CHT CHT Hand Anatomy & Biomechanics

Question 1

Which pulley in the flexor tendon sheath is considered the most biomechanically critical for efficient finger flexion?

Accepted Answer

A2 pulley

Answer

The A2 pulley, located over the proximal phalanx, is the most critical annular pulley because its integrity prevents bowstringing of the flexor tendon during finger flexion.

Question 2

The intrinsic muscles of the hand are primarily responsible for which combined finger motion?

Accepted Answer

IP extension with MCP flexion

Answer

The intrinsic muscles (lumbricals and interossei) produce MCP flexion combined with IP extension, enabling the intrinsic-plus hand posture.

Question 3

Which carpal bone is most commonly fractured and is at high risk for avascular necrosis due to its retrograde blood supply?

Accepted Answer

Scaphoid

Answer

The scaphoid receives its blood supply distally and retrogradely, so proximal pole fractures disrupt perfusion and risk avascular necrosis.

Question 4

The ulnar nerve provides motor innervation to all of the following EXCEPT:

Accepted Answer

Abductor pollicis brevis

Answer

The abductor pollicis brevis is innervated by the median nerve (recurrent motor branch), not the ulnar nerve.

Question 5

The normal range of motion for metacarpophalangeal (MCP) flexion in the index finger is approximately:

Accepted Answer

85–90°

Answer

Normal MCP flexion in the index finger ranges from approximately 85° to 90°, progressively increasing toward the small finger.

(CHT) Certified Hand Therapist Practice Test

(CHT) Certified Hand Therapist Practice Test

CHT CHT Hand Anatomy & Biomechanics