Originally Posted by
marcf
Super hard to tell from this angle, but I think your back might be going into flexion. You're not very tight, and each rep looks different from the last. You're raising/leading with your chest out of the hole with every rep, and your knees don't look like they're tracking out wide enough. Also, did you breathe between your first and second rep?
I think you should get tighter and get your knees out more and think of leading with your hips instead of your chest. Take a deep breath before every rep and brace your torso/abs/back hard. Keep that tightness all the way down to the bottom and then lead up out of the bounce with your hips, not your chest.