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13 Jan 2026
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Comprehensive P.E. Notes: Bones, Muscles, and Joints
kamea
@kameasnotes
1 / 5
The Skeletal System and Bone Functions
Think of your skeleton as your body's ultimate support framework - without it, you'd literally be a blob of soft tissue! Your bones have six crucial jobs that keep you moving and healthy.
The main bones you need to know include the femur , humerus (upper arm), tibia (shin bone), and your cranium (skull). These come in different shapes: long bones like your femur, flat bones like your ribs, and irregular bones like your vertebrae.
Your skeleton's six functions are support, protection, movement, shape and structure, blood cell production, and mineral storage. For example, your ribs protect your lungs while supporting your intercostal muscles, and your cranium acts like a helmet protecting your brain during contact sports.
Quick Fact: Your bone marrow produces all your blood cells - that's millions of new cells every day!
Synovial Joints and Movement Types
Synovial joints are where the real action happens in sports - they're your body's most moveable joints and include two main types you'll encounter constantly.
Ball and socket joints (like your shoulder and hip) are the superstars of movement. They can move in every direction - away from your body, back towards it, and rotate completely around. This is why you can throw a cricket ball or swing a tennis racket with such range.
Hinge joints (elbow, knee, ankle) work exactly like a door hinge - they only bend one way. Your elbow can only flex and extend, which is why you can't bend your arm backwards! The key components include synovial fluid (nature's lubricant), cartilage (your shock absorber), and ligaments (the strong bands holding bones together).
Remember: Ball and socket = maximum movement, hinge = one direction only!
Joint Movements in Action
Every sport movement has a specific name, and knowing these will help you understand exercise instructions and improve your technique.
Flexion decreases the angle at a joint (bending your elbow), while extension increases it (straightening your arm). Abduction moves limbs away from your body's centre line (jumping jacks arm movement), and adduction brings them back in.
Your ankles have special movements: plantar flexion points your toes down (like a ballet dancer), while dorsiflexion pulls them up towards your shin. These are crucial for running, jumping, and landing safely.
The major muscle groups include quadriceps (front thigh), hamstrings (back thigh), pectorals (chest), deltoids (shoulders), and abdominals (core). Each has specific jobs in different sports movements.
Top Tip: Practice identifying these movements during your favourite sports - it'll make PE theory much easier!
Muscles in Sport and Antagonistic Pairs
Your muscles are like a perfectly coordinated team - while one contracts to create movement, its partner relaxes to allow it. This system is called antagonistic pairs, and it's happening in every single movement you make.
The working muscle is called the prime mover or agonist - it's doing the heavy lifting. Meanwhile, the opposite muscle (the antagonist) relaxes and stretches to allow the movement. Think bicep curls: your biceps contract while your triceps relax.
Common antagonistic pairs include biceps and triceps at the elbow, quadriceps and hamstrings at the knee, and hip flexors and gluteals at the hip. Understanding these helps explain why balanced training matters - you can't just work your 'show muscles'!
Different sports actions use different prime movers: sit-ups target abdominals, kicking uses quadriceps, and shooting in netball relies on triceps.
Key Point: Muscles can only pull, never push - that's why you need pairs working together!
Types of Muscle Contractions
Not all muscle work creates visible movement, and understanding the difference will help you appreciate why certain exercises feel challenging even when you're not moving.
Isotonic contractions change muscle length and create movement - these split into concentric (muscle shortens) and eccentric (muscle lengthens under control). Press-ups, rowing, and bicep curls are perfect examples where you can see the muscle changing length.
Isometric contractions involve muscles working hard without changing length or creating movement. Think rugby scrums or holding a plank position - your muscles are firing intensely, but nothing's moving.
Both types are essential for sports performance. Concentric builds power for explosive movements, eccentric controls landing and deceleration, while isometric develops stability and core strength.
Training Tip: The best athletes use all three contraction types in their training programmes!
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THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
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very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
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Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
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Comprehensive P.E. Notes: Bones, Muscles, and Joints
kamea
@kameasnotes
Your skeleton isn't just a bunch of bones holding you up - it's actually a complex system that supports every movement you make in PE and sports. Understanding how your bones, joints, and muscles work together will help you perform... Show more
The Skeletal System and Bone Functions
Think of your skeleton as your body's ultimate support framework - without it, you'd literally be a blob of soft tissue! Your bones have six crucial jobs that keep you moving and healthy.
The main bones you need to know include the femur , humerus (upper arm), tibia (shin bone), and your cranium (skull). These come in different shapes: long bones like your femur, flat bones like your ribs, and irregular bones like your vertebrae.
Your skeleton's six functions are support, protection, movement, shape and structure, blood cell production, and mineral storage. For example, your ribs protect your lungs while supporting your intercostal muscles, and your cranium acts like a helmet protecting your brain during contact sports.
Quick Fact: Your bone marrow produces all your blood cells - that's millions of new cells every day!
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Synovial Joints and Movement Types
Synovial joints are where the real action happens in sports - they're your body's most moveable joints and include two main types you'll encounter constantly.
Ball and socket joints (like your shoulder and hip) are the superstars of movement. They can move in every direction - away from your body, back towards it, and rotate completely around. This is why you can throw a cricket ball or swing a tennis racket with such range.
Hinge joints (elbow, knee, ankle) work exactly like a door hinge - they only bend one way. Your elbow can only flex and extend, which is why you can't bend your arm backwards! The key components include synovial fluid (nature's lubricant), cartilage (your shock absorber), and ligaments (the strong bands holding bones together).
Remember: Ball and socket = maximum movement, hinge = one direction only!
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Joint Movements in Action
Every sport movement has a specific name, and knowing these will help you understand exercise instructions and improve your technique.
Flexion decreases the angle at a joint (bending your elbow), while extension increases it (straightening your arm). Abduction moves limbs away from your body's centre line (jumping jacks arm movement), and adduction brings them back in.
Your ankles have special movements: plantar flexion points your toes down (like a ballet dancer), while dorsiflexion pulls them up towards your shin. These are crucial for running, jumping, and landing safely.
The major muscle groups include quadriceps (front thigh), hamstrings (back thigh), pectorals (chest), deltoids (shoulders), and abdominals (core). Each has specific jobs in different sports movements.
Top Tip: Practice identifying these movements during your favourite sports - it'll make PE theory much easier!
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Muscles in Sport and Antagonistic Pairs
Your muscles are like a perfectly coordinated team - while one contracts to create movement, its partner relaxes to allow it. This system is called antagonistic pairs, and it's happening in every single movement you make.
The working muscle is called the prime mover or agonist - it's doing the heavy lifting. Meanwhile, the opposite muscle (the antagonist) relaxes and stretches to allow the movement. Think bicep curls: your biceps contract while your triceps relax.
Common antagonistic pairs include biceps and triceps at the elbow, quadriceps and hamstrings at the knee, and hip flexors and gluteals at the hip. Understanding these helps explain why balanced training matters - you can't just work your 'show muscles'!
Different sports actions use different prime movers: sit-ups target abdominals, kicking uses quadriceps, and shooting in netball relies on triceps.
Key Point: Muscles can only pull, never push - that's why you need pairs working together!
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Types of Muscle Contractions
Not all muscle work creates visible movement, and understanding the difference will help you appreciate why certain exercises feel challenging even when you're not moving.
Isotonic contractions change muscle length and create movement - these split into concentric (muscle shortens) and eccentric (muscle lengthens under control). Press-ups, rowing, and bicep curls are perfect examples where you can see the muscle changing length.
Isometric contractions involve muscles working hard without changing length or creating movement. Think rugby scrums or holding a plank position - your muscles are firing intensely, but nothing's moving.
Both types are essential for sports performance. Concentric builds power for explosive movements, eccentric controls landing and deceleration, while isometric develops stability and core strength.
Training Tip: The best athletes use all three contraction types in their training programmes!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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4.9/5
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
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This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user