Lever systems Flashcards
(27 cards)
What are the three types of levers?
.1st class
.2nd class
.3rd class
What is the function of levers?
To increase the speed at which the body can turn a small force into a larger force or movement
What are the four components of a lever?
Lever arm, fulcrum, effort, load
What is another name for the load?
Resistance
What is the fulcrum?
The fixed point or pivot
What is the fulcrum in the body?
The joint
What is the resistance?
Point where the weight / resistance is coming from
What is the resistance in relation to body movements?
Body weight or piece of equipment
What is the effort?
Point where the force/ effort is applied
What is the effort in the body?
Working muscle (agonist)
What is the rhyme to remember which lever it is?
FRE-123
What is the middle component in a 1st class lever?
Fulcrum
What is the middle component in a 2nd class lever?
Resistance/load
What is the middle component in a 3rd class lever?
Effort
What is the only example of a 2nd class lever in the body?
When the ankle is in plantar flexion
What is the symbol for the effort?
Arrow
What is the symbol for the fulcrum?
Triangle
What is the symbol for the resistance/load?
Square
What is the mechanical advantage like on an advantage of a 1st class lever and why?
High and low because the fulcrum can move and therefore the length of either the effort arm or the load arm will vary
How do you work out mechanical advantage?
Effort arm / load arm
What is the mechanical advantage like on a 2nd class lever and why?
High because the effort arm will always be longer than the load arm
What is the mechanical advantage like on a 3rd class lever and why?
Low because the load arm will always be longer then the effort arm
What is the effort arm?
The distance between the fulcrum and the effort
What is the load/resistance arm?
The distance between the fulcrum and the load arm
