Movement Analysis Flashcards
What is a Lever?
A lever is a rigid bar that moves about a fixed point when force is applied to it.
What are the four components of a Lever?
The lever arm, the fulcrum, the effort, and the load.
What is the lever arm?
Its the bone or the body part that is being moved about a point.
What is the fulcrum?
This is the joint, where the lever arm pivots.
What is the effort?
This is the force applied by the muscles to the lever arm.
What is the load or resistance?
The weight of the body part or something that is being lifted.
How is the lever arm represented on a lever system?
The straight line
How is the fulcrum represented on a lever system>
The triangle
How is the effort represented on a lever system?
An arrow pointing in the direction of the force
How is the load represented on a lever system?
Represented as a square.
What are the three lever systems?
First class lever
Second class Lever
Third class lever
Describe a first class lever?
The load and the effort are at opposite ends, and the fulcrum is at the center.
Describe a second class lever?
The fulcrum and the effort are at opposite ends, and the load is at the center.
Describe a third class lever?
The fulcrum and the load are at opposite ends, and the effort is at the center.
What is the way to remember the levers.
FLE, fulcrum middle in first, load middle in second, and effort middle in third.
Give an example of a first class lever?
First class levers are used in elbow extensions. The fulcrum will be in the middle (elbow joint), your effort will be on one end (the force of your triceps) and your load would be the weight of your hand.
Give an example of a second class lever?
Second class levers are used in plantar flexion and dorsiflexion at the ankle while standing. The fulcrum will be at one end (toe joints) the effort on the other side (force of gastrocnemius) with the load in the center (body weight)
Give an example of a third class lever?
Third class levers are used in elbow flexion. the effort is at the center (force of biceps) and the fulcrum (elbow joint) and load (weight of hand) on both sides.
What is mechanical advantage?
How efficient it is at moving heavy loads.
Formula for mechanical advantage>
mechanical advantage = effort arm / weight (resistance) arm
A lever in the body with high mechanical advantage can move
large load with small effort from muscles. However it can only move the load short distances at low speeds.
Second class levers have a …. mechanical advantage
high, the effort arm is longer than the weight arm.
A lever with low mechanical advantage requires
large effort from the muscles to move a small load.
Third class levers have a …. mechanical advantage?
low, the effort arm is shorter than the weight arm.
Movements happen in
planes
What is a plane>
is an imaginary flat surface that runs through the body.
What are the 3 planes ?
Sagittal plane, Transverse plane, frontal plane.
What is the sagittal plane?
divides the body into left and right sides. the flat surface goes through the back to the front.
What is the transverse planes?
Divides the body into top and bottom
What is the frontal plane?
it divides the body’s front and back and the flat surface goes from left to right.
Movements happen around?
Axis?
What is an axis?
Is a imaginary line which runs through the body
What are the three types of axis?
sagittal axis, transverse axis, and longitudinal axis.
What is sagittal axis?
line that runs through the body from front to back
What is transverse axis>
line that runs through the body from left to right.
What is longitudinal axis?
Runs through the body from top to bottom.
What plane, axis, movements, and direction happen at flexion and extension
forwards and backwards
sagittal plane
transverse
running, forwards roll.
What plane, axis, movements, and direction happen at abduction and adduction
left or right
frontal plane
sagittal axis
cartwheel
What plane, axis, movements, and direction happen at rotation
clockwise or anticlockwise
Transverse plane
longitudinal axis
full twist jump and ice skating spin
