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