Topic 1 Chapter 2: 1.1.4 - 1.1.8 Muscular Skeletal System - Biomechanics

Question 1

What is an Internal Force

Answer 1

When a muscle pulls on it Origin (O) and Insertion (I)

Question 2

What is a lever?

Answer 2

A lever is a means of applying force at a distance from the source of the force.

Question 3

What three components make up a lever?

Answer 3

Fulcrum (pivot), effort and load

Question 4

What is a class 1 lever?

Answer 4

When the fulcrum is in between the effort and load (see-saw lever)

Question 5

What is an example of a 1st class lever?

Answer 5

The triceps/elbow/forearm lever
The atlas/neck muscles used in a nodding movement

Question 6

What is a class 2 lever?

Answer 6

When the load is bigger than the effort, and the fulcrum is at one end of the lever (wheelbarrow lever)

Question 7

What is an example of a 2nd class lever?

Answer 7

The Achilles tendon/calf muscles (gastrocnemius and soleus) and ankle joint

Question 8

What is a class 3 lever?

Answer 8

When the effort is bigger than the load, and the fulcrum is at one end of the lever

Question 9

What is an example of a 3rd class lever?

Answer 9

The knee/quadricep/tibia/fibula systems
The elbow/bicep/forearm lever

Question 10

Which lever class is most commonly found in the body?

Answer 10

3rd class lever

Question 11

How does the length of a lever affect the load that can be exerted?

Answer 11

The longer the lever the less load can be exerted

Question 12

How does the length of a lever affect the speed of the load that can be exerted?

Answer 12

The longer the lever the quicker the load can be exerted

Question 13

How is a mechanical advantage created?

Answer 13

Mechanical Advantage:
Longer effort arm → Less force needed

Question 14

How is a mechanical disadvantage created?

Answer 14

Mechanical Disadvantage:
Shorter effort arm → More force needed

Question 15

Name and Explain Newton’s 1st Law of Motion

Answer 15

Law of Inertia:
- An object maintains current velocity
It can be stationary or a constant velocity
- An object / body remains constant until acted on by an external force - gravity, friction, air resistance/drag

Question 16

Give a sporting example of Newton’s 1st Law

Answer 16

When a sprinter is running at a constant speed

Question 17

Name and Explain Newton’s 2nd Law of Motion

Answer 17

Law of Acceleration:
- When a net force acts on a body / object which causes acceleration or deceleration
- Bigger the force the greater the impact on body
- Force (N or kg/m^2) = Mass (kg) * Acceleration (m/s^2)

Question 18

Give a sporting example of Newton’s 2nd Law

Answer 18

When a sprinter is accelerating or decelerating

Question 19

Name and Explain Newton’s 3rd Law of Motion

Answer 19

Law of Action and Reaction:
- Two bodies act upon each other (action / reaction)
- Forces can be equal or opposite (every action has an equal and opposite reaction)

Question 20

Give a sporting example of Newton’s 3rd Law

Answer 20

When a sprinter pushes down an backwards on the ground

Question 21

What is the definition of Centre of Mass?

Answer 21

CofM is the single point (on a body) which represents all the spread out mass of the body OR the balance point of the body

Question 22

Where must the CofM be to ensure balance of a body?

Answer 22

The CofM must be over the base of support

Question 23

How is toppling caused?

Answer 23

It is caused by weight acting vertically at the CofM

Question 24

How can an body achieve equilibrium?

Answer 24

If the body has it’s CofM over the base of support

Question 25

What is a force?

Answer 25

A force is a Push or Pull

Question 26

What is a force measured in

Answer 26

It's measured in Newtons

Question 27

What is a vector?

Answer 27

A vector is a quantity which has size (magnitude) and direction

Question 28

What is a scalar?

Answer 28

A scalar is a quantity which only has size (magnitude)

Question 29

Is force a Vector? and why?

Answer 29

Yes. It has direction and size (magnitude)

Question 30

What is a net force?

Answer 30

A net force is the vector sum of all forces acting on an object, representing the total effect of these forces on the object's motion

Question 31

What is weight?

Answer 31

Weight is the force due to gravity on a mass

Question 32

What is mass?

Answer 32

Mass is a scalar and represents the total quantity of matter in an object

Question 33

What is a warm-up?

Answer 33

A series of low-level aerobic exercises, which can be sport-specific or general in nature, aimed at preparing the body for physical activity.

Question 34

Give examples of general warm-up activities.

Answer 34

Jogging, SAQ (Speed, Agility, Quickness), cycling on a cycle ergometer, and stretching.

Question 35

What are the four main components of a warm-up?

Answer 35

Pulse-raiser, mobilising exercises for the joints, stretching exercises, and sport-specific skill elements.

Question 36

What is the aim of the sport-specific element of a warm-up?

Answer 36

To prepare the athlete for the activity, practice specific skills, increase intensity, get into rhythm and flow, and build confidence before the event.

Question 37

How does warm-up improve strength of muscle contraction?

Answer 37

Through improved elasticity of muscle fibres.

Question 38

How does warm-up affect nerve transmission?

Answer 38

It increases the speed of nerve transmission to the muscle fibres.

Question 39

How does increased muscle temperature benefit contraction and relaxation?

Answer 39

It leads to faster contraction and relaxation of muscle fibres.

Question 40

What causes improved coordination between antagonistic pairs during warm-up?

Answer 40

A reduction in muscle viscosity.

Question 41

How does warm-up impact enzyme activity?

Answer 41

Warmer muscle fibres have increased enzyme activity, enhancing contraction.

Question 42

Why is the risk of injury reduced during a warm-up?

Answer 42

Due to increased blood flow and oxygen supply to muscles.

Question 43

How are tendons affected by a warm-up?

Answer 43

They are better prepared for activity, improving skeletal muscle stability and contractile activity.

Question 44

How does warm-up affect skeletal flexibility?

Answer 44

It improves the range of motion around joints.

Question 45

What effect does warm-up have on synovial fluid?

Answer 45

It increases its production, helping lubricate joints and reduce friction.

Question 45

What theory explains the lubrication of joints during warm-up?

Answer 45

McCutchen's weeping theory of lubrication.

Question 46

How does synovial fluid benefit joints during warm-up?

Answer 46

It provides nutrients and oxygen to the articular cartilage and reduces friction.

Question 47

Is the effect of warm-up on bone density known?

Answer 47

No, it is not known.