Reported July 2007

BACKGROUND: Researchers at the Mayo Clinic have found evidence that carpal tunnel syndrome begins with a shearing injury of the tissue that lines the tendons within the carpal tunnel. As the injury heals, the resulting scar tissue impedes the sliding motion of the tendon, compresses the median nerve, cuts off the nerve’s blood supply, and eventually leads to the pressure buildup characteristic of carpal tunnel. This could lead to earlier diagnosis and possibly better treatments for preventing or reversing carpal tunnel.

ABOUT CARPAL TUNNEL SYNDROME: Carpal tunnel syndrome is a pressure buildup in the carpal tunnel that affects the circulation nourishing the nerves. This can lead to pain, numbness and tingling. Although carpal tunnel is a well-known condition, the specific cause is unknown. While rest, exercise and some medications can treat carpal tunnel, severe carpal tunnel syndrome usually requires surgery to release the pressure buildup. The Mayo study compared electron microscope images of tissue affected by carpal tunnel syndrome with images of normal tissue. Why does the pressure increase? Healthy tissue looks like puffed pastry, many multiple layers with air in between, and these different layers slide on top of each other. But in carpal tunnel, the tissue lining around the tendon becomes thickened, or gummed up, preventing the natural sliding motion of the tissue layers. Understanding how carpal tunnel develops before the nerve becomes damaged gives doctors the chance to spot the disease progression at an earlier stage and stop it before permanent damage occurs – possibly by using biomarkers to test people at risk.

WHAT IS ERGONOMICS: This is a branch of science that strives to design the job to fit the worker, rather than the other way around. In the modern office, it most commonly relates to the physical stresses placed on joints, muscles, nerves, tendons, bones, even hearing and eyesight, along with other environmental factors that can adversely affect comfort and health. Ergonomics deals with the interaction of technology and work environments with the human body, and involves anatomy, physiology and psychology in the design of chairs, desks, computer accessories, the design of car controls and instruments -- in short, any kind of product that could help relieve potential repetitive strain from a given job or task.

TO AVOID REPETITIVE STRESS INJURIES:

• Place your keyboard at a level slightly lower than normal desk height.

• Use a footrest to avoid dangling your legs.
• While typing, wrists should not be bent up, down or to the side. The knuckle, wrist and top of the forearm should form a straight line.
• Elbows should form a 90-degree angle while hanging at the sides from the shoulders, and the shoulders should remain relaxed in a lowered position while typing.
• Do not use wrist supports or rests while you are typing, only when pausing to rest.
• Take frequent breaks from repetitive tasks to give your body a rest.

If you would like more information, please contact:

Mayo Clinic
Department of Orthopedic Surgery
locations in Jacksonville, FL; Rochester, MN and Phoenix AZ
(507) 538-3270

DID YOU KNOW?

Carpal tunnel syndrome affects about 5% of the US adult population.

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