Explain carpal tunnel syndrome. What structures are involved, and what pathology exists here? Recommend prevention tips and treatments for this syndrome. Explain the modified Allen test and Tinel's sign. Carpal tunnel syndrome is a condition that causes pain, numbness, and tingling in the hand and arm caused by a pinched median nerve in the wrist. The carpal tunnel is a narrow passageway that travels through the wrist. The floor and sides of the tunnel are formed by small wrist bones called carpal bones. The median nerve is one of the main nerves for the hand. It starts in the neck as a group of nerves and forms into one nerve in the arm the roofof the tunnel is a band of connective tissue called the transverse carpal ligament. These boundaries are rigid and have little compacity to stretch or increase in size. It goes down the arm, passes through the carpal tunnel, and goes into the hand. The nerve provides feeling in the thumb, index, middle, and ring fingers. It also controls the muscles around thebase of the thumb. Carpal tunnel is most common in women and elderly. Not all tunnels are the same some people have smaller carpal tunnels with less space for the nerve.