A lever is a stiff rod that can rotate about a fulcrum or pivot point. This rotation transmits force.
When the lever is at equilibrium the tendency for it to rotate clockwise is balanced by the tendency to rotate counterclockwise.
What factors determine the equilibrium point of a lever?
What is the relationship of these two products? Check yourself
What happens if one of the weights moves closer to the fulcrum? Check yourself
In the muscle/skeletal system a contracting muscle functions as a weight. When it contracts it creates an in-force that is translated into an out-force by the lever system.
Changes in the length of skeletal elements can result in more efficient transmission of an in-force to an out-force. Based on the equation there are several ways to increase the force efficiency of a lever:
Make sure you are comfortable with the above ideas before you explore the different types of levers. Return to beginning
Explore the types of levers