My developmentally delayed daughter could not sit up when others her age were sitting up.  Our therapist recommened the seat to us after trying her in it at therapy.  She loved being upright.  I would hang toys out in front of her and she gained lots of strenghth using those muscles with the support of the deep seat for her trunk control.  We did have to be very careful not to leave her alone in the seat.  She was on the skinny side and could arch her way right out of the seat when she was done being in it.  It should never be used anywhere but on the… read full review »