From the Guidelines
Most babies can sit on their own at around 9 months of age, as indicated by the gross motor milestones in the study by 1.
Developmental Milestones
The study outlines the gross motor milestones for developmental surveillance at preventive care visits, which includes sitting without support at 9 months of age.
- At 2 months, babies can lift their head and chest in prone position.
- At 4 months, babies can roll over prone to supine and support on elbows and wrists in prone.
- At 6 months, there is no specific mention of sitting without support, but by 9 months, babies can roll over supine to prone, sit without support, pull to stand, come to sit from lying, and crawl.
Supporting Development
Parents can support this development by providing supervised sitting practice with pillows for support, encouraging tummy time, and using supportive seating like Bumbo chairs for short periods.
- It is essential to monitor a baby's progress and consult with a pediatrician if they are not showing signs of sitting by 9 months, as this could indicate developmental concerns, as discussed in the study by 1.
Clinical Considerations
The study emphasizes the importance of developmental surveillance, including eliciting and attending to parents' concerns, documenting and maintaining a developmental history, making accurate observations of the child, identifying risk and protective factors, and maintaining an accurate record of documenting the process and findings.
- Clinicians should carefully watch the child's posture, play, and spontaneous motor function without the stressful demands of performance under deliberate observation, as recommended in the study by 1.
From the Research
Motor Skill Development in Infants
- The age at which a baby can sit on their own is not explicitly stated in the provided studies, but we can look at the age ranges mentioned in the studies to get an idea of when infants typically develop this skill.
- A study published in 2021 2 recruited infants with motor delay at 7 to 16 months of age, suggesting that some infants may not be able to sit on their own until around 7 months or later.
- Another study published in 2019 3 mentions that developmental delays, including delays in motor skills, can be identified during routine checks by primary care physicians, but does not provide a specific age range for sitting.
Developmental Milestones
- A study published in 2025 4 found that among autistic 8-year-old children, 71.5% had motor milestone delays, but this study does not provide information on when these delays typically occur.
- A clinical practice guideline published in 2020 5 provides recommendations for physical therapy management of children with developmental coordination disorder, but does not specify the age at which infants typically develop the ability to sit on their own.
- A study published in 2025 6 compared the effects of two physical therapy interventions on dyadic emotional availability in children with neuromotor delay and their families, but does not provide information on the age at which infants typically develop the ability to sit on their own.
Age-Related Motor Skills
- While the provided studies do not explicitly state the age at which a baby can sit on their own, they suggest that motor skill development can vary widely among infants, and that some may experience delays in developing certain skills, including sitting 2, 4.
- The studies also highlight the importance of early identification and intervention for infants with motor delays, as well as the need for physical therapy management and family-centered care 2, 5, 6.