Actually, that's true in or out of a carseat for those that don't have legs long enough so that their knees can bend. Straight legs with a reclined seat is a recipe for seat kicking, with very little that can be done to prevent it - switching the parent's and child's seats would be about the only possible solution, and that's not possible if you're using a car seat since the child MUST go in the window in almost every case.