Here you will obtain the benefits of good support and helping the child to see his world. This position can also help muscles which tend to be stiff to be relaxed. Sitting is a natural position to use and has many advantages. A child looks more mature in sitting than when lying down. Other people will tend to talk to the child more.
Many children are more alert in sitting.
Also, if materials are placed on the child's lap, gravity will assist in arm movements. There are also some potential drawbacks to sitting. In a sitting position the demand for head and trunk control increases. If we ask a child to use more muscle power to sit, and at the same time him to use his arms, he may quickly get tired. The rule of thumb is that trunk support should be increased in sitting.