In the above image, the tendons of forearm muscles that are responsible for bending fingers, pass down the carpal tunnel. These muscles start at the elbow and when you use your fingers in a flexed position, they tend to get tight. Once tightened, the muscles pull their tendons away from the attachment (elbow). Then, the tendons get closer to the tunnel and can even touch it.

In addition, if the thumb and pinky muscles holding the tunnel on both sides get tight, due to the same reason mentioned above, they will pull the tunnel on both sides and the tunnel itself can become tight and flat.

This can lead to two situations. Firstly, friction between the tendons and tunnel causes the tendon itself to swell or become inflamed. This can then affect the median nerves in between. Secondly, the median nerve may get stuck between the tendons and tunnel, which can irritate the nerve itself. In particular, if you use a mouse with the carpal tunnel area touching the desk as shown in the image below, more friction/compression can occur.

Occasionally, although it is rare, the main nerve roots where the median nerve starts gets pressed around the cervical disc/spine, weakening the median nerve and leading to the weakening/tightening of the surrounding muscles. Therefore, if you have neck pain or neck disc symptoms, please include 'Routine 5' in your exercise routine.

Rounded shoulders can also affect carpal tunnel syndrome. When the shoulder rolls forward/inwards, the entire arm gets rolled in and then the wrist flexors that go under the tunnel are placed in a shortened position. This also increases the probability of the above mentioned mechanism occurring.