My baby is 5months and 19 days(172days) old. He can't sit on his own but he can take tummy time on his own. Recently I have bought a high chair for him as he is going to be 6months of age soon and will start to have solids. So I make him sit on his chair for a few minutes to see his reaction and he was happy with it. But at the same time I am worried about that if it will affect his spine. If I make him sit with support will it affect his spine?????? please please please help me regarding this.