Intrinsic Muscles of the Hand - Thenar Eminence Flashcards
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 are the direction of fibres of the muscles of thenar eminence?
inferolateral
what is the nerve supply to the muscles of the thenar eminence?
median nerve T1
what muscles make up the thenar eminence?
abductor pollicis longus (lateral) flexor pollicis brevis (medial)
opponens pollicis (deep & lateral)
what is the action of abductor pollicis brevis?
abduction at 1st CMMC 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
What are the attachments of adductor pollicis?
O: oblique head - bases of 2nd, 3rd and 4th metacarpals, trapezoid and capitate
Transverse head - anterior surface of shaft of 3rd metacarpal
I: medial side of base of proximal phalanx
What are the attachments of the 1st palmar interosseous muscle?
O: shaft of 1st metacarpal
I: via DDE of extensor pollucis longus into medial side of base of proximal phalanx - with adductor pollicis
what is the DOF of adductor pollicis?
oblique head - inferolaterally
transverse head - horizontally
what is the DOF of the 1st palmar interosseous?
inferiorly
what is the nerve supply to adductor pollicis?
deep branch of the ulnar nerve - C8, T1
what is the nerve supply to the 1st palmar interosseous muscle?
deep branch of the ulnar nerve - C8, T1
