Elbow Joint Anatomy: Ligaments, Movements, and Muscle Attachments

elbow joint complex includes

humero-ulnar joint

humero-radial joint

proximal radio-ulnar joint

distal radio-ulnar joint

humero-ulnar joint

very stable because of trochlea and trochlear notch tight fit

- most of forearm weight bearing

humero-radial joint

radial head buttresses against capitulum

-most weight of hand

modified hinge joint

slight amount of axial rotation and side to side motion

carrying angle

normal: 13 (women 2 degrees greater)

excessive cubitus valgus (20-25)

cubitus varus (gunstock deformity): inward

hueter line and hueter triangle

normal alignment of medial epicondyle, later epicondyle and olecranon

ligaments of elbow joint: joint capsule

articular capsule

reinforced anteriorly by oblique and vertical bands

strengthened by collateral ligaments: medial (anterior, posterior and transverse band)

ligaments of elbow joint: lateral ligaments

radial collateral ligament

lateral (ulnar) collateral ligament

annular ligament

radial collateral ligament proximal attachment

apex of lateral epicondyle

radial collateral ligament distal attach

upper margin of the annular ligament

UCL prox attach

apex of lateral epicondyle

lateral collateral ligament distal attachment

supinator crest (lateral side of the ulna

why is the lateral collateral ligament significant

posterior-superior elbow stability in elbow flexion

annular ligament attachment

lateral part of the ulna

what does the annular ligament do

provides stability for the proximal head of the radius

what happens with nursemaids elbow

the head of the radius comes out of the annular ligament

anterior band of UCL

between medial epicondyle of humerus and medial margin of the coronoid process

where does anterior band of UCL provide stability

in full extension

which part of UCL is most damaged

anterior and posterior band

posterior band of UCL

between medial epicondyle of the humerus to the medial side of the olecranaon

where does posterior band of UCL provide stability

full flexion

transverse band of UCL

between medial margin of olecranon and coronoid process

interosseous membrane

fibrous sheet that connects the interosseous margins of the radius and the ulna

how does interosseous membrane contribute to radio-ulnar stability

central band: directed distal medially from the radius (20deg)

as strong as patellar tendon

oblique cord: resists distal migration of radius

distal oblique fibers: add to stability of distal radioulnar joint

function of interosseous membran

central band is to bind radius to ulna

serve as attachment site for extrinsic muscles of hand

provide mechanism for transmitting force proximally from radius to ulna

prox attach biceps brachii (long head)

supraglenoid tubercle of scapula

distal attach of long head and short head biceps brachii

radial tuberosity and bicipital aponeurosis

nerve of biceps brachii long head & short head

musculocutaneous C5-C6

blood supply of biceps brachii long and short head

brachial artery

action of long head biceps brachii

elbow flexion, supination, assists shoulder flexion

prox attachment of short head biceps brachii

coracoid process

action of short head biceps brachii

elbow flexion and supination

brachialis prox attach

distal half of anterior humerus

distal attach of brachialis

coronoid process and ulnar tuberosity

nerve of brachialis

mucsculocutaneous C5-6

radial n (lateral part) C5-7

blood supply of brachialis

brachial artery

recurrent radial artery

action of brachialis

primary elbow flexor

coracobrachialis prox attachment

coracoid process

distal attachment of coracobrachialis

middle 1/3 of medial humerus

nerve of coracobrachialis

musculocutaneous C5-7

blood supply of coracobrachialis

brachial artery

action of coracobrachialis

shoulder flexion and adduction

brachioradialis proximal attachment

lateral supraondylar ridge

distal attachment of brachioradialis

radial styloid process

brachioradialis nerve

radial C5-7

blood supply of brachioradialis

radial recurrent artery

action of bracioradialis

elbow flexion in neutral position

long head tricps proximal attachmetn

infraglenoid tubercle

distal attachment of long head triceps

olecranon process

innervation of triceps

radial n

long head c6-8

lateral head c5-6

medial head c7-8

primary function of triceps long head

elbow extension, assists shoulder extension/adduction

triceps brachii lateral head proximal attachment

posterior humerus ABOVE radial goove

distal attachment of lateral and medial head of triceps brachii

olecranon process

action of lateral head triceps

elbow extension

medial head triceps brachii proximal attachment

posterior humerus BELOW radial groove

action of medial head of triceps brachii

primary extensor

anterior compartment superficial layer muscles

flexor carpi ulnaris

palmaris longus

flexor carpi radialis

pronator teres

anterior compartment intermediate layer muscles

flexor digitorum superficialis

anterior compartment deep layer muscles

flexor digitorum profundus

flexor pollicis longus

posterio compartment superficial layer muscles

extensor carpi ulnaris

extensor digiti minimi

extensor digitorum

posterior compartment deep layer muscles

extensor pollicis longus

abductor pollicus long

extensor indicis

lateral compartment (Mobile Wad) muscles

brachioradialis

extensor carpi radialis longus

extensor carpi radialis brevis

pronator teres prox attachment

medial epicondyle and coronoid process

pronator teres distal attachment

lateral radius (midshaft)

nerve of pronator teres

medial n C6-C7

blood supply of pronator teres

ulnar artery

function of pronator teres

forearm pronation, weak elbow flexion

flexor carpi radialis prox attach

medial epicondyle

flexor carpi radialis distal attachment

bases of 2nd metacarpal

nerve of flexor carpi radialis

medial n (C6-7)

blood supply of flexor carpi radialis

ulnar (prox)

radial (distal)

flexor carpi radialis action

wrist flexion and radial deviation

palmaris longus prox attachment

medial epicondyle

palmaris longus distal attach

palmar aponeurosis

palmaris longus nerve

median nerve C7-C8

palmaris longus blood supply

ulnar artery

palmaris longus action

wrist flexion, tenses palmar fascia

flexor carpi ulnaris prox attachment

medial epicondyle, olecranon, posterior ulna

flexor carpi ulnaris distal attachment

pisiform, hook of hamate base of 5th metacarpal

flexor carpi ulnaris nerve

ulnar C7-T1

flexor carpi ulnaris blood supply

ulnar artery

flexor carpi ulnaris action

wrist flexion and ulnar deviation

flexor digitorum superficialis prox attachment

medial epidondyle, coronoid process, anterior radius

flexor digitorum superficialis distal attach

middle phalanges 205

flexor digitorum superficialis nerve

median C7-T1

flexor digitorum superficialis blood supply

ulnar artery

flexor digitorum superficialis action

flexes PIP joints, MCPs, wrist

flexor digitorum profundus lateral and medial half prox attach

proximal ulna and interosseous membran

flexor digitorum profundus lateral half distal attachment

distal phalanges 2-3

flexor digitorum profundus medial half distal attach

distal phalanges 4-5

flexor digitorum profundus lateral half nerve

anterior interosseous n C8-T1

flexor digitorum profundus medial half nerve

ulnar C8-T1

flexor digitorum profundus lateral half blood supply

anterior interosseous artery

flexor digitorum profundus medial half blood supply

ulnar artery

flexor digitorum profundus lateral half action

flexes DIP joints 2-3

flexor digitorum profundus medial half action

flexes DIP joints 4-5

flexor pollicis longus prox attach

anterior radius and interosseous membrane

flexor pollicis longus distal attach

distal phalanx of thumb

flexor pollicis longus nerve

anterior interosseous n C8-T1

flexor pollicis longus blood supply

anterior interosseous artery