Ok, the running acually wasn't half bad, I think the legs could have extended more, but it was pretty good considering.
When the first stick throws the knife up in the air in the beginning, there isn't nearly enough easing at the top of the throw. That knife should hang up there for a while. Now, knifes and things are harder to show than say, a ball, because the spin on them is so noticeable. But, make sure that the center of the knife, or wherever the center of it's weight is, stays on a curving path.
Here's an example I've made with a ball. It's only at 12 fps, you don't need ot have ridiculous frame rates to have a graceful motion, though I do think that your animation could use some more frames in between each motion. They seem a bit choppy. But, that might not be all in the speed, but just that you aren't keeping movements steady.
Anyway, the example.
http://www.swfme.com/view/1114582
Try and make the center of the knife decrease the distance to the top of the throw by around half every time, maybe more. Then on the way down, simply double it.
Here's the same animation at 24 fps. Not much different, but it does admittedly look smoother. I did take out a few frames at the top of the curve, it seemed too slow.
http://www.swfme.com/view/1240302
Keep at it, I like how long your animations are. I can never get past like five seconds.
And yes, the animations are in flash. I don't have pivot, but the concept is the same.
