Its not about the baby equipment, it's about the time your baby use those equipment. So it doesn't matter whether you are using a baby bouncer or a baby swing, if your baby is using too much, then it will effect on the motor skills development. For example, many experts recommend to use baby swing not more than 1 hour a day. so it means even baby swing has no effect on the motor development, if it is not used excessively. Same goes for baby bouncers.