[rickmichaels]

...and the head appearing to move backward from a shot from the front would seem to indicate there is more at work here.

I also heard a theory (from a doctor) on TV who stated that Kennedy's muscles throughout his body were stimulated for a fraction of a second by the nerve impulses being fired when his brain was destroyed, and that accounted for his movements. I think that's bull, though.

And, if the head shot was from the back, why did his head not move at least somewhat to the front before moving back and left?

A 1988 NOVA show on PBS compared frames 313 and 314 back and forth rapidly. There is an almost imperceptible movement of Kennedy's head slightly forward (i.e., about an inch) before it snaps backward. I'm not sure where you can get a copy of the Zapruder film (maybe it can be downloaded from some site), but if you get your hands on it and are able to compare 313 and 314 back and forth quickly, you might be able to see his head moving very slightly forward -- but I admit it's quite hard to see.

Nothwithstanding the conspiracy theories that say the Zapruder film was doctored, that's one of the reasons I'm convinced the third (fatal) shot hit Kennedy from the rear.

[GaryL]

It's not hard to see at all! Here's the link again:

http://graffiti.virgin.net/paul.seaton1/jfk/diagrams/kennedy_graphics5.htm

[jwalsh07]

Scroll down to the graphic with the reference lines on the three frames of film. The forward head movement from the initial hit and the rear movement from the jet effect, chin rebounding off chest and/or neurological reflex are quite well illustrated with reference lines drawn agaisnt the car for forward motion of the vehicle as a baseline.

McAdams on President Kennedys assasination