Levers in Movement & Sport: Structure and Function

Levers

Rigid rods that can rotate about a fixed pivot, or fulcrum, when force is applied.

Fulcrum

The fixed pivot point about which a lever rotates.

Load

The force that is being moved or resisted by the lever.

Effort

The force applied to the lever to move the load.

Moment Arm

The perpendicular distance at which the force acts from the fulcrum.

Load Arm

The distance at which the load acts from the fulcrum.

Effort Arm

The distance at which the effort acts from the fulcrum.

Mechanical Advantage (MA)

A measure of the efficiency of a lever, calculated as the effort arm / load arm.

Efficient Lever

A lever with a mechanical advantage greater than 1.0.

First Class Lever

A lever where the fulcrum is between the load and the effort, e.g., a hammer used to pry a nail.

Second Class Lever

A lever where the load is between the fulcrum and the effort, e.g., a wheelbarrow.

Third Class Lever

A lever where the effort is between the fulcrum and the load, e.g., a shovel.

Magnitude of Force

The amount of force applied to the lever.

Distance between Fulcrum and Line of Action

The distance that affects the rotation of the lever.

Human Movement

Bones act as levers when muscle contraction generates tension and tendency for rotation.

Applications in Sport

The use of levers to enhance functionality and performance in physical activities.

Classifying Levers

Identifying the type of lever (1st, 2nd, 3rd) based on the position of the fulcrum, load, and effort.

FLE

F - Fulcrum in middle, 1st class lever

L - Load in middle, 2nd class lever

E - Effort in middle, 3rd class lever

Sporting example of 1st class lever

Heading a football, where the neck is the lever

Sporting example for 3rd class lever

Hitting a tennis ball, where the tennis racket is the lever

Sporting example of a 2nd class lever

Pushing against blocks in a sprint start, where lower leg and foot is the lever