Slate demands to know why female superheroes take men down with their legs, instead of punching and kicking like male superheroes. "Is this even practical?"
There are two answers to that question, speaking as someone who has trained in and taught several martial arts. The harsh answer is that the impractical thing is the idea that a 120 pound woman is capable of beating the three or four men arrayed against her in hand-to-hand combat under any circumstances. She's going to need a weapon for the scene to be "practical" in any strict sense.
However, we're doing fantasy, aren't we? So if we're fantasizing, why not fantasize that she can do it? She's got 'spider-senses' or whatever.
The less harsh answer is that grappling arts -- which frequently use the lower body -- are much more female-friendly than "hard" striking arts. There are a lot of mechanical reasons for this. One is that female limbs are shorter, and the limb functions as a kind of lever in striking ('the longer the lever, the greater the force'). Another is that female limbs are lighter-weight on average, and with less muscle-to-bone, and force is a function of mass times acceleration. They both have less mass, and less muscle to accelerate it. Females also tend to have smaller bones in the striking surfaces, making them more prone to shattering or cracking on impact.
The leg grapples thus use the strongest part of their body to its greatest effect. Although the silly acrobatics that appear in these movies are not terribly practical -- nor, again, are they meant to be -- showing women fighting with a focus on leg-grappling is the most plausible non-weapon form.
But, I suppose, if you're going to fantasize, why not fantasize they can punch like Rocky? Why would you want the more-plausible still-implausible fantasy?
This policing of the fantastic is becoming tiresome.