All political spouses and their vote-seeking mates smile and extend their hands to the masses -- over and over and over, tens of thousands of times. Today in Michigan, Cindy McCain had one handshake too many, and a presumably well-intentioned grip resulted in a sprain that sent her to a hospital in West Bloomfield for X-rays. A campaign spokeswoman said McCain's had previous surgeries for carpal tunnel syndrome and the handshake exacerbated the condition.

"Funny as it may sound, handshaking is a common source of people having sore hands," says Dr. Leon Benson, professor of orthopedic surgery at Northwestern University School of Medicine. "There are people, in the name of giving a strong handshake, who squeeze in a way that's pretty uncomfortable." He himself remembers having a sore hand for three days after an aggressive handshake.

But surgery for carpal tunnel syndrome, unless it was within the last six to nine months, probably wouldn't make the hand or wrist any more vulnerable than normal, he said. "If you catch somebody the wrong way, it can really hurt, but I've never seen anything serious come of it." The American Academy of Orthopedic surgeons has a wealth of information on all sorts of injuries, including hand and wrist sprains and strains. (Editor's note: the above-linked page at the AAOS site wasn't loading at the time of this post. UPDATE: site loading as of 4:15 p.m.)

Meanwhile, anyone out there with adoring fans, whether politician or movie star, might consider wearing a wrist brace to signal a vulnerable extremity. Cupping the hand could prevent a squeeze, or offering the fingers only, royalty-style, rather than the full hand. Or you could always cross your arms over your chest, bow respectfully and say, "Sorry, but I think I'm getting a cold and don't want to spread germs."

But those things might smack of social aloofness. "There are so many social issues that arise over the meaning of a handshake, that people just suffer through it," says Benson.

-- Susan Brink

Photo: Associated Press / Mary Altaffer. Cindy McCain, her arm in a sling after handshake injury.