3.2 Biomechanical Principles Flashcards
Centre of mass
Point at which a body is balanced in all directions: the point from which weight appears to act
Frosby flop technique
J curve allows greater velocity at approach lifts inside leg along with arms to raise
COM as high as possible Extends spine so COM is below the bar so only one section of body is below the bar
Stability
Ability of body to resist motion and remain at rest
4 factors that affect stability
Mass of body
Height of COM
Base of support
Line of gravity
How does mass of body affect stability
Higher mass=greater inertia= greater stability
How does height of COM affect stability
Lower = greater stability
How does base of support affect stability
greater size = greater stability moving two points of contact further apart ( FEET) or Increasing number of points of contact
How does line of gravity affect stability
More central line of gravity to base of support greater stability
how would a sprinter minimise stability when starting off
Lifts hips raising COM leans forward shifting line of gravity to edge of base of support
When gun is fired Chest lifts and lean forward so line of gravity falls out of base of support
Causing body to fall forwards
Two functions of lever systems
Generate muscular effort to overcome a given load
Increase speed of a given movement
4 parts of a lever system
lever (Bone)
Fulcrum (joint)
Effort (Muscular Force)
Load ( Weight/ Resistance)
Diagram notation for : Lever Fulcrum Load Effort
Line
triangle
arrow
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Order of first class lever
E - F - L
Example of first class lever
Extending neck to head football
order of second class lever
F - L - E
Load = down
Effort = Up
example of seconf class lever
Ball of the foot in take off jumping for a header
order of third class lever
F - E - L
Effort + up
Load = Down
example of a third class lever
Bicep Curl
F E L
Distance from fulcrum to effort is known as
Effort arm
Distance from fulcrum to load is known as
Load arm
Mechanical Advntage
Second class lever where effort arm is greater than load arm so a large load can be moved with small effort
Mechanical Disadvantage
Third class lever system where the load arm is greater than the effort arm so a large effort is required to move a large load
