Why is my animation shaking so much? It's not smooth. When he is in the air in one frame he falls down suddenly. His head and upper body shakes. I hope you understand what i mean, you can see my animation here: http://screencast-o-matic.com/watch/cIlo6wnV5D
It's not that bad I think? But if you want to see motion over time, use the graph editor. Here you can see how transformation happens over time. The more vertical the curve is, the more rapidly the change are. If the curve delta (change over time) differs, the movement may appear jerky.
In the screenshot below I have circles a jerky translation.