Inclined only from the waist up?

I was wondering if the same benefits of IBT are experienced when inclining the bed from only the waist up? In other words, does the bed need to remain straight head to toe in order to get the benefits of IBT? We are considering the Sleep Number bed but I don't believe it can raise the head of the bed while keeping the entire bed straight. Another question would be...like a hospital bed, does raising the bed (bending at the knees) negate the benefit of raising the head? Thanks.

No, sleeping with legs flat or raised is counter productive. You spine would be compressed at night, whereas IBT decompresses the spine. Also tendons will contract if you can't stretch out. You would be in a sitting position, not and Inclined Position.

Hope this makes sense.

Kind regards

Andrew