Lecture 10: upper extremity

humerus

shaft

head

neck

greater tubercle

lesser tubercle

trochlea (medial)

capitulum (lateral)

medial epicondyle

lateral epicondyle

coranoid fossa (anterior)

olecranon fossa (posterior)

deltoid tuberosity

D

humerus

C

elbow

B

radius

F

ulna

A

thumb

E

wrist

upper arm nerve

musculocutaneous nerve

muscles of anterior compartment

Biceps brachii

(O = supraglenoid tubercle, coracoid)

(I = radial tuberosity, forearm fascia )

F = forearm flexion at elbow, supination (supinator magnus), assists shoulder flexion

brachialis

(O = anterior surface of humerus)

(I = coranoid of ulna)

F = flexion of forearm at elbow

Coracobrachialis

F = assists flexion of arm at shoulder

biceps brachii

brachialis

coracobrachialis

movements of the forearm

pronation

supination

pronation

supination

Posterior compartment muscles

Triceps brachii

(O = infraglenoid tubercle, upper lateral & lower medial halves of the posterior shaft of humerus )

(I = olecranon of ulna )

F = extension of forearm at elbow

Anconeus

(O = lat epicondyle)

(I = olecranon of ulna)

F = assists triceps brachii

• not upper arm muscle - helps with elbow extension

triceps brachii

anconeus

arteries

Brachial artery

• Anteromedial in upper arm

• Moves laterally and anteriorly at elbow to form ulnar and radial art.

• profunda brachii artery

brachial artery

profunda brachii

radial artery

ulnar artery

nerves

musculocutaneous

median

ulnar

radial

musculocutaneous nerve

median nerve

ulnar nerve

radial nerve

A (green)

ulnar nerve

B (orange)

median nerve

C

radial nerve

radius

radius head

interosseus membrane

ulna

trochlear notch

olecranon process (posterior)

coronoid process (anterior)

radial notch

coronoid fossa

joint type elbow

synovial

hinge

humeroradial joint

proximal radioulnar joint

humeroulnar joint

capsular ligaments

medial (ulnar) collateral ligaments

lateral (radial) collateral ligament

annular ligament

movements elbow

Flexion

extension

Note: pronation & supination occur at radioulnar joint

Cubital fossa

Anteriorly; inverted triangle

Contains median and radial nerve, brachial artery and its derivatives, and tendon of biceps brachii

cubital fossa

Radioulnar Joints

Joint type

• synovial

• pivot

Articulations

• Proximal

  • Radial head and radial notch of ulna

  • Annular ligament

• Distal

  • Ulnar styloid & ulnar notch of radius

  • Fibrocartilage disc, capsule, capsular ligaments

• Notes: interosseus membrane

radial head

ulnar styloid

ulnar notch

fibrocartilage disc

muscles supination

biceps brachii

supinator

supinator

pronation muscles

pronator teres (proximal)

pronator quadratus (distal)

pronator quadratus

pronator teres (proximal)

pronated or supinated to mid-range

brachioradialis

brachioradialis

styloid process

anterior compartment

superficial

• pronator teres

• flexor carpi radialis

• palmaris longus

• flexor carpi ulnaris

intermediate

• flexor digitorum superficialis

deep

• flexor digitorum profundus

• flexor pollicis longus

• pronator quadratus

innervated by median nerve

• pronator teres

• flexor carpi radialis

• palmaris longus

• flexor digitorum superficialis

• flexor digitorum profundus

• flexor pollicis longus

• pronator quadratus

innervated by ulnar nerve

• flexor carpi ulnaris

• flexor digitorum profundus

posterior compartment muscles

innervated by radial nerve

superficial

• Brachioradialis

• Extensor carpi radialis longus (ECRL)

• Extensor carpi radialis brevis (ECRB)

• Extensor digitorum (ED)

• Extensor digiti minimi (EDM)

• Extensor carpi ulnaris (ECU)

deep

• Anconeus

• Supinator

• abductor pollicis longus (APL)

• extensor pollicis brevis (EPB)

• extensor pollicis longus (EPL)

• Extensor indicis (EI)

flexion of hand at wrist

FCR

FCU

FDS

FDP

FPL

extension of hand at wrist

ECRL

ECRB

ECU

ED

EDM

EI

APL

EPB

EPL

adduction ulnar deviation of hand at wrist

FCU

ECU

abduction radial deviation of hand at wrist

FCR

ECRL

ECRB

circumduction of the hand

requires

flexion

extension

adduction

abduction

pronation

supination

proximal carpal bones

scaphoid

lunate

triquetral

pisiform

distal carpal bones

trapezium

trapezoid

capitate

hamate

scaphoid

lunate

triquetral

pisiform

trapezium

trapezoid

capitate

hamate

palmar radiocarpal ligament

ulnar collateral ligament

radial collateral ligament

dorsal intercarpal ligaments

palmar intercarpal ligaments

retinacula

Extensor

Flexor (N.B., roof of carpal tunnel)

extensor retinaculum