a special program of the National Emergency Medicine Association (NEMA) 

Week: 524.3 Guest: Neal Zimmerman, M.D. Topic: Carpal Tunnel Prevention - Part Two Host: Steve Girard Producer: Ed Graham

NEMA: We've talked recently with Dr. Neal Zimmerman, a hand specialist and surgeon, about carpal tunnel syndrome, the most prevalent of repetitive stress injuries ... and today we'd like to talk about how to avoid having to go through the pain and treatment that accompanies the condition. Dr. Zimmerman, recap for us why carpal tunnel syndrome occurs....

Zimmerman: "The essential problem in carpal tunnel is that the nerve at the base of the hand is in a very tight canal that is bone on the bottom and a very tight, fibrous tissue on top. That area, the carpal canal, is solid, it can't expand, its very locked. That tunnel is absolutely packed with stuff, there's nine tendons that move your fingers and your thumb that's surrounded by a tissue called tynosinovium. That tynosinovium swells when you use it a lot, such as on a keyboard or forceful gripping. Along with that, there's one soft, mushy nerve in there, and if you get the swelling of the tynosinovium, the nerve can get squeezed, to the point where its blood supply actually gets cut off, and when the blood supply of the nerve gets cut off, that causes the carpal tunnel.

NEMA: Why has the incidence of carpal tunnel increased so dramatically?

Zimmerman: "One of the real culprits that we have now , and part of the reason why its become so prominent, is the word processor. In the days of manual typewriters, or even electric typewriters, people were forced to take breaks, either to return the carriage, or to take the paper out, or crank it was an enforced break and during that enforced break, the tissues that surrounded the nerve got a change of environment. With the word processor, people can sit there and type for hours on end and not vary their position."

NEMA: So, how does one avoid putting the pressure on the carpal canal....

Zimmerman: "The pressure within the carpal canal, which is what we want to keep down, varies with the position of your wrist. The pressure is least with your wrist straight out in relationship with your forearm. It gets much higher if you either bend your wrist down or bring your wrist way back. So, people working on a keyboard want to try their best, either with supports under their hands...or changing the height of either their chair or keyboard want to keep their wrist as straight as they can in relationship to their forearm. Also, the repetitiveness, meaning continuous typing, on and on, also causes swelling and people have to give themselves an enforced break to let that swelling decrease. Stand up, walk around, shake their hands out, do something different than just sitting in that same position for hour after hour."

NEMA: So, a wrist rest for your keyboard is a help.....

Zimmerman: "It can help quite a bit. The goal of the wrist rest is to put your wrist in close to a neutral position, which means straight out with relationship with your forearm....if the wrist rest is in such a position that it actually brings your wrist too far back, it can be detrimental. So, the thing is not that you necessarily need the rest, but you need to look at the position of the wrist. The other thing is, that people with really long nails have to bring their wrists way back to get the fingertips on the short nails will help, too."

NEMA: For Dr. Zimmerman, the bottom line is making people aware that they can avoid a repetitive stress injury like carpal tunnel syndrome...and if they are having problems with numbness in their fingers or thumb or swelling and pain in the wrist, see your doctor early, so you can begin treatment and change the activity that may be causing the condition before permanent damage is done. I'm Steve Girard.