Sitting 101

Once your baby starts rolling, their new-found movements will support the next set of motor milestones, like sitting up all by themselves.

How can I tell if my baby hit their sitting milestone?

Although this may seem self-explanatory, there are a few accepted definitions. Sitting independently, as defined in the US, is the ability to maintain an upright, seated position for an extended period of time without support. However, others would say it is when a baby can maneuver themselves into (and out of) an upright sitting position without help.

Regardless of which definition you choose, it’s important that your baby has the following:

Appropriate head and neck control
Strength in the upper body, trunk, and legs
Balance and coordination of large motor muscles

Sitting is their first upright position against gravity, and like all developmental motor milestones, it takes time and effort.

Why is it important?

Sitting adds a new element to your baby’s perspective about the world around them. It’s also another step towards independence. Infants who can sit unassisted are able to visually observe and scan their environment by just turning their head and torso. From here, they can use their hands to grab, investigate, and manipulate objects, and communicate through gesturing.

Sitting also provides another layer of understanding their midline, allowing them to reach across their body and transfer objects from one hand to another. Also, the ability to shake and bang toys repeatedly while seated has been linked to the onset of babbling in babies, the first step towards language development.

When does it start?

Babies will attempt to sit up between 4-6 months of age, but will still be wobbly. By 6 months, they can sit on their own, but they will need some support. Around 7-9 months, they should be able to get into a seated position and maintain it independently. These age estimates are just that: estimates.

Other signs for determining if your baby is ready for sitting are:

When starting (around 4-6 months)

Having good head control
Having controlled and purposeful movements
Attempting to push themselves up during tummy time
Rolling over in one direction
Trying to sit for short periods of time when placed in an upright position

As they get closer to independent sitting (around 7-9 months)

Rolling in both directions
Scooting or crawling
Trying to push themselves into a tripod position (using arms to prop themselves while sitting)

Should I be concerned if my baby is W-sitting?

W-sitting is when a child sits on the floor with their knees turned out in front of them, while their ankles and feet are on either side of their hips, forming the letter W. You probably have heard the dangers of this position as it could lead to postural weakness and tight muscles in the hips and legs, affecting their balance and coordination as they age.

However, this sitting posture is typical during the first couple years of your child’s development. The W-sit provides a wide base of support and minimal effort to maintain as it doesn’t activate their core muscles to sit upright. They’re also pretty flexible at this age and can contort their bodies in this fashion with little to no pain.

As your baby develops more strength and control in their movements for other milestones (like walking, running, jumping, etc), W-sitting will no longer be their go-to position and should go away by age 3.

How I can I help my baby sit?

Trial and error. Giving your baby plenty of opportunities to practice exploring and experimenting this skill on their own will help them develop body awareness while in an upright position and build the strength and postural control necessary to maintain it.
Explore on the floor. Allowing your child to move around on a flat surface will let them figure out how to move in and out of positions, especially when trying to get to their favorite toys. Let them do it often, like 2-3 times a day.
Be a bit dynamic. Challenging their posture by shifting their weight forward, back, and side-to-side will help build the postural muscles and sensory responses to maintain balance while sitting. A simple way to do this is by having them sit on your lap and rocking (or even bouncing) them.
If they’re a bit tipsy. If your baby is trying to prop themselves up into a tripod sit, they do not have the core muscles needed to fully sit up. Feel free to use a Boppy pillow or place cushions around them for either support or if they lose their balance and need a soft crash landing.
Work that core. One way to do that is by slowly pulling your baby up to a sitting position from their back, and then rolling them back down. Be mindful of their head and neck control when doing this. Other baby core workouts include baby-assisted V-ups, leg lifts, knee tucks, and bicycles.

Thoughts on baby seats and positioners?

Okay, baby positioning seats are designed to be used on the floor and help your baby sit up, especially if they are first learning how. Although they are pretty helpful for parents who need a hands-off moment from their baby, it is not really needed for your baby to reach this milestone. In fact, if overused, it can hinder the development of essential muscles and coordination needed to get into and maintain an independent sitting posture, compared to if they were left to their own devices.

When a baby is placed in these seats for long periods of time, it can cause their pelvis and lower extremities to be locked into an unnatural fixed position. This locked-in position doesn’t allow for the core muscles to engage and adjust to any dynamic movement your baby may try to do when reaching for nearby objects.

Like any piece of baby equipment, use it sparingly for no more than 20-30 minutes at a time.

When should I worry?

Please remember that all babies develop differently, some attaining skills earlier or later than others. But after 9 months of age, if your baby is struggling to sit up independently or if you notice any of the following, contact your pediatrician: