Ulnar nerve entrapment is classified by location of entrapment. The ulnar nerve passes through several small spaces as it courses through the medial side of the upper extremity, and at these points the nerve is vulnerable to compression or entrapment—a so-called "pinched nerve".
Ulnar nerve entrapment is categorized by the specific area where compression occurs. The ulnar nerve has multiple narrow points of passage in the upper limb, and it's at these locations that the nerve can become compressed or trapped—a condition known as a "pinched nerve".