The CDC study on baby developmental milestones caused a bit of an uproar in the child development circles because of the changes to the list of skills parents will be presented with at their well checks. Many skills (such as walking, saying their first word, and obeying simple commands) were moved to a later age, meaning parents should not expect their child to do something that most children before them were expected to do. Crawling was also removed from the list of expected gross motor skills. Why?

The schedule of developmental milestones changed because babies have changed.

The CDC simply reported what a study from the AAP found to be happening among children today. Their error was changing the norms to reflect those findings. In other words, they implied that “normal development” is what we as pediatric PTs, OTs, and SLPs consider “developmental delay.” Yikes.

As a pediatric PT my colleagues and I see more developmental delay in otherwise healthy children than ever before. This is consistent with what the AAP and CDC found. This is where we differ: we shouldn’t accept those findings as normal; we should be identifying the root cause behind why so many babies are developing their skills later than babies have ever done in the history of the world, and educating parents on how to promote natural and healthy baby development.

Some parents may wonder why we are so worried about babies not crawling. It’s just one skill, right? But the underlying reason that causes them to skip crawling will impact many other skills in subtle and not-so-subtle ways in the future. Another reason is that physical development is directly correlated to cognitive, intellectual, communication, emotional, and even nutritional development.

I have worked as a pediatric PT for 8 years under the mentorship of experienced and highly educated PTs in this field. I also have three children of my own. With this in mind, I’m writing this article to describe the Developmental Sequence that every typical baby is designed to go through. In this article I’ll focus on birth - crawling stage.

Head Control

… emerges around 3 months of age. This means Baby can be held vertically with their head in line with their body and no bobbing or loss of control for an extended period of time. Between 6 and 8 weeks they will begin to be able to hold their head in midline, or the nose in line with the middle of their body, momentarily and with bobbing. Slowly their endurance and control improves until they do not need your support.

At this time they should also be able to pick their head off the surface during Tummy Time, and rotate their head to scan their environment. They should be able to hold their head steady, or even tuck their chin to their chest, when they are being picked up from a flat position.

NOTE: If your little one only has good head control with their head rotated and/or bent to one side, then they may have torticollis. True head control occurs in midline and Baby should be able to rotate their head to both sides.

Rolling

Pre-rolling skills that Baby will move through include: being able to rotate head to each side when laying down, having good head control, and being able to lift legs off the surface when laying on their back.

Rolling usually begins around 3 months old and should be easy by 5 months old. At this time they should be able to roll to and from back to tummy, and roll over the right and left side with equal ease. If they are only able to roll to one side, or only from back or tummy, they may have fascial restrictions causing weakness and difficulty.

NOTE: True rolling should involve lifting the legs up and over, not extending their back and pushing themselves over with their feet. They should lift the head and tuck the chin, not extending the head to push themselves over. Both of these are signs of core weakness and may impact the quality of future skills.

Baby should initiate rolling by lifting their legs, rotating their lower half, and picking up their head.

Tummy Time Skills

After head control is gained, Baby should be able to push onto their elbows, and then on hands while on their tummy by about 5 months old. This strengthens their shoulders to prepare for crawling and strengthens the glutes in preparation for walking, believe it or not! Babies who are unable to push up onto hands have more difficulty shifting their weight back in standing to walk normally.

example of pushing through hands in prone.

Between 5 and 6 months, Baby should begin reaching in prone (Tummy Time), and pivoting to each side. This is important for their play ability and to prepare for crawling. They will also start reaching for toys on their tummy, which develops the ability to weight shift—an essential skill for proper crawling and walking. They should be able to reach with either hand, and should not have a “preference.”

Once these skills are learned, Baby will explore transitioning from the floor to sitting, which is usually seen by 8 months old. This is an important skill that gives Baby autonomy over their position and ability to play. Babies who are not in control of their position changes, especially at this vital exploratory phase, are at risk to be more passive partakers of their environment.

Sitting

… emerges around 6 months of age. Baby will probably not be able to do more than rotate their head without losing their balance at first. By 7 months they should be able to play with a toy in both hands and move their head smoothly without losing their balance. By 8 months they should be able to reach out to grab a toy and return to sitting, and catch their balance by putting their hand out. By 9 months, Baby should be able to get in and out of sitting with ease, and catch their balance backward.

There are major implications for feeding and nutrition when sitting skills are not achieved in a healthy window. Self-feeding and oral (tongue) control cannot mature if core control and independent sitting is not present. Since sitting occurs at a wonderfully efficient age of exploration, this is the ideal time to introduce foods and help Baby become a well-rounded eater. This is also the time that the gag reflex is far forward on the tongue, allowing Baby to explore age- appropriate foods with a low chance of choking. By 8 months old, these benefits begin to decrease.

NOTE: the typical sitting pattern for babies is “ring sitting” or “long sitting.” Abnormal sitting patterns include “W” sitting, prop sitting, and squat sitting. These are signs of core weakness that should be addressed.

example of ring sitting, a typical way to sit.

example of long sitting, a typical way of sitting.

example of “W” sitting, an abnormal way of sitting.

example of prop sitting, an abnormal way to sit.

Crawling

Pre-crawling skills include pushing onto hands on their tummy (5 months), moving backward and then forward with tummy on the ground (6 months), rocking on hands and knees (7 months), and finally crawling on all fours around 8 months old. These pre-crawling skills integrate specific reflexes that will impede crawling if they are allowed to remain intact. So, we don’t recommend rushing babies through the pre-crawling skills by encouraging them to get up on hands and knees. They need to do each of these steps. Specifically, rocking on hands and knees directly integrates the Symmetric Tonic Neck Reflex, or STNR. If the STNR persists, it causes issues with depth perception, coordination deficits, sensory regulation, and more.

The benefits of crawling on hands and knees includes

Strengthening the intrinsic hand muscles. Lack of crawling is linked to poor handwriting and issues in school.
Deepening the hip joint. This is the only movement to put direct pressure through the hip joint. Babies who do not crawl are at a higher risk for hip dysplasia and costly hip issues in adulthood.
Depth perception. Because the body is moving forward in the same plane as walking, their brain makes the connection between their body, the ground, and space with all four limbs in contact with the ground. Babies who don’t crawl often toe walk for stability and/or have issues with stairs and coordination.
Reflex integration. The movement of crawling helps integrate other reflexes, such as the ATNR. This is necessary for safe eating, school success, and more.

It is found that babies should crawl on hands and knees for their primary mode of mobility for at least 3 months in order to gain the maximum benefits listed above. Of course, it is normal for crawling to overlap with standing, cruising, and even walking skills, but crawling should be the default way to travel. We generally do not recommend rushing babies to stand and walk for this reason.

NOTE: typical crawling is on hands and knees. Atypical crawling includes bear crawling (see below), hitching (see below), and bunny hopping (moving forward by moving legs together instead of reciprocally). These patterns are a sign of core weakness or another underlying cause and should be addressed.

example of bear crawling, an abnormal way to crawl.

example of hitching, an abnormal way to crawl.

You can see why child development experts like us did not appreciate the CDC implying that crawling was not a necessary or expected skill for babies to perform. This is arguably one of the most important skills in regards to the number of body systems affected when a baby fails to achieve it.

Remember, the CDC did not remove crawling because they found that it wasn’t important. They removed it because they found that many children were not doing it. More on that here.

So, is it ok if my baby skips crawling?

I would argue that no, it isn’t ok. But it’s not the end of the world either. We work with children every day who are either delayed in crawling, or who did not crawl at all and we have to creatively give them the movement opportunities that they missed out on. Yes, there is always something you can do. But, yes, it’s easier to foster normal development in the first place.

How do I make sure my baby crawls?

Floor time on their back and tummy.
Avoid Positioners that rob Baby of movement opportunities.
Be generally educated on what typical development looks like. Vet your resources and consider what you are being “sold.” You are your child’s best caregiver and your intuition is worth as much as the newest products or recommendations.
Don’t wait too long to address a delay in their skills. Every baby develops at a slightly different rate, but there are healthy windows of time in which a skill should be gained to avoid bottlenecking their future development. Find a happy medium between “wait and see” and rushing them to the next skill.

Need some one on one advice about your baby’s development? Schedule a virtual consult with Dr. Caitlin today!