Anatomy of the region:
Q/A (from wisegeek.com)
WHAT CAUSES TENDINITIS ?
“Tendinitis is a condition that is created by some type of irritation or inflammation of the tendon. Since tendons are the connecting tissue that adheres muscles to the skeletal structure of the body, this inflammation can be extremely painful. Tendinitis can come about as the result of certain types of physical activity and exertion, as well as be the product of other health ailments that are creating adverse effects on other parts of the body as well as the tendons.
WHAT IS THE CARPAL TUNNEL ?
“The carpal tunnel is a narrow area that is located under the ligament, a band of tough tissue, of the wrist. It consists of both tendons, which are connective tissue between the bones and muscles, and nerves. One of the primary nerves in this area is known as the median nerve, which is located down the forearm into the wrist. When the median nerve becomes irritated or otherwise affected, it can cause pain in the tunnel and lead to the condition known as carpal tunnel syndrome.
When the area near the carpal tunnel, especially its tendons, becomes swollen or inflamed, it can result in the tunnel becoming more narrow and pressing down on the median nerve. This narrowing of the tunnel is often due to repetitive movements of the wrist that may end up irritating the median nerve. It can also be caused by having a naturally smaller carpal tunnel, which can make even slight constriction of the tunnel press down on the median nerve and cause symptoms.”