What is it?
Compression on the median nerve as it passes through the carpal tunnel will result in numbness and tingling in the hand. This can be from injury or chronic over use that results in direct irritation to the nerve. Refer to the image to the right to see a breakdown of the structures that make up the carpal tunnel.
The carpal tunnel is composed of 10 structures. Nine tendons that attach to our muscles that flex the fingers and wrist along with gripping objects. In addition to the tendons, there is the median nerve which is the involved structure. The carpal tunnel boarder is created by carpal bones and the flexor retinaculum. All the tendons are covered by a synovial sheath to help with gliding back and fourth throughout the space.
When the nerve is damaged one will experience numbness and tingling into the palm of the hand. The nerve itself can be damaged by a crush injury or stretching the structure beyond what it is able to move. When increased inflammation in the area occurs due to ligament, muscle, or bone damage that additional swelling can also cause pressure on the nerve. This ultimately leads to symptoms in the hand.
How This Happens
Trauma to this area can be the due to many reasons. When someone types with poor ergonomics the nerve can be placed on stretch which will eventually lead to irritation. When someone strains or tears one of the wrist flexor muscles the tendons can become irritated. This will result in increased swelling in the carpal space. Another factor could be a dislocation or instability of the carpal bones that make up the boarder.
Any reason that could cause a decrease in carpal space will potentially result in compression on the median nerve. This is an important piece of information when dealing with this issue. It is necessary to know the root cause of the issue before getting an invasive treatments or surgeries.
Many people have heard of carpal tunnel surgery or is aware of someone who has dealt with this issue. The purpose of the surgery is to cut the flexor retinaculum (one boarder) to increase space in the area to reduce pressure on the median nerve. However, if the underlying cause is not addressed then it is very likely the symptoms will eventually return.
Picture a city that has a sudden increase in population for an unknown cause. The solution is to cut down all the trees around the city limits to help create space. More people arrive and eventually fill in that added space and the population issue returns.
Now think of your carpal tunnel in the same way. Say there is wrist instability within the joints which causes increased irritation and inflammation. The surgery cuts the flexor retinaculum but the instability in the wrist bones are never addressed. It is very possible the symptoms never progress or return. But ask the question why do a surgery, or cut something in your body that isn’t the root cause. Do you want a temporary or a long term solution?