UPPER EXTREMITY

Surface Anatomy

  • Clavicle

  • Jugular notch (suprasternal notch): REN 22

  • Acromioclavicular (AC) joint

  • Acromion: Landmark for the Large Intestine and San Jiao meridian

  • Coracoid process of scapula: LU 2

  • Superior border of the scapula: T2 level (SI 13 at the medial end)

  • Inferior border of the scapula: T7 level

  • Medial border of the scapula: 3 cun

  • Greater tubercle of the humerus: Inferolateral to the acromion

  • Medial and lateral epicondyles

  • Olecranon

Surface Anatomy (cont’d)

  • Radial styloid process: LU 8

  • Anatomical snuff box: LI 5

  • Head of the ulnar: SI 6

  • Pisiform: HT 7

Superficial Structures: Cutaneous Nerves

  • Supraclavicular nerve (C3, 4)

  • Axillary nerve (C5, 6)

  • Radial nerve (C5, 6, 7, 8, T1)

  • Musculocutaneous nerve

  • Lateral antibrachial cutaneous nerve of forearm (C5, 6, 7)

  • Intercostobrachial nerve (T2)

  • Medial cutaneous nerve of arm (C8, T1, T2)

  • Medial antibrachial cutaneous nerve of forearm (C8, T1)

  • Median nerve (C6, 7, 8, T1)

  • Ulnar nerve (C8, T1)

Superficial Structures: Segmental (dermatomal) Innervation

  • Note: Schematic demarcation of dermatomes (according to Keegan and Garrett) shown as distinct segments.

  • There is actually considerable overlap between adjacent dermatomes.

  • C6, C7, C8, C2, C3, C4, T1

Dermatome map diagram - anterior and posterior view

Superficial Structures: Vessels

  • Veins

    • Cephalic vein: Joins axillary vein; LU meridian

    • Median cubital vein: Connects cephalic and basilic veins

    • Basilic vein: Joins brachial vein

Osteology of Upper Extremity

  • Shoulder Girdle

    • Clavicle

    • Scapula

    • Humerus

    • Ulna and Radius

    • Hand

Shoulder Girdle: Clavicle

  • Connects the upper extremity to the trunk

  • Sternoclavicular (SC) joint: Articular facet for manubrium of the sternum

  • Acromioclavicular (AC) joint: Articular facet for acromion of the scapula

  • Clavicle fracture: Typically occurs in middle and lateral thirds

Shoulder Girdle: Scapula

  • Triangular flat bone

  • Anterior surface: Subscapular fossa

  • Posterior surface: Divided by the spine of scapula

    • Supraspinous fossa

    • Infraspinous fossa

  • Scapula spine

  • Acromion: Lateral continuation of the scapula spine

  • Glenoid cavity: Articular facet for humerus

    • Supraglenoid tubercle: Attachment for long head of biceps brachii

    • Infraglenoid tubercle: Attachment for long head of triceps brachii

  • Coracoid process: Anterior projection that is medial to neck of glenoid cavity

Humerus

  • Proximal extremity

    • Head

    • Neck

    • Anatomical neck

    • Surgical neck

    • Shaft

    • Deltoid tuberosity: Anterolateral

    • Distal extremity

    • Medial epicondyle: Origin for superficial group of forearm flexor muscles

    • Lateral epicondyle: Origin for superficial group of forearm extensors

    • Capitulum: Articulates with radial head

    • Radial fossa: Anterior

    • Trochlea: Articulates with ulna

    • Olecranon fossa: Posterior

    • Coronoid fossa: Anterior

Humerus: Posterior View

  • Superior angle

  • Supraspinous fossa

  • Spine

  • Infraspinous fossa

  • Medial border

  • Supraspinatus muscle

  • Inferior angle

  • Trapezius muscle

  • Levator scapulae muscle

  • Rhomboid minor muscle

  • Clavicle (cut)

  • Acromion

  • Greater tubercle

  • Head of humerus

  • Anatomical neck

  • Groove for circumflex scapular vessels

  • Deltoid tuberosity

  • Scapula

  • Muscles identified:

    • Deltoid muscle

    • Supraspinatus muscle

    • Infraspinatus muscle

    • Teres minor muscle

    • Rhomboid major muscle

    • Triceps brachii muscle (lateral head & long head)

    • Latissimus dorsi muscle (small slip of origin)

    • Teres major muscle

Tennis Elbow

  • Tear in tendons of the lateral epicondyle

Forearm

  • Ulna

    • Olecranon

    • Trochlear notch

    • Coronoid process: Anteriorly

    • Radial notch: Articulates with head of radius

    • Ulnar styloid process

    • Ulnar notch: Attachment with radius

Forearm

  • Radius

    • Head of radius: Articulates with capitulum of humerus

    • Radial notch: Articulates with ulna at the proximal end of forearm

    • Radial styloid process: Landmark for LU 7, 8, and 9 acupuncture points

    • Ulnar notch: Medial aspect of distal end of the radius; articulates with ulnar head

Forearm: Colles Fracture

  • Fracture of ulna and radius

  • Dinner fork deformity: Palmar view

  • Avulsed ulnar styloid process

  • Distal fragment of radius overrides the rest of bone

Hand

  • Carpal Bones

    • Proximal part:

    • Scaphoid

    • Lunate

    • Triquetrum

    • Pisiform

    • Distal part:

    • Trapezium

    • Trapezoid

    • Capitate

    • Hamate

  • Metacarp Bones

    • Head

    • Tubercle

    • Shaft

    • Base

  • Phalanges

    • Distal

    • Middle

    • Proximal

  • Scaphoid Fracture

    • Caused by fall on the palm with the hand abducted

    • Avascular necrosis

    • Multiple metacarpal fractures

Shoulder Muscles

Posterior Axioappendicular Muscles

  • Trapezius mm.

  • Latissimus mm.

  • Levator scapulae mm.

  • Rhomboid minor and major mm.

Anterior Part Muscles

  • Pectoralis major mm.

  • Pectoralis minor mm.

  • Serratus anterior mm.

Scapulohumeral Muscles

  • All originate from scapula

  • Innervated by C5-6

    • Deltoid mm.

    • Supraspinatus mm.

    • Infraspinatus mm.

    • Teres Minor mm.

    • Teres Major mm.

    • Subscapularis mm.

Shoulder Muscles: Deltoid

  • Origin: Clavicle and scapula spine

  • Insertion: Deltoid tuberosity

  • Action:

    • Whole: Abduct arm

    • Anterior: Flex and medially rotate arm

    • Posterior: Extend and laterally rotate arm

  • Innervation: Axillary (C5 – 6)

Shoulder Muscles: Subscapularis

  • Origin: Subscapular fossa

  • Insertion: Lesser tubercle

  • Action:

    • Whole: Medially rotate

    • Upper: Flex and abduct

    • Lower: Extend and adduct

  • Innervation: Upper and lower subscapular

Shoulder Muscles: Supraspinatus

  • Origin: Supraspinous fossa

  • Insertion: Greater tubercle

  • Action: Abduct arm

  • Innervation: Suprascapular

Shoulder Muscles: Infraspinatus

  • Origin: Infraspinous fossa

  • Insertion: Greater tubercle (middle impression)

  • Action:

    • Whole: Laterally rotate arm

    • Upper: Abduct arm

    • Lower: Adduct arm

  • Innervation: Suprascapular

Shoulder Muscles: Teres Minor

  • Origin: Axillary border of scapula

  • Insertion: Greater tubercle (lowest impression)

  • Action: Laterally rotate and adduct arm

  • Innervation: Axillary

Shoulder Muscles: Teres Major

  • Origin: Inferior angle of scapula

  • Insertion: Intertubercular groove

  • Action: Medially rotate, adduct, and extend arm

  • Innervation: Lower subscapular (Not a rotator cuff muscle)

Shoulder Muscles: Rotator Cuff Muscles

  • Provide stability to glenohumeral joint

  • Composed of four muscles:

    • Subscapular (anterior)

    • Supraspinatus (superior)

    • Infraspinatus (posterior)

    • Teres minor (posterior)

  • Most dislocations occur anterior-inferiorly

  • Supraspinatus muscle is the most commonly injured muscle

Axilla: Subclavian/Axillary Arteries

  • Source of blood for the upper extremity

  • Runs between the anterior and middle scalenes mm.

  • Origin:

    • Right: Brachiocephalic trunk

    • Left: Aortic arch

  • Name changes to axillary artery at the outer border of the first rib

  • Continuation of the Subclavian Artery

  • Surrounded by the brachial plexus

  • Begins at the outer border of the 1st rib and ends at the lower border of teres major (continues as brachial artery)

Axilla: Brachial Plexus

  • Components:

    • Trunks: Superior, middle, inferior

    • Divisions: Anterior and posterior

    • Cords: Medial, lateral, posterior

    • Branches: Peripheral nerves

  • Surrounds axillary artery

  • Arises from the union of the C5-T1 ventral rami (C4 and T2 are variable)

Upper and Lower Arm

Upper Arm: Anterior Part Muscles

  • Coracobrachialis

  • Biceps brachii

    • Origin:

    • Long head: Supraglenoid tubercle and glenoidal labrum

    • Short head: Coracoid process

    • Insertion: Radial tuberosity and bicipital aponeurosis

    • Action: Flex arm and shoulder (Biceps brachii)

    • Innervation: Musculocutaneous (C5 – 6)

  • Brachialis

    • Origin: Humeral shaft

    • Insertion: Ulnar tuberosity

    • Action: Flex arm

    • Innervation: Musculocutaneous (C5 – 6)

Upper Arm: Posterior Part Muscles

  • Triceps brachii

    • Origin:

    • Long head: Infraglenoid tubercle

    • Lateral head: Posterior humeral shaft (proximal to radial groove)

    • Medial head: Posterior humeral shaft (distal to radial groove)

    • Insertion: Olecranon process

    • Action: Extend and adduct arm; long head extends forearm

    • Innervation: Radial (C6-8)

Upper Arm: Blood Supply

  • Subclavian artery

  • Axillary artery

  • Brachial artery

  • Veins: Connect to previous mentioned veins

  • Brachial artery

  • Thoracodorsal artery

  • Thyrocervical trunk

Anterior Upper Arm: Nerves

  • Musculocutaneous nerve (C5-6):

    • Sensory to lateral forearm

    • Motor to arm muscles

  • Median nerve (C5 – 8, T1)

  • Ulnar nerve (C7, C8, T1)

Posterior Upper Arm: Nerves

  • Axillary nerve (C5-6): Innervates

    • Deltoid mm.

    • Teres minor mm.

  • Radial Nerve (C5 – T1): Innervates triceps brachii mm.

  • Suprascapular nerve (C5-6): Innervates

    • Supraspinatus mm.

    • Infraspinatus mm.

Forearm: Muscles

Superficial Flexion (and Intermediate) Muscles

  • Originate from medial epicondyle

  • Pronator teres (2 heads): Lateral radius

  • Flexor carpi radialis: Base of 2nd & 3rd metacarpals

  • Palmaris longus: Aponeurosis & flexor retinaculum

  • Flexor digitorum superficialis: Middle phalanges – digits 2-5

  • Flexor carpi ulnaris: Pisiform & flexor retinaculum

  • Ulnar nerve

Deep Flexion Muscles

  • Flexor digitorum profundus

  • Flexor pollicis longus

  • Pronator quadratus

Superficial Extensor Muscles

  • Originate from near lateral epicondyle

  • Brachioradialis: Radius - styloid process; does not cross wrist; flexes forearm (in mid-pronation)

  • Extensor carpi radialis longus: Base of 2nd metacarpal

  • Extensor carpi radialis brevis: Base of 3rd metacarpal

  • Extensor digitorum: Proximal phalanges of digits 2-5 (extensor expansion) then continues to middle & distal phalanges

  • Extensor digiti minimi: Proximal phalanx digit 5

  • Extensor carpi ulnaris: Base of 5th metacarpal

  • All of these muscles are innervated by the radial nerve

Deep Muscles (innervated by radial nerve)

  • Supinator

  • Abductor pollicis longus

  • Extensor pollicis brevis

  • Extensor pollicis longus

  • Extensor indicis

Forearm: Nerves

  • Ulnar N. (C7, C8 – T1):

    • Sensory: ½ of 4th and 5th fingers

    • Motor: Muscles of the hand

    • Canal of Guyon: Thoracic Outlet Syndrome (TOS)

  • Median N. (C5 – C8, T1):

    • Sensory: Lateral 3 ½ fingers

    • Motor: Elbow, wrist, and finger flexors

    • Innervates 2 muscles of the thenar eminence and the lateral 2 lumbricals

    • Carpal Tunnel Syndrome (CTS)

  • Radial N. (C5 – T1):

    • Sensory: Posterior forearm and dorsum of the hand

    • Motor to the wrist extensors: Brachioradialis, triceps

    • Wrist drop

Forearm: Carpal Tunnel

  • Contents (10):

    • Flexor digitorum superficialis (4)

    • Flexor digitorum profundus (4)

    • Flexor pollicis longus

    • Median nerve

Hand: Muscles and Nerves

  • Thenar eminence

  • Hypothenar eminence

  • Median nerve

  • Radial nerve

  • Ulnar nerve

Meridians: Upper Extremity

Lung Meridian

  • Superficial part starts from one cun down from delto-pectoralis triangle

  • One cun lateral to the medial edge of the deltoid muscle

  • Between humerus bone and biceps brachii muscle on upper arm

  • The lateral side of the tendon of biceps brachii muscle

  • Between the radial artery and the tendon of abductor pollicis longus muscle on the wrist

  • The radial border of the nail of the thumb

Pericardium Meridian

  • Located in the center of chest

  • Superficially starts from one cun lateral from nipple

  • Arches over the axilla

  • Medial to the tendon of biceps brachii muscle

  • Between tendons of flexor carpi radialis and palmaris longus muscles

  • Ends at tip of the middle finger

Heart Meridian

  • Positioned in the middle of the axilla

  • Between the humerus bone and biceps brachii muscle

  • Extends on the medial aspect of the upper arm to the elbow at the end of the transverse cubital crease

  • Between flexor carpi ulnaris and palmaris longus

  • The radial side of the dorsal aspect of the fifth finger

Large Intestine Meridian

  • Located on the radial side of the tip of the index finger

  • Between the first and second metacarpal bones

  • Anatomical snuff box

  • Lateral aspects of the arm

  • The anterior and inferior aspect of the acromion

San Jiao Meridian

  • Found on the ulnar aspect of the tip of the ring finger

  • Between the tendons of extensor digitorum communis and extensor digiti minimi on the dorsum of the hands

  • Between the ulna and radius on the forearm

  • Directly proximal to the olecranon

  • The posterior and inferior of the acromion (LI 15)

Small Intestine Meridian

  • Located on the ulnar side of the little finger

  • Ascends along the ulnar side of the arm

  • Taiyang side of arm: medioposterior side

  • Extends to the upper back on the scapular area