The backward tilted seat prohibits good sitting position
At Learn to move, we do not recommend using the bumbo chair, as it is negative for the child's development. Bumbo chairs are designed in a way that makes it impossible for the child to learn to sit straight. When the child holds his head himself, the back ought to be straight. In chairs where the child is in a resting position, the child can lean backwards. The problem with the bumbo is that the child is asked to hold his head himself but the design of the bumbo makes it impossible for the child to sit with a straight back and straight neck which is the normal. The back is normally a straight "pillar". On a flat seat, the child has a posture where eyes, neck and vestibular system cooperate to program the goal: a beautiful posture with a straight back, activation of back muscles and the eyes in a horizontal position. In the bumbo seat the child makes a "sit-up" with abdominal muscles or "collapses" with lack of activation. The seat in the bumbo chair leans backwards, it is not flat. The pelvis becomes backward tilted, the back becomes rounded, and when the back is rounded, it becomes weak. It is impossible to learn balance in this position because you "fall backwards". Often the child leans his head or entire body to one side. Many children sitting in bumbo chairs get confused and when they sit on the floor they sit with poor posture and are weak. They cannot balance. It is therefore better to put the child in a high chair before he learns to sit on the floor. In the high chair you need to give side support and a low backrest to begin with, the child learns to sit straight and to move forward and return to the erect position. Eventually, the child learns to balance sideways, and lastly, the child learns posterior balance.