Muscles of the UE

deltoid

PA: lateral third of the clavicle (anterior head), acromion (middle head) and spine (posterior head) of the scapula

DA: deltoid tuberosity of humerus

N: axillary nerve (C5, C6)

A: anterior part flexes and medially rotates the shoulder, middle part abducts the shoulder, posterior part extends and laterally rotates the shoulder

supraspinatus

PA: supraspinous fossa of scapula

DA: superior facet of greater tubercle of the humerus

N: suprascapular nerve (C4, C5, C6)

A: initiates and assists deltoid in abduction of the arm and acts with the rotator cuff muscles

infraspinatus

PA: infraspinous fossa of scapula

DA: middle facet of greater tubercle of the humerus

N: suprascapular nerve (C5, C6)

A: laterally rotates the arm, acts with the rotator cuff muscles

teres minor

PA: middle part of lateral border of the scapula

DA: inferior facet of greater tubercle of the humerus

N: axillary nerve (C5, C6)

A: laterally rotates the arm, acts with the rotator cuff muscles

teres major

PA: posterior surface of inferior angle of the scapula

DA: medial lip of the intertubercular sulcus of the humerus

N: lower subscapular nerve (C5, C6)

A: adducts and medially rotates the arm

subscapularis

PA: subscapular fossa of the scapula

DA: lesser tubercle of the humerus

N: upper and lower subscapular nerves (C5, C6, C7)

A: medially rotates the arm, as part of rotator cuff, helps hold humeral head in glenoid cavity

pectoralis major

PA: clavicular head attaches to anterior surface of medial half of the clavicle, sternocostal head attaches to anterior surface of the sternum, superior 6 costal cartilages, and aponeurosis of external oblique muscle

DA: lateral lip of the intertubercular sulcus of the humerus

N: lateral pectoral nerve (C5, C6) and medial pectoral nerve (C7, C8, T1)

A: adducts and medially rotates the humerus, draws scapula anteriorly and inferiorly - acting alone, clavicular head flexes humerus and sternocostal head extends it from the flexed position

pectoralis minor

PA: Ribs 3-5 near costal cartilages

DA: medial border and superior surface of the coracoid process of the scapula

N: medial pectoral nerve (C8,T1)

A: stabilizes scapula by drawing it anteriorly and inferiorly against thoracic wall

subclavius

PA: junction of 1st rb and its costal cartilage

DA: inferior surface of the middle third of the clavicle

N: nerve to subclavius (C5,C6)

A: anchors and depresses clavicle

serratus anterior

PA: external surfaces of lateral parts of ribs 1-8

DA: anterior surface of medial border of the scapula

N: long thoracic nerve (C5, C6, C7)

A: protracts scapula and holds it against thoracic wall, rotates scapula (upward)

biceps brachii

PA: short head attaches to the tip of the coracoid process of the scapula, long head attaches to the supraglenoid tubercle of the scapula

DA: tuberosity of radius and fascia of forearm via bicipital aponeurosis

N: musculocutaneous nerve (C5, C6, C7)

A: supinates forearm and, when it is supine, flexes forearm; short head resists dislocation of the shoulder

coracobrachialis

PA: top of coracoid process of scapula

DA: middle third of medial surface of humerus

N: musculocutaneous nerve (C5, C6, C7)

A: helps flex and adduct arm, resists dislocation of the shoulder

brachialis

PA: distal half of anterior surface of humerus

DA: coronoid process and tuberosity of the ulna

N: musculocutaneous nerve (C5, C6) and radial nerve (C5, C7)

A: flexes forearm in all positions

triceps brachii

PA: long head attaches to the infraglenoid tubercle of the scapula, lateral head attaches to the posterior surface of the humerus, superior to the radial groove, medial head attaches to the posterior surface of the humerus, inferior to the radial groove

DA: proximal end of the olecranon of the ulna and fascia of the forearm

N: radial nerve (C6, C7, C8)

A: chief extensor of the forearm, long head resists dislocation of the humerus, especially important during adduction

anconeus

PA: lateral epicondyle of the humerus

DA: lateral surface of olecranon and superior part of posterior surface of the ulna

N: Radial nerve (C7, C8, T1)

A: assists triceps in extending the forearm, stabilizes elbow joint, may abduct ulna during pronation

pronator teres

PA: ulnar head attaches to the coronoid process of the ulna, humeral head attaches to the medial epicondyle of the humerus

DA: middle of convexity of lateral surface of radius

N: median nerve (C6, C7)

A: pronates and flexes forearm (at elbow)

flexor carpi radialis (FCR)

PA: medial epicondyle of humerus

DA: base of 2nd metacarpal

N: median nerve (C6, C7)

A: flexes and abducts hand (at wrist)

palmaris longus

PA: medial epicondyle of the humerus

DA: distal half of flexor retinaculum and apex of palmar aponeurosis

N: median nerve (C7,C8)

A: flexes hand (at wrist) and tenses palmar aponeurosis

flexor carpi ulnaris (FCU)

PA: ulnar head attaches to olecranon and posterior border of the ulna (via aponeurosis), humeral head attaches to medial epicondyle of the humerus

DA: pisiform, hook of hamate, 5th metacarpal

N: ulnar nerve (C7, C8)

A: flexes and adducts hand (at wrist)

flexor digitorum superficialis (FDS)

PA: humero-ulnar head attaches at medial epicondyle and coronoid process, radial head attaches at the superior half of the anterior border (on radius)

DA: shafts of middle phalanges of medial 4 digits

N: median nerve (C7, C8, T1)

A: flexes middle phalanges at proximal interphalangeal joints of middle 4 digits; acting more strongly, it also flexes proximal phalanges at metacarpophalangeal joints

flexor digitorum profundus

PA: proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane

DA: medial part attaches at the bases of distal phalanges of 4th and 5th digits, lateral part attaches at the base of distal phalanges of 2nd and 3rd digits

N: medial part innervated by ulnar nerve (C8, T1), lateral part innervated by anterior interosseous nerve from the median nerve (C8, T1)

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 (FPL)

PA: anterior surface of radius and adjacent interosseous membrane

DA: base of distal phalanx of thumb

N: anterior interosseous nerve from median nerve (C8,T1)

A: flexes phalanges of 1st digit (thumb)

pronator quadratus

PA: distal 1/4 of anterior surface of ulna

DA: distal 1/4 of anterior surface of radius

N: anterior interosseous nerve from median nerve (C8, T1)

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

brachioradialis

PA: proximal 2/3 of supra-epicondylar ridge of humerus

DA: lateral surface of distal end of radius proximal to styloid process

N: radial nerve (C5, C6, C7)

A: relatively weak flexion of the forearm, maximal when forearm is in midpronated position

extensor carpi radialis longus (ECRL)

PA: lateral supra-condylar ridge of humerus

DA: dorsal aspect of base of 2nd metacarpal

N: radial nerve (C6, C7)

A: extend and abduct hand at the wrist joint, active during fist clenching

extensor carpi radialis brevis (ECRB)

PA - lateral epicondyle of humerus

DA - dorsal aspect of base of 3rd metacarpal

N - deep branch of the radial nerve (C7, C8)

A - extend and abduct hand at the wrist joint

extensor digitorum

PA: lateral epicondyle of humerus

DA: extensor expansions of medial 4 digits

N: deep branch of radial nerve (C7, C8)

A: extends medial 4 digits primarily at metacarpophalangeal joints, secondarily at interphalangeal joints

extensor digiti minimi (EDM)

PA: lateral epicondyle of humerus

DA: extensor expansion of 5th digit

N: deep branch of radial nerve (C7, C8)

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

extensor carpi ulnaris (ECU)

PA: lateral epicondyle of humerus, posterior border of the ulna via a shared aponeurosis

DA: dorsal aspect of base of 5th metacarpal

N: deep branch of radial nerve (C7, C8)

A: extends and adducts hand at the wrist joint, active during wrist clenching

supinator

PA: lateral epicondyle of the humerus, radial collateral and annular ligaments, supinator fossa, crest of ulna

DA: lateral, posterior, and anterior surfaces of proximal third of radius

N: deep branch of radial nerve (C7, C8)

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

extensor indicis

PA: posterior surface of distal third of ulna and interosseous membrane

DA: extensor expansion of 2nd digit

N: posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve

A: extends 2nd digit (enabling its independent extension), helps extend hand at wrist

abductor pollicis longus (APL)

PA: posterior surface of proximal halves of ulna, radius, and interosseous membrane

DA: base of 1st metacarpal

N: posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve

A: abducts thumb and extends it at the carpometacarpal joint

extensor pollicis longus (EPL)

PA: posterior surface of middle third of ulna and interosseous membrane

DA: dorsal aspect of base of distal phalanx of thumb

N: posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve

A: extends distal phalanx of thumb at interphalangeal joint; extends metacarpophalangeal and carpometacarpal joints

extensor pollicis brevis (EPB)

PA: posterior surface of distal third of radius and interosseous membrane

DA: dorsal aspect of base of proximal phalanx of thumb

N: posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve

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

opponens pollicis

N: median nerve (C8, T1)

A: opposition of thumb (draws 1st metacarpal medially to center of palm and rotates it medially)

abductor pollicis brevis

N: median nerve (C8, T1)

A: abduct thumb, helps oppose it

flexor pollicis brevis

N: superficial head innervated by the median nerve (C8, T1), deep head innervated by the deep branch of the ulnar nerve (C8, T1)

A: Flexes thumb

adductor pollicis

N: deep branch of the ulnar nerve (C8, T1)

A: adducts thumb toward lateral border of the palm

abductor digiti minimi

N: deep branch of ulnar nerve (C8, T1)

A: abducts 5th digit, assists in flexion of its proximal phalanx

flexor digiti minimi brevis

N: deep branch of ulnar nerve (C8, T1)

A: flexes proximal phalanx of 5th digit

opponens digiti

N: deep branch of ulnar nerve (C8, T1)

A: opposes pinky (draws 5th metacarpal anterior and rotates it, bring it into opposition with the thumb)

lumbricals

N: 1st and 2nd innervated by median nerve (C8, T1), 3rd and 4th innervated by deep branch of ulnar nerve (C8, T1)

A: flex metacarpophalangeal joints, extend interphalangeal joints of digits 2-5

dorsal interossei, 1st-4th

N: deep branch of ulnar nerve (C8, T1)

A: abduct digits 2-5 from axial line; act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints

palmar interossei, 1st-3rd

N: deep branch of ulnar nerve (C8, T1)

A: adduct 2nd, 4th, and 5th digits towards the axial line, assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints

trapezius

PA: medial third of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae

DA: lateral third of clavicle, acromion and spine of scapula

N: spinal accessory nerve (CN XI)

A: descending part elevates, ascending part depresses, and middle part (or all parts together) retracts the scapula, descending and ascending parts act together to rotate the glenoid cavity superiorly

rhomboid major

PA: spinous processes of T2-T5 vertebrae

DA: medial border of the scapula from level of spine to inferior angle

N: dorsal scapular nerve (C4, C5)

A: retracts scapula and rotate its glenoid cavity inferiorly, fix scapula to thoracic wall

rhomboid minor

PA: nuchal ligament, spinous processes of C7 and T1 vertebrae

DA: smooth triangular area at medial end of scapular spine

N: dorsal scapular nerve (C4, C5)

A: retract scapula and rotate its glenoid cavity inferiorly, fix scapula to thoracic wall

levator scapulae

PA: posterior tubercles of transverse processes of C1-C4 vertebrae

DA: Medial border of scapula superior to the foot of the scapular spine

N: dorsal scapular (C4-C5) and cervical (C3-C4) nerves

A: elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula

latissimus dorsi

PA: spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs

DA: floor of intertubercular sulcus of humerus

N: thoracodorsal nerve (C6, C7, C8)

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