This is one of the thing I appreciate with respect to Ghost in the Shell: Stand Alone Complex: the technicalities and physics of combat are made bare.
Let’s look at it:
The Major (purple-haired, cybernetic cop protagonist) is trapped in a head lock by the dude in red. The dude in red is bigger than her in both height and mass.
IMMEDIATELY, she starts inching her way to the nearest cargo container (they are fighting in a cargo warehouse) with all the strength she can muster and when she’s ready to make her move (within the space of a SECOND (an important technicality itself)),
runs her feet up the wall,
kicks herself and her WEIGHT backward and into the upper half of the torso of her assailant (the Dude in red),
and effectively breaks free (also, it’s important to note she lands on her upper back when she hits the ground while noting she needs to protect her neck for impact and PROMPTLY punches him unconscious after quickly getting up).
If you’re curious as to how this works, let’s look at how and where force is being applied via comparison. Essentially, you have the whole of a bowling ball flying at bolting speed at the head of a bowling pin (albeit, a rather sturdy one). Even with it being a sturdy “bowling pin”, she (the Major) is applying her backwards force to a part of his body which is going to offer little resistance (aside from his abs contracting, which is rather demanding given the instant in which she executes her move and the location at which she applies the force of her weight onto him, which is rooted exclusively to the rest of him rather than the ground).
I’ve actually seen a variation of this done in real life; same result (with an added thud of the taller person’s head against a wall).
In the end, short folks, smaller folks, remember, if you ever get put in a headlock, here is a method you can use to escape. There are others too; it’s a matter of knowing how to apply your strength or weight (or pressure).