Levers and planes and axes Flashcards
What is the load,effort and fulcrum
The load is the object you are trying to move. The effort is the force applied to move the load. The fulcrum (or pivot) is the point where the load is pivoted.
First class lever – the fulcrum is in the middle of the effort and the load.
This type of lever is found in the neck when raising your head to head a football. The neck muscles provide the effort, the neck is the fulcrum, and the weight of the head is the load.
Second class lever – the load is in the middle between the fulcrum and the effort.
This type of lever is found in the ankle area. When standing on tiptoe, the ball of the foot acts as the fulcrum, the weight of the body acts as the load and the effort comes from the contraction of the gastrocnemius muscle. This second class lever is used when taking off for a jump or pushing against the blocks in a sprint start.
Third class lever – the effort is in the middle between the fulcrum and the load.
During a biceps curl, the fulcrum is the elbow joint, the effort comes from the biceps contracting and the resistance is the weight of the forearm and any weight that it may be holding.
Mechanical advantage
When a lever’s effort arm is longer than its load arm, it is said to have high mechanical advantage. Levers with high mechanical advantage can move large loads with a relatively small amount of effort. Second class levers always have high mechanical advantage. First class levers can have high mechanical advantage, if the fulcrum is close to the load.
What is ‘FLE’
First class lever - Fulcrum is in the middle.
Second class lever - Load is in the middle.
Third class lever - Effort is in the middle.
What is the Sagittal plane and what movements does it allow?
It passes through the body front to back, dividing it left and right. Movements in this plane are up and down movements of flexion and extension. This could include walking, jumping or squatting.
What is the frontal plane and what movement does it allow?
Passes from side to side and divides the body from front to back
First class level
Effort, fulcrum, load
EFL
Second class lever
Fulcrum,load,effort
FLE
3rd class lever
Load,effort,fulcrum
LEF
Example of a first class level
See saw/head
Example of a 2nd class lever
Wheel barrow/tiptoes
Example of a 3rd class lever
Fishing rod/bicep lifting a muscle
Which lever is a mechanical advantage
The second class lever( lifting a heavy weight with little effort)