Hello, my name is Mrs. Mehrin and I am so excited to be learning with you today all about muscle strength, and we are going to be planning an investigation.

We are going to do brilliantly.

Welcome to today's lesson from the unit, introduction to the human skeleton and muscles.

Your learning outcome for today is, I can plan a simple test to investigate muscle strength in humans.

Now, we are going to be touching on some of your previous learning about why humans have muscles and how we can use muscles to help us to move.

I know sometimes learning can be a bit challenging, but that's okay, because we're going to work hard together and we're going to learn lots of fabulous new things.

I can't wait to do some fantastic learning with you.

So, I'm going to go through the keywords with you today.

Now, you don't need to write these down, but once I have gone through them, if you'd like, you can pause the video and jot them down, but I will refer to them throughout the video today.

Now, here are the meanings to our keywords.

Again, you don't need to write these down, but if you'd like, once I've gone through them all, you can pause the video and you can have a read through.

I will be referring to these throughout the video today.

Fantastic! I am really excited to begin our learning.

So our learning today is split into two parts.

Let's begin with the first part, muscle strength.

All of these people need strong muscles to move their bodies for these activities.

We have karate, weightlifting, running, and arm wrestling.

Now, I want you to think really carefully about this question.

Do you think they all have the same muscle strength? I'll give you five seconds to have a think about this question, but if you do need longer, you can pause the video here.

Off you go.

Fantastic thinking, well done.

So muscle strength is often different in different people.

Now, these animals use their muscles to move in different ways.

Here we have a frog, cheetah, and sloth.

Now, they need strong muscles to be able to hop, to run, to climb, and balance, and muscle strength is often different in different animals, just the same way that muscle strength is different in different humans as well.

Let's do a quick check of your learning.

So true or false, all adult humans have the same muscle strength.

Is that true or is that false? I'll give you five seconds to think about your answer, but if you do think you're going to need longer, you can pause the video here.

Off you go.

Fantastic, well done.

The answer is false.

Adult humans do not all have the same muscle strength.

Now let's see if we can justify our answer.

So is it because A, taller people have stronger muscles, or B, muscle strength is often different in different people? Again, I'll give you five seconds to think about your answer, but if you need longer you can pause the video here.

Off you go.

Fantastic, well done.

The answer is B.

Muscle strength is often different in different people.

It doesn't have anything to do with how tall or short a person might be.

Now let's have a look at the next question here.

It says, which person would need the most muscle strength? Would it be A, a person running a marathon, B, a person sleeping, C, a person climbing some stairs, or D, a person reading a book? I'll give you five seconds to think about your answer, but if you think you need longer you can pause the video here.

Off you go.

Fantastic, well done.

The answer would be A, a person running a marathon.

You are doing so well! Well done.

So these children all have different muscle strength.

Andeep says, "I've got strong leg muscles which help me to score goals." Sofia says, "I've got strong finger muscles which help me to rock climb." Lucas says, "I have strong arm muscles as I use them to make my wheelchair move." Do you think some of your muscles are different strengths to your friends' muscles, and why do you think that might be? I'd like you to think about this question.

Have a look at what Andeep said, what Sofia said, and what Lucas said, and think about how your muscles might have a different strength to your friends' muscles and why that might be.

So I'd you to pause the video here so you can have a really good think and then come back to our video.

Off you go.

Fantastic, well done.

So you will have noticed that your muscles may have a different strength to your friends' muscles.

So that might be that your arm muscles are stronger or their leg muscles might be stronger, so we have different strengths to other people.

Now, Lucas says, "I have to do exercises to strengthen the muscles in my hands," and, "The nurse measures my muscle strength." "My cousin is a gymnast.

He has to measure his arm muscle strength to make sure he can swing on the high bar." And Laura says, "My gran is a marathon runner and has to measure her leg strength.

I wonder how muscle strength is measured?" So I'd like you to think about the question that Laura just asked.

I'll give you five seconds to think about that question, or if you think you are going to need longer, you can pause the video here.

Off you go.

Fantastic, well done.

So muscle strength can be measured in different ways.

So you might use this tool here, which is called a hand grip.

And Lucas' nurse could measure how hard Lucas could squeeze these grips with his hand.

Jun's cousin could time how long he could hold himself up on the high bar.

And Laura's gran could measure how much weight she could push with her legs on this leg press.

Let's do a quick check of your learning so far.

Which piece of equipment could you use to measure muscle strength? Would it be A, a ruler, B, a measuring jug, or C, a hand grip? I'll give you five seconds to think about your answer, but if you need longer you can pause the video here.

Off you go.

Fantastic, well done.

The answer is C, hand grip.

So for your first task then, I want you to think of a famous sports person you know of, so they might be a footballer, a swimmer, an athlete, or a dancer, and I want you to try to explain which of their muscles need to be strong for them to succeed in their sport, and what could they do to further strengthen those muscles? So I'm going to give you some time now.

I'd like you to pause the video here and have a go at this activity.

Off you go.

Fantastic, well done.

So, you may have written something like this.

The footballer I chose would have strong leg muscles so they can score goals and run fast on the pitch.

They could do lots of sprinting to strengthen their leg muscles.

The wrestler I chose would have strong chest, arm, and back muscles so they can lift and throw opponents to the floor.

They could do lots of weight lifting to strengthen these muscles.

Or, the gymnast I chose would have strong core muscles, so they can balance on the beam.

They could do lots of cross-training to strengthen these muscles.

So have a look at your explanation and then have a look back at this one.

Do you think yours is similar or different to these explanations? Off you go.

So, let's move on to the second part of our learning today, which is planning a muscle strength investigation.

So the children in Izzy's class are training for a school sports event.

Izzy says, "I have the strongest leg muscles, so I will be able to run the fastest." Sam says, "Fast running does not just depend on leg muscle strength." Who do you agree with and why? I'll give you five seconds to think about your answer, but if you need longer you can pause the video here and then come back.

Off you go.

So Izzy wonders if there is a link or pattern between the strength of people's leg muscles and how fast they can run.

So she asks the question, "Do people with stronger leg muscles run faster?" Now, Izzy will need to plan the right type of investigation to answer her question.

So when scientists investigate humans, they often plan a pattern seeking investigation.

This is because humans can be very different in lots of ways, such as size, age, height, and strength, and these are variables that scientists can't easily control.

So scientists observe living things doing something and then they measure and compare them by looking for patterns.

So which type of investigation do you think Izzy should do in order to answer her question: do people with stronger leg muscles run faster? Who do you think is right? So Aisha says that Izzy should carry out a fair test, Sam says that Izzy should carry out a pattern seeking investigation, and Jacob says that he thinks Izzy should make and compare observations over time.

So I'll give you some time now to think about that answer.

I'd like you to pause the video here and have a really good think.

Which of those children do you think is right? Which type of investigation should Izzy do to answer her question? I'd like you to pause the video here and have a go.

Off you go.

Fantastic, well done.

So the one that Izzy should choose should be Sam's, where she would carry out a pattern seeking investigation.

So, Izzy starts to plan her investigation, and she needs to measure leg muscle strength and measure running speed.

So Izzy says, "I will measure how many kilogrammes people can push across the floor with both feet." And, "I will measure how long it takes for people to run 100 metres." Let's do a quick check of your learning before we carry on.

So which unit would you use to measure how long it takes people to run 100 metres? Would it be A, metres, B, kilogrammes, or C, seconds? So I'd like you to have a really good think about that question.

I'll give you five seconds to think about your answer, but if you need longer you can pause the video here.

Off you go.

Fantastic, well done.

The answer would be C, seconds.

So it says here to help Lucas to plan a pattern seeking investigation to find answers to this question.

So his question is, "Do people with stronger arm muscles throw further?" So when you are making this plan, I want you to include any equipment that you're going to need, how you plan on measuring arm muscle strength, how you are going to measure the throwing distance, who you're going to collect your data from, and how you are going to record any of the data that is collected.

So I'd like you to pause the video here, I'd like you to give this a go, and then we can have a look at ways that you may have done your plan.

So pause the video here now and have a go at that.

Off you go.

Fantastic, well done.

So, we have got Aisha, we've got Sofia, and we've got Jacob here.

Now, it says Lucas would need to use some kilogramme masses, bean bags, a stopwatch, and a tape measure.

And Aisha says, "In order to test arm muscle strength, he could see who could hold a mass the longest." Sofia says, "He could measure how far different people can safely throw a small bean bag." And Jacob says, "He could draw a table to record the data he collects from his pattern seeking investigation." So if we have a really good look at this, it explains exactly the equipment that Lucas is going to need, which is some kilogramme masses, bean bags, stopwatches, and a tape measure.

So make sure that when you are doing your plan that you have got all of those things that you are going to need to use to carry out the investigation.

We can see that Aisha's thought really carefully about how she's going to test that arm muscle strength.

Sofia's thought really carefully about safety when doing an experiment like this and measuring how far different people can throw it.

And Jacob is talking about drawing a results table to record the data that he collects from this pattern seeking investigation.

So these are all things that you're going to have to think really carefully about when you come to doing your investigation.

So I'd like you to pause the video here.

Just have a quick look at your plan.

Have you included some of the really important parts of your plan? Have you included all of the equipment that you're going to need to use? Have you thought about how you're going to record the investigation? Have you thought about safety? And have you thought about how he can measure arm strength? So pause the video here and have a look.

Off you go.

Fantastic, well done.

So, let's have a look at what your plan might have looked like then.

So you may have put something along the lines of, I will need 10 friends, a stopwatch, 3 kilogramme masses, a tape measure, and a bean bag.

So we can see here we're being really specific with the exact number of items that we need.

So make sure that you have been really, really specific in your planning too.

First, I will measure the muscle strength of 10 friends by timing how long they can hold the weight out in front of them.

So again, in this plan we can see they've thought really carefully about how they are going to measure that muscle strength and how they are going to record and make sure that this is a fair test.

So they're going to be timing how long the friends can hold the weight out in front of them.

Next I will measure how far they can throw a bean bag.

And I will record these measurements in a table.

So pause the video here, have a look back at your planning.

Have you included all of the really important parts? Off you go.

Fantastic, well done.

If you have included all of those things, this is going to be a fantastic investigation.

So let's go through the summary of our learning today.

Muscle strength is often different in different people.

Muscle strength can be measured in different ways.

Scientists ask questions, then plan how to carry out an investigation to find answers.

And scientists choose the correct equipment to take accurate measurements.

Well done.

I have really enjoyed planning out an investigation to measure muscle strength.

You have worked so hard.

There's been lots of new information, but you have worked brilliantly.

You have thought really hard and worked well.

Fantastic learning today.

Well done.