Neck Muscles

We are trying to help the boys get their neck muscles. We have been using these infant boppy loungers since the boys came home from the NICU 3 months ago but I truly think that it has hindered them from gaining neck muscle and turning over. Before about a week ago I never really laid them just in the floor except to play on the play mat. Well, I am retiring the boppy loungers!! They will for now on be in a infant seat, bumbo, swing, play mat or just hanging out on the floor. Brandon loves tummy time and does great at holding his head up. He even loves to stand. John however HATES tummy time so I think the bumbo is best for him now. He is temper mental so tummy time is short!!!