College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which nerves innervate the forearm flexor muscles and thenar eminence muscles?

1. Musculocutaneous and axillary nerves

2. Median nerve

3. Radial nerve

4. Ulnar nerve

The correct answer is: Median nerve

The median nerve plays a crucial role in innervating both the forearm flexor muscles and the muscles of the thenar eminence. This nerve primarily supplies most of the flexor muscles in the forearm except for the flexor carpi ulnaris and the ulnar half of the flexor digitorum profundus, which are innervated by the ulnar nerve. Additionally, the median nerve is responsible for innervating the thenar muscles, which are essential for the thumb's opposition, abduction, and flexion. Understanding the specific roles of other nerves is important for context. The musculocutaneous nerve mainly innervates the flexor muscles of the arm, such as the biceps brachii, and does not play a major role in innervating forearm flexors. The radial nerve is primarily responsible for innervating the extensor muscles in the forearm, which are involved in extending the wrist and fingers, rather than flexion. Lastly, the ulnar nerve does innervate some flexor carpi muscles and most of the intrinsic muscles of the hand, but it is not the main nerve for the forearm flexor muscles or the thenar eminence. In