Intrinsic Hand Muscles

Question 1

What muscles perform Opposition?

Answer 1

Opponens Pollicis - opposition of the thumb (Thenar eminence)

Opponens Digiti Minimi - opposition of the little finger (Hypothenar eminence)

Question 2

What muscles perform Little finger and thumb flexion?

Answer 2

Flexor Pollicis Brevis - thenar eminence

Flexor Digiti Minimi - hypothenar eminence

Question 3

What muscles perform little finger and thumb abduction?

Answer 3

Abductor Pollicis Brevis - Thenar eminence

Abductor Digiti Minimi - Hypothenar eminence

Question 4

What muscles perform digit adduction? Where are they situated?

Answer 4

All PAD muscles lie on the medial side of the bone

First Palmar Interosseous - adducts index finger

Second Palmar Interosseous - adducts 3rd finger

Third Palmar Interosseous - adducts little finger

Question 5

What muscles perform digit abduction? Where are they situated?

Answer 5

All DAB muscles lie on the lateral side of the bone

First Dorsal Interosseous - abducts index finger

Second Dorsal Interosseous - abducts middle finger (left and right)

Third Dorsal Interosseous - abducts ring finger

Fourth Dorsal Interosseous - abducts little finger

Question 6

What do the lumbricals do and what are their origins and insertions?

Answer 6

First, second, third, fourth lumbricals

Lumbricals serve to flex at the metacarpal joints while extending @ the interphalangeal joints

Lumbricals originate from the tendon of flexor digatorum and insert @ the extensor expansions

Question 7

Where is the thenar eminence and hypothenar eminence?

Answer 7

Thenar eminence - Lateral side of the palm

Hypothenar eminence - Medial side of the palm

Question 8

What are the different movements of the thumb?

Answer 8

Opposition - thumb and pinky touch

Flexion/Extension

Abduction (palmer/radial)

Adduction