The tummy time position is important because it helps baby to strengthen the neck, back, and shoulder muscles. This strength allows baby to pick up his/her head and look around at the world. It strengthens the back muscles (those that run down the sides of the spine) so that the trunk (body) can eventually support the head and neck when moved into an upright or sitting position. Tummy time is important for all babies starting at birth to six months and beyond.