Chapter 10

Question 1

What defines intrinsic hand muscles?

Answer 1

Their origins and insertions are both distal to the carpal bones.

Question 2

How many joints does the thumb have and what are they?

Answer 2

Three — carpometacarpal (CMC), metacarpophalangeal (MCP), and interphalangeal (IP).

Question 3

How are the fingers numbered?

Answer 3

Digits 2–5, from the index finger (2) to the small finger (5).

Question 4

What is thumb opposition?

Answer 4

The tip of the thumb touching the tip of a finger — a combo of thumb flexion and abduction.

Question 5

What is thumb reposition?

Answer 5

The return of the thumb from opposition.

Question 6

What motions make up the intrinsic thenar group of the thumb?

Answer 6

CMC palmar abduction, adduction, opposition, and CMC/MCP flexion.

Question 7

What motions are performed by the hypothenar group of the little finger?

Answer 7

Opposition, abduction, and flexion at the CMC joint.

Question 8

What do the palmar and dorsal interossei muscles do?

Answer 8

Palmar interossei adduct MCP joints; dorsal interossei abduct MCP joints.

Question 9

What motion is created by dorsal interossei and lumbricals together?

Answer 9

MCP flexion with PIP and DIP extension — the “intrinsic plus” position.

Question 10

Which digits abduct away from digit 3?

Answer 10

Digits 2, 4, and 5.

Question 11

What unique motion does digit 3 (middle finger) perform?

Answer 11

It abducts in both directions but does not adduct.

Question 12

What motions do intrinsic thumb muscles control versus extrinsic?

Answer 12

Intrinsic: CMC joint; Extrinsic: MCP and IP joints.

Question 13

What motions do intrinsic finger muscles control versus extrinsic?

Answer 13

Intrinsic: MCP joint; Extrinsic: PIP and DIP joints.

Question 14

What causes rheumatoid arthritis (RA)?

Answer 14

Autoimmune disorder of unknown cause that attacks joint tissues.

Question 15

What are key symptoms of rheumatoid arthritis?

Answer 15

Fatigue, pain, inflammation, edema, warmth, redness, joint deformity, and disability.

Question 16

What are occupational therapy goals for RA?

Answer 16

Prevent deformity, protect joints, conserve energy, reduce pain, and improve function through splinting and gentle ROM.

Question 17

What causes osteoarthritis (OA)?

Answer 17

Wear and tear on joints leading to stiffness and pain.

Question 18

What are OT treatments for OA?

Answer 18

Strengthening, use of heat, and approaches similar to RA.

Question 19

What are repetitive stress injuries (RSI)?

Answer 19

Cumulative trauma disorders from overuse, such as carpal tunnel, trigger finger, or de Quervain’s disease.

Question 20

What are common OT treatments for RSI?

Answer 20

Education, splinting, modalities, tendon/nerve glides, and ergonomic adaptation.

Question 21

What is Dupuytren’s disease?

Answer 21

A contracture of the palmar aponeurosis causing loss of finger extension.

Question 22

Who is most affected by Dupuytren’s disease?

Answer 22

Men over 50; often hereditary.

Question 23

What are OT roles in Dupuytren’s disease treatment?

Answer 23

ROM, splinting, wound and scar management, edema control, and strengthening after surgery or injection.

Question 24

What is Skier’s thumb?

Answer 24

An acute injury to the ulnar collateral ligament (UCL) of the thumb.

Question 25

What typically causes Skier’s thumb?

Answer 25

A FOOSH injury causing thumb hyperextension.

Question 26

What are symptoms of Skier’s thumb?

Answer 26

Pain, swelling, tenderness on ulnar side of MCP joint, and instability.

Question 27

How are Skier’s thumb injuries graded and treated?

Answer 27

• Grade I – rest, immobilization • Grade II – same as I, longer healing • Grade III – surgery, casting, therapy

Question 28

What are the four intrinsic muscle groups of the hand?

Answer 28

Thenar, hypothenar, interossei, and lumbricals.

Question 29

What are the four thenar muscles and their actions?

Answer 29

• Abductor pollicis brevis – abducts CMC • Flexor pollicis brevis – flexes MCP • Opponens pollicis – opposition • Adductor pollicis – adducts CMC

Question 30

What are the three hypothenar muscles and their actions?

Answer 30

• Opponens digiti minimi – opposes MCP • Abductor digiti minimi – abducts small finger • Flexor digiti minimi – flexes small finger

Question 31

What do the palmar and dorsal interossei muscles do?

Answer 31

• Palmar – adduct MCPs of index, ring, and small fingers • Dorsal – abduct MCPs of digits 2–5

Question 32

What do the lumbrical muscles do?

Answer 32

Flex MCP joints and extend PIP/DIP joints of digits 2–5 (intrinsic plus position).

Question 33

What nerve innervates the thenar muscles?

Answer 33

Median nerve (C6–C7)

Question 34

What nerve innervates the adductor pollicis?

Answer 34

Ulnar nerve (C8–T1)

Question 35

What nerve innervates the hypothenar and interossei muscles?

Answer 35

Ulnar nerve (C8–T1)

Question 36

What nerves innervate the lumbricals?

Answer 36

• 1st & 2nd – median nerve (C6–C7) • 3rd & 4th – ulnar nerve (C8)

Question 37

What ligaments stabilize the carpal bones?

Answer 37

Palmar and dorsal midcarpal ligaments.

Question 38

What do interosseous ligaments do in the hand?

Answer 38

Connect and stabilize individual carpal bones.

Question 39

What does the transverse carpal ligament do?

Answer 39

Stabilizes the carpal arch and forms the carpal tunnel.