Wrist posture contributes to carpal tunnel

SAN FRANCISCO, Feb. 27 (UPI) -- U.S. and Canadian researchers have identified wrist posture as a contributor to carpal tunnel pressure syndrome.

Researchers at the University of California at San Francisco and McMaster University in Ontario have conducted the first study that systematically identifies how one contributor to CTS can be examined in detail to establish limits on how much a wrist can be flexed before nerve damage sets in.

The research team studied the pressure that is placed on the nerve in the carpal tunnel in various wrist postures in 37 healthy men and women between the ages of 22 and 50. Wrist postures that are not neutral -- bent or flexed -- cause increased pressure on the nerve. The researchers concluded that when sustained pressure on the carpal tunnel reaches 30 mmHG, injury is likely to occur.

The researchers believe that a set of guidelines could be developed from their data -- guidelines that could, if applied by engineers and designers during the design of work and tools, protect workers. Such guidelines could also be used to identify tasks that may put workers at risk for developing or aggravating CTS, according to the study published in Human Factors: The Journal of the Human Factors and Ergonomics Society.