Biomechanics Key Concepts and Principles for Sports Performance

Biomechanics

the physics underlying physical movement and sport

Statics

The study of forces acting on a body at rest or in equilibrium.

Dynamics

The study of forces acting on a body in motion.

Force

A push or pull that can cause an object to accelerate, decelerate, or change direction.

Velocity

Speed in a given direction.

Acceleration

The rate of change in velocity (speeding up, slowing down, or changing direction).

Inertia

An object's resistance to changes in motion. Greater mass = greater inertia.

Momentum

The quantity of motion an object has. Momentum = mass × velocity.

Impulse

The product of force and the time over which it is applied. Impulse = force × time. Impulse changes momentum.

Angular Motion

Movement that occurs around an axis.

Angular Velocity

The speed at which an object rotates around an axis.

Torque

A force that causes rotation around an axis.

Angular Momentum

The amount of rotational motion an object has. Angular momentum depends on angular velocity and moment of inertia.

Moment of Inertia

A measure of how mass is distributed relative to the axis of rotation. Mass farther from the axis = greater moment of inertia.

First-Class Lever

Fulcrum is between effort and load. Example in body: neck (nodding head).

Second-Class Lever

Load is between fulcrum and effort. Example in body: ankle during plantar flexion (standing on toes).

Third-Class Lever

Effort is between fulcrum and load. Example in body: elbow flexion (biceps curl).

Force-Motion

Force causes movement or changes in movement.

Force-Time (Impulse)

Increasing time or force increases momentum.

Range of Motion

Greater ROM allows greater speed or force.

Balance & Stability

Wider base and lower center of gravity increases stability.

Newton's First Law

An object remains at rest or in motion unless acted upon by an external force.

Newton's Second Law

Force = mass × acceleration. More force = more acceleration.

Newton's Third Law

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

First Class Lever

has the fulcrum between the effort and the load. In the body, this occurs during neck extension. In sport, it is seen in push-ups and rowing.

Second Class Lever

has the load between the fulcrum and the effort. An example in the body is standing on tiptoes. In sport, it is used during jumping and sprint starts.

Third Class Lever

 has the effort between the fulcrum and the load. A body example is a biceps curl. In sport, it occurs during kicking and throwing.

Two Main Functions of Levers

increase force and to increase speed or range of motion.

Explain how you would coach an athlete to make them more stable.

I would coach them to widen their base of support, lower their centre of gravity, keep their line of gravity within the base of support, and improve balance and core strength.

state newtons 3 laws of physics and give 3 examples of newtons third law in sports

Newton’s first law states that an object will remain at rest or in motion unless acted upon by an external force.

Newton’s second law states that force equals mass times acceleration (F = ma).

Newton’s third law states that for every action, there is an equal and opposite reaction.

 

Examples of Newton’s third law in sport include a sprinter pushing against the ground, a swimmer pushing water backward, and a basketball player jumping off the court.

Linear Motion

movement in a straight line, such as sprinting.

Angular Motion

rotation around an axis, such as a somersault.

General Motion

combination of linear and angular motion, such as running.

Using rowing as an example, explain the principle of impulse.

In rowing, applying force to the water for a longer period of time increases impulse. Greater impulse results in increased momentum, which improves boat speed.

Explain how a figure skater can control their rate of spin. Use the proper biomechanical terminology.

A figure skater controls their rate of spin by changing their moment of inertia. Pulling the arms and legs closer to the axis of rotation decreases moment of inertia and increases angular velocity, while extending the limbs increases moment of inertia and slows the spin