Parents are very aware of the motor milestones their baby will meet in their first year of life. Sitting independently is a big one because now your baby can sit alone on the floor and begin to use both hands to grasp and manipulate toys. They can also now sit well in a high chair for feeding, and can sit in a grocery cart safely with supervision. This affords baby a little more independence and offers parents a little reprieve!
Sitting independently is typically a 6-month milestone. Keep in mind that some babies achieve this a little earlier and some a little later. The sitting milestone can be affected by their personality – are they active and want to move, or more content and want to observe? The sitting milestone can be affected by the amount of time they have previously spent in the precursor skills (tummy time, feet to mouth, and rolling). PT’s usually recommend lots of floor time play so that babies can work on the precursor skills needed for sitting.
Parents often ask what they can do to help baby sit up independently. The answer starts with making sure they have achieved precursor skills that begin to strengthen the body for the skill of sitting.
Precursor Skills to Sitting Up:
1. Holding baby in upright postures with support
- When you hold a 0-2 month old baby upright at your shoulder, he is learning to use his neck muscles to control his head position. (Initially the head bobs forward and back and needs to be supported).
- When holding baby in your lap: As he gains head control, you can move the support downward, first supporting at his upper body, then mid-body, then lower body, then hips.
- Gently tipping baby out of midline (center) – allows them to begin to react and use their muscles to bring themselves back to the middle.
2. Tummy time play – Placing a baby on their tummy is a good way to begin to strengthen the muscles on the back of their body (the extensors).
- When baby lifts his head he is strengthening his neck extensors.
- When baby lifts higher and props on his elbows, and begins to use his arms to reach for toys, he is strengthening the muscles around his shoulders and strengthening his upper back extensors
- When baby pushes way up to prop on extended arms, he is strengthening his back extensors all the way down to his hips
3. Play time on his back – This is a good way for baby to begin to strengthen the muscles on the front of their body (the flexors)
- When baby lays on his back and reaches for dangling toys, he is using the flexors of his chest and upper trunk
- When baby lays on his back and brings his feet up to his hands, and then brings his feet to his mouth, he is strengthening his abdominal muscles
4. Rolling – Strengthens the muscles of his trunk as they work together with coordination
Positions to Help Baby Sit Up:
If your baby is successfully completing the precursor skills, and showing good head control and beginning to show control of their mid-body, you can use the following sitting positions to help them gain control of sitting independently:
- Sitting on your lap (3-6 months) – vary your hand placement (moving them from high on chest to low at hips) to get them to take control with their trunk strength
- Sitting on the floor between your legs (4-5 months) – they can lean safely to the right or left, and can use their arms to push back to midline if they are tipping)
- Sitting in a Bumbo chair (4-5 months) – This is useful for the younger child who is just beginning to work on upper trunk control, but falls easily in all directions on his own. Placing toys on the tray, or reaching for dangling toys at chest height or higher, helps to strengthen shoulders and upper back.
- Sitting in the corner of a box or a laundry basket (4-5 months) – This can be used instead of the Bumbo chair. It will provide support on both sides of body. You can then pull it or gently tip side to side to encourage baby to react and balance while still being safely supported.
- Sitting on the floor, using a Boppy pillow (4-5 months)that surrounds them, or surround them with pillows – place toys a little farther away to encourage them to reach and return to midline, using the Boppy to push on if needed.
- Tripod sit – (4-6 months) – Sitting on the floor, baby props forward on his arms. Place toys in front of him on a pillow at eye level to encourage sitting up straighter (using trunk muscles) as he reaches to touch or grasp the toy.
- Ring sit – (6-8 months) – Baby’s legs are wide apart, but feet together, making a “ring”. This wide base provides a sturdy base of support for the new independent sitter. He may tip to the right or left, but is now able to catch and support on one arm and can return to the middle. He can now sit with straight back and can use both hands for play.
As your baby becomes an independent sitter, he will soon begin to reach for toys that are farther away, and soon will be able to move from sitting position to his tummy safely using his trunk control.
Here are a few more advanced sitting positions that your baby will discover after they have achieved independent midline sitting:
- Figure 4 sit (8-9 months) – one leg straight, one leg bent – allows for weight shift to the bent leg side
- Side-Sit (8-9 months) – both legs bent to one side – allows for full weight shift to one side
- Long-Sit (9 months) – both legs close together and straight – requires more core trunk strength
- Bench-sit (12 months) – Use a low bench so that feet are flat on the floor and hips and knees are bent. Works on core trunk strength and them to begin to use feet to assist in balancing.
As your baby moves into the more advanced sitting positions, he will begin to weight shift as he attempts to explore his environment. This will take him to the next motor milestone – CRAWLING!
By Lori Novak, PT