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Women are turning sexy stilettos into a high-kick headache for their male co-stars on the big screen this summer.

The battle of the sexes has been turned on its head at the box office as Charlie’s angels and a new, curvier Terminator pummel their leading men using some serious fighting skills.

The Charlie's Angels: Full Throttle director who goes by the name "McG" said he deliberately upped the sequel’s fight scenes, packing the film with punches and kicks that literally bring guys to their knees.

“We all wanted to make this film decidedly more muscular and show that these girls can hang with the guys,” he said in statement. “We ramped it up to include wrestling, motocross, car crashes and leaps off tall buildings. The Angels hold their own in arenas normally reserved for idealized male action heroes."

But this is Hollywood, so even if she's kicking a man's butt the female character must also ooze sex appeal, said Amanda D. Lotz, Ph.D., and assistant professor of communications at Denison University who's writing a book about dramas starring women.

Bond girls illustrate how roles in action flicks have changed, she said. "Jinx (Halle Berry’s (search) character in Die Another Day) is an active agent with her own story, compared to Pussy Galore, but she’s still highly sexualized."

Kristanna Loken (search), who plays Arnold Schwarzenegger's enemy in Terminator 3: Rise of the Machines, said the roles can be tricky to cast.

“It’s hard to find women you really buy being able to pull off roles like these, and not just run around with a gun looking good,” she said

Loken, 23, who said she was inspired by Sigourney Weaver (search) in Aliens, added that her character is more than eye candy. “I did all the legwork. It’s not something I was just thrown into to look sexy."

And the increasing number of femme fight flicks has inspired fans to explore their own strengths.

After seeing the original Angels, Desiree Koh, of Chicago, enrolled in kickboxing (search) classes with a friend. “We thought, ‘that looks like fun. We have to try that out.’”

Now, two years later, Koh, 26, is still kicking. “When I walk down the street now I think, 'You’d be picking the wrong person if you tried to attack me.’”

Many women have grown up being told they are targets, so these films can be liberating, Lotz said.

”We've been told, ‘don’t go running at night’ and ‘don’t go out alone,’ so it’s nice to not be told what you can’t do — and to see women who can do.”

Jennifer Lawler, a second-degree black belt in Lawrence, Kan., said she was inspired to try martial arts after seeing Renee Russo’s (search) cop character hold her own next to Mel Gibson in Lethal Weapon III.

When she left the theatre, Lawler said, "For the first time, I thought about a women being as powerful as a man.”

Eleven years later, Lawler is a martial arts expert — but cautions that being able to fend off a male attacker isn’t as easy as Drew Barrymore (search), Lucy Liu (search) and Cameron Diaz (search) make it seem.

“I get concerned about that — that the people taking these classes think they can defend themselves,” she said. “However, women consistently underestimate how strong they are and how capable they are of taking care of themselves. “

For Loken, morphing into a killing machine took some serious prep work. She did weight and weapons training, and learned Krav Maga (search), an Israeli form of martial arts.

“You gain a real sense of dominance through strength training, which is sexy and sensual," she said.

Strength may be attractive, but having sex appeal doesn’t hurt either. Cameron Diaz’s backside has so many close-ups in Full Throttle it should receive a credit.

This blatant mix of sexuality and violence is a combination American audiences lap up, Lawler said. “If we can have a really sexy woman doing something violent, that’s exciting in this culture."

Indeed, to score a summer blockbuster, women have to do everything men do — and more.

“I did sprints in heels that were at least 2 inches tall,” Loken said of her T3 training. “I had to do everything Arnold did but backwards and in heels.”