Baby’s Milestone: Sitting
Let’s talk sitting! How to know when your LO might be ready to start & how to know when they’re not, how to support them, helping them practice getting in/out of sitting, and more!
In general, supported sitting comes first, followed by sitting independently when placed. Typically around 6 months, your baby will be able to maintain a sitting position when you place them there for anywhere from a few seconds to minutes. Sitting when placed typically comes after rolling belly to back and back to belly have been mastered, when the muscles on the front and back of their bodies have strengthened and they can activate equally to maintain a sitting position.
However, if the muscles are unequal, it would pull them over in one direction or the other. Think- if the muscles on the back are more active than the front, it would make them topple over backwards. The muscles on the front have to be activate to create the control to stay in sitting.
After this, they’ll start to play with toys in sitting (passing toys between hands, banging toys together), and as they get stronger and protective reactions develop to the front, sides, and back (meaning they put their hands out instinctually to brace a fall), they will start to learn how to get in/out of sitting. This happens anywhere from a few days to weeks after learning to sit when placed.
When Should A Baby Be Sitting?
Sitting when placed around 6 months
Independent sitting and playing with hands 6 1/2-7 months
More consistent protective reactions 7 1/2-8 1/2 months
Getting in/out of sitting 7 1/2- 8 1/2 months
I really, really mean it when I say loose timelines- some babies start sooner, some are later! Do not panic if your little one is following a different timeline!
Early sitting typically occurs between 5-6 months or so.
What are the progressions for learning to sit?
Sitting when placed with support to ensure spinal alignment is ideal
Using a boppy in front (if leaning far forward), with you behind helping as needed
Using a boppy behind to gently support and provide cues to sit upright before protective reactions are consistent
Propped on hands in sitting
Emerging protective extension forward
So often, parents are frustrated by their little one wanting to push backwards in sitting! It can be so common, and it’s usually a pretty quick fix! The main reason I find that babies push backwards is related to their trunk position over their pelvis and thighs. If you think about how a child looks when they’re in sitting propped on their hands- their trunk is over their legs, making more than a 90* angle at their hips. Think- the angle between their thigh and stomach kind of looks like this <.
As they come up into sitting and off of their hands, their stomach is at more of a 90* angle to the thighs, like this L.
This position is the prime position for the muscles in the front and back of their body to work together to hold them here.
As you can imagine if the muscles on the front are way stronger, it’ll pull them forward off balance. Alternately, if the muscles in the back are way stronger, it’ll pull them over backwards. Now if you think back to why tummy time is important from day 1- it’s time get those back muscles active and ready to work during belly to back rolling.
A few months later, the front muscles start to kick in during activities like hands to midline, hands to knees/feet, and beginning to roll to the sides. Inherently due to the developmental sequence, the back muscles have had more time to strengthen! If they haven’t quite mastered the balance between both sets of muscles front and back, as they’re in that L position, the muscles on the back may take over, causing them to push forcefully backwards, even if they don’t mean to. Remember- those muscles have been awake and active in tummy time way longer than the muscles on the front!
So how can you help? Try keeping them in a 90* trunk/thigh position OR LESS (meaning closer to the propped on hands position). Encourage a ring sitting position of their legs, rather than legs straight out in front of them. You can also use the boppy in front of them to encourage that position, but make sure you’re always behind them to catch if they go backwards!
Want More?
For developmental questions, tips and guidance related to milestones about tummy time, rolling & sitting, crawling and walking, check out KC’s developmental Masterclasses linked here.
KC is a pediatric doctor of physical therapy, wife and mom of three! She has spent her career working with children and young adults of all ability levels, and currently specializes in birth to three years.
