Intrinsic Muscles of the Hand - Adductor/Interosseous Compartment

Question 1

palmar interossei (PAD)

Answer 1

origin: metacarpals
insertion: proximal phalanx and extensor expansion of digits 2-5
innervation: deep ulnar n.
action: adduction of the digits 2-5, assist in MP flexion and IP extension

Question 2

dorsal interossei (DAB)

Answer 2

origin: metacarpals
insertion: proximal phalanx and extensor expansion of digits 2-5
innervation: deep ulnar n.
action: abduction of the digits 2-5, assist in MP flexion and IP extension

Question 3

adductor pollicis (transverse head)

Answer 3

origin: 3rd metacarpal
insertion: base of the proximal phalanx of digit 1
action: deep ulnar n.
action: adduction of the thumb

Question 4

adductor pollicis (oblique head)

Answer 4

origin: capitate
insertion: base of the proximal phalanx of digit 1
action: deep ulnar n.
action: adduction of the thumb