1.7 Interactions of muscles and bones to produce movement

Question 1

Lever

Answer 1

A rigid structure that rotates around a fixed point

Question 2

Axis

Answer 2

The joint in the body that the lever moves around

Question 3

Force

Answer 3

The muscles that contract to generate the force to move the lever

Question 4

Resistance

Answer 4

The bone of the body and whatever is being held or moved by the bone

Question 5

Third class levers, and how they create movement

Answer 5

Force is applied between axis and resistance or load to be moved

Bones act as levers, creating attachment points for muscles

Muscle contracts, drawing origin and insertion together

Muscle pulls on the bone, causing movement in specific direction

Force (muscular effort) is applied between axis and resistance, enabling desired anatomical movement

Question 6

Why are levers so important in physical activity?

Answer 6

They amplify speed by increasing range of motion

Force (muscle insertion) is close to the axis, while resistance (body part or object) is further away

This increases speed at which the lever end can move

Lever performance can be imposed through equipment use

Longer lever and resistance arm increases range of movement and speed

This mechanical disadvantage allows for increased distance