PE Studies - Biomechanics

What is biomechanics?

The study of the mechanical laws relating to the movement or structure of living organisms.

What are the three main types of motion in biomechanics?

Linear, angular, and general motion.

What is linear motion?

Where movement is along a straight or curved line, there is no rotation, and all body parts move in the same direction at the same speed

What is rectilinear motion?

Movement is linear and occurs through a straight line

What is curvilinear motion?

Movement is linear, but objects move through a curved trajectory

What is angular motion?

Motion around a fixed point or axis.

What is general motion?

A combination of linear and angular motion.

What is the difference between distance and displacement?

Distance is the total path traveled; displacement is the shortest straight-line distance from start to finish.

What is speed?

The rate at which an object covers distance (Speed = Distance

What is velocity?

Speed in a given direction

What is acceleration?

The rate at which the velocity of a body changes with respect to time.

What is angular displacement?

Represents the difference in the angle between the start and end position of the body.

Angular Distance

Represents the sum of all angles as a body moves from its start position to its end position

What is angular speed?

Angular speed is calculated by dividing angular distance by time.

What is angular velocity?

Angular velocity is calculated by dividing angular displacement by time

What is Newton’s First Law?

A body continues in its state of rest or state of motion unless acted upon by force (Law of Inertia).

Inertia

Describes the amount of resistance to a change in an object’s state of motion.

What is Newton’s Second Law?

The acceleration of a body is proportional to the force applied to it and inversely proportional to the object's mass.

What is Newton’s Third Law?

For every action, there is an equal and opposite reaction.

What is a first-class lever in biomechanics?

The axis is located in the middle, with the force and resistance on either side (e.g. heading a spccer ball).

What is a second-class lever in biomechanics?

The axis is located at the end, with the resistance in the middle and force applied at the end. (e.g. pushup)

What is a third-class lever in biomechanics?

The axis is located at one end, with the application of force in the middle and resistance applied at the opposite end.(e.g., bicep curl).

What are the three factors that affect projectile motion?

Angle of release, height of release, and speed of release.

How does the angle of release affect a projectile?

It determines the shape and length of the flight path; 45° typically gives maximum range.

How does the height of release affect projectile motion?

A higher release point increases range when the object lands lower than it was released.

How does the speed of release affect projectile motion?

The greater the speed, the further and higher the object will travel.

What is static balance?

The ability to maintain equilibrium when stationary.

What is dynamic balance?

The ability to maintain stability while moving.

What is the centre of gravity?

The point at which the body’s mass is equally distributed in all directions.

What is the line of gravity?

An imaginary vertical line that passes through the centre of gravity to the ground.

What is the base of support?

The area beneath a person that includes every point of contact with the supporting surface.

How do you improve balance?

By increasing the base of support, lowering the centre of gravity, and keeping the line of gravity within the base.

What are the 6 factors affecting balance?

1. Mass of the object

2. Size of BOS

3. The height of the COG above the BOS

4. The position of the LOG relative to the BOS

5. Increasing the size of the BOS in the direction of the oncoming force

6. Horizontally positioning the COG near the edge of the BOS on the side of the external force

Sports requiring low balance

• Sprint starts - swimming and running

• Tennis

• Any aspect of sport requiring quick lateral movement or change of direction

Sports requiring high balance

• Wrestling

• Weight lifting

• Collision sports

Momentum

A measure of the amount of motion possessed by a moving body. It is the product of mass and velocity (Momentum = Mass x Velocity)

Impulse

The application of force over a period of time to change the momentum of an object.