Carpal Tunnel Syndrome
Carpal Tunnel Syndrome (CTS) is irritation of the median nerve as it passes through the carpal tunnel at your wrist. The median nerve provides signals to the muscles in the forearm and hand causing them to move, as well as providing the hand with sensation to the thumb, index finger, middle finger and half of the ring finger. As the median nerve passes into the hand it passes through the carpal tunnel. The carpal tunnel houses a number of tendons, connective tissue and the median nerve.
If the carpal tunnel narrows or becomes irritated, it can cause irritation to the structures that pass through it, especially the median nerve. If the median nerve becomes irritated or compressed then the patient will experience neural symptoms into the area of the hand that it provides sensation and movement. This may include pins and needles, numbness, deep aching pain or loss in movement. The median nerve needs to be able to glide within its sheath in the carpal tunnel as the wrist moves, however with long term compression to the nerve, scarring can develop. When the nerve becomes scarred it will adhere to other tissue close to it, inhibiting its ability to glide and move within the carpal tunnel. This will cause irritation and the symptoms above may become apparent.
What Causes Carpal Tunnel Syndrome?
There are a number of different contributing factors to CTS and it is believed that it is a combination of factors which predispose the nerve to become irritated. These contributing factors include:
- Osteoarthritis and Rheumatoid Arthritis
- Under-active thyroid
- People who take oral contraception
- People who have a manual job – forceful and repetitive use of the hands and wrists.
- Women who are pregnant
- People who have a poor posture – This leads to abnormal biomechanics and with repetitive movements the median nerve can be predisposed to excessive, repetitive compression in the carpal tunnel.