Thumb and Hand Musculature

Clinical Anatomy II - ATTH 5P02

abductor pollicis longus

O: posterior radius/ulna, interosseous membrane

I: base of first metacarpal

A: abduction (thumb), extension (thumb), radial deviation

N: radial

extensor pollicis longus

O: posterior ulna, interosseous membrane

I: base of distal phalanx

A: extension (IP, MCP, CP), radial deviation

N: radial

extensor pollicis brevis

O: posterior radius, interosseous membrane

I: base of proximal phalanx

A: extension (MCP, CP), radial deviation

N: radial

flexor pollicis longus

O: anterior radius, interosseous membrane

I: base of distal phalanx

A: flexion (IP, MCP, CP), flexion (wrist, assists)

N: median

abductor pollicis brevis

O: flexor retinaculum, trapezium, scaphoid

I: base of proximal phalanx

A: abduction (MCP, CP), opposition (assists)

N: median

flexor pollicis brevis

O: flexor retinaculum, trapezium, trapezoid, capitate

I: base of proximal phalanx

A: flexion (MCP, CP), opposition (assists)

N: median, ulnar

opponens pollicis

O: flexor retinaculum, trapezium

I: radial surface of first metacarpal

A: opposition (CP)

N: median

adductor pollicis

O: capitate, metacarpals (II-III)

I: base of proximal phalanx

A: adduction (MCP, CP), flexion (thumb, assists)

N: ulnar

lumbricals

O: tendons of flexor digitorum profundus

I: extensor aponeurosis

A: extension (digits II-V, IP), flexion (digits II-V, MCP)

N: median (digits II-III), ulnar (digits IV-V)

palmar interossei

O: base of metacarpals I-II, IV-V

I: base of proximal phalanx, extensor aponeurosis

A: adduction (digits I-II, IV-V)

N: ulnar

dorsal interossei

O: sides of all metacarpals

I: base of proximal phalanx (digits II-IV), extensor aponeurosis

A: abduction (digits II-IV)

N: ulnar

abductor digiti minimi

O: pisiform, tendon of flexor carpi ulnaris

I: base of proximal phalanx (digit V)

A: abduction (digit V), opposition (assists)

N: ulnar

flexor digiti minimi brevis

O: hook of hamate, flexor retinaculum

I: base of proximal phalanx (digit V)

A: flexion (digit V), opposition (assists)

N: ulnar

opponens digiti minimi

O: hook of hamate, flexor retinaculum

I: fifth metacarpal

A: opposition (digit V)

N: ulnar