Muscles Of The Hand Flashcards
Thenars
Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis
O: scaphoid and trapezium
Innervation: median nerve (C8-T1)
Abductor pollicis brevis insertion and action
I: Lateral aspect of proximal phalanx of digit 1
Action: abducts thumb
Flexor pollicis brevis insertion and action
I: lateral aspect of proximal phalanx of digit 1 (a little more anterior than APB)
Action: flexes thumb
Opponens pollicis insertion and action
I: metacarpal 1
Action: opposes thumb to digit 5
Adductor pollicis origin and insertion
O: capitate, hamate, metacarpals 2, 3, 4
I: medial aspect of proximal phalanx of digit 1
Adductor pollicis innervation and action
Innervation: ulnar nerve (C8-T1)
Action: adducts thumb
Hypothenars
Abductor digiti minimi
Flexor digiti minimi brevis
Opponens digiti minimi
Innervation: ulnar nerve (C8-T1)
Abductor digiti minimi origin and insertion and action
O: pisiform bone
I: medial aspect of proximal phalanx of digit 5
Action: abducts digit 5
Flexor digiti minimi brevis origin and insertion and action
O: hook of hamate bone
I: medial aspect of proximal phalanx of digit 5
Action: flexes digit 5
Opponens digiti minimi origin and insertion and action
O: hook of hamate bone
I: metacarpal 5
Action: opposes digit 5 to digit 1
Lumbricles origin and insertion
O: tendons of the flexor digitorum profundus
I: extensor expansions of digits 2-5
Lumbricles innervation and action
Innervation: lumbricles 1&2 - median nerve, lumbricles 3&4 - ulnar nerve
Action: flexes MCPs, extends IPs
Dorsal interossei origin and insertion
O: metacarpals (dorsal interossei 1- metacarpals 1&2, dorsal interossei 2- metacarpals 2&3, dorsal interossei 3- metacarpals 3&4, dorsal interossei 4- metacarpals 4&5)
I: extensor expansions of digits 2,3,4
Dorsal interossei innervation and action
Innervation: ulnar nerve (C8-T1)
Action: abducts digits 2,3,4
Also flexes MCPs and extends IPs
Palmar interossei origin and insertion
O: metacarpals 1,2,4,5
I: extensor expansions digits 1,2,4,5
