Kinesiology, Biomechanics and Sports – Class 12 Physical Education Notes
Axes and Planes
Human body movements take place in a plane and around an axis.
Axis
An axis is an imaginary line around which a body or body part rotates.
Types of Axis
Frontal (Horizontal) Axis
Passes horizontally from left to right
At right angles to the sagittal plane
Vertical Axis
Passes from head to foot
At right angles to the transverse plane
Sagittal (Horizontal) Axis
Passes from front to back
At right angles to the frontal plane
Plane
A plane is an imaginary flat surface along which movement takes place.
Types of Planes
Sagittal Plane
Vertical plane dividing body into left and right halves
Transverse Plane
Horizontal plane dividing body into upper and lower parts
Frontal (Coronal) Plane
Vertical plane dividing body into front and back parts
Types of Movements
Flexion
Decrease in angle between two bones at a joint
Occurs in sagittal plane about frontal axis
Extension
Increase in angle between two bones at a joint
Occurs in sagittal plane about frontal axis
Adduction
Movement towards the midline of the body
Occurs in frontal plane about sagittal axis
Abduction
Movement away from the midline of the body
Occurs in frontal plane about sagittal axis
Major Muscles Involved in Sports
Muscles Used in Running
Primary Muscles
Quadriceps (Quadriceps Femoris)
Rectus femoris
Vastus medialis
Vastus lateralis
Vastus intermedius
Functions: knee extension, hip flexion
Hamstrings
Semitendinosus
Semimembranosus
Biceps femoris (long & short head)
Functions: knee flexion, hip extension
Gluteus Maximus
Largest muscle of buttocks
Maintains erect posture
Extends hip joint
Hip Flexors (Iliopsoas)
Iliacus
Psoas major
Responsible for hip flexion
Calf Muscles
Gastrocnemius
Soleus
Function: plantar flexion of ankle, knee flexion
Muscles Used in Jumping
Quadriceps
Hip flexion and knee extension
Hamstrings
Hip extension and knee flexion
Hip Flexors
Explosive movement during jump
Calves
Plantar flexion during take-off
Muscles Used in Throwing
Shoulder Muscles (Deltoids)
Rotate and lift the arm
Triceps
Extension of arm at elbow
Latissimus Dorsi
Transfers force from lower body to upper body
Abdominals
Core stability and power transfer
Quadriceps
Provide power while stepping into the throw
Newton’s Laws of Motion
Sir Isaac Newton proposed three laws of motion.
First Law of Motion (Law of Inertia)
A body at rest remains at rest and a body in motion remains in motion unless acted upon by an external force.
Second Law of Motion
The rate of change of momentum is directly proportional to the force applied and inversely proportional to mass.
Third Law of Motion
For every action, there is an equal and opposite reaction.
Application of Newton’s Laws in Sports
First Law
Soccer ball stops due to friction
Basketball follows parabolic path due to gravity
Second Law
Greater force → greater acceleration
Heavier objects need more force
Third Law
Swimmer pushes water backward, moves forward
Athlete jumps higher on solid surface than sand
Projectile and Projectile Motion
A projectile is an object thrown into the air and influenced only by gravity.
Projectile motion is the curved path followed by the projectile.
Factors Affecting Projectile Trajectory
Propelling Force
Direction and point of application affect motion
Force of Gravity
Pulls the object downward
Air Resistance
Opposes motion and reduces speed
Friction
Friction is the force that opposes motion between two surfaces in contact.
Types of Friction
Static Friction
Prevents motion when object is at rest
Dynamic Friction
Acts when object is already moving
Methods of Reducing Friction
Polishing
Makes surfaces smooth
Lubrication
Reduces friction by making surfaces slippery
Streamlining
Reduces air resistance
Use of Ball Bearings
Converts sliding friction into rolling friction
✍️ Top 10 Short Question–Answers
Q1. What is an axis?
👉 An axis is an imaginary line around which a body or body part rotates.
Q2. Name the three types of axis.
👉 Frontal (horizontal), Vertical and Sagittal (horizontal) axis.
Q3. What is a plane?
👉 A plane is an imaginary flat surface along which movement takes place.
Q4. Name the three planes of movement.
👉 Sagittal, Transverse and Frontal (Coronal) plane.
Q5. What is flexion?
👉 Decrease in the angle between two bones at a joint.
Q6. What is extension?
👉 Increase in the angle between two bones at a joint.
Q7. Define abduction.
👉 Movement of a body part away from the midline.
Q8. Name one major muscle used in running.
👉 Quadriceps.
Q9. Who proposed the laws of motion?
👉 Sir Isaac Newton.
Q10. What is friction?
👉 Friction is the force that opposes motion between two surfaces in contact.
📝 Long Answer Questions
Q1. Explain axes and planes of the human body.
Axis:
Frontal axis: Left to right; perpendicular to sagittal plane
Vertical axis: Head to foot; perpendicular to transverse plane
Sagittal axis: Front to back; perpendicular to frontal plane
Plane:
Sagittal plane: Divides body into left and right
Transverse plane: Divides body into upper and lower parts
Frontal plane: Divides body into front and back
Q2. Explain types of movements with examples.
Flexion: Decreases joint angle (bending elbow)
Extension: Increases joint angle (straightening knee)
Adduction: Movement towards midline
Abduction: Movement away from midline
Q3. Describe major muscles involved in running and jumping.
Running:
Quadriceps – knee extension
Hamstrings – knee flexion
Gluteus maximus – hip extension
Hip flexors – hip flexion
Calf muscles – plantar flexion
Jumping:
Quadriceps – knee extension
Hamstrings – hip extension
Hip flexors – explosive movement
Calves – take-off
Q4. Explain Newton’s Laws of Motion and their application in sports.
First Law (Inertia):
A stationary ball stays at rest unless kicked
Second Law:
More force produces more acceleration
Third Law:
Swimmer pushes water backward and moves forward
Q5. Explain projectile motion and factors affecting it.
A projectile is an object thrown into the air and influenced only by gravity.
Factors:
Propelling force
Gravity
Air resistance
Q6. Explain friction and methods to reduce it.
Types of friction:
Static friction
Dynamic friction
Methods to reduce friction:
Polishing
Lubrication
Streamlining
Use of ball bearings
📝 Previous Years’ Questions (PYQs ONLY)
🔹 Very Short Answer Questions (1 Mark)
What is an axis?
What is a plane?
Name any one type of axis.
Name any one plane of the human body.
What is flexion?
What is extension?
Define abduction.
Name any one muscle used in running.
Who proposed the laws of motion?
What is friction?
🔹 Short Answer Questions (2–3 Marks)
Differentiate between axis and plane.
Explain sagittal plane.
Write any two types of movements.
Explain flexion and extension.
Name major muscles involved in running.
Write any two muscles used in jumping.
Explain Newton’s first law of motion with example from sports.
What is projectile motion?
Write any two factors affecting projectile motion.
Explain static and dynamic friction.
🔹 Long Answer Questions (4–5 Marks)
Explain types of axes and planes of the human body.
Explain major muscles involved in running, jumping and throwing.
State and explain Newton’s three laws of motion with sports examples.
Explain projectile motion and factors affecting projectile trajectory.
What is friction? Explain its types and methods of reducing friction.
Explain types of movements with reference to axes and planes.
❓ FAQs (5)
FAQ 1. Why are axes and planes important in sports?
👉 They help understand body movements accurately.
FAQ 2. Which muscles are most important for sprinting?
👉 Quadriceps, hamstrings and calf muscles.
FAQ 3. Why does air resistance affect projectile motion?
👉 It reduces speed and distance.
FAQ 4. How does friction help athletes?
👉 It prevents slipping and improves grip.
FAQ 5. Why is Newton’s third law important in sports?
👉 It explains actions like jumping, swimming and throwing.
| Chapter No. | Chapter Name | Visit |
|---|---|---|
| 1 | Planning in Sports | Visit |
| 2 | Sports and Nutrition | Visit |
| 3 | Yoga and Lifestyle | Visit |
| 4 | Physical Education and Sports for CWSN (Divyangs) | Visit |
| 5 | Children and Sports | Visit |
| 6 | Women and Sports | Visit |
| 7 | Test and Measurement in Sports | Visit |
| 8 | Physiology and Sports | Visit |
| 9 | Sports Medicine | Visit |
| 10 | Kinesiology, Biomechanics and Sports | Visit |
| 11 | Psychology and Sports | Visit |
| 12 | Training in Sports | Visit |
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