DURHAM — The first time she arm-wrestled, Jayme Johnson competed under the assumed identity of Ze Monsta, a homicidal she-beast who had escaped from a mental institution in Ukraine, kept at bay only by heavy chains and a tranquilizer gun.

For her second bout, she appeared as Ze Lunch Lady, a deranged cafeteria worker dressed in a hair net and frumpy pink dress, glowering at her opponents through horn-rimmed glasses.

This week, she fights her third match in the costume of a manure mover, flanked by a litter of pigs, pushing a wheelbarrow full of dung. Her character's name: Turdley McStinkfinger.

"The thing I like about arm-wrestling is it really supports the idea that strong women are awesome," said Johnson, 27, who in real life studies genetics at Duke University. "We're often inundated with the idea that small, skinny, weak women are beautiful."

Johnson morphed from bookworm to brawler when she saw a recruiting poster for LUEWWD, pronounced "lewd," which stands for the League of Upper Extremity Women Wrestlers in Durham. In no time, she was draping herself in chains and growling at barroom crowds, fighting opponents with names like The Red Menace, Hardcore Heidi and Monster Cookie.

But here's the thing about women's arm-wrestling: It's not just girl fights. It's girl fights for charity. In two bouts, LUEWWD raked in more than $5,000 for the Durham Crisis Response Center and InStepp, both small nonprofits serving women.

Borrowing a page from roller derby, women's arm wrestling combines trash-talk theatrics with mild violence to coax dollars out of barroom wallets, and this oddball brand of fundraising has sprouted in a dozen-odd cities nationwide. New Orleans. Chicago. Charlottesville, Va.

A year ago, The Washington Post chronicled the sweat-soaked antics of the Virginia league, which not only drew combatants with names like Bridezilla and Stiletto Southpaw, but had bouts featuring its own house band: Straight Punch to the Crotch. "It sounded ridiculous," LUEWWD founder Diana Barden said. "Ridiculously interesting. It definitely sounded more interesting than a walk-a-thon."

To win a bout, you've got to out-grapple your opponent left- and right-handed. But LUEWWD also crowns a Durham Diva for best costume, which Johnson earned last fall for her hair-netted lunch lady, and Madame Moneymaker, which last went to Hardcore Heidi for scoring $400.

At 5-foot-5 and 130 pounds, Johnson isn't exactly a behemoth. She doesn't bring tree-trunk arms or shoulders wide enough to rest a pitcher of beer.

But she's concentrating on brawn. For the first time, she's lifting weights, hoping her wrestling hand lands palm-down on the loser's flabby fist.

Whoever flexes hardest, Johnson stands for the untapped Hulk power inside all of us, writhing like muscle that aches to burst through the prison of skin and bone.

josh.shaffer@newsobserver.com or 919-829-4818