Originally Posted by Povl Carstensen
Edit: Recliner chairs is a bit different, because the whole back is supported. But I believe a good reclining chair (and Cinema and car seats and so on), has a support in the lower back that encourages the s-shape, instead of just being scoop-shaped. Otherwise it is possible to use a small pillow, or you can look up the "McKenzie Lumbar Roll" for instance.
So you would say that if recliner provides lumbar support, or if you provide it with a lumbar roll, one needn't worry about the knees being above the hips in a recliner?