When my eldest was just a tiny baby, my husband and I noticed this baby kicking legs, flailing arms, and crying on several occasions. Particularly, the baby was kicking his legs and flailing his arms at night.
But after talking with lots of my mom friends, I found that when a newborn is flailing arms or kicking legs in sleep, it’s pretty normal, depending on the circumstance.
I’ve even had my youngest baby flailing arms while nursing, though that one was easy to figure out. My milk letdown was overflowing, and she was expressing her desire for help before she got washed away.
The truth is a baby thrashing arms and legs is seldom anything to get upset about. It is normal for a baby to be flailing arms while sleeping too. Let’s break it all down to get to the bottom of this interesting phase, shall we?
Why is my baby flailing her arms and legs?
It’s not your imagination. All healthy babies will cry more often after they hit the 2-week mark. They’ll keep this up until usually around 6 weeks. Then things will get better. They will, I promise.
But when they’re crying and flailing those arms and legs, you have to wonder what’s up. As I mentioned above, if you’re nursing, it could be flailing because of milk flow. If your letdown isn’t going fast enough or is flowing too fast, your baby may be trying to tell you about it.
However, this can also be a sign of colic if the crying is happening after feeding. Colic happens when your baby cries for more than 3 hours each day for more than 3 days of the week. If this goes on for 3 weeks continuously, your baby might have colic.
The good news is that it will end at 3 or 4 months of age, but colic is a pain for parents as much as it is for the babies themselves.
In addition to the crying and the flailing of arms and legs, a colicky baby will clench fists, arch their back, draw legs to their abdomen, and struggle with an angry baby face when you hold your baby. They’re not entirely sure what causes colic though one of the guesses is that gas plays a role.
And even if your baby doesn’t have colic, having pent-up gas could cause those flailing limbs. Your best bet? Try to distract your baby. A ride in a stroller works wonders. Those baby swings may be helpful too. And for goodness sake, burp that baby! Help her work that gas out. That will usually help.
What does it mean when a baby constantly kicks his legs?
But what if your baby is just kicking their legs nonstop? Not crying, just kicking?
That was a question that I recently received from someone in Denver. I want to assure you that this is nothing to panic about, either. When a baby is constantly kicking their legs, it is a sign that he’s overstimulated.
See, babies can’t tell us, “Hey Mom! I really like your cool rock music, but I’ve had enough of this now. And these toys…there’s SO many of them. Could we like, put them away? And why the F is it so bright in here?!? Help! Must. Run. Away.” kicks legs incessantly
If you notice your baby is doing this, look around and see what’s happening. The music could be too loud, or your baby might be tired of hearing it. The lights could be too bright. See if something is overstimulating your baby.
But if nothing is stimulating your baby, you don’t need to panic. Babies are working to develop the muscles they need to crawl. So when you reach the 6-month mark, upward to 11 months, you may notice more leg movement. This is prepping baby to take those crawling journeys around your house.
Why is my baby flailing her arms and legs while sleeping?
If your baby is flailing her arms and legs in her sleep, you can rest easy. This is a normal reflex called the Moro reflex. I’ve written about this before. It’s also known as the startle reflex, which happens in their sleep.
As a newborn, this will wake them up, which is why I’m all for the swaddle. You can read about my swaddling tips here.
Plenty of adults jerk their legs and make arm movements in their sleep. I should know. My husband does it all the time!
Essentially, babies flailing their arms and legs in their sleep is normal. They will eventually stop, but to keep them from waking themselves up and from waking you in the process, swaddling your baby until they show signs they’re done with swaddling can help. I wrote about that too, which you can read here.
When do babies stop flailing their arms and legs?
The good news is that at night, the Moro reflex will disappear around the age of 5 or 6 months. If your baby is flailing her arms and legs during the daylight hours and doesn’t seem upset, she’s probably strengthening her muscles ahead of crawling.
However, if the baby seems upset, she could be overstimulated or need to pass some gas. She may even have made an epic poop, and the smell might not have made itself known just yet. Either way, this is all normal behavior.
For a baby that never seems to calm down and keeps kicking and flailing all the time, you will want to speak to your pediatrician to see if it’s colic. Your doctor can certainly help with that and restore peace in your home.
Leslie Berry lives with her husband and two young daughters in Los Altos, California, where she loves helping other moms get comfortable with motherhood and embracing the insanity with facts peppered with laughs.
She loves eating too much sushi, exercising, and jamming out on her Fender. Read more about Leslie here.