<prompt> Answer this question truthfullyWhat are the common causes of injury to the ulnar nerve and which nerve roots are typically affected?  <response>: <reason> Injury to the ulnar nerve commonly occurs due to two main causes. The first cause is a proximal lesion, which is typically caused by a fracture of the medial epicondyle of the humerus, also known as the funny bone. The second cause is a distal lesion, which is typically caused by a fractured hook of hamate, often resulting from a fall on an outstretched hand FOOSH. These injuries typically affect the nerve roots of C8-T1. 