Babies build the arm strength they need for crawling through everyday activities like tummy time, reaching for toys, and bearing weight on their hands. Most babies start crawling between 7 and 10 months old, but the groundwork begins much earlier. If your baby is approaching that window and seems to need a boost, or you simply want to support their development, there are specific ways to help their arms, shoulders, and core get ready.
Why Arm Strength Matters for Crawling
Learning to crawl is more complex than it looks. Babies need to coordinate the movement of their arms and legs simultaneously while supporting their full body weight on their hands and knees. That requires strength in the shoulders, arms, and chest that most babies haven’t needed before this stage. Belly crawling, where babies drag themselves forward on their stomachs, typically appears around 7 or 8 months. The classic hands-and-knees crawl comes later, usually between 9 and 10 months, because it demands even more upper body control.
Before any of that happens, babies spend months gradually loading weight onto their arms during tummy time, pushing up, and reaching for things. Each of these small efforts builds the shoulder stability and arm endurance that crawling requires. If your baby is army crawling but not getting up onto all fours, arm strength is often the missing piece.
Start With Tummy Time (and Build It Up)
Tummy time is the single most effective way to strengthen your baby’s arms, and it can begin the day you come home from the hospital. For newborns, the AAP recommends 2 to 3 short sessions per day lasting 3 to 5 minutes each. By 7 weeks, you should be working up to 15 to 30 minutes total per day. As your baby gets older and stronger, they’ll naturally tolerate longer stretches and start pushing up higher, which increases the load on their arms and shoulders.
If your baby fusses during tummy time, placing interesting toys nearby gives them something to focus on. Toys that light up, make sounds, or have high-contrast patterns work well for younger babies. The goal is to keep them engaged long enough that they’re working those muscles without realizing it. You can also lie on the floor face-to-face with your baby, which gives them a reason to lift their head and push up to see you.
Baby Planks and Weight-Bearing Activities
Once your baby can push up on their arms during tummy time, you can introduce more targeted activities. Baby planks are one of the most effective exercises for building the arm strength needed to transition from belly crawling to hands-and-knees crawling.
To do a baby plank, gently support your baby’s hips or legs while they bear weight through their hands on the floor. This forces their arms and shoulders to hold more of their body weight than they would during regular tummy time. You can vary this by supporting just one leg, which makes the exercise slightly harder and mimics the weight shifts that happen during actual crawling. Another variation is placing your baby’s hands on a low step or slightly elevated surface, which changes the angle and recruits different parts of the shoulder.
Weight-bearing through one arm is another useful skill to practice. When your baby is sitting, offer them a toy on one side so they lean and prop themselves up with the opposite hand. This builds the ability to support their weight on a single arm, which is exactly what happens with every crawling stride. You can also try placing their hands on a slightly unstable surface, like a soft cushion, which forces the small stabilizing muscles around the shoulder to work harder.
Use Toy Placement to Encourage Reaching
Strategic toy placement turns everyday play into arm-strengthening practice. When your baby is on their tummy, place a toy just out of reach so they have to extend one arm forward while supporting themselves with the other. This single-arm weight-bearing is excellent preparation for crawling. Choose toys small enough that your baby can grab them with one hand, so the other stays planted on the floor doing the real work.
When your baby successfully reaches a toy, move it to a different angle or slightly farther away. This encourages them to pivot on their belly and shift their weight in new directions, strengthening the arms from multiple angles. Over time, you can place toys progressively farther away to encourage your baby to actually move toward them rather than just reach. This natural motivation is often more effective than any structured exercise.
The Surface Your Baby Practices On Matters
The floor surface can make a real difference in how effectively your baby practices. Research published in Applied Ergonomics found that babies crawling on hardwood floors had significantly slower crawling rates and spent more time with their hands in contact with the floor compared to textured surfaces like woven mats. Hardwood’s low friction makes it harder for small hands to grip and push off, which can actually discourage crawling practice.
Surfaces with moderate texture and some cushioning, like carpet, foam play mats, or woven mats, give babies the traction they need while also absorbing impact from the inevitable face-plants. A firm, safe surface on the floor is ideal. Avoid overly soft surfaces like beds or couches, which are too unstable for a baby learning to bear weight on their arms. Going barefoot (and bare-handed) also helps, since skin grips better than socks or sleeves on most surfaces.
Floor Time Over Container Time
Every minute your baby spends in a bouncer, swing, or infant seat is a minute they’re not loading weight onto their arms. These devices support your baby’s body for them, which means the muscles that need strengthening don’t get used. This doesn’t mean you can never use a bouncer, but the balance matters. Babies who spend more of their awake time on the floor, free to push up, roll, pivot, and reach, build upper body strength faster than those who spend most of their time contained.
Give your baby as much supervised floor time as possible throughout the day. A clean, safe area with a few motivating toys is all you need. The floor provides the firm resistance their arms need to push against, and the freedom to move in any direction lets them practice the weight shifts that lead to crawling.
Preparing Your Home for a Mobile Baby
As your baby’s arms get stronger, they’ll start moving in ways that surprise you. It’s worth baby-proofing before they’re fully crawling, because the transition from stationary to mobile can happen fast. Install safety gates at the top and bottom of stairways, and avoid older accordion-style gates that can collapse and trap a baby. Secure heavy furniture like bookshelves and dressers to the wall to prevent tip-overs, since a newly mobile baby will pull on anything within reach.
Keep small objects off the floor, especially round items like marbles or coins that are easy to choke on. Secure windows with guards, and move any breakable or dangerous items to higher ground. The Consumer Product Safety Commission also warns against placing babies in infant seats on countertops or tables, since a baby’s increased movement at this stage can cause the seat to slide off the edge.