Muscles of the Thumb Flashcards
what are the attachments of abductor pollicis longus?
O: middle part of posterior surface of radius and ulna & interosseous membrane
I: dorsal base of proximal phalanx of thumb
what is the nerve supply of abductor pollicis longus?
posterior interosseous branch of radial nerve -C7,8
what is the action of abductor pollicis longus?
abducts the thumb
what is the function of the abductor pollicis longus?
opening hand to grip large object
What are the attachments of extensor pollicis longus?
O: middle 1/3rd posterior surface of ulna and adjacent interosseous membrane
I: dorsal surface of base of distal phalanx of thumb
What is the nerve supply to extensor pollicis longus?
posterior interosseous branch of radial nerve - C7, c8
what is the action of extensor pollicis longus?
extends 1st IP, MCP, CMC and wrist joint abducts the wrist
what is the function of extensor pollicis longus?
releasing grip
what are the attachments of extensor pollucis brevis?
O: middle 1/3 posterior surface of radius and interosseous membrane
I: dorsal surface base of proximal phalanx of thumb
what is the nerve supply of extensor pollicis brevis?
posterior interosseous nerve C7, C8
what is the action of extensor pollucis brevis?
Extends CMC and MCP joints of thumb
Helps to extend and abduct wrist
what is a function of extensor pollucis brevis?
release of grip
What are the attachments of flexor pollucis longus?
O: anterior surface of radius - between radial tuberosity and pronator quadratus & adjacent interosseous membrane
I: palmar surface of base of distal phalanx of thumb
what is the nerve supply of flexor pollucis longus?
Anterior interosseous branch of median nerve C8, T1
what is the action of flexor pollucis longus?
Flexion of the IP joint @ thumb
Flexes MCP and wrist
Functional activity of flexor polluclis longus?
Gripping small object
What are the attachments of Abductor Pollucis Brevis?
O: Flexor retinaculum, scaphoid tubercles and tubercle on trapezium
I: to radial side of base of proximal phalanx of thumb - via DDE of extensor pollucis longus
What are the attachments of Flexor Pollicis Brevis?
O: flexor retinaculum, tubercle of trapezium, capitate and trapezoid
I: radial side of base of proximal phalanx of thumb
What are the attachments of Opponens pollucis?
O: flexor retinaculum and tubercle of trapezium
I: lateral half of anterior surface of 1st metacarpal
what is the action of abductor pollicis brevis?
abduction at 1st CMC and MCP joint
what is the action of the flexor pollicis brevis muscle?
flexion at the 1st MCP and CMC joint
what is the action of the opponens pollicis muscle?
medial rotation of the 1st metacarpal during opposition
Nerve supply of abductor pollicis brevis
median nerve t1
nerve supply to flexor pollucis brevis
median nerve t1
