A patient is unable to oppose the tip of the thumb to the tip of the index finger. Which muscle and nerve are most likely affected?

Here are the solutions to the questions:

Question 53:
The correct answer is D.

• The patient is "not able to oppose the tip of the thumb to the tip of the index finger, as in making the OK sign." This describes a loss of thumb opposition.
• The opponens pollicis muscle is primarily responsible for thumb opposition and is innervated by the recurrent median nerve (also known as the thenar motor branch of the median nerve).
• While the "OK sign" also involves the anterior interosseous nerve (AIN) for flexion of the thumb's interphalangeal joint (via flexor pollicis longus) and the index finger's distal inter