Having worked in Early Intervention with littles aged 0-3, I worked alongside pediatric physical therapists daily and learned a lot about motor milestones. One question I see a lot is: when do children typically sit with support and unsupported? And how can you help support this milestone without forcing it or hindering it? These are all really great questions, as we as parents are always worried our children are hitting all the right milestones at the right times!
The first phase we look for is kiddos sitting up with support.
By 6 months most children can sit with support. An example of that would be a child sitting on the floor with a Boppy surrounding their hips or sitting in between your legs. Some children use that support longer than others, and that is okay! The main thing to observe is whether your child can sit without much support and for how long. The more they practice sitting without support the longer they will be able to do it as long as their muscles are strong and they are developing typically.
The next phase of sitting is doing the triangle where children can support themselves with their hands and are beginning to experiment with lifting their hands and reaching for things in front of them. They may do this with support surrounding themselves, as well as independently.
By 9 months most children are able to sit by themselves and get into and out of sitting by themselves. They can reach for things in front of them without falling over and are more or less totally self sufficient in a sitting position.
Just a word about sitting supports
I highly discourage using the Bumbo and other "chairs" for infants as it gives their body a false sense of security and can actually hinder children from learning how to use their muscles in the way they need to in order to learn and master a new skill. The best tool is a boppy or surrounding your child with pillows as it's more of a cushion for when they topple over instead of a sturdy container that doesn't allow them to move their bodies to figure out what to do. The goal with supports as they learn to sit is to allow their bodies to practice sitting on their own, with gentle support so they don’t fall over and hurt themselves. The goal is NOT to confine them into the sitting position, as this won’t help them work their muscles as if they were sitting on their own. As they get older it’s ok to let them sit unsupported and be nearby. If they topple over, and they will, that’s ok. It’s a short fall and they learn from every topple.
Are you feeling like your child is not meeting the sitting up milestone?
Children's bodies develop in a linear way and even though one child might be able to master a skill at 6 months another peer might not master it until 8 months. That's okay, for the most part. There is a spectrum of ages by which children should typically be doing certain things, not just one age, but rather a range of ages. If you are concerned your child is behind with sitting, or your child is not even trying to sit, then you might want to ask your pediatrician about it. If your child is 9 months and is either not able to sit by themselves or can sit by themselves but CANNOT get into or out of sitting by themselves and simply doesn't seem to know what to do you will want to talk to your pediatrician or get a free evaluation by your local Early Intervention organization.
Remember, these milestones are not a race. As your child continues to grow, make sure you are providing the right kind of support your child needs to allow them to flourish into that next milestone, but do not force it. You’ve got this, mama.