Your pose is your first problem.
Your character doesn't have an ass or by the looks of it hips, his legs just grow from his torso.
So I'd suggest to make this process easier on yourself that you fix the stance, regardless if you want to keep it it's wrong.
And until that error is fixed this will look wrong, I mean you can lean backwards standing still, but you wouldn't do it while you were walking.
Unless your were seriously handi-capped.
5 min edit.