Here's a similar analysis using the CNN version of the Oswald shooting footage. It's very different, and they deliberately try to show you less. But, there is still something worth seeing.
This first frame is post-shooting. Ruby has already shot Oswald. We've already heard the shot. Oswald's immediately starts going down, crumbling. And he naturally goes forward because that's what the body does: it folds forward.
But then, Oswald goes backward and slightly upward. Notice above that because he's crumbling, Oswald's head is lower than Ruby's hat.
By the time of this frame, Ruby has moved in front of Oswald, which is not where he was when he shot him. and Oswald is crying out, and he has moved backward and upward. Notice that Oswald's head is higher than Ruby's hat now.
So, he started crumbling in response to the shot, but then jumped back and got higher. It corresponds to when he was on his toes, which we could see in the other version.
Now, what happens next is really weird. Oswald goes straight down. He goes down like an elevator. And it happens so fast that even when I slow the speed to one-fourth normal (.25) which you can do on Google Chrome, I can barely see it.
It's a blurry mess on the right, but that's Oswald collapsing like the Twin Towers on 9/11 except much faster. Straight down.
So, this divides his reaction to being shot into three parts: 1) he starts to crumble, where he flexes and starts going down, then 2) he rears backwards and extends and in the process goes upward; then 3) he goes straight down like an elevator, and it's so fast, it makes me wonder if they cut out frames. That's the story that this footage is telling me. Here is the link: