First, rocking is a proven, natural sleep aid. But why? It is the same safe motion that we felt, gently floating in our mother’s womb. Nature selected this motion for its calming effect. It has positive effects on the limbic, circulatory, and other systems. It activates a deep, powerful relaxation response. Mothers intuitively rock babies from head to toe, using that same floating motion. Every mother knows that rocking is good for a baby. But science has found that motion is good for adults too. Source: http://www.floatingbed.com/features-benefits/better-sleep/