Originally Posted by
Tom Campitelli
I suspect you are flexing your spine a little, but since this was filmed from the side, I cannot really say.
Please read the sticky.
I think I am going to go out of mind if I have to type that sentence much more.
You are on your toes, your knees are traveling too far forward, your spine may be flexing, you are underweight, and you need some lifting shoes. Let's get a video from the rear oblique shot from about hip height so that I can confirm this and potentially provide some cues to help.