Babies | First Steps | FULL EPISODE |

As adults, we take walking for granted. This incredibly weird and unique form of locomotion that we find ourselves doing all the time. But if you really sit and think about it, there's a lot going on. Incredible amount of things have had to come together for humans to be able to do this. How do you expect a tiny little body to stand up and master that? One of the most important moments in the development of the child's motor skills during the first year of life. It's a really beautiful and special moment. For the first time, the child lets go and takes these first insecure steps. One of the main things that we're interested in looking at is not just when do kids walk, but what happens to their world when they walk. This is a really difficult question because really walking changes every part of the baby's lives. And so where do we begin to even untangle that whole mess of threads? I think they're very close to walking, both of them. Eloisa pretty much is standing up all the time. The only thing she doesn't do is just go ahead and walk. It looks like she's more ready than him because she is more stable. It's always funny to watch Augusto when he's jumping. He just goes really quickly everywhere. And he looks so happy doing it that it makes you laugh every time. When you look at him, I think, oh, he's a bit slow. He's not learning as quick as his sister. But then he's very clever. He can see there's more than one way to do it. And one is more difficult for him. So he's clever enough to choose the easy way and just get on with whatever he wants to do. Augusto was so far away from her that I think Eloisa was kind of waiting. And one Tuesday, she just did her first steps. It was a memorable moment. You did it! The way science allows you to understand what's happening around you. When a baby is born, there's a movement that looks a lot like a walk. We can call it the walk of a newborn. When I had my children, it was the first thing I did and I tried. You support the baby by about 70% of its weight. And its little feet are in contact with a smooth surface. The baby is able to put these steps in front of each other, to move the legs alternately in front of each other. And this is one of the most mysterious reflexes he has, because you don't know the origin of this reflex. In 2010, with my colleagues from the Santa Lucia Foundation in Rome, we wanted to study whether newborns are already born with an innate ability to walk. We wanted to know if the walk of a newborn represents the foundations from which the baby builds its independent walk, or if it's just a strange behavior that disappears completely after birth, and therefore the independent walk has a completely new type of movement. Our hypothesis was that the walk of a newborn, the baby's first steps, were connected. Hi! Thank you for coming. And who have we got here today? This is Benjamin, and now he's three weeks old. Oh, wow! I will just explain a little bit what will happen during the experiment. So we will put really like small sensors to record the muscular activity. Everything is safe and everything is properly done for babies. Ready to walk, yes? We did this study in collaboration with the neonatology department of the Sant'Eugenio Hospital in Rome, where there were these two or three-day-old babies. We wanted to study the muscular activity of the walk of a newborn and then compare it with the muscular activity of the independent walk. Ready? Okay, you can start. Number one. Okay? Yes. I don't remember when they are so young. What we're gonna do now is we start the treadmill and he will start to walk. Try it. Wow! Yay! Here we go. Walking. Let's try it. Yay! Where is your mommy? Yay! Mommy! It was quite a challenging research, but beautiful. In the end, we were able to record 46 newborns. Before, the technology was not at the level that would allow you to do this type of experiment. We tried it and we did it. I'm happy to say. Yay! To test our hypothesis, we had to collect more data on the first steps of the babies. To see the relationship that there was between the different phases of the development of the walk. To see if there was at least a correlation between the walk of the newborn and the independent walk. That's mommy's phone. Just ignore it. He's absolutely shifting his weight from the left leg to the right leg and he's trying to use his feet to get to his toy. Good boy. Keep coming. Nelson, come. Come, Nelson. Yeah, come. Come. Do you want to let go? And you can walk to mommy. Do you want to do that? Do you want to walk to me? Come on, then. Go. There you go, little Nelson. Come on. Nelson is a good boy. He's walking now. He's a big boy. You've done such a great job, my son. Well done, you. Well done, Nelson. Good girl. Today, he walked all the way from the sitting room and all the way up to here, baby. Wow. Without grabbing onto anything. Proper little jump. Like proper walking. Proper little jump. I just can't get over. Look at this. I just can't get over. He's like a little speedy Gonzales. Look at that. That's just amazing. He's gone from a few really sensitive steps to like just going nuts. I haven't quite grasped how terrifying this is going to be. Okay, let's look to one of the little children. So different from the others. They're so big. A big boy. Doopie, doopie, doopie. So good boy. Stand up. Stamp, stamp, stamp. Lars, jig dancing? Yeah. Obviously, naturally, the child begins to walk. Ah! It's important for parents to know that they can stimulate this walk in the newborn. Sumo boy, I guess. Our little man. A child needs to grow, develop at the brain level, develop physical strength before he can walk on his own. That's it, go on. But the more you can encourage the child to walk and use his muscles, the more you can help him in his physical development. Augusto doesn't seem too interested in walking yet. Because he's a twin, I can obviously compare him all the time with Eloisa and I can see he's a late developer. At the beginning, I was really worried. When he was born, I immediately noticed he had a weak side. Eloisa was two kilos and 700 grams and Augusto was a little bit under two. He was really tiny, so we had to stay in the incubator for ten days. It felt really scary. We had him checked, seen by a special pediatric development specialist. They gave us a lot of reassurance that he's fine, he doesn't have any problem. He's just lower in the development. Particular interest is how exercise and physical activity ends up reflected in skeletal remains. I come from a long line of people who like to pick up very heavy objects and put them down again. In my spare time, I am a powerlifter and a CrossFit instructor. My grandfather was a bodybuilder and a gymnast. He was one of the only people to ever do a gymnastics routine on top of the Empire State Building. One of the ideas that's fascinated me my whole life is not only how exercise shapes and grows your muscles, but the fact that it can also shape and grow your skeleton as well. If you do a lot of activity, your body is going to lay down more bone. If you're a couch potato, it's going to take away bone. Infants were my big interest when I was in graduate school. What I was really interested in knowing was how does the young human skeleton respond to the challenges of standing upright and taking your first steps. Hey, do you want to come? Do you want to come to mommy? By the way, he can pick himself up now. If he fell on the floor or if he sat down, he can go from sitting position to standing position to walking. In my field, people have always thought that there was some sort of line in the sand where after a particular age, the activity that you did was affecting your body, but before that it wasn't. We tended to ignore how activity affects the bones of very young children, of infants and toddlers. I realized that there was this huge gaping hole, this deficit in our knowledge. So in 2006, I visited about 15 different museums throughout Europe and Africa and the United States and the Middle East, essentially carrying about 130 pounds of scientific equipment on my back to look at infant bones. I was really interested in exploring developmental changes, but across a broad range of time and space. So I was looking at individuals as recent as the 20th century, but also dating all the way back to 250,000 years ago across multiple countries and continents. One of the things about working with the remains of very young individuals is that the remains are very fragile, and when you're handling them and studying them, it's easy to sometimes think about the children that they were, the children that died thousands, hundreds, decades ago, right? But if you pay attention to them, right, those children get to speak to you again in a new way. You can get these very brief snapshots at different phases of growth, and that's incredibly valuable. The data that I collect is bone cross-sections. I mold the outside of the bone to get a nice replica of the outside of the bone cross-section, and then I take a couple of x-rays from different angles in order to reconstruct the inside of the bone. I ended up collecting data on over 600 infants and children. Back, what I ended up doing was developing all these different films by hand. It was such an enormous relief to see the slow, hazy emergence of these young kids' bones finally coming out on film. Yeah, so this one's actually pretty small. This one's probably around one year old, actually. Little. As I looked at the data, I could see that there were interesting patterns in early childhood growth that didn't look very much like adults at all. When you look at the cross-section of an adult leg bone, it looks like an upside-down teardrop. So it's really long from front to back. However, what I was looking at when I was seeing the kids, they were not this upside-down teardrop shape. They were sort of like a wide oval. And then it started to normalize and go back towards this adult-like pattern by the time they were around 5 or 6. Seeing the bones get suddenly wide was really surprising and was really exciting because it looked like there might be unique patterns of bone growth that you only see in little kids in response to walking. At the time, this was kind of an unusual idea. We were still stuck in this mindset that it was really only adult bones that responded to exercise. I'll never forget reviewer 2 on my very first paper of trying to publish this who left me a one-sentence review that simply said, children's bones don't respond to exercise. So that was the kind of pushback that I was dealing with from some members of the academic community at the time. But once I'd seen this pattern, I really knew that I wanted to explore this further. A unique shape just wasn't enough. So I started talking to a few of my colleagues about how we could possibly add some data from living children to this issue. It's imbalancing, imbalancing. You've got to come and get it. That's it. Turn yourself around. Good boy! He just had no interest in crawling and then he sort of started cruising quite a lot, sort of walking around the table and along the sofa. Yay! He's almost got him. Where's the fuzzy feet? He's got him! But still finds that he needs that safety net. Even when he's walking up the corridor, he's sort of got one hand on the wall just as a bit of a safety. Round the corner. I don't feel like he's quite ready yet to take that hand away. It's quite a nice sort of comfort for him being able to hold on to the side of it. Come on up to Dad, bud. Hey, buddy. Paz. Hey, come here. Come to Dad. Come on. Yay! Then all of a sudden it was like, oh, oh, oh, he's doing it. And he sort of did about three or four steps and then fell over. We were like, wow, that was his first steps. It was a real proud moment. I feel like out of all the milestones that a baby has in the first year of their life, for me, walking was a really big one. Where's Daddy? Come on. Sometimes I do feel like a bone detective. It's interesting because I'm always investigating this thing, the human skeleton, that most people would not find that informative. But I had this hunch that the unique shape of the bone I was seeing in individuals right after they started walking had something to do with shifting their weight back and forth. I needed more information. I really needed some living babies. Hi. Are you going to give it back to him? That is much more exciting. That's so nice. I contacted Dr. Kara Akebak. She works primarily with locomotion and activity in living humans. Sure is hard. You want it? Stick it on your hand. So what we're going to do is put several of these kind of all throughout her body, highlighting the major joints so we can see how they move when she walks across the floor. We're going to see how many will stay on before they get torn off and put into mouths. And basically, when the cameras look at them, they're turned into this collection of dots. And we'll get to see just specifically how those different joints are moving as they walk along. Yeah. Come back, buddy. Come back. Yeah. Big boy. Come back. You guys are doing great. I think we're going to have some great walks. Yes. I wanted to test the fact that baby's bodies can change, that baby's bodies do actually respond to exercise and loading in the same way that adults do. Go in. All right. We're going to... That's awesome. It will be helpful for you to hold her. The type of data that I wanted to have is called force plate data. When you look at how adults walk, the knees are underneath their center of mass, underneath their bodies. This allows them to lift up one foot and not go toppling over and stay balanced on that stance leg. One of the things that you see is that most of their force is angled front to back. What we're actually measuring is something called ground reaction force. You can see, essentially, the ground pushing back up at these individuals who are walking across the force plates. Let's go see what Dad is doing. With these little toddlers, their legs just go straight down from the thigh to the knee to the foot, which results in this really wide base. You got it. Who is it? Where's Dad? Where is Dad? What we needed to measure was the relative amount of front-to-back force, also side-to-side force. Go get him. Perfect. We used 3D imagery to capture how their body moves as they walk across the force plate. One more time, Mabel. One more. That's a beautiful shot. You did so good. Mabel is our all-star walker. Each red line is the step that she's taking, and that's the force. She pushes down on the ground, and the ground pushes back up at her. So that's what you're seeing. Look at that. That's fantastic. It's very seldom that we actually get to combine skeletal data with data on living children, and it couldn't have worked out more seamlessly. With the 3D data, we could capture how young walkers actually do shift from side to side, and in addition to that, the force plates were actually capturing this side-to-side motion. Essentially what's happening is during this very unique brief period of development, the body is laying down more bone on the sides of the legs in order to resist these forces of toddling back and forth. It was a long path, but it was really exciting to get to the point where I could finally confirm my original hunch. Once they do manage to stand upright and start walking, that this enterprise actually changes the shape of their skeletons, and we can actually see that. Gotta jump. Your kid's bones are affected by everything that child does on a day-to-day basis. Exercise isn't just important for adults. The bones that are actively forming in a child's body need that stimulus in order to be healthy. So letting your kids run, letting your kids jump, letting your kids play, all those things are really important not only for their metabolic health, but for the actual health of their skeleton. Do you see the body? Okay, you want to walk by yourself? Fair enough. You're a big boy now. Good boy. He's now the one who's dictating what's happening around him, so he's walking towards what he himself wants to see. It's like he was sleeping, and he just all of a sudden woke up to this new, big, wild world. Good Nelson. It's just fascinating to watch him become his own person, although it's a little bit bittersweet because I see my little baby kind of just drifting into this toddler. Travel broadens the mind. It's true for adults, and it's also true for babies. One thing they've always been interested in, when babies begin to walk, their whole world expands. They can travel faster, travel further, point at things in their environment. Everyday occurrences become entirely different. One of the big questions that I've been interested in is what happens when children begin to walk, and how does that change their world? When I was a graduate student, I devised an experiment. Okay. Alright, so we're just going to come right in. We're trying to test whether or not walking and crawling babies remember objects differently. You can just have a seat here on the couch. Okay. And Nadia can just play on the floor, and I'll be back to check on you in 10 minutes. Perfect, thank you. We showed crawling and walking babies different objects. We gave an emotion towards those objects, and we just looked to see what object did the child play with? Can you roll it? There you go. As part of that experiment, I happened to give the parent a language survey. And this was primarily just to distract the parents so they wouldn't interfere during the actual experiments. What have you got there? The main finding was not at all about emotion. What we learned from the questionnaire was that walking infants had significantly larger vocabulary sizes, both in terms of how many words they understood, but also how many words that they could say, regardless of their age. Are you playing fetch with yourself? That's a doorstop. Can I have the ball? Finding this was a shock, to say the least. This was something that we had never seen before. The next decade or so of my life would be spent looking into why was there this difference that I found by accident? As a new professor at UC Merced, I knew that I really wanted to find out what is it about walking babies that's different from crawling babies that explains this difference in their language? My first hypothesis was that the walking infants would hear more words. I thought they'd be getting into more things, and that would elicit more parent talk about the things that they were getting into. So we went into about 20 families' homes to really capture how do parents and children talk when they're just in their everyday home environments? Come on in. You want to chat out back? Sure. Let's go have a seat. All right. Oh, it's so nice out here. So the idea for today's visit is to get a normal day in Penelope's world. So what we want to see is all the words that Penelope hears and all the babbling that she does, and to do that, we're going to have her wear this Lina recording device. Yeah, and so we're going to have Penelope wear this the whole day. Once we turn it on, it just stays recording, and we'll put it into this little vest so she can simply wear the vest all day, and then you don't have to do anything. Okay. You want to give me a hand? Thank you. The Lina recording device is a great tool that researchers can use. It records all the words that the child hears as well as all the babbling and talking that the baby might be doing, and it really gives us kind of the quantity of language that the infant is being exposed to in their day. There you go. You're ready. And that's it. You and Penelope just have a normal day. Go about your daily life, and then tomorrow, I'll come by and pick it up. Say bye-bye. Bye. Hello, fox. Do you see the coyotes? Whoa. They're fast, too. Yeah, the pens. Yeah, that goes. Goats. Yeah, goats. What do goats say? Goats say mah. Kind of like that. Yeah, that works up on a log. This is the output that we get from the little recording device. It actually can extract all the words that the child heard during the day as well as the words that she might have said. What we see here are the ebbs and flows, the parent talking, and the number of words that the parent said in 5-minute stretches. So for example, at 10.50, the child heard 374 adult words. The other thing that the software can do for us is also look at the child's vocalizations. The last thing that we can look at are what are called conversational turns. So this is almost like a discussion that might be happening, a ping-pong happening. That's a lion. What does a lion say? What are you doing there? When we looked at the data, it was pretty clear. In terms of how much the parents said, walking and crawling babies seem to be hearing the same number of words during a day. Similarly, walking and crawling infants seem to be making the same number of vocalizations during the day. Not at all what I was predicting. So the next thing we want to do was to peel back another layer and say, let's just not look at quantity. Let's actually look at the quality of the language environment, particularly those rich segments during the child's day. You are a good walker. So from Penelope's day at the zoo, we had some really nice interactions. Oh, look at this white duck coming up. Hello, duck. What does the duck say? Is that a rooster? This little bit really tells me as a researcher a whole lot more. We hear Penelope trying to say duck. Say duck. Duck. Struggling with it, the parent then noticing that, helping to shape that babbling, repeating the word, yes, duck. Duck. Duck. And then what does Penelope do? She learns in that moment how to pronounce the word duck. Duck. Good job. Duck. Yes, there are ducks in there. What's really interesting with a lot of our findings so far is that there are qualitative differences in how parents are interacting with their child as they're crawling and walking, and that then is one of the main predictors of the child's vocabulary development. Let's go this way. It seemed as if once they made that transition from crawling to walking, no matter what age they were when it happened, you saw this inflection in their vocabulary development, and really this dramatic increase in terms of the rate of word learning has a lifelong impact. You don't go backwards. You only go forwards. At the age of your child, talking to your baby is important. What our research is showing is that when your child starts walking, it matters even more. What is this? That is the Red River Hawk. I think it's really important to think about development as interconnected. This way. How did something like language and motor development, social interactions, how did they work together to foster this amazing creature that's unlike any other? You're always up for the camera. The first year of life for these little guys is incredibly challenging. But it's something that's going to shape their body and shape their anatomy for the rest of their lives. Thank you for my phone. There we go. Finally, we get you walking. Walking is a complete game changer for the infant. It's actually setting them on a cascade of changes that are going to happen. The baby's life is forever changed. The parent's life is forever changed. And most importantly, the way the baby and the parent interact is forever changed. Learning to walk is the key moment for their development. Because from this moment on, the world is theirs. They can go and conquer. Augusto was just jumping on his bottom as usual. And on one of those jumps, he just stood up and kept on walking as if he had been doing that forever. We're very happy. It took him some time, but he caught up. He's always dancing and jumping and proving he can do things.