Think of a mountain blocking the path of a train. Rather than spend additional time plotting a course to weave around the mountain, a tunnel is built for the train to move through it. That tunnel is the carpal tunnel; it is the transition area where the wrist becomes the hand. It consists of a series of small bones in a U-shape in the wrist with a ligamentous band creating the “roof” of the mountain tunnel.
What train runs through the carpal tunnel? That would be the many ligaments, nerves, tendons, and vascular structures that supply mobility and strength to the hand. These structures run the length of the carpal tunnel and allow the wrist to flex, extend, and deviate from side to side without pain. These structures also allow the fingers to flex and extend, bend, grip objects, and supply sensations and tactile information to the brain.
However, like other parts of the body, compromise and injury can occur in the tunnel area of the wrist. Inside the carpal tunnel is a specific nerve known as the median nerve, which supplies sensation to the palm side of the hand and the first 3 ½ fingers.
Compression of the median nerve creates carpal tunnel syndrome symptoms. Carpal tunnel syndrome is the most common entrapment neuropathy of the upper extremity, hands, and wrists, affecting people who use their hands for a living. Carpal tunnel syndrome affects approximately 3% of the population!
Symptoms of carpal tunnel syndrome can come on suddenly or gradually. Different injuries affect the integrity of the carpal tunnel in different ways; as such, carpal tunnel syndrome is associated with both trauma and repetitive activity.
Acute injuries can damage or tear ligaments and tendons, fracture bones, create inflammation, cause swelling, and compress or pinch the nerve directly. Repetitive injuries, such as working an assembly line, grasping a steering wheel to drive, or typing on a keyboard, can cause injury to the carpal tunnel by creating tendinopathy or inflammation of the tendons that run the span of the carpal tunnel. These irritated, inflamed tendons cause swelling and other mechanical problems in the wrist, including carpal tunnel syndrome.
Space-occupying tumors, using construction equipment and vibrational tools, and pregnancy can also contribute to the development of carpal tunnel syndrome.
Because the bony tunnel is narrow with little room for expansion or flexibility, injury and inflammation create a painful condition that can be slow to heal. Here is a link to read more about carpal tunnel: