ECU stands for the extensor carpi ulnaris tendon, one of the major wrist tendons, located on the ulnar side of the wrist, which is the same side as the small finger. The ECU tendon starts on the back of the forearm and crosses the wrist joint directly on the side.
De Quervain’s tenosynovitis is a painful condition that occurs when two of the thumb’s tendons—located on the thumb side of your wrist—become overused or irritated.
The Smith’s fracture is a specific type of injury to the forearm bone (the radius) near the wrist joint. In this injury, there is displacement of the bone such that the wrist joint rests in front of its normal anatomic position.
Most people are probably familiar with carpal tunnel syndrome where impingement of the wrist (carpal tunnel) causes pain, tingling, and numbness primarily in the thumb, two adjacent fingers, and part of the palm. A similar condition can take place on the other side of the wrist where impingement of the ulnar nerve causes a radiating pain or numbness in the pinky finger, ring finger, and edge of the hand.
Thumb pain can occur from damage to various structures in your hand, including ligaments, tendons, bones, and nerves. Common conditions that cause thumb pain include arthritis, tendonitis, trigger thumb, carpal tunnel syndrome, and ligament injuries. Thumb pain can come on suddenly or develop over time from overuse of the thumb joints and muscles.
