Movement Analysis Flashcards
What is a lever made up of
The fulcrum
Effort (force)
Resistance(load)
What is the fulcrum
The part of a lever system that pivots; joints are the fulcrums in the body’s lever system
What is effort?
The force applied to move the resistance or weight ; I’m the body, the effort is provided by muscles exerting a force
What is resistance
The plead to be moved by a lever system ; Usually involves weight when the body’s lever systems are involved
How many classes of levers?
3
Describe the first class lever
Fulcrum lies between the effort and resistance
An example of first class lever
At the elbow joint where the triceps cause extension at the lower arm
Elbow is fulcrum
Hand is load
Triceps are the effort
Describe second class lever
Fulcrum lies at one end
Effort at the other end
Resistance in middle between effort and fulcrum
An example of second class lever
At ankle where gastrocnemius causes plantar flexion
The ball of the foot is the fulcrum
Contraction of gastrocnemius muscle is effort
The weight of the person is the resistance
Describe 3rd class lever
Fulcrum at one end
Resistance at other end
Effort is between fulcrum and resistance
Example of 3rd class lever
At the arm the biceps muscle acting on the elbow joint to cause flexion
Biceps is effort
Elbow joint is fulcrum
Hand is resistance
Another example of 3rd class lever
At ankle during dorsiflexion
Resistance is weight of foot
Effort is tibialis anterior
Fulcrum is ankle joint
Mechanical advantage formula
Effort arm/resistance arm
What is mechanical advantage
The benefit to a lever system having a short effort or resistance arm
Benefit of short effort arm
Giving rapid movements over a large range of movement
