Which nerve, when compressed at the elbow during elbow flexion, can cause tingling and numbness in the little finger and half of the ring finger?

Which nerve, when compressed at the elbow during elbow flexion, can cause tingling and numbness in the little finger and half of the ring finger?

• A. Ulnar
• B. Median
• C. Radial
• D. Musculocutaneous

Answer: (A)

Compression of the ulnar nerve at the elbow, especially when the elbow is flexed, is the classic setup for numbness and tingling in the little finger and the medial half of the ring finger. The ulnar nerve runs behind the medial epicondyle in the cubital tunnel, where elbow flexion can squeeze it, producing sensory changes exactly in its distribution. The other nerves don’t match this pattern: the median nerve would numb the thumb side of the hand (and part of the ring finger), the radial nerve would affect the back of the hand on the thumb-to-middle fingers, and the musculocutaneous nerve mainly changes sensation on the lateral forearm. So the described symptoms point to the ulnar nerve being compressed at the elbow.

Compression of the ulnar nerve at the elbow, especially when the elbow is flexed, is the classic setup for numbness and tingling in the little finger and the medial half of the ring finger. The ulnar nerve runs behind the medial epicondyle in the cubital tunnel, where elbow flexion can squeeze it, producing sensory changes exactly in its distribution. The other nerves don’t match this pattern: the median nerve would numb the thumb side of the hand (and part of the ring finger), the radial nerve would affect the back of the hand on the thumb-to-middle fingers, and the musculocutaneous nerve mainly changes sensation on the lateral forearm. So the described symptoms point to the ulnar nerve being compressed at the elbow.