Crawl Before You Walk
The adage, You must learn to crawl before you can walk, is one of the oldest and truest for a good reason. Scientists and doctors keep finding new evidence to support that crawling is crucial to the development of not only a child's ability to later walk, but to many other aspects of development, as well. In fact, crawling forms the basis for most other motor skills including the ability to hold a pencil or more importantly the ability to even find and focus on a pencil in the first place.
In this first of three blogs on the benefits of crawling we'll be discussing all that is learned and developed through a baby's time spent on the floor before to learning to crawl. You can navigate to Volume 2: Crawling and to Volume 3: Developing the Other Senses here or at the bottom of this first volume.
The Benefits of Crawling Volume 1: Pre-Crawling or Tummy Time
Tummy time, as it's commonly referred to, is when a baby is placed on their tummy on the floor and allowed time to develop the skills and strength required to crawl. Strengthening begins in the early weeks and months of life as babies practice tummy time, rolling, and sitting.
Symmetrical Tonic Neck Reflex, or STNR, also known as the, Crawling Reflex, kicks in around 69 months of age. STNR is considered a transitional reflex that helps babies transition from being stuck on their belly to being able to get up on their hands and knees. STNR can be observed during tummy time when babies lift their head up, which then helps their arms straighten and push into the ground while simultaneously allowing them to bend at the hips and knees so they can bear weight on their knees.
This STNR reflex begins to disappear as babies gain more stability and postural control while becoming super crawlers. STNR integration typically occurs by the first birthday. STNR that doesn't integrate can mean challenges with skills such as maintaining appropriate sitting posture, balance, eye-hand coordination, and ability to efficiently copy from the board in school while repeatedly moving the head to look up and down.
To hold the head steady and move it efficiently, all the muscles around the neck must be able to contract at the same time; this is called co-contraction. The muscles all around the trunk must be able to co-contract to hold the body steady so that it won't be easily pulled or pushed off balance. Co-contraction of muscles all around the shoulder, elbow, wrist, and finger joints helps us to move well or work with tools.
After babies begin to develop the ability to move, such as with rolling, they then gain the ability to co-contract in order to do things like sitting without falling over and stabilizing against gravity while bearing weight in their hands. You can see this when they're pushing up on their forearms and, eventually, up on their hands during tummy time and in their knees when learning to hold that hands-and-knees quadruped position.
Once they become stable in these positions they can begin to experiment with rocking back and forth and side to side on hands and knees. Finally, through practice in pre-crawling postures, babies develop enough postural control to be able to manage one hand on the ground at a time as they take their first steps into crawling.
Co-contraction leads to postural control, which leads to the ability to blend stability and mobility, which leads to motor development, which then leads to the ability to move well and work with tools. The muscles involved in developing postural control will help your baby develop a variety of motor skills- including breathing, speaking, and eating. As postural control begins, motor development gets better because postural control and motor development go hand in hand.
When a young baby lies on their back and their head is turned to one side, it causes the arm and leg on that side to straighten out or extend, while the arm and leg on the other side bend or flex. This reflex develops in utero where it helps create muscle tone before birth, and it assists with the birthing process. Its also the beginning of hand-eye coordination once the baby is born. The ATNR (Asymmetrical Tonic Neck Reflex) typically integrates by six months of age through tummy time as babies develop the ability to push their chest off the floor and turn their head to look around with control. If, for some reason, the ATNR hasn't integrated by the time babies begin to crawl, it can be helped along through crawling practice.
For a baby whose ATNR hasn't integrated, you'll notice that their elbow on the opposite side of where they're looking will bend. Sometimes this happens dramatically as if collapsing, and sometimes more subtly. But with continued practice of turning the head to scan their environment while crawling, and with practice reaching for objects in front of them instead of to the side, babies can integrate their ATNR response.
ATNR that doesn't integrate can contribute to later challenges with skills like completing motor activities that require working at and crossing the middle of the body, balancing while looking around, coordinating the use of two hands together, reading, writing, and copying.
As babies approach the crawling phase, they'll start to experiment with transitions between positions that require shifting weight in different directions and executing more complex, planned out movements, such as going from sitting to hands-and-knees, from hands-and-knees to sitting, and from sitting to standing.
Being able to transition between positions is a huge accomplishment for babies because it gives them more freedom and independence in exploring and play. Transitional movements are also important because they allow babies to develop more dynamic movement in the trunk, pelvis, and shoulders. All of which are needed for healthy development of crawling and later motor skills such as throwing a ball, climbing on a playground, and swimming.
As babies learn to support themselves in the hands-and-knees position, you'll often see them start to rock back and forth. They go forward, backward, side-to-side, and diagonal. They're working on lengthening the long finger muscles that go from the forearm, down across the wrist, through the palm, and all the way into the fingertips. This extreme extending of the wrist while rocking stretches the long finger flexors.
When babies are rocking on their hands and knees in a front to back, side to side, and diagonal motion, not only are they developing the center-of-the-body stability and control to prepare for crawling as well as lengthening the long muscles of the hand, but they are also developing all three types of arches in their palms, which they'll use later when learning to grasp and manipulate objects. Hand arches are significant because they help the hand form correctly around differently shaped and sized objects when grasping. They also contribute to skilled movements of the fingers by providing a stable base in the palm, and they help adjust the amount of force used when grasping objects such as blocks, crayons, or a pencil.
There are types of baby holding devices, such as a Bumbo, exersaucer, jumper, or a walker, that do not encourage babies to shift their weight, rotate at the trunk, or transition between positions the way playtime on the floor does. Instead, these devices allow babies to get used to playing in an upright position. Spending too much time in these types of play devices can discourage and frustrate them when they realize that playtime on the floor is way harder because it requires a level of skill and transitional abilities that aren't required in play equipment. They may protest when challenged, or simply appear to remain stuck when on the floor.
Next, we move on to Volume 2: Crawling where we learn the skills and senses developed through crawling and then on to Volume 3: Developing the Other Senses where well learn about all the other benefits that crawling provides to babies.
If you have concerns that your child did not spend enough time crawling or did not achieve some of these important milestones, please make an appointment to see one of our specialists at AdventHealth Sports Med and Rehab.