Hand Muscles

Question 1

Lumbricals

Answer 1

A: Extend the 2nd-5th fingers at the interphalangeal joints
Flex the 2nd-5th fingers at the metacarpophalangeal
joints
O: Surfaces of the flexor digitorum profundus tendons
I: Extensor aponeurosis on dorsal surface of phalanges
N: 2nd-3rd fingers: Median C6, 7, 8, T1
4th&5th fingers: Ulnar C7, 8, T1

Question 2

Dorsal Interossei

Answer 2

A: Abduct the 2nd, 3rd, and 4th fingers at the metacarpophalangeal joints
Assist to flex of the 2nd, 3rd and 4th fingers at the metacarpophlangeal joints
O: Adjacent sides of all metacarpals
I: Base of the proximal phalanx of the 2nd, 3rd, and 4th fingers and the extensor aponeurosis
N: Ulnar C8, T1

Question 3

Palmar Interossei

Answer 3

A: Adduct the thumb, 2nd, 4th and 5th fingers toward the 3rd finger
Assist to flex the thumb 2nd, 4th and 5th fingers at the metacarpophlangeal joints
Assist to extend the thumb, 2nd, 4th and 5th fingers at the interphlangeal joints
O: Base of 1st, 2nd, 4th and 5th metacarpals
I: Base of the proximal phalanx of the related finger and the extensor aponeurosis
N: Ulnar C8, T1