Anatomical Levers Flashcards
Lever
> A long bar that pivots (bone)
Fulcrum
> The point where the load is pivoted
Load
> The weight trying to move (body/object)
Effort
> The force applied to move the load (muscle)
First class lever
> The fulcrum is in the middle, between to effort and load
First class lever: examples
1) Football header
E: neck muscles
F: neck joint
L: head weight
2) Throw in
E: tricep muscle
F: elbow joint
L: football weight
3) Oar of rowing boat
E: arm pulling oar
F: oar lock on boat
L: water resistance
Second class levers
> The load is in the middle, between the effort and the fulcrum
Second class levers: example
> A diver on their tiptoes at the edge of the board
E: gastrocnemius muscle
L: body weight
F: toe joints (ball of foot)
Third class levers
> The effort is in the middle, between the load and the fulcrum
Third class levers: example
> A bicep curl
F: elbow joint
E: bicep muscle
L: dumbell weight
Mechanical advantage
> A large load can be lifted by a relatively small amount of effort (effort arm is longer)
1st class
2nd class
Mechanical disadvantage
> Cannot lift a large a load with the same amount of effort (load arm is longer)
Can produce a large range of movement with relatively low effort
1st class
3rd class