Chapter 2 - Movement Anaylsis Flashcards
Lever
A rigid bar that turns about an axis to create movement.
What do all levers contain
Fulcrum, load, effort
Fulcrum
The fixed point at which a lever turns or is supported. It can also be referred to as the axis
Load
The weight or resistance that the lever must move
Effort
The force required to move the load. It can be referred to as the force.
Load arm
The distance from the load to the fulcrum
Effort arm
The distance from the effort to the fulcrum
Mechanical advantage
- Measures efficiency of a lever
- high advantage = longer effort arm, move large loads with low effort
How is the mechanical advantage calculated
Effort arm/load arm
FLE
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First class levers
- Fulcrum in the middle
- quite close to both effort and the load
Second class lever
- load in the middle
- large load moved with low effort
Third class lever
- effort in the middle
- large range of movement with low effort
- Low mechanical advantage
- longer load arm
Flexion
Angle of the bones at a joint decreases
Where can flexion occur
Shoulder, hip, elbow, knee