Levers

First class lever

Third class lever

Second class lever

Functions of levers

increase the load that a given effort can move

increase the speed at which the body moves

example: heading a ball - effort is the neck muscles (traps/delts), load is the ball, fulcrum is the neck - fulcrum is in the middle

the three components

Fulcrum

Effort

Load

the point at which the lever rotates

the location where the resistance is being moved

muscles - the location where the force is applied

the most common lever in the body

the most efficient lever

mechanical disadvantage - the load can be moved quickly - if resistance arm in extended, greater speed at the resistance and the load is released at a greater speed

example: kicking a football - effort is the quads, fulcrum is the hinge joint at the knee, load is the ball

innefficient at applying force

example: standing on tip toes to mark a player a netball - effort is contraction of gastrocnemius muscle, loads is the body weight, fulcrum is the toes - load is in the middle

FLE/123