Which extensor muscle can be palpated alongside the shaft of the ulna?

The extensor muscle that can be palpated alongside the shaft of the ulna is the extensor carpi ulnaris. This muscle is located on the posterior aspect of the forearm and runs along the ulnar side, making it accessible for palpation. It functions to extend and adduct the wrist. When the wrist is extended and ulnar deviated, the muscle becomes more prominent along the ulna.