Levers Flashcards
Lesson 23 (13 cards)
What are the 3 components of levers?
Fulcrum (The Joint)
Resistance/Load (The object lifted or the body)
Effort (The Insertion point of the muscle which is contracting)
What are the three classifications of levers?
(Remember 123 FRE)
1st Class Lever
2nd Class Lever
3rd Class Lever
Depends on which component is in the middle
What is a 1st Class Levers
The fulcrum is in the middle
Where can 1st Class levers be found?
-Extension in the elbow
-Flexion & Extension in the neck (Nodding)
What are 2nd class levers?
The resistance/load is in the middle
Where are 2nd class levers found?
-Planterflexion at the ankle
(standing on your tiptoes)
What are 3rd class levers?
the effort is in the middle
Where can 3rd class levers be found?
in all joints in the body
-flexion in the elbow
-extension in the knee
What do you need to add when drawing levers?
The effort arm (Force arm)
Resistance arm
What is the effort arm?
The effort arm is the shortest perpendicular distance between the fulcrum and the effort
What is the resistance arm?
The resistance arm is the shortest perpendicular distance between the fulcrum and the resistance
What is a Mechanical advantage?
When the effort arm is longer than the resistance arm this is known as a mechanical advantage
can lift large load with little effort but can only move slowly
Only found in 2nd class lever during planter flexion
What are mechanical disadvantages?
When the resistance arm is longer than the effort arm this is know as mechanical disadvantage
Cannot lift a large load but can move small load quickly
It had a greater range of movement (Flexibility)
