Starting in month 4 (or whenever he holds his head up well and seems interested and ready), you can prop your baby up to sit with support and give him an amazing new vantage point on the world around him. Help your baby develop neck and head control by making a game of pulling him up to sit.
Baby Sitting Movement:
By the fourth month, your baby enjoys tummy time and rolling over. They can see you and others through close up and movement. They are able to visually follow, grab, and release a toy. They babble and are getting ready to grab their feet, cross midline, and go in and out of airplane position as they play on the floor. You are not even concerned with head control.
Your baby's 'head control' comes from their pelvis.As they can counter from side to side through the pelvis in tummy time. Their pelvis goes to the floor and their head rises.
Baby Sitting Developmental Warning Sign:
When a baby is on their tummy, when their bum constantly rises, their head will come to the floor. They are struggling to go into the necessary movements for vertical positioning.
If you feel, for any reason, your baby is 'weak', 'stiff', or unable to be in sitting. Do not pull your baby into sitting. They will still have head lag no matter how many times you do this. This is not a functional movement.