Intrinsic Hand Muscles Flashcards
The fleshy part at the base of the thumb, which is made up of 3 muscles.
Thenar Eminence
What are the 3 thenar muscles?
1) Opponens Pollicis
2) Abductor Pollicis Brevis
3) Flexor Pollicis Brevis
Proximal Attachment: flexor retinaculum and tubercle of trapezium
Distal Attachment: lateral side of 1st MC
Opponens Pollicis
What are the 2 actions of opponens pollicis?
1) Thumb Flexion (component of opposition)
2) Thumb Medial Rotation (component of opposition)
Proximal Attachment: flexor retinaculum and tubercles of scaphoid and trapezium
Distal Attachment: lateral side of base of proximal phalanx of thumb
Abductor Pollicis Brevis
What is the action of abductor pollicis brevis?
Thumb Abduction (Assist in Opposition)
Proximal Attachment: flexor retinaculum and tubercles of scaphoid and trapezium
Distal Attachment: lateral side of base of proximal phalanx of thumb
Flexor Pollicis Brevis
What is the action of flexor pollicis brevis?
Thumb Flexion (Assist in Opposition)
The fleshy part at the base of the 5th digit, which is made up of 4 muscles.
Hypothenar Eminence
What are the 4 hypothenar muscles?
1) Opponens Digiti Minimi (most deep)
2) Abductor Digiti Minimi (most superficial)
3) Flexor Digiti Minimi Brevis
4) Palmaris Brevis
Proximal Attachment: hook of hamate and flexor retinaculum
Distal Attachment: medial border of 5th MC
Opponens Digiti Minimi
What is the action of opponens digiti minimi?
Draws 5th MC anteriorly and rotates it to oppose thumb
Proximal Attachment: pisiform
Distal Attachment: medial side of base of proximal phalanx of 5th digit
Abductor Digiti Minimi
What is the action of abductor digiti minimi?
5th Digit Abduction
Proximal Attachment: hook of hamate and flexor retinaculum
Distal Attachment: medial side of base of proximal phalanx of 5th digit
Flexor Digiti Minimi Brevis
What is the action of flexor digiti minimi brevis?
5th Digit Flexion (Proximal Phalanx)
Proximal Attachment: flexor retinaculum and palmar aponeurosis
Distal Attachment: skin on medial side of palm
Palmaris Brevis
Palmaris brevis ________ the skin on the medial side of the palm and covers/protects the _____ nerve and artery.
Wrinkles
Ulnar
Proximal Attachment: base of 2nd MC, trapezoid and capitate (oblique head) and shaft of 3rd MC (transverse head)
Distal Attachment: medial side of base of proximal phalanx of thumb
Adductor Pollicis
What is the action of adductor pollicis?
Thumb Adduction
Which muscle forms the bulk of the thumb web space on the anterior surface?
Adductor Pollicis
Proximal Attachment: FDP tendon
Distal Attachment: extensor expansion of 2nd-5th digits
Lumbricals
What are the 2 actions of the lumbricals in the hand?
1) MCP Flexion
2) IP Extension
Proximal Attachment: adjacent sides of two MC bones
Distal Attachment: extensor expansions and bases of proximal phalanges of 2nd-4th digits
Dorsal Interossei
What is the action of the dorsal interossei in the hand?
Abduction of Digits
Proximal Attachment: palmar surfaces of 2nd, 4th and 5th MCs
Distal Attachment: extensor expansions and bases of proximal phalanges of 2nd, 4th and 5th digits
Palmar Interossei
What is the action of the palmar interossei in the hand?
Adduction of Digits
