Anatomy 1: Muscles (O+I) and Superficial Landmarks

Origin: clavicular head (medial clavicle), sternocostal head (sternum, upper 6 costal cartilages), abdominal head (external oblique aponeurosis); Insertion: lateral lip of intertubercular groove of humerus

Pectoralis major

Origin: ribs 3-5 (anterior surface); Insertion: coracoid process of scapula

Pectoralis minor

Origin: junction of 1st rib and costal cartilage; Insertion: subclavian groove of clavicle

Subclavius

Origin: ribs 1-8 (external surfaces); Insertion: costal surface of medial border of scapula

Serratus anterior

Origin: superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes C7-T12; Insertion: lateral third of clavicle, acromion, spine of scapula

Trapezius

Origin: spinous processes T7-L5, thoracolumbar fascia, iliac crest, ribs 9-12, inferior angle of scapula; Insertion: floor of intertubercular groove of humerus

Latissimus dorsi

Origin: transverse processes of C1-C4; Insertion: superior angle of scapula

Levator scapulae

Origin: spinous processes T2-T5; Insertion: medial border of scapula, below the spine

Rhomboid major

Origin: spinous processes C7-T1; Insertion: medial border of scapula, at root of the spine

Rhomboid minor

Origin: lateral third of clavicle, acromion, spine of scapula; Insertion: deltoid tuberosity of humerus

Deltoid

Origin: supraspinous fossa; Insertion: greater tubercle of humerus, superior facet

Supraspinatus

Origin: infraspinous fossa; Insertion: greater tubercle of humerus, middle facet

Infraspinatus

Origin: upper 2/3 of lateral border of scapula; Insertion: greater tubercle of humerus, inferior facet

Teres minor

Origin: subscapular fossa; Insertion: lesser tubercle of humerus

Subscapularis

Origin: inferior angle of scapula (posterior surface); Insertion: medial lip of intertubercular groove of humerus

Teres major

Origin: long head from supraglenoid tubercle, short head from coracoid process; Insertion: radial tuberosity and bicipital aponeurosis

Biceps brachii

Origin: coracoid process; Insertion: middle third of medial humeral shaft

Coracobrachialis

Origin: distal half of anterior humerus; Insertion: coronoid process and ulnar tuberosity of ulna

Brachialis

Origin: long head from infraglenoid tubercle, lateral head from posterior humerus above radial groove, medial head from posterior humerus below radial groove; Insertion: olecranon of ulna

Triceps brachii

Origin: lateral epicondyle of humerus; Insertion: olecranon and posterior ulna

Anconeus

Origin: medial epicondyle (humeral head) and coronoid process (ulnar head); Insertion: middle of lateral radius

Pronator teres

Origin: medial epicondyle (common flexor tendon); Insertion: base of 2nd metacarpal

Flexor carpi radialis

Origin: medial epicondyle; Insertion: palmar aponeurosis

Palmaris longus

Origin: medial epicondyle (humeral head) and olecranon/posterior ulna (ulnar head); Insertion: pisiform, hamate, and 5th metacarpal

Flexor carpi ulnaris

Origin: medial epicondyle, coronoid process, and radius; Insertion: middle phalanges of digits 2-5

Flexor digitorum superficialis

Origin: proximal 3/4 of ulna and interosseous membrane; Insertion: distal phalanges of digits 2-5

Flexor digitorum profundus

Origin: anterior radius and interosseous membrane; Insertion: distal phalanx of thumb

Flexor pollicis longus

Origin: distal anterior ulna; Insertion: distal anterior radius

Pronator quadratus

Origin: lateral supracondylar ridge of humerus; Insertion: styloid process of radius

Brachioradialis

Origin: lateral supracondylar ridge of humerus; Insertion: base of 2nd metacarpal

Extensor carpi radialis longus

Origin: lateral epicondyle (common extensor tendon); Insertion: base of 3rd metacarpal

Extensor carpi radialis brevis

Origin: lateral epicondyle; Insertion: extensor expansions of digits 2-5

Extensor digitorum

Origin: lateral epicondyle; Insertion: extensor expansion of 5th digit

Extensor digiti minimi

Origin: lateral epicondyle and posterior ulna; Insertion: base of 5th metacarpal

Extensor carpi ulnaris

Origin: lateral epicondyle, radial collateral/annular ligaments, supinator crest of ulna; Insertion: proximal lateral radius

Supinator

Origin: posterior ulna and interosseous membrane; Insertion: extensor expansion of the index finger

Extensor indicis

Origin: posterior radius and ulna, interosseous membrane; Insertion: base of 1st metacarpal

Abductor pollicis longus

Origin: posterior ulna and interosseous membrane; Insertion: distal phalanx of thumb

Extensor pollicis longus

Origin: posterior radius and interosseous membrane; Insertion: proximal phalanx of thumb

Extensor pollicis brevis

Triangular gap between deltoid and pectoralis major, under the clavicle; cephalic vein runs through it

Deltopectoral (clavipectoral) triangle

Anterior axillary wall, formed by pectoralis major and pectoralis minor

Anterior wall of axilla

formed by subscapularis, teres major, and latissimus dorsi

Posterior wall of axilla

formed by serratus anterior over the ribs

Medial wall of axilla

Lateral axillary wall, formed by the intertubercular groove of the humerus

Lateral wall of axilla

Triangular depression anterior to the elbow; bounded by brachioradialis (lateral), pronator teres (medial), line between epicondyles (superior)

Cubital fossa

Lateral-to-medial contents of the cubital fossa (mnemonic TAN)

Tendon (biceps), Artery (brachial), Nerve (median)

Triangular depression on the dorsum of the hand at the base of the thumb; floor is scaphoid and trapezium, radial artery runs through it

Anatomical snuffbox

Ulnar (medial) border of the anatomical snuffbox

Extensor pollicis longus tendon

Radial (lateral) border of the anatomical snuffbox

Abductor pollicis longus and extensor pollicis brevis tendons

Formed by the lower border of pectoralis major; front wall of the axilla, visible as a fold of skin

Anterior axillary fold

Formed by latissimus dorsi and teres major; back wall of the axilla, visible as a fold of skin

Posterior axillary fold

Vertical line through the middle of the sternum

Midsternal line

Vertical line through the midpoint of the clavicle

Midclavicular line

Vertical line along the anterior axillary fold

Anterior axillary line

Vertical line midway between anterior and posterior axillary lines, through the apex of the axilla

Midaxillary line

Vertical line along the posterior axillary fold

Posterior axillary line

Vertical line along the medial border of the scapula, arm at side

Scapular line

Vertical line running along the spinous processes

Posterior median (vertebral) line

Most prominent spinous process at the base of the neck, easily felt when the neck is flexed

Vertebra prominens (C7)

Vertebral level of the root (medial end) of the scapular spine

T3

Vertebral level of the inferior angle of the scapula, arm at side

T7

Vertebral level of the iliac crest; key landmark for locating spinal levels/lumbar puncture

L4

Marked by a skin dimple in the lower back, level with S2

Posterior superior iliac spine (PSIS)

Groove between deltoid and pectoralis major; contains the cephalic vein

Deltopectoral groove

Bony point palpable about 2.5 cm below the lateral clavicle, anteriorly

Coracoid process

Furrow along the medial arm containing the basilic vein

Medial bicipital furrow (groove)

Furrow along the lateral arm containing the cephalic vein

Lateral bicipital furrow (groove)

Palpable bony point just distal to the lateral epicondyle that rotates during pronation/supination

Head of radius

The more distal and more lateral of the two wrist styloid processes

Styloid process of radius

Subcutaneous, palpable border running the entire length of the posterior forearm

Posterior (subcutaneous) border of ulna

Prominent tendon at the anterior wrist used for grafts; congenitally absent in some people

Palmaris longus tendon