Q. My son is almost 9½ months old, and he still hasn't started crawling yet. Is this normal?
A. The timing of certain milestones is extremely variable, especially in the area of large motor development (such as sitting, crawling, and walking). While 9 months is the average age that babies start to crawl, it's neither unusual nor abnormal for babies to put off crawling until 11 or 12 months -- or in some cases, not crawl at all. Two main factors seem to influence when babies crawl:
1. Baby's personality. Babies with mellow or laid-back personalities generally tend to sit up, crawl, and walk a month or so later than "hyper" or "motor" babies who can't wait to move. Instead, mellow babies tend to be earlier in their visual and social development.
2. Baby's weight. Bigger babies tend to sit up, crawl, and walk later than leaner babies. This stands to reason since they have more weight to lift off the ground.
Here's how to tell whether you need to worry, plus some tips for encouraging your beginning crawler:
When to worry. The main consideration in all developmental milestones is progression, not timing. Timing varies widely among babies; progression does not. Your baby should be gradually getting more and more of his body off the ground, first sitting up, then crawling, then cruising while holding on, and finally walking. Keep a developmental diary to track when your baby does what. As long as he is developing more motor skills this month in comparison to the previous month, you don't need to worry. However, if your baby reaches a plateau, showing no progression over a two- to three-month period, this is a cause for concern and should be reported to your baby's health care provider at his next checkup. Another indication that a developmental problem is causing your baby to be a late crawler is if he is late in many other milestones as well, such as social, visual, and fine motor (hand-play) development.
If you are worried about neuromuscular development (such as a muscular problem in his legs), again "progression" is the key word. Each month your baby should be able to bear more weight on his legs, beginning with holding on with two hands, then one hand, and then walking on his own. Over the next couple of months he should be able to cruise around the coffee table holding on with one hand. If you notice a lack of progression in muscle strength in his legs, be sure to report this to his doctor. Finally, keep in mind that some healthy and normal babies bypass the crawling stage altogether, going quickly from sitting, to standing, to walking. One of our sons (now my partner in our pediatric practice) scooted on his bottom for several months and never really crawled.
Play copycat. Do lots of floor movements with your baby. Crawl around on the floor yourself and encourage him to copy you. Or try a little peer encouragement by placing baby in a playgroup with lots of other beginning crawlers. I've always imagined lining up ten 9-month-olds for a "race." They would all reach the finish line at various times with a wide variety of wiggly and funny movements!
Play crawling games. Lie on the floor a few feet away from your baby and give an enticing command such as, "Come to mommy!" Your baby may crab-crawl at first, going backward and sideways. Or your baby may inch along the floor in a commando-crawl before mastering the most efficient crawling skill, called cross-crawling. This is when your baby alternates his arms and legs in a rhythmic motion, each leg and opposite hand touching the floor at the same time. Try to encourage cross-crawling, since this style of movement will teach your baby balance.
As long as your baby is generally progressing in other developmental skills, don't worry that he's not crawling. Instead, look on the bright side -- it's been proven that late crawlers and late walkers tend to be less accident-prone.