Bodies in Motion

  • The following pages show animals with different orders of levers that move their bodies.

  • Some tips for figuring out how levers operate within an organism's body:
           1) Identify the bones that are pivoting around one another- label this as the fulcrum.
           2) Identify the muscle that is contracting to produce movement- label this as the in-force or effort.
           3) Identify the load that the muscle is moving- label this as the resistance.
           4) Identify the direction the load is moving- label this as the out-force.
           5) Draw a line perpendicular to the in-force that connects to the fulcrum- this is the in-lever arm.
           6) Draw a line perpendicular to the out-force that connects to the fulcrum- this is the out-lever arm.

   
Horse

Cow

Bear

Human Shoulder

Human Foot

Bird Wing

Macaw