Add "pricer palsy" to the list of occupational hazards.

It happened, a Wisconsin neurosurgeon reports, to a right-handed grocery store checker. Numbness in the left hand was the give-away symptom, accompanied by occasional aching. The problem was worst when she was moving products over the store's universal product code reader.

"She demonstrated the activity needed for this operation, which involved very fast pronation with flexion of the left wrist," writes Dr. Jacqueline J. Wertsch of Milwaukee in a letter to The New England Journal of Medicine. "Pronation with flexion of the left wrist" is a doctor's way of saying turning over and bending the wrist at the same time.

This irritated a nerve, she writes, causing the symptoms. "It's a pinched nerve, basically," she said in an interview, and it was repaired by a small operation to relieve tension on the nerve.

In this case, the checker prevented recurrence of what Wertsch calls "pricer palsy" by turning her checking motion into a two-step process -- first turning over each item so that the price code faces down, then moving it over the scanner.

In the long run, Wertsch says, other steps might include training all checkers in this method of scanning the products, or changing the angle of the electronic scanner.