncture?
CEPHALIC VEIN
BASILIC VEIN
Cephalic and basilic veins are superficial and connect to the deep vein
- deep veins travel with arteries
Cephalic vein drains into the axillary
Basilic vein goes to the deep brachial or deep axillary?
Where is the common place for venipuncture?
- median cubital vein
MEDIAN CUBITAL
VEIN
Where is the common place for venipuncture?

34. Cutaneous innervation of the upper limb
Branch of median nerve

35. =
Dinner fork deformity

36. Questions of the day!
Which muscle of the forearm has a double innervation?
Flexor digitorum profundus
Loss of pronation of the hand suggests a lesion of which nerve?
Median
Numbness to the skin on the lateral half of the palm of the
hand would be caused by a lesion to which nerve?
- Median
Dorsal scapular