Which of the following is true about the extensor carpi ulnaris?

The extensor carpi ulnaris is indeed responsible for extending the wrist. This muscle, part of the posterior compartment of the forearm, plays a key role in the motion of wrist extension, allowing the hand to move backward. Its primary function is to assist in extending the wrist joint, which is critical in various activities involving the use of the arms and hands, such as throwing or punching.

Additionally, it's important to mention that the extensor carpi ulnaris also aids in adducting the wrist when combined with the flexor carpi ulnaris, although its primary role is extension. The muscle is innervated by the radial nerve, which contrasts with the median nerve innervating other flexor muscles in the forearm. It is also located on the dorsal side of the forearm, rather than the palmar side. This anatomical positioning and function clarify why extending the wrist is a defining characteristic of this muscle.