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?

Motion along a straight or curved path where all parts of the body move the same distance in the same direction at the same time.

What is rectilinear motion?

A type of linear motion where movement occurs in a straight line.

What is curvilinear motion?

A type of linear motion where movement occurs along a curved path.

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?

The rate of change of displacement (Velocity = Displacement

What is acceleration?

The rate of change of velocity over time.

What is angular displacement?

The change in the angle as an object rotates around a point or axis.

What is angular speed?

The rate at which an object rotates (Angular speed = angle

What is angular velocity?

The rate of change of angular displacement, including direction.

What is Newton’s First Law?

An object remains at rest or in uniform motion unless acted on by an external force (Law of Inertia).

What is Newton’s Second Law?

Force = Mass × Acceleration (F = ma). The acceleration of an object is directly proportional to the force and inversely proportional to its 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?

A lever where the fulcrum is between the effort and the load (e.g., neck when nodding).

What is a second-class lever in biomechanics?

A lever where the load is between the fulcrum and the effort (e.g., standing on tiptoes).

What is a third-class lever in biomechanics?

A lever where the effort is between the fulcrum and the load (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