Developmental Milestone Delays: When Should I actually be worried?
By Kaitlin | Paediatric Physiotherapist, Maylands Healthcare Hub
If you have ever Googled 'when should my baby be walking' at 1am, you are not alone. Developmental milestones are one of the most common sources of parental anxiety, and understandably so. There is a lot of information out there, and not all of it is clear, accurate, or reassuring.
This post is here to help you understand what milestones actually are, what the research tells us about normal variation, and, more importantly, what signs are worth a conversation with a professional rather than another late-night search.
First, what is a developmental milestone?
Developmental milestones are skills or behaviours that most children can do by a certain age. They cover four main areas:
Motor development: how children move and use their bodies
Communication and language: how they understand and express themselves
Cognitive development: how they think, learn, and problem-solve
Social and emotional development: how they relate to others and regulate their feelings
Milestones are not a checklist or a pass/fail test. They are ranges, based on population data, that tell us when most children develop particular skills. The word 'most' is doing a lot of work in that sentence.
Variation is normal. Ranges exist for a reason.
The research on motor development consistently shows wide variation in the age at which children reach key physical milestones. Sitting independently typically emerges anywhere between five and nine months. Independent walking commonly occurs between nine and fifteen months, with some children not walking until closer to eighteen months and still developing typically.
That is a six-to-nine month window. A child walking at twelve months and a child walking at sixteen months can both be developing well.
What this means in practice: your child being later than another child in a mother's group is not, by itself, a red flag. Children are not on identical timelines, and comparison within a small social group is rarely a useful indicator of developmental health.
So when should you be paying attention?
There are patterns and presentations that do warrant further assessment. These are not reasons to panic, but they are reasons to seek a professional opinion rather than waiting and watching indefinitely.
Motor development: signs worth following up
Persistent asymmetry. If your child strongly favours one side of their body, consistently uses one hand well before the age of two, or has a noticeable difference in how they move their left versus right side, this is worth investigating. Early hand dominance before eighteen to twenty-four months can be associated with motor difficulties on the weaker side.
Not meeting broad age markers. While ranges are wide, there are outer limits. If a child is not sitting independently by nine to ten months, not pulling to stand by fourteen to fifteen months, or not walking by eighteen months, a physiotherapy assessment is appropriate. These are not panic points, but they are points of action.
Quality of movement, not just timing. Sometimes the milestone appears to be reached, but the way a child moves is worth a closer look. Toe walking beyond age two to three, W-sitting as a primary floor position, or a child who seems unusually stiff or floppy compared to peers are all patterns a paediatric physiotherapist would want to assess.
Regression. Losing skills a child previously had is always worth medical review, regardless of age.
Communication and language: what to watch for
Language development has its own wide normal range, but there are some markers that consistently appear in the research as meaningful:
No babbling by nine to twelve months
No single words by sixteen months
No two-word combinations by twenty-four months
Any loss of language at any age
The 'wait and see' approach to speech delays has limited support in the evidence. Early intervention in language development consistently produces better outcomes than delayed referral. If you have a concern, raise it early.
The role of gut instinct
Parents are often the first to notice that something is different. If something about your child's development is nagging at you, that is worth taking seriously, even if a well-meaning relative tells you to stop worrying, or your child seems 'fine' at a six-week check.
Parents observe their children across environments, over time, and in far more detail than a brief clinical encounter allows. Your observations matter.
What a paediatric physiotherapy assessment actually looks like
If you do seek an assessment, here is what to expect at Maylands Healthcare Hub:
A detailed history of your child's development, pregnancy, and birth
Observation of how your child moves, plays, and interacts in the session
Standardised movement and strength assessments where appropriate
A clear explanation of findings, with practical guidance for home
Referral to other services if indicated, including speech pathology, occupational therapy, or your GP for further investigation
Assessment does not mean there is a problem. In many cases, it provides reassurance and a set of strategies to support development at home. When there is something to address, early input makes a significant difference to outcomes.
The bottom line
Developmental milestones are guides, not rigid rules. Variation is normal and expected. But variation has limits, quality of development matters as much as timing, and early assessment is always better than prolonged uncertainty.
If something is on your mind, it is worth a conversation. That is what we are here for.
Book a paediatric physiotherapy assessment
Kaitlin sees children of all ages at Maylands Healthcare Hub.
To book or enquire, contact us at admin@maylandshealthcarehub.com or call 0402 283 352
