I like that they use a spring unit as a foundation since that is key for proper spinal alignment. (mommypotamus.com)
This can also be rolled along baby's spine after birth to promote and support healthy proper spinal alignment. (stillbeingmolly.com)
Promotes proper spinal alignment while nursing in bed, eliminating pillow propping: Having baby s spine and pelvis aligned during the nursing process prevents spinal misalignment and the complications that result from it. (motheringfromtheheart.com)