Hand Muscles

Thenar muscles

opponens pollicis

abductor pollicis brevis

flexor pollicis brevis

adductor pollicis

Hypothenar muscles

abductor digiti minimi

flexor digiti minimi brevis

opponens digiti minimi

opponens pollicis

opposition of thumb

recurrent branch of median nerve

attachments: flexor retinaculum and tubercles of scaphoid and trapezium; lateral side of 1st metacarpal

abductor pollicis brevis

abduction of thumb

recurrent branch of median nerve

attachments: flexor retinaculum and tubercles of scaphoid and trapezium; lateral side of base of proximal phalanx of thumb

flexor pollicis brevis

flexes thumb

recurrent branch of median nerve

attachments: flexor retinaculum and tubercles of scaphoid and trapezium; lateral side of base of proximal phalanx of thumb

adductor pollicis

adducts thumb

deep branch of ulnar nerve

attachments:

oblique: base of 2 and 3 metacarpals and capitate; medial side of base of proximal phalanx of thumb

transverse: anterior surface of shaft of 3 metacarpal; medial side of base of proximal phalanx of thumb

abductor digit minimi

abducts 5th finger, helps proximal phalanx flexion

deep branch of ulnar nerve

attachments: pisiform; medial side of base of proximal phalanx of 5th finger

flexor digit minimi brevis

flex proximal phalanx of 5th finger

deep branch of ulnar nerve

attachments: hook of hamate and flexor retinaculum; medial side of base of proximal phalanx of 5th finger

opponens digiti minimi

opposes 5th finger

deep branch of ulnar nerve

attachments: hook of hamate and flexor retinaculum; medial border of 5th metacarpal

Lumbricals 1-2

flexion of MCP joints

extension at DIP and PIP joints

median nerve

attachments: tendons of FDP; extension expander hood

Lumbricals 3-4

flexion of MCP joints

extension at DIP and PIP joints

deep branch of ulnar nerve

attachments: tendons of FDP; extension expander hood

dorsal interossei (1-4)

abduct 2-4 fingers

deep branch of ulnar nerve

attachments: adjacent sides of metacarpals; base of proximal phalanges

palmar interossei (1-3)

adduct 2, 4, and 5 fingers

deep branch of ulnar nerve

attachments: palmar surfaces of 2, 4, and 5 metacarpals; bases of proximal phalanges

lateral cutaneous nerve of forearm

origin: musculocutaneous nerve

skin: lateral forearm to wrist

medial cutaneous nerve of forearm

origin: medial cord

skin: medial forearm to wrist

median nerve (cutaneous innervation)

lateral 3.5 digits on palmar side, distal phalanges/nail beds on dorsal side

ulnar nerve (cutaneous innervation)

medial 1.5 digits on palmar side, distal 1.5 digits up to DIP joints on dorsal side

radial nerve (cutaneous innervation)

only dorsal side; first 3.5 digits up to PIP only

proximal row of carpals

scaphoid

lunate

triquetrum

pisiform

distal row of carpals

trapezium

trapezoid

capitate

hamate

MCP

metacarpophalangeal joint

PIP

proximal interphalangeal joint

DIP

distal interphalangeal joint

carpal tunnel contents

median nerve

flexor pollicis longus tendon

flexor digitorum superficialis tendon

flexor digitorum profundus tendon

Guyon’s canal contents

ulnar nerve (superficial and deep)

ulnar artery

ulnar veins

carpal tunnel boundaries

floor and sides: (lateral to medial)

trapezium, trapezoid, capitate, hamate

roof: transverse carpal ligament (flexor retinaculum)

guyon’s canal boundaries

floor: flexor retinaculum

roof: palmar carpal ligament

medial: pisiform

lateral: hook of hamate

superficial layer posterior forearm/hand muscles

brachioradialis

extensor carpi radialis longus

extensor carpi radialis brevis

extensor digitorum

extensor digiti minimi

extensor carpi ulnaris

deep layer posterior forearm/hand muscles

supinator

abductor pollicis longus

extensor pollicis brevis

extensor indicis

brachioradialis 

radial nerve

weak flexion of elbow

proximal lateral supra-epicondylar ridge of humerus and lateral surface of radius proximal to styloid process

extensor carpi radialis longus

radial nerve

extend and abduct wrist; extend carpometacarpal joints

lateral supra-epicondylar ridge and dorsal 2nd metacarpal 

extensor carpi radialis brevis

deep branch of radial nerve

extend and abduct wrist; extend carpometacarpal joints; active during fist clench

lateral epicondyle of humerus and dorsal 3rd metacarpal 

extensor digitorum

posterior interosseous nerve

extend wrist and carpometacarpal joints; extend medial 4 fingers at MCP (and IP)

lateral epicondyle of humerus and extensor expansion of medial 4 fingers

extensor digiti minimi 

posterior interosseous nerve

extend wrist and carpometacarpal joints; extends 5th finger at MCP (and IP)

lateral epicondyle of humerus and extensor expansion of 5th finger

extensor carpi ulnaris

posterior interosseous nerve

extend and adduct wrist; extend carpometacarpal joints; active during fist clench

supinator 

deep branch of radial nerve

supinate forearm; rotates radius when palm turns 

lateral epicondyle of humerus, radial collateral and supinator fossa and lateral posterior and anterior surface of radius 

abductor pollicis longus

posterior interosseous nerve

abduct thumb and extend at carpometacarpal joint; extend wrist and CMC joints

posterior surface of ulna and radius and base of 1st metacarpal 

extensor pollicis longus 

posterior interosseous nerve

extend distal phalanx at IP, extend MCP and CMC joints; extend wrist joint

posterior surface of ulna and dorsal aspect of distal phalanx

extensor pollicis brevis

posterior interosseous nerve

extend proximal phalanx at MCP joint; extend CMC joint, wrist joint

posterior surface of radius and dorsal aspect of proximal phalanx

extensor indicis

posterior interosseous nerve

extend 2nd finger; extend wrist and CMC joints; help extend hand

posterior surface of ulna and extensor expansion of 2nd finger

anatomical snuffbox boundaries

radial/lateral: abductor PL and extensor PB tendons

ulnar/medial: extensor PL tendon

floor: scaphoid and trapezium

roof: skin/superficial fascia

anatomical snuffbox contents

radial artery

cephalic vein

superficial branch radial nerve