🌱 Health Promotion · Lesson 1 of 6 · 6 min
Rolls at Four, Sits at Six, Walks at Twelve
👶 A mother says her 10-month-old 'isn't walking yet' and is worried. A different mother says her 10-month-old 'doesn't sit up alone.' One of those is a question for the pediatrician. The exam expects you to know which.
💡 Key idea
Smile 2, head 3–4, roll 4–6, sit 6–8, crawl 8–10, pincer 9–12, walk 12–15. Losing a skill already gained is always a red flag.
🧠 Why it matters
Development proceeds HEAD TO TOE (cephalocaudal) and CENTER OUTWARD (proximodistal). Roughly: SOCIAL SMILE by 2 months; HEAD CONTROL by 3 to 4 months; ROLLS over at 4 to 6 months (front to back first); SITS without support at 6 to 8 months; STRANGER ANXIETY begins 6 to 8 months; CRAWLS at 8 to 10 months; PINCER GRASP by 9 to 12 months; PULLS TO STAND around 9 months; WALKS at 12 to 15 months; first WORDS around 12 months and two-word phrases by 2 years. Birth weight DOUBLES by about 6 months and TRIPLES by 12 months. The posterior fontanel closes by 2 to 3 months and the anterior by 12 to 18 months. The first tooth erupts around 6 months. A skill not yet due is normal; a milestone missed past its expected range, or a loss of skills already gained, needs follow-up and developmental screening rather than 'wait and see'.
🏥 In the real world
🧸 A 7-month-old is brought to the clinic. She rolls both ways, sits with a little support, babbles and cries when the nurse approaches. Every finding is on schedule, including the crying; stranger anxiety at this age is development, not a problem. The exam's 'concerning' option would be a 7-month-old with no head control.
📌 Takeaways
- Head to toe, center outward
- Weight doubles by 6 months, triples by 12
- Not yet due: normal; missed or lost skills: report for screening
📖 Terms in this lesson
Pincer grasp: Picking up a small object between the thumb and forefinger, expected by 9 to 12 months.
✅ Test yourself
Which finding in a 9-month-old should the nurse report for further evaluation?
- Uses a raking grasp for small objects
- Cannot sit without support
- Cries when a stranger picks him up
- Is not yet walking
Answer: B · Cannot sit without support
Sitting unsupported is expected by 6 to 8 months. Walking is expected by 12 to 15 months, so not walking at 9 months is normal, and stranger anxiety and a raking grasp are typical at this age.
An infant weighed 7 lb (3.2 kg) at birth. Which weight at 12 months is expected?
- About 10 lb
- About 21 lb
- About 14 lb
- About 30 lb
Answer: B · About 21 lb
Birth weight triples by one year: 7 lb × 3 = 21 lb (about 9.5 kg).
At what age does the anterior fontanel typically close?
- By 12 to 18 months
- By 2 to 3 months of age
- By 6 months of age
- By 2 to 3 years of age
Answer: A · By 12 to 18 months
The anterior fontanel closes between 12 and 18 months; the posterior closes by 2 to 3 months.
NCLEX-style questions, XP and streaks in the app. No sign-up needed.