C2 - Biomechanics Flashcards
What is a lever?
A lever is a rigid bar that pivots around a fixed point called the fulcrum to move a load with the application of force (effort).
What are the components of a lever system?
Fulcrum, Load, and Effort. The position of these components defines the type of lever.
How do you remember the orders of the components of levers?
123
FLE
How does the position of the fulcrum affect the type of lever?
The position of the fulcrum relative to the load and effort determines whether a lever is first, second, or third class.
What is mechanical advantage in a lever system?
Mechanical advantage is the ability of a lever to amplify the force applied. It depends on the relative distances of the load, effort, and fulcrum.
How does the mechanical advantage affect the movement of a lever?
A greater mechanical advantage allows for a greater force to move a load with less effort, while a lower mechanical advantage allows for greater speed and range of motion.
What is Newton’s First Law of Motion?
Law of Inertia: An object will stay at rest, or move at a constant velocity, unless acted upon by an external force.
How does Newton’s First Law apply to sports performance?
Athletes must apply an external force to overcome inertia, such as pushing off the starting blocks in a sprint or changing direction in football.
What is Newton’s Second Law of Motion?
Law of Acceleration: The force on an object is directly proportional to its mass and acceleration (F = ma).
How does Newton’s Second Law relate to performance in sport?
The amount of force generated by an athlete determines their acceleration, meaning that for a given mass, higher force leads to faster acceleration.
What is Newton’s Third Law of Motion?
Action and Reaction: For every action, there is an equal and opposite reaction.
How does Newton’s Third Law apply in sport?
When a sprinter pushes off the ground, the ground pushes back with an equal force, propelling the athlete forward.
What is stability?
- State of equilibrium
- Ability of body to resist motion/remain at rest
What factors affect stability?
- Base of Support
- Centre of Mass
- Mass
- Posture/Alignment
How does the centre of mass affect stability?
The lower the centre of mass and the closer it is to the base of support, the more stable the body is.
What role does posture play in maintaining stability?
Proper posture ensures that the centre of mass stays over the base of support, enhancing balance.
How does increasing the mass of a body affect stability?
A greater mass increases stability by providing more resistance to being displaced from a balanced position.
How does the base of support influence stability?
A larger base of support (e.g., a wider stance) increases stability, while a smaller base makes it easier to lose balance.
What is the centre of mass?
The centre of mass is the point at which an object’s mass is evenly distributed. It is the balance point of an object.
How does the centre of mass affect balance?
Balance is maintained when the centre of mass is kept within or near the base of support.
How does body position affect the centre of mass?
A person’s centre of mass can shift depending on their posture (e.g., standing vs. crouching). Lowering the centre of mass improves stability.
How can athletes control their centre of mass during sport?
Athletes control their centre of mass by adjusting body posture, such as lowering the body in a sprint start or a diving position.
How does the centre of mass affect sports like gymnastics and diving?
Gymnasts and divers shift their centre of mass to control rotations and maintain stability during aerial movements.
How can the centre of mass change during movement?
The centre of mass moves as the body changes posture or as different body parts move in relation to one another (e.g., running, jumping).
What is a first-class lever and its advantages?
A first-class lever has the fulcrum between the load and the effort.
Example: The neck during flexion and extension - heading a football.
Advantage: Can provide either mechanical advantage or disadvantage
What is a second-class lever and its advantages?
A second-class lever has the load between the fulcrum and the effort.
Example: A calf raise.
Advantage: Provides a mechanical advantage, requiring less force to move a greater load.
What is a third-class lever and its advantages?
A third-class lever has the effort between the fulcrum and the load.
Example: A bicep curl.
Advantage: Provides speed and range of motion, but at a mechanical disadvantage.
What is the equation for mechanical advantage?
MA = effort arm / load arm
