At about 4 months, diaper changes with my son, Miles, became quite a challenge. With those little legs moving like he was running a sprint, getting the diaper on and off was quite a feat. But that motion had a purpose. He was building up the leg muscles he needed to crawl, stand, and eventually walk. And the way he seemed as if he couldn't stop himself from moving? In a way, he couldn't -- the part of the brain that would tell him to stop before wearing himself out, the part responsible for impulse control, just doesn't exist yet in an infant. So babies kick and kick, and that's a good thing, because if they had control of their impulses they wouldn't build up the muscles needed to be walking by 15 months.
Muscle development tends to progress from head to toe, with babies gaining head control, then developing arm strength, and lastly building up those leg muscles. Babies often move backward first, because it's easier to push those heavy legs backward than drag them along forward. Once babies learn to crawl, usually around 7 months, their whole world changes and widens. Curiosity motivates crawling, says University of California at Berkeley psychology professor Joseph J. Campos, PhD, a leading researcher in infant mobility. "It gives them a reason to put the muscles together to crawl." Babies become more curious about the world because they can see more of it. That toy on the other side of the room used to be just a blur, but by 8 months vision focuses to nearly perfect 20/30. Space and distance become real concepts. Before your baby can crawl, if you point at something, he will look at your finger. But by 10 months, he'll look instead in the direction you're pointing that finger. He understands that there is a world beyond his line of sight.
This awareness of distance will lead to a habit called "emotional refueling," where the baby will crawl away from Mom, explore something, then crawl back just to "check in." This is a leap in cognitive development, as your baby realizes that he can choose how much distance there will be between the two of you and he tests how far away he can be and feel safe.
Babies have an intense need to be just like Mommy and Daddy, and that's what drives the desire to walk. "Balance is so tricky," says neuroscientist Lise Eliot, PhD, author of What's Going On in There? How the Brain and Mind Develop in the First Five Years of Life (Bantam). "You have got so many muscles in the legs, abdomen, and back that have to be precisely coordinated so you don't topple in one direction or another."
Babies are actually born with an innate knowledge of the movements needed for walking. Stand a newborn up on her feet and she will move one foot in front of the other in a walking-like motion. This so-called stepping reflex seems to disappear at around 4 months, but in actuality babies' legs simply become too heavy for their muscles to lift. By 6 months, when you support her standing up, she won't slump over because she is learning how to use her leg muscles for strength and her feet for balance. Once the muscles are built up, walking can begin in earnest. This just happens to coincide with the time when the brain is developed enough to handle balance and spatial understanding. Once babies can stand upright, one way we encourage them to walk is by holding them by their hands and helping them get across the room. So by creating a safe cruising environment and helping your baby balance, you're providing invaluable stimulation.
Once children master walking -- usually by 15 months -- it seems that they immediately start to run. And why not? Running is a rush. Aside from requiring improved balance, running also teaches children a lot about terrain. After all, running on a bumpy road could lead to a nasty fall, says kinesiologist Rosa Angulo-Barroso, PhD, director of the Brain/Behavior Relationships in the Developing Child program at the University of Michigan. You'll see your child start to alter his gait depending on his environment -- maybe even get back down on all fours if the surface looks particularly intimidating. This assessing and adapting shows that your naturally egocentric child is starting to understand that the red carpet isn't rolled out everywhere he goes. There will be challenges, and he has to learn to adapt to them. And then he'll experiment. A 2-year-old loves to practice standing on one foot. Then it's just a matter of time before he's jumping, skipping, hopping, and galloping. "If the only thing you were to ever do was walk, and always at the same speed, you would develop only one set of muscles," Angulo-Barroso says. "But we need to learn how to use our muscles in different ways."
Your child's mastery of motion will result in many skinned knees to kiss and anxious tears to hug away. But before you know it, you'll have a toddler who can walk up and down the stairs (alternating feet, even) and run circles around the playground -- a child whose favorite line will be, "Mommy, look what I can do!"
Don't panic if your child isn't crawling or walking on the same schedule as the kid next door. What accounts for the wide variety in milestone achievement? If he's not crawling, odds are, he's focused on learning to talk or on picking up that raisin and getting it in his mouth. But there does come a point when a lack of mobility becomes a concern. Here are signs to look for: difficulty lifting his head while lying on his stomach by 3 months, inability to hold his body weight while standing at 9 months, difficulty standing on his own by 12 months, and inability to walk independently or walking only on toes at 15 months. If you notice any of these red flags, ask your pediatrician if your child needs further testing.
The way your baby crawls could also be influenced by the clothing he is wearing. At the turn of the century, babies crawled by using their arms to pull their bottoms across the floor because their long dresses got in the way. Clothing still makes a difference today, says Campos. "Babies who are born in the winter and hence begin to reach the stage of crawling in the summer will crawl earlier by 4 weeks than babies who are born in the summer and learn to crawl in the winter," he says. "That's because winter crawlers are more likely to be wearing heavy clothes." And that's going to get in the way of practicing certain skills. So take off those socks, strip your baby down to his bodysuit, and let him explore.
Turn the family room into a baby gym with the amazing, giant, climbable blocks in this Block Party set from Parents ($180; www.target.com).
Encourage baby to look up, roll over, reach, and crawl with Tiny Love's Tropic Isle ActiviTot ($80; www.tinylove.com).
Copyright © 2008. Used with permission from the February 2008 issue of American Baby magazine.
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