Before your baby can even start thinking about putting one foot in front of the other, she needs to master that skill of coordinating her limbs. Many children work this part out through crawling, which strengthens their trunk muscles as well as their limbs, and is often an important part of their development of vision, hand-eye coordination, and dexterity. While there are other ways to develop these skills, enough children get them through crawling that there’s a widespread school of thought that cross-crawling, the skill of moving alternate arms and legs forward at the same time, is a necessary milestone for creating neural pathways that coordinate the two sides of her brain.
The school of thought based around the importance of crawling, introduced by Glenn Doman, is widespread enough to have made it into certain therapies for developmental delays, but it’s a theory that has its challengers. Parents of early walkers who skipped crawling often share anecdotal evidence about how not crawling hasn’t hurt their children, and anthropologists point out that certain cultures bypass crawling altogether, and that, historically, widespread crawling may be a relatively new phenomenon, and not a universal developmental step.
Cross-crawling is what happens when babies figure out that they can move a lot faster if, instead of moving just one limb at a time, they move their leg forward at the same time as their alternate hand, so that their left leg moves forward at the same time as their right hand. It takes a lot more coordination than the alternative of moving one limb, then the next, but once they figure it out, it can help them move across the floor faster than you might think is possible, which may be why so many babies do develop cross-crawling as a way to get around.
Depending on who you talk to, either very or not much at all. Cross-crawling can be a great way to get started with the hand-eye coordination and left side-right side coordination, but that doesn’t mean it’s the only way to get that coordination. A 1987 study showed a potential connection between difficulty reading during childhood and skipping crawling, but for one thing, it’s certainly not something that happens in every, or even most, cases, and for another it doesn’t mean that one causes the other. Other scholarship, including a 2006 article in Child: Care, Health and Development, found no long-term effects of skipping crawling.
If you’re concerned, you can encourage your baby to crawl just by making sure she gets plenty of time on her tummy, even as she gets older, and by giving her time to explore, and maybe put a few things you know she will want just out of her reach now and then as encouragement.