Thumb Joint Flashcards
Flexor Pollicis Longus
O: anterior surface of middle half of radius; interosseous membrane
I: distal phalanx of thumb
A: flexion of distal phalanx of thumb
N: median nerve
Flexor Pollicis Brevis
O: flexor retinaculum and tubercle of trapezium
I: lateral side of base of proximal phalanx of thumb
A: flexes proximal phalanx of thumb
N: median nerve (recurrent branch)
Opponens Pollicis
O: flexor retinaculum and tubercle of trapezium
I: lateral side of 1st metacarpal
A: draws 1st metacarpal forward and rotates it medially
N: median nerve (recurrent branch)
Extensor Pollicis Longus
O: posterior surface of middle third of ulna; interosseous membrane
I: distal phalanx of thumb
A: extension of proximal and distal phalanges of thumb; extension and adduction of metacarpal of thumb
N: radial nerve
Extensor Pollicis Brevis
O: posterior surface of radius; interosseous membrane
I: proximal phalanx of thumb
A: extension of proximal phalanx and metacarpal of thumb; abduction of hand and wrist
N: radial nerve
Abductor Pollicis Longus
O: posterior surface of ulna and radius; interosseous membrane
I: base of 1st metacarpal
A: abduction and extension of thumb; flexion of hand at wrist; radial deviation
N: radial nerve
Abductor Pollicis Brevis
O: flexor retinaculum, tubercles of scaphoid and trapezium
I: lateral side of base of proximal phalanx of thumb
A: abducts thumb
N: median nerve (recurrent branch)
Adductor Pollicis
O: Transverse Head:Palmar base of metacarpal bone 3
Oblique head: Capitate bone, palmar bases of metacarpal bones 2 & 3
I: Medial base of proximal phalanx 1
A: carpometacarpal joint 1; thumb adduction
N: ulnar nerve (deep branch)
Opponens Digiti Minimi
O: flexor retinaculum and hook of hamate bone
I: palmar surface of 5th metacarpal
A: draws 5th metacarpal anteriorly and rotates it to face thumb
N: ulnar nerve (deep branch)
