Tinel's sign

Tinel's sign is a way to detect irritated nerves. It is performed by lightly tapping (percussing) over the nerve to elicit a sensation of tingling or "pins and needles" in the distribution of the nerve.

For example, in carpal tunnel syndrome where median nerve is compressed at the wrist, Tinel's sign is often "positive" causing tingling in the thumb, index, and middle finger. Tinel's sign is sometimes referred to as "distal tingling on percussion" or DTP.