Upper Extremity Origin, Insertion, Innervation, Action

Pectoralis Major origin

Clavicular Head ->anterior/medial half of clavicle, Sternocostal Head -> anterior surface of the sternum, superior 6 costal cartilages, aponeurosis of external oblique muscle

pectoralis major insertion

lateral lip of bicipital groove

pectoralis major innervation

lateral & medial pectoral nerves

pectoralis major function

adducts/medially rotates humerus, draws scapula anterior & inferiorly, clavicular head flexes humerus, sternocostal head extends humerus from flexed position

Pectoralis Minor origin

3rd-5th ribs near costal cartilages

pectoralis minor insertion

medial & superior surface of coracoid process

pectoralis minor innervation

medial & lateral pectoral nerve

pectoralis minor function

Stabilizes scapula draws it inferior & anteriorly against thoracic wall

Subclavius

O: junction of 1st rib and its costal cartilage

I: inferior surface of middle third of clavicle

N: nerve to subclavius

A: anchors & depresses clavicle

Serratus Anterior

O: external surfaces of lateral 1st-8th ribs

I: anterior surface of medial border of scapula (includes superior & inferior angles)

N: long thoracic nerve

A: Protracts scapula & holds against thoracic wall, rotates scapula

Trapezius

O: medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament, spinous process C7-T12

I: lateral 1/3 of clavicle, acromion, spine of scapula

N: spinal accessory nerve & C3-C4 nerves

A: descending part elevates scapula, ascending part depresses scapula, middle part retracts scapula, descending & ascending part rotate glenoid cavity superiorly

Latissimus Dorsi

O: spinous process of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, inferior 3 or 4 ribs

I: floor of bicipital groove

N: thoracodorsal nerve

A: extends, adducts, and medially rotates humerus, raises body towards arms while climbing

Levator Scapulae

O: posterior tubercles of C1-C4 vertebrae

I: medial border of scapula superior to root of scapular spine

N: dorsal scapular & C3-C4 nerves

A: elevates scapula, downward rotation of scapula

Rhomboid Minor

O: nuchal ligament, spinous process C7 & T1

I: medial end of scapular spine (triangular area)

N: dorsal scapular nerve

A: retract scapula & downward rotation of scapula, fix scapula to thoracic wall

Rhomboid Major

O: spinous process T2-T5

I: medial border of scapula from spine of scapula to inferior angle

N: dorsal scapular nerve

A: retract scapula & downward rotation of scapula, fix scapula to thoracic wall

Deltoid

O: lateral 1/3 of clavicle, acromion, spine of scapula

I: deltoid tuberosity

N: axillary

A: clavicular part -> flexes & internally rotates arm, acromial part -> abducts arm, spinal part-> extends & externally rotates arm

Supraspinatus

O: supraspinous fossa of scapula

I: superior facet of greater tubercle of humerus

N: suprascapular nerve

A: assists deltoid in abducting arm

Infraspinatus

O: infraspinous fossa of scapula

I: middle facet of greater tubercle of humerus

N: suprascapular nerve

A: externally rotates arm

Teres Minor

O: middle part of lateral border of scapula

I: inferior facet of greater tubercle of humerus

N: axillary nerve

A: externally rotates arm

Teres Major

O: posterior surface of inferior angle of scapula

I: medial lip of bicipital groove

N: lower subscapular nerve

A: adducts & internally rotates arm

Subscapularis

O: subscapular fossa

I: lesser tubercle

N: upper & lower subscapular nerve

A: internally rotates arm, holds head of humerus in glenoid cavity

Biceps Brachii

O: short head-> coracoid process, long head: supraglenoid tubercle of scapula

I: radial tuberosity, fascia of forearm via bicipital aponeurosis

N: musculocutaneous nerve

A: supinates forearm, flexes shoulder, when supine it flexes forearm, short head resists dislocation of shoulder

Coracobrachialis

O: tip of coracoid process

I: middle third of medial humerus

N: musculocutaneous nerve

A: flex & adduct arm, resists dislocation

Brachialis

O: distal 1/2 of anterior humerus

I: coronoid process & ulnar tuberosity

N: musculocutaneous & radial nerve

A: flexes forearm in all positions

Triceps Brachii

O: long head -> infraglenoid tubercle, lateral head-> posterior surface of humerus superior to radial groove, medial head -> posterior surface of humerus inferior to radial groove

I: proximal end of olecranon & fascia of forearm

N: radial nerve

A: forearm extension, shoulder extension, long head resists dislocation

Anconeus

O: lateral epicondyle of humerus

I: lateral surface of olecranon & superior part of posterior surface of ulna

N: radial nerve

A: assists tricep in extending forearm, stabilizes elbow, abducts ulna during pronation

Brachioradialis

O: proximal 2/3 of lateral supra-epicondylar ridge

I: lateral surface of distal radius proximal to styloid process

N: radial nerve

A: weak forearm flexion, maximal forearm flexion when in neutral

Extensor Carpi Radialis Longus

O: lateral supra-epicondylar ridge

I: dorsal aspect of base of 2nd metacarpal

N: radial nerve

A: extend & radial deviation of wrist

Extensor Carpi Radialis Brevis

O: lateral epicondyle

I: dorsal aspect of base of 3rd metacarpal

N: radial nerve

A: extend & radial deviation of wrist

Extensor Digitorum

O: lateral epicondyle

I: extensor expansions of medial four digits

N: radial nerve

A: extends medial four digits at mainly metacarpophalangeal joints, secondly interphalangeal

Extensor Digiti Minimi

O: lateral epicondyle

I: extensor expansion of 5th digit

N: radial nerve

A: extends 5th digit at metacarpophalangeal joint, secondarily interphalangeal joints

Extensor Carpi Ulnaris

O: lateral epicondyle, posterior border of ulna via aponeurosis

I: dorsal aspect of base of 5th metacarpal

N: radial nerve

A: extends and ulnar deviation of wrist

Supinator

O: lateral epicondyle, radial collateral & annular collateral ligaments, supinator fossa, crest of ulna

I: lateral, posterior, and anterior surfaces of the proximal 1/3 of radius

N: radial nerve

A: supinates forearm, rotates radius to turn palm anteriorly & superiorly (if elbow is flexed)

Extensor Indicis

O: posterior surface of distal 1/3 of ulna & interosseous membrane

I: extensor expansion of 2nd digit

N: posterior interosseous nerve, radial nerve

A: extends 2nd digit, helps extend wrist

Abductor Pollicis Longus

O: posterior surface of proximal 1/2s ulna, radius, interosseous membrane

I: base of 1st metacarpal

N: posterior interosseous nerve, radial nerve

A: abducts thumb & extends it at carpometacarpal joint

Extensor Pollicis Longus

O: posterior surface of middle third of ulna & interosseus membrane

I: dorsal aspect of base of distal phalanx of thumb

N: posterior interosseous nerve, radial nerve

A: extends distal phalanx of thumb at interphalangeal joint, extends metacarpophalangeal & carpometacarpal joints

Extensor Pollicis Brevis

O: posterior surface of distal third of radius & interosseus membrane

I: dorsal aspect of base of proximal phalanx thumb

N: posterior interosseous nerve, radial nerve

A: extends proximal phalanx of thumb at metacarpophalangeal joint, extends carpometacarpal joint

Pronator Teres

O: ulnar head -> coronoid process, humeral head-> medial epicondyle

I: middle convexity of lateral surface of radius

N: median nerve

A: pronates & flexes forearm

Flexor Carpi Radialis

O: medial epicondyle

I: base of 2nd metacarpal

N: median nerve

A: flexes & radial deviation wrist

Palmaris Longus

O: medial epicondyle

I: distal 1/2 of flexor retinaculum, apex of palmar aponeurosis

N: median nerve

A: flexes wrist and tenses palmar aponeurosis

Flexor Carpi Ulnaris

O: humeral head-> medial epicondyle, ulnar head-> olecranon & posterior border of ulna

I: pisiform, hook of hamate, 5th metacarpal

N: ulnar nerve

A: flexes & ulnar deviation of wrist

Flexor Digitorum Superficialis

O: humero-ulnar head-> medial epicondyle + coronoid process, radial head-> superior half of anterior border

I: shafts of middle phalanges of medial 4 digits

N: median nerve

A: flexes middle phalanges at proximal interphalangeal joints, flexes proximal phalanges at MCP joints

Flexor Digitorum Profundus

O: proximal 3/4 of medial & anterior ulna & interosseous membrane

I: medial part-> bases of distal phalanges of 4th & 5th digits, lateral part -> bases of distal phalanges of 2nd & 3rd digits

N: medial head -> ulnar, lateral head -> anterior interosseus nerve from median nerve

A: medial part: flexes distal phalanges 4 & 5 at distal interphalangeal joints, lateral part-> flexes distal phalanges 2 & 3 at distal interphalangeal joints

Flexor Pollicis Longus

O: anterior surface of radius & adjacent interosseus membrane

I: base of distal phalanx of thumb

N: anterior interosseous nerve from median nerve

A: flexes phalange of 1st digit (thumb)

Pronator Quadratus

O: distal 1/4 of anterior ulna

I: distal 1/4 of anterior radius

N: anterior interosseous nerve from median nerve

A: pronates forearm, deep fibers bind radius & ulna together

Oppenens Pollicis

O: flexor retinaculum, scaphoid, & trapezium

I: lateral side of 1st metacarpal

N: median nerve

A: oppose thumb, draws metacarpal medially to center of palm, rotates it medially

Abductor Pollicis Brevis

O: flexor retinaculum, scaphoid, & trapezium

I: lateral side of proximal phalanx of thumb

N: median nerve

A: abducts thumb, helps oppose it

Flexor Pollicis Brevis

O: flexor retinaculum, scaphoid, & trapezium

I: lateral base of proximal phalanx of thumb

N: median nerve & ulnar nerve

A: flexes thumb

Adductor Pollicis

O: oblique head -> base of 2nd & 3rd metacarpals, capitate, & adjacent carpals, transverse head -> anterior surface of shaft of 3rd metacarpal

I: medial side of base of proximal phalanx of thumb

N: ulnar nerve

A: adducts thumb toward lateral border of palm

Abductor Digiti Minimi

O: pisiform

I: medial side base of proximal phalanx of 5th digit

N: ulnar nerve

A: abducts 5th digit

Flexor Digiti Minimi Brevis

O: hook of hamate & flexor retinaculum

I: medial side base of proximal phalanx 5th digit

N: ulnar nerve

A: flexes proximal phalanx of 5th digit

Opponens Digiti

O: hook of hamate & flexor retinaculum

I: medial border of 5th metacarpal

N: ulnar nerve

A: draws 5th metacarpal anterior & rotates it, brings 5th digit into opposition with thumb

Lumbricals 1st & 2nd

O: lateral two tendons of flexor digitorum profundus

I: lateral sides of extensor expansions 2nd-5th digits

N: median nerve

A: flex metacarpophalangeal and extend interphalangeal joints 2nd-5th

Lumbricals 3rd & 4th

O: medial three tendons of flexor digitorum profundus

I: lateral sides of extensor expansions 2nd-5th digits

N: ulnar nerve

A: flex metacarpophalangeal and extend interphalangeal joints of 2nd-5th

Dorsal Interossei, 1st-4th

O: adjacent sides of two metacarpals

I: bases of proximal phalanges, extensor expansions of 2nd-4th digits

N: ulnar nerve

A: abducts 2nds-4th digits from axial line

palmar interossei origin

palmar surfaces of 2nd, 4th, and 5th metacarpals

palmar interossei insertion

bases of proximal phalanges, extensor expansions of 2nd, 4th, & 5th digits

palmar interossei innervation

ulnar nerve

palmar interossei function

adducts 2nd, 4th, & 5th digits toward axial line