Levers Flashcards
define what a lever is
a rigid structure that moves around a fixed point when a force is applied
what are the three components of a lever?
fulcrum
load
effort
define fulcrum
the fixed point/pivot
define load
where the weight/resistance is coming from
define effort
where the force is coming from
in the body…
bones act as ____________
the joints are the ____________
the muscles provide the ____________
levers
fulcrum
effort
what are the two main functions of levers (2)
- to increase the speed and range of motion at which a body / limb can move through
- to generate maximal force against a given load / resistance
features of a first class lever (2)
- fulcrum is in the middle
- the load is at one end and the effort applied at the other
examples of first class levers in the body (2)
the joint at the neck
fulcrum = neck joint
load = weight of the head
effort = muscles in the neck
elbow extension
sporting examples wherein a first class lever is used (2)
heading the ball in football
tricep extension
features of a second class lever (2)
- load is in the middle
- the fulcrum is at one end, the effort applied at the other
example of a second class lever in the body
ankle joint
fulcrum = ankle joint
load = weight of the foot
effort = gastrocnemius
sporting examples wherein a second class lever is used (3)
high jump
long jump
calf raises
features of a third class lever (2)
- effort is in the middle
- the load is at one end, the fulcrum at the other
examples of third class levers in the body (4)
elbow flexion
the knee
the shoulder
the hip
sporting examples wherein a third class lever is used (4)
bicep curl
kicking a football
uppercut
backhand shot in tennis
mechanical advantage (3)
where a lever’s effort arm is longer than it’s load arm
- can lift heavy weights
- can not move at fast speeds and has limited range of motion
mechanical disadvantage (4)
where a lever’s load arm is longer than it’s effort arm
- can move quickly
- greater range of motion
- requires more effort to lift heavy weights
