Which of the following is the most common recording site for the median motor nerve?

The most common recording site for the median motor nerve is indeed the abductor pollicis brevis (APB). This muscle is primarily innervated by the median nerve, making it an ideal site for evaluating the function of this nerve. When performing nerve conduction studies, the APB is often selected because its location allows for easy access and provides clear, reproducible readings of motor nerve function.

Using the APB as a recording site helps capture the electrical activity that reflects the integrity of the median nerve pathway. In addition, the APB is directly involved in thumb opposition and abduction, which are valuable functions to assess when evaluating the median nerve, particularly in clinical conditions like carpal tunnel syndrome.

In contrast, while the other muscles listed do have connections to either the median nerve or its branches, they are less commonly used for direct median motor recording due to either anatomical accessibility or clinical relevance. For instance, the abductor digiti minimi, being innervated by the ulnar nerve, and the first dorsal interosseous, which does not primarily receive median nerve innervation, are not ideal for this purpose. The flexor pollicis longus does respond to median nerve stimulation, but its deep location makes it