Week 11: Levers Flashcards
Define lever
A rigid bar resting on a pivot, used to move a heavy or firmly fixed load with one end when pressure is applied
What is the order of a 1st class lever?
Effort (torque), Fulcrum, Load
What happens if effort=load?
No movement
What happens if Effort>load?
Positive movement
What happens if Effort
Negative movement
Define moment length
The distance between the load and the fulcrum and the effort and the fulcrum
What happens when the moment length is increased between the effort and fulcrum?
Decreases moment length between load and fulcrum, makes lifting load easier
What happens when the moment length is decreased between the effort and the fulcrum?
Increases moment length between load and fulcrum, makes lifting load harder
What is the order of a second class lever?
Effort, load, fulcrum
What is the order of a third class lever?
Fulcrum, effort, load
What is resistance a combination of?
load and the effect of moment length
How do you calculate load?
Mass x Gravity (9.81m^2)
How do you calculate resistance?
Load x Moment length
Define active insufficiency
When a muscle is pre-shortened by our body position and cannot produce enough force.
Define passive insufficiency
When a muscle is in a lengthened position or is too inflexible to be able to support thr movement
