0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:11# Ask Nina for some help Cos she's got a science show
0:00:11 > 0:00:14# She makes sense of her senses While helping all her fans
0:00:14 > 0:00:17# By doing her experiments with potions and with bangs
0:00:17 > 0:00:19- # Touch your tongue - Tongue
0:00:19 > 0:00:21- # Fingers - Fingers
0:00:21 > 0:00:22- # Eyes- Eyes - Ears- Ears
0:00:22 > 0:00:24- # Nose- Nose
0:00:24 > 0:00:26# Nina and the Neurons find out what you need to know
0:00:26 > 0:00:29# Nina and the Neurons find out what you need to know
0:00:29 > 0:00:32# Luke he helps us with our eyes and Felix with our touch
0:00:32 > 0:00:35# Ollie sniffs out smells and scents and Belle she hears so much
0:00:35 > 0:00:38# Bud is Ollie's brother he helps us with our taste
0:00:38 > 0:00:41# They're Nina's little Neurons and they're coming to your place
0:00:41 > 0:00:43- # Touch your tongue - Tongue
0:00:43 > 0:00:45- # Fingers- Fingers
0:00:45 > 0:00:46- # Eyes- Eyes- Ears- Ears
0:00:46 > 0:00:47- # Nose- Nose
0:00:47 > 0:00:50- # Nina and the Neurons find out what you need to know- Yeah!
0:00:50 > 0:00:53# Nina and the Neurons find out what you need to know!
0:00:53 > 0:00:56# Oh, yeah! #
0:00:56 > 0:01:00# Doo, duh, doo, duh, doo, duh, doo... #
0:01:00 > 0:01:02Ho, ho, ho! Hello there!
0:01:02 > 0:01:05I'm just doing some different types of jumps.
0:01:05 > 0:01:10I can jump and land on two feet. Oh! Or I can jump and land on one foot.
0:01:10 > 0:01:13Ho, ho! I'm a bit wobbly on one foot. Woh!
0:01:13 > 0:01:16- Two feet are much better. - BEEPING
0:01:16 > 0:01:21Oh! I hear a beep, I see a flash - I wonder what they're going to ask.
0:01:24 > 0:01:26- BOTH:- Hi, Nina! - Hi!
0:01:26 > 0:01:29We've got a question for you...
0:01:29 > 0:01:31Why do we bend our knees when we land?
0:01:31 > 0:01:36That's a great question. Why do we bend our knees when we land?
0:01:36 > 0:01:39I've been jumping and landing and it was great fun.
0:01:39 > 0:01:44Why don't you come down to my lab and we'll investigate?
0:01:44 > 0:01:46- BOTH:- See you soon, Nina! Bye!
0:01:46 > 0:01:50Bye! Well, I'm going to need some help to answer this one
0:01:50 > 0:01:52and I know just who to ask.
0:01:52 > 0:01:55OK, Neurons, time to get to work.
0:01:55 > 0:01:57WHIZZING
0:01:57 > 0:02:00MUSIC PLAYS
0:02:09 > 0:02:12Neurons at the ready, Nina!
0:02:12 > 0:02:16OK, today's question is why do we bend our knees when we land?
0:02:16 > 0:02:19Which Neuron will help us find the answer?
0:02:19 > 0:02:22- ALL:- Me! Me! Me!
0:02:22 > 0:02:25Will it be fabulous Felix?
0:02:25 > 0:02:29I can help so very much if you need the sense of touch.
0:02:29 > 0:02:31Will it be beautiful Belle?
0:02:31 > 0:02:35I send messages to brain from ear, if there's a sound, I'll help you hear.
0:02:35 > 0:02:37Will it be lovely Luke?
0:02:37 > 0:02:39For looking and seeing, day or night,
0:02:39 > 0:02:42I'll help you with your sense of sight.
0:02:42 > 0:02:44Will it be awesome Ollie?
0:02:44 > 0:02:46If it's pongy or whiffy but you can't tell,
0:02:46 > 0:02:49my messages help your sense of smell.
0:02:49 > 0:02:51Or will it be Baby Bud?
0:02:51 > 0:02:56Sour, salty, bitter or sweet, I'm your taste buddy whenever you eat.
0:02:56 > 0:02:59COMPUTER BLEEPS
0:02:59 > 0:03:03- It's Felix! - CHEERING
0:03:03 > 0:03:07- THEY CHANT:- Go, Felix! Go, Felix! Go, Felix! Go, Felix!
0:03:07 > 0:03:09Go Felix! Go Felix!
0:03:09 > 0:03:14Marvellous! A little touch can mean so much, Nina.
0:03:14 > 0:03:17Today's question - why do we bend our knees when we land?
0:03:17 > 0:03:20As jumping and landing is something we feel,
0:03:20 > 0:03:23Felix, our touch Neuron will help us today.
0:03:23 > 0:03:28Right, I need to get the lab ready before the experimenters arrive.
0:03:28 > 0:03:31Imogen loves helping in the kitchen. Grace loves art.
0:03:31 > 0:03:36- I love jumping off things. - I like landing in puddles.
0:03:36 > 0:03:40They both want to know, why do we bend our knees when we land?
0:03:40 > 0:03:43So today, for one day only, Imogen and Grace become...
0:03:43 > 0:03:45the experimenters!
0:03:48 > 0:03:50- Hi, guys! - BOTH:- Hi, Nina!
0:03:50 > 0:03:53Welcome to my lab. Thanks for your question -
0:03:53 > 0:03:56why do we bend our knees when we land?
0:03:56 > 0:04:00To find out the answer, let's start by using our senses.
0:04:00 > 0:04:04Woot woo! A senses experiment! We're ready, Nina!
0:04:04 > 0:04:06To find out more about landing,
0:04:06 > 0:04:10let's take a look at some gymnasts landing.
0:04:10 > 0:04:15Gymnasts are specially trained. You should never try this.
0:04:15 > 0:04:18Gymnasts learn how to tumble and twist and turn
0:04:18 > 0:04:23and they do lots of landing, so it's important they can land safely.
0:04:23 > 0:04:26The gymnasts bend their knees when they land.
0:04:26 > 0:04:28That's right, Luke.
0:04:28 > 0:04:31And we can see it even better in slow motion.
0:04:31 > 0:04:34And the reason gymnasts bend like this is to do with
0:04:34 > 0:04:36something called impact.
0:04:36 > 0:04:40Impact is what happens when something bumps into something else.
0:04:40 > 0:04:43If we high-five... Give me a high-five... Very good!
0:04:43 > 0:04:48When your hand bumped into mine, it made an impact.
0:04:48 > 0:04:52Do you want a go? Excellent high-fives, girls.
0:04:52 > 0:04:56And the faster the bump happens, the bigger the impact is.
0:04:56 > 0:04:59So, let's do an experiment to find out more.
0:04:59 > 0:05:02I have something over here...
0:05:02 > 0:05:06I have two eggs on blocks. OK...
0:05:06 > 0:05:11This egg is stuck onto a hard block, so let's push down on the block...
0:05:12 > 0:05:16- Push down... Does the block bend? - No.
0:05:16 > 0:05:19I didn't feel any bending, Nina.
0:05:19 > 0:05:23- It stayed just where it was. - That's right, Felix.
0:05:23 > 0:05:28But this egg is stuck onto a block with bendy bits.
0:05:28 > 0:05:33Let's push down on this block. That's it. What was that like?
0:05:33 > 0:05:38- It was bendy.- Yes, it was bendy!
0:05:38 > 0:05:42Now let's see what happens to the eggs when the blocks land.
0:05:42 > 0:05:45Let's go here. I'll bring these...
0:05:45 > 0:05:47OK, Grace...
0:05:47 > 0:05:50It's your turn first. Can you have the hard block?
0:05:50 > 0:05:53I'd like you to hold it over the top of this tube. That's it.
0:05:53 > 0:05:57Are you holding on to it tight? I want you to drop it when I say.
0:05:57 > 0:05:59One...two...three... Drop!
0:05:59 > 0:06:05- Oh! Ha, ha, ha!- Wow! What a crack!
0:06:05 > 0:06:11- Is it time to make scrambled eggs, Nina? Yummy!- No, sorry, Bud.
0:06:11 > 0:06:13Imogen, it's your turn.
0:06:13 > 0:06:16I'd like you to do the same with the bendy block.
0:06:16 > 0:06:20Hold it over the top of this tube...
0:06:20 > 0:06:22OK, I want you to drop it when I say.
0:06:22 > 0:06:25One...two...three... Drop!
0:06:25 > 0:06:29- Hey... Did it break? - No.- No, it didn't.
0:06:29 > 0:06:31- It's amazing, isn't it? - BOTH:- Yes!
0:06:31 > 0:06:34Hee-hee! So, the first egg broke
0:06:34 > 0:06:37because it landed really hard on the tray
0:06:37 > 0:06:41and made a big impact. The big impact broke the eggshell.
0:06:41 > 0:06:45When the second egg was dropped, the bendy bits hit the tray first.
0:06:45 > 0:06:48They bent and slowed the egg down.
0:06:48 > 0:06:51So, it had a much softer landing and didn't break.
0:06:51 > 0:06:55Our knees are a bit like the bendy bits in this block.
0:06:55 > 0:06:57They bend and slow us down when we land,
0:06:57 > 0:07:01so we have a softer landing and the impact doesn't hurt.
0:07:01 > 0:07:04It's not just our bendy knees that help us to land.
0:07:04 > 0:07:07Let's go somewhere squidgy to find out more.
0:07:11 > 0:07:15- Where are we going today? - Nina said it was somewhere squidgy.
0:07:15 > 0:07:21Beds are squidgy. Maybe we're going to jump up and down on a giant bed.
0:07:21 > 0:07:23That sounds like fun, Bud.
0:07:23 > 0:07:28I can't see a bed, Neurons. But it looks like we're here.
0:07:28 > 0:07:32This is Bellahouston Gymnastics Centre.
0:07:32 > 0:07:36Now, look... The gymnast is bending his knees when he lands -
0:07:36 > 0:07:39to make it a softer landing with less impact.
0:07:39 > 0:07:42That way, he won't hurt himself.
0:07:42 > 0:07:45Those mats look nice and soft, Nina.
0:07:45 > 0:07:46Oh, yes, Felix.
0:07:46 > 0:07:51- They do look soft. What does this soft mat remind you of?- A bed.
0:07:51 > 0:07:55Yes, it does look a bit like a soft mattress on a bed.
0:07:55 > 0:08:00Why do you think gymnasts land on soft mats rather than hard floor?
0:08:00 > 0:08:03- So that they don't hurt themselves. - That's right.
0:08:03 > 0:08:07Gymnasts are moving really quickly, so when they land,
0:08:07 > 0:08:09they make a big impact.
0:08:09 > 0:08:13And the soft mats help them to land more gently.
0:08:13 > 0:08:16Let's look at something that's inside our bodies that
0:08:16 > 0:08:19works a bit like the soft mats when we land.
0:08:19 > 0:08:22This is what our knees look like under the skin.
0:08:22 > 0:08:25These are the bones at the top of our legs.
0:08:25 > 0:08:28And these are the bones at the bottom.
0:08:28 > 0:08:30These pads at the ends of our bones
0:08:30 > 0:08:33work a bit like the soft mats where the bones meet.
0:08:33 > 0:08:36Let's do an experiment to find out how they work!
0:08:40 > 0:08:45This giant water balloon is a bit like the pads inside our knees.
0:08:45 > 0:08:48I'd like you guys to jump onto the water balloon
0:08:48 > 0:08:51and I'm going to film it with this special camera
0:08:51 > 0:08:56to see what happens when there's an impact.
0:08:56 > 0:08:58SPLOSH
0:08:59 > 0:09:01SPLOSH
0:09:01 > 0:09:03- Go for it! - SPLOSH
0:09:06 > 0:09:09Hee-hee-hee! That was brilliant!
0:09:09 > 0:09:12Let's watch it back and see what happened when you jumped
0:09:12 > 0:09:16on the balloon. We're going to watch it in slow motion.
0:09:16 > 0:09:20Can you see the balloon moving, even at the sides,
0:09:20 > 0:09:23- where your body didn't touch it? - BOTH:- Yes!
0:09:23 > 0:09:26Your bodies landed on one part of the water balloon.
0:09:26 > 0:09:28Because the balloon is squishy,
0:09:28 > 0:09:32the impact was spread out throughout the whole balloon.
0:09:32 > 0:09:35That helped to soften your landing.
0:09:35 > 0:09:40Landing on crash mats can help us to land safely by softening the impact.
0:09:40 > 0:09:43Our knees are the place where our leg bones meet.
0:09:43 > 0:09:46We have squishy pads at the ends of our leg bones
0:09:46 > 0:09:49and they spread out the impact when we land, so it doesn't hurt.
0:09:49 > 0:09:54Well remembered, Neurons! Have a look at this gymnast landing.
0:09:54 > 0:09:58It looks like it might be quite hard to balance when you land!
0:09:58 > 0:10:02Keeping our balance is really important when we land.
0:10:02 > 0:10:06Let's go back to the lab for one final experiment.
0:10:06 > 0:10:07So, you asked...
0:10:07 > 0:10:10why do we bend our knees when we land?
0:10:10 > 0:10:14So far, we've discovered that, when the land, we feel an impact.
0:10:14 > 0:10:18And the faster we move, the bigger the impact is.
0:10:18 > 0:10:19So take a look at this.
0:10:19 > 0:10:22In lots of different sports, it's difficult
0:10:22 > 0:10:27to keep your balance when you land. Gymnasts train hard to become
0:10:27 > 0:10:31great at keeping their balance when they land.
0:10:31 > 0:10:35Let's do an experiment to find out more. Over here, girls.
0:10:35 > 0:10:37Here we have two balance boards.
0:10:37 > 0:10:40I'd like you guys to try standing on the balance boards
0:10:40 > 0:10:42with your legs straight.
0:10:42 > 0:10:46I want you to try to keep balanced without bending your knees.
0:10:46 > 0:10:49OK, step onto it and keep those legs straight!
0:10:49 > 0:10:54That's it. Try and balance with straight legs...
0:10:54 > 0:10:55Whoo!
0:10:58 > 0:10:59Oh, ho, ho, ho!
0:11:01 > 0:11:03Oh! They keep falling off, Nina!
0:11:03 > 0:11:07OK, girls... And step off safely...
0:11:07 > 0:11:10- Was it easy to stay balanced? - BOTH:- No...
0:11:10 > 0:11:14OK, let's try again, but this time, you can bend your knees.
0:11:16 > 0:11:20That's it. And you can bend your knees... Go for it!
0:11:21 > 0:11:25Oh, my goodness! Look at those fantastic bent knees.
0:11:25 > 0:11:27Very good balancing indeed.
0:11:27 > 0:11:30Was it easier to keep balanced with your legs
0:11:30 > 0:11:34- straight or bent?- Bent.- Bent. - Bent, that's right!
0:11:34 > 0:11:37So, when our knees are bent, we're lower to the ground,
0:11:37 > 0:11:40so it's much easier to stay balanced.
0:11:40 > 0:11:43That's another reason why sportspeople bend their knees
0:11:43 > 0:11:47when they land. And it's important to land safely
0:11:47 > 0:11:49so you can keep on jumping!
0:11:49 > 0:11:52# Nina and the Neurons! #
0:11:53 > 0:11:55You asked...
0:11:55 > 0:11:57why do we bend our knees when we land?
0:11:57 > 0:11:59And I think we've answered it.
0:11:59 > 0:12:02When we land on something, we make an impact.
0:12:02 > 0:12:05Big impacts can feel painful.
0:12:05 > 0:12:09Gymnasts bend their knees to help them land more gently.
0:12:09 > 0:12:14Landing on soft mats helps us to land safely by softening the impact.
0:12:14 > 0:12:17Inside of our knees, we have squidgy pads
0:12:17 > 0:12:20that spread the impact when we land.
0:12:20 > 0:12:23Bending our knees also helps us get closer to the ground
0:12:23 > 0:12:26and stay balanced, so we don't fall over.
0:12:26 > 0:12:31- So, I hope that's answered your question.- BOTH:- Thanks, Nina. Bye!
0:12:31 > 0:12:32You're welcome. Bye!
0:12:34 > 0:12:38If you want to know more about the science that's all around us,
0:12:38 > 0:12:43go to the Nina section on the CBeebies website. Have fun!
0:12:43 > 0:12:46- ALL:- On your marks, get set, go!
0:12:46 > 0:12:48# Get sporty
0:12:48 > 0:12:51# Dooby, dooby, doop, doop, dooby, dee, doo
0:12:51 > 0:12:52# Get sporty
0:12:52 > 0:12:54# Dooby, dooby, doop, doop, dooby, dee, doo
0:12:54 > 0:12:57# If you're itching for some exercise
0:12:57 > 0:12:59- # From your head down to your toes - Toes!
0:12:59 > 0:13:01# Why not try out something new?
0:13:01 > 0:13:03- # And give it a real go? - Go!
0:13:03 > 0:13:08- # Whenever you are restless and feeling kind of bored- Bored...
0:13:08 > 0:13:14# Grab your friends and go outside and try a brand-new sport
0:13:14 > 0:13:16# Get sporty
0:13:16 > 0:13:19# Dooby, dooby, doop, doop, dooby, dee, doo
0:13:19 > 0:13:21# Get sporty
0:13:21 > 0:13:23# Dooby, dooby, doop, doop, dooby, dee, doo
0:13:23 > 0:13:27# Spinning, throwing, running, jumping, lots of fun to do
0:13:27 > 0:13:31# Cycling, diving, sliding, rolling, it's really up to you
0:13:31 > 0:13:32# Yoo-hoo!
0:13:32 > 0:13:36# If you're wondering how a swimmer swims or a bike can go so fast
0:13:36 > 0:13:41# Give it a bash and make it last, it's time to go get sporty
0:13:43 > 0:13:44# Get sporty
0:13:44 > 0:13:47# Dooby, dooby, doop, doop, dooby, dee, doo
0:13:47 > 0:13:49# Get sporty
0:13:49 > 0:13:52# Dooby, dooby, doop, doop, dooby, dee, doo
0:13:52 > 0:13:54# Get sporty
0:13:54 > 0:13:55# Dooby, dooby, doop, doop, dooby, dee, doo
0:13:55 > 0:13:57# Get sporty
0:13:57 > 0:14:00# Dooby, dooby, doop, doop, dooby, dee, doo. #
0:14:00 > 0:14:03And remember, whether it's inside, outside,
0:14:03 > 0:14:06on a bike or in a pool, we can all try something new
0:14:06 > 0:14:07and get sporty!
0:14:07 > 0:14:11- See you again soon. Bye! - ALL:- Bye!
0:14:11 > 0:14:13Get sporty!