Just a little point, but landing heel first when running is very bad for your legs due to forceful impact. Also, instead of propelling yourself forward, you're actually creating a breaking force. In animation, it reads pretty much like that.. Most people land mid foot or fore foot. Also to run efficiently you should also try to land as close to your centre of gravity, too far forward and you're also create a breaking force.
Thought you might find that interesting ,and give you something to think about when making running animations.
clearly. though this was rather rushed, wich kinda shows why nothing onthe torso was touched.
IT looks very stiff, usually when animating it is best to redraw as much of the entire image in every frame as possible
While this is rather true, it should be noted that its rather the "best way" to run(and you'll find profesional runners doing so, if you look closely on a replay). most people will naturally use the weight of their torso(by pushing it foward) to push themselves foward to gain speed, letting the gravity do the job.
you can see the difference on this clip.