Developmental Milestones are the skills babies and young children learn as they grow like walking and talking. They are also the bane of many medical students and pediatric residents because there are quite a few different milestones that we are required to memorize and we have to know exactly at what age we should expect each of these to develop. It is a lot of information. When I had to memorize this stuff I memorized it from this chart:
Needless to say none of this stuff ever stuck in my brain much past the day of the test. So after having to re-memorize the milestones I tried to come up with a better, more efficient way to not only commit the information to memory, but also get a deeper understanding of the topic of development in general. The following is a paper I wrote that gives a broad overview of the concepts at play in assessing childhood development followed by a methodology for learning the milestones in a fast, efficient, and clinically useful way that will hopefully stick in your head better than a series of loosely related facts. I start with a general overview and then get into the details about how to commit this information to memory in a functional way for both standardized tests as well as use in the clinic.
Why learn it? Development is an integral part of pediatric practice. Knowing and understanding developmental milestones has important diagnostic application, it separates us from adult medicine, and is infinitely pimpable both by attendings and on our licensing exam. In other words, this stuff is important to know. How does this all fit together/Global Overview? We will first discuss why this is clinically important, how it is used in practice, why we define development in four discrete categories (gross motor, fine motor/vision, language/hearing, and social), go through an overview of each developmental category, and most importantly, how to memorize this stuff in a way that is clinically/functionally relevant and will serve you when in clinic, when pimped and, eventually, on our licensing exam. Why is learning/applying developmental milestones important? Why do we use this modality?
We use milestones for two main reasons: During early childhood (basically until the age of 5), when kids cannot articulate their inner state, developmental milestones are used as clues to what is going on inside and if any pathology is brewing. By assessing where the child is in each category, we can tell if delays are isolated to one category (speech delay for example) or appears in multiple categories which will change your diagnostic concerns How do we use developmental milestones in every day clinical practice? We assess if the child is meeting milestones in each category for his or her particular age. There are ranges of ages when milestones arrive (refer to Denver Scale). A lot of the classic milestones that we memorize are later in the average range, so if a milestone is not seen by this age, this is possibly a problem.
We will later go over some big red flags for certain milestones if not seen by a certain age (a child not walking by 15 months is a concern).. Example of how we evaluate a six month old at a well child check: At six months, a child should be able to sit up (gross motor), pick up things with a raking grasp (vision &fine motor), babble (language), and recognize family members (social). We ask parents if they see this at home, and observe whether the infant is doing these things in clinic. Why do we use only these particular four categories? It seems kind of limited in scope. Does this really adequately define a child’s development or are there things we are leaving out? And why do we only really memorize these milestones to the age of 5? We use these four categories because they are the most easily observable behaviors and we have therefore been able to create norms for when we can expect children to do them.
There are absolutely aspects of development not covered in these four categories. How a child plays is very important in how a child develops, but is way too diverse and individual to create any meaningful way to assess/measure it or create norms. So the four categories that we do use, though chosen out of utility, are good enough to diagnose the vast majority of developmental problems that may arise during a child’s first five years of life. We only memorize up to age 5 because after that, children are better able to communicate to us their thoughts and feelings, and this is about the age that they enter school and any developmental issue will likely become readily apparent when the child is placed with other children who they will have to interact using all four milestone categories. Any deficiencies will be more obvious because things outside the norm will be visible by comparison to other kids. Also, development is no longer as rapid after age 5, and therefore there is less urgency in diagnosing any problems, and more reliance on things to get lagged socially or academically at school.
So how do I learn all this stuff? Should I learn each milestone category individually? Should I learn a milestone across each category for each age? What information is best learned in a conceptual way? What information do I need to just memorize? The goal is to learn these milestones in a way that we can use them effectively, quickly, and easily when assessing patients (either at well child checks, outpatient urgent care appointments, or when a child is admitted to the hospital), and also be able to answer quickly when we are pimped or when we see it on a boards exam. I have tried to memorize these milestones many times since Step 1. I never got a good sense of understanding how everything fits. I’ve had to rememorize these things many times (3rd year pediatric exam, Step 2, Step 3, intern year, board exam) which is clearly not efficient and likely not very effective. So how do we learn this? It is a mix of conceptual understanding and rote memorization.
The best way we have been able to figure out is to (1) Generate an overarching understanding of the development categories (2) Learn why each milestone category progresses as it does in children (why do we crawl before we walk?), and (3) use some memory tricks to learn the most clinically important and most tested milestones for each age. This way you create an overall understanding of what is going on (which is actually fascinating in and of itself) but are still able to quickly recall necessary/important milestones for assessing children and getting pimped. General Understanding of Each Domain/Domain Overview The Categories: We use four categories for assessing child development- Don’t memorize the rest of this section, it is only for getting a conceptual overview of the categories, so when we start memorizing details we have a framework to understand the progression of kids’ acquisition of skills. Gross Motor: this category is the use of all muscles in a way that does not involve hand/eye coordination, which ends up being essentially everything except eye/finger movements: head control, rolling over, sitting, walking, running, throwing (overhand, from the shoulder), stairs, riding bikes, etc. Fine Motor/Vision: this group is called “fine motor” but should be called hand/eye coordination. Initial milestones involve fixating and following objects with their eyes, and eventually manipulating objects with hands and fingers.
Both dexterity and vision are necessary to achieve many of these milestones (block stacking) so that is why these abilities are grouped together. Language/Hearing: like “fine motor,” “language” should include hearing as the two are intertwined. If you can’t hear, your language is going to be delayed or nonexistent. Language is divided into two categories; the distinction is clinically important. How someone speaks and how many words they know are often the most obvious milestones, and are examples of expressive language (remember Broca). But language is also receptive (does a child understand what is being said; think Wernicke) and this may be less obvious initially. Receptive language deficits are rarer but more concerning, assuming hearing is intact, as it then implies a brain/cognitive problem, as opposed to expressive language deficits which are more likely to be secondary to mechanical issues. For example, kids with Cerebral Palsy may be intelligent and fully aware of their surroundings, but often the initial erroneous assumption on the part of the provider is that they have poor cognition.
Social: This is how a child interacts with other people. Does a child respond to other people’s behavior and show recognition that other people are sentient beings? For example, do they attempt to draw another person’s attention to an object, indicating that they understand other people even have attention to redirect? Kids with Autism can have trouble with this kind of understanding. General Overview of Milestones for Each Category It is very helpful to understand the general progression of each milestone category so you can conceptually understand the progression of each category and why most children develop in a predictable manner. This is most helpful in gross motor development, which we will use as a base on which to memorize the milestones of all the other categories for a particular age. Also, we choose which months to assess a child based on when they have well-child visits (because we most commonly won’t see these kids except at these times) Gross motor Development: Children develop their gross motor skills from head to toe because myelination of nerves happens from head to toe during the first year of life.
You first lift your head up (neck), then you roll (using arms), then you sit (waist), then you crawl (knees), then you stand, and then you walk. The goal of the first year is to walk. Fine Motor Overview: since children don’t use their hands until a few months old, early on we focus on whether the child appears to be able to see things (track objects with their eyes for example). Around four months the fingers come in to play. The goal of the first year is to have a controlled “pincer grasp,” which is the infant being able to pick up small things using the tips of their thumb and index finger. So you look for vision until 4 months, then the kid can grasp objects with all fingers, then discovers their thumb, then learns to use the thumb and fingers together in a controlled way. Language Overview: just as we watch for vision first in fine motor, a child has to be able to hear to learn to speak.
Thus evidence that the child can hear is an important part of the early milestones. The goal of the first year is to be able to say one word (with meaning—i.e. the child says the word with intent and it means the same thing every time). After the first year, we start looking for increased vocabulary, better pronunciation, and combining words into phrases and sentences. Social Overview: this covers how children relate to other people. We start by looking for how they react to people, initially with a smile, laughs, and then whether they can discriminate parents vs strangers. After that we we assess when a child develops the insight that other people are thinking beings (and thus different from other objects). They will show this by pointing to draw attention, peekaboo, and more advanced ways of playing and interacting). A child with autism will not be attracted to people, faces and language as distinct from objects.
How to Commit This Stuff to Memory 1. First memorize the months of the well child checks. This is important for creating a framework for memorizing the milestones and will also help when you start memorizing vaccine schedules. The timing of both milestones and vaccines is based on this well child check schedule. The visits are 2 days, 2 weeks, 2 months, then add 2 months twice (4 months, 6 months) then space it out as we get less anxious and the rate of expected milestone acquisition declines. So 2d, 2w, 2m, 4m, 6m, 9, 12, 15, 18, 24m, 3y, 4y, 5y. -So initially think “2,” 2 days, 2 weeks, 2 months, 4 months, 6 months -after month 6, it is by 3 for four visits, so 9, 12, 15, 18 -after this it is by full years, 2, 3, 4, 5 2. Once this is down, we memorize the gross motor milestones for each visit.
This will be the only milestone category that we have to rotely associate with months. We will use it as a memory base and hook the other milestones in to it. A good way to memorize motor is to divide these milestones into two categories: birth to 1 year, and 15 months to 5 years. Birth to 1 Year: Remember that the goal of the first year is to be able to walk (walk at 12 months). At six months you are halfway there (remember “sit at six”). Just with these two milestones you can pretty much fill in everything else. Remember that everything is from head to toe. So 2 months (the first time we really check milestones) you check for head lifting (neck control). You roll at 4 months (at level of shoulders and chest). Then, again, at six you sit. You crawl at 9 months and pull to stand (crawl, pull to stand at 9 months) which makes sense as being between sitting and walking.
In Review: 2 months: lift head 45 degrees 4 months: roll over (front to back first, then back to front, easier if you can push off with hands) 6 months: sit (halfway to goal, halfway through year, “sit at six”) 9 months: crawl, stand (halfway between sitting and goal) 12 months: walk (the goal) 15 months – 5 years: Memorize these milestones in a story as they are harder to associate with particular months like the first year. Using this progression story may help you. 15 months: walks well 18 months: throws objects 24 months/2 years: up and down stairs (one foot at a time); run 3 years: Tricycle (3 wheels, 3 years), jump in place 4 years: up and down stairs alternating feet (2 feet x up/down = 4), balance on 1 foot for 4 seconds (legs look like a 4 when on 1 foot), hop 5 years: skip (5 looks like an “S”kips) Story: a child on the 1st floor of her house sits up, crawls, cruises, then 1) WALKS to stairs, 1.5) THROWS object up stairs, 2) CLIMBS up the stairs and RUNS to his trike, 3) RIDES a trike upstairs, JUMPS off, 4) RUNS down the stairs, HOPS off the stairs and 5) SKIPS away 3.
Once you’ve memorized the months of well child checks and corresponding gross motor milestones, begin to memorize the archetype babies for each age group. These little stories incorporate all the other milestones into a single image which is much easier than trying to memorize many unrelated facts. There are some ways to conceptually link milestones across categories, but they are not frequent enough to be useful for fast recall and the salient milestones and timing which is what happens on tests and during morning report. Here are all the babies with milestones listed: 2 months: lift head 45 degrees (when laying on face), turns to sound, follows objects past midline, social smile Parent’s Little Baby: looks up to sound, smiles because he sees both his parents, one on either side of midline 4 months: lift head 90 degrees/raise up to chest, roll over, find midline, reach for objects, puts objects in mouth, coos (these are vowel sounds), and laughs Fat Happy Baby: baby is rolling and laughing and cooing because he just discovered midline and is reaching for cake that he will cram into his mouth 6 months:
sit up with no head lag, raking grasp, transfer objects between hands, babbles (consonants), recognizes familiar faces Street-Corner Baby: sitting up on sidewalk, transferring a rake from hand to hand while babbling at people he thinks he recognizes 9 months: Crawl, pull to stand, point, specific babbling (mama, dada), stranger anxiety Watch Dog Baby: crawls to window, pulls to stand to see out, points at stranger in yard and says “mama” to get attention of parents. 12 months: Walk, pincer grasp, 1 word, patacake, bye bye, peekaboo Playful Zombie Baby: walking at you, snapping pincers, repeating one word over and over (brrraaaaains), and just wants to play patacake and peekaboo before waving bye bye. 15 months: walks well, imitates, controlled release of blocks (can stack 2) Little Sister Baby: wants to be just like big sister, walks confidently to the blocks and imitates making a 2 block tower 18 months:
Throw, scribble, 4 block tower, 1 step command, uses spoon/cup, points to parts of body Sir Charming Baby: needs to get note to Rapunzel so scribbles note on paper to throw into high 4 block tower, catapult has cup on end, shoves note in with spoon, and throws note at tower, hitting Rapunzel in the face 2 years: Run, stairs (1 foot at a time), 20-50 words, 2 step command, parallel play Bad Twins: mom gives two commands to twin boys to run to the stairs, then walk up the 25 stairs. Each walks up the 25 stairs not helping the other. 3 years: Jump, Tricycle, dresses self (shirt, pants, shoes), full name, “you, me, I” James Bond Baby: springs into action . . . jumps into 3-piece suit, stands in front of mirror and says full name, jumps on tricycle.
“You.Me. I,” is his pickup line. 4 years: Stairs (alternating feet), hop, undresses, 1 foot (4 seconds), 4 word phrases (complete sentences), cooperative play Bedtime Story Baby: really wants story time, so runs up stairs, hops on one foot to undress, so she and mom can read a story together. A Wrinkle in Time. 5 years: Skip, Tie shoes, Difference between reality/fantasy Oz Baby: ties ruby shoes, skips down Yellow Brick Road back to Kansas Review of Approach to Memorization 1.
Learn ages of well child checks from birth to 5 years. It’s not important to memorize in and of itself, but will really help you keep milestones and vaccine schedules straight: -be able to rattle off all the checks (2, 4, 6 . . . remember 2-5 years are only annual checks so you really only have to memorize up to 2 years old) -a flash card is helpful for this, just know it cold. 2. Learn associated gross motor milestones for each visit (make sure you understand the physiologic basis for the gross motor milestone progression as it will help you figure things out if you ever forget a particular milestone for a given month and can only remember the milestones around that month) -flashcards helpful 3. Learn the archetype baby for each age (make sure you can visualize everything that baby is doing, the more vivid the picture, the faster you learn it, the easier it is to retain, and the faster you will be able to recall the milestones) -again, flashcards helpful That should do it! Knock this stuff out early in residency so you can move on to learning more conceptually difficult stuff. Here is a few examples of how you’ll see it during your education.