One rule of thumb in Krav Maga actually does involve the thumb.
"When you are attacked, find the cheek," says Don Melnick, who teaches the Israeli self-defense system in Cherry Hill.
If you can find your attacker's cheek, he continues, "you can find the eye."
At this point it dawns on me that Krav Maga (krahhv muh-GAHH), Hebrew for "contact combat," probably isn't a good fit for a columnist with gray hair and a torn rotator cuff. Even a columnist who practices yoga with devotion, if not finesse.
Or perhaps the real reason I voluntarily sideline myself after 10 minutes on the training floor is all the talk about how best to deliver a kick to the groin.
Let's just say I'm not dressed for that.
"Krav Maga is a practical, effective defense that can save your life if you're attacked," says Melnick, 39. "It's one defense for multiple scenarios."
A fierce mix of street-smart moves and martial arts, Krav Maga was developed for the Israel Defense Forces and imported to the United States about 30 years ago.
It's popular with members of the military and law enforcement types, but men and women of varying ages and backgrounds, as well as children older than 7, train at Melnick's Israeli Krav Maga.
The no-frills center opened in a former warehouse on Springdale Road last year.
"I turned my hobby into my career," says the former salesman, who grew up just outside Baltimore and lives in Cherry Hill with his wife, Debbie, and their two daughters. The older girl, Bryce, 8, loves her Krav-Maga-for-kids class.
Melnick's partners in the business include David Kahn, the internationally known instructor who stars in several DVD series about the system.
Krav Maga, which is taught at a number of locations around Philadelphia, is seeping into popular culture. TV's The Simpsons and Happy Endings have taken note of it, and the ladies of the already departed fall series Charlie's Angels practiced it.
Though students of Krav Maga achieve various "belts," as in karate and tae kwon do, the discipline is less ceremonial and cerebral than those martial arts. Training is more about muscle memory.
"Reaction drills" help students develop a repertoire of instinctive responses to emergencies, such as tucking one's chin when grabbed around the neck.
"We'll be doing a lot of chokes tonight," says Melnick, commanding the floor on the night of my visit.
Ten men and two women breathe heavily after warming up with stretches and sprints on the rubber-tiled surface. Everyone is in dark T-shirts and sweats, and the atmosphere is as studious as possible among people who are taking turns grabbing each other by the throat.
"I've always wanted to learn how to fight," says Christianne Lapierre, 41, a self-described "perpetual student" from Palmyra. She started training three months ago and takes one class a week.
"You can either fight like a girl," Lapierre says, "or fight like this."
Douglas Cours, 37, has been interested in martial arts for several years.
Krav Maga "doesn't get boring," says the Mount Laurel resident, who particularly enjoys the reaction drills.
Watching the class, I'm impressed by the directness of Krav Maga. It doesn't pretend to be about enlightenment. It's about avoiding injury, or worse.
"We're not training you to win fights," Melnick says. "We're teaching you not to get in fights. . . . You learn to react quickly, so you can defuse a situation."
This explains the aforementioned emphasis on groin kicks and other rules of thumb about disabling and escaping attackers.
"People come in here because they want to feel confident," he says. "Some people come for the fitness aspect. But most people love Krav Maga for the hard-core intensity."
Me? I'm more of a lotus position kind of guy. But namaste, anyway.
To view a video of a Krav Maga class in Cherry Hill go to www.philly.com/kravmaga