Ch. 3 (Midterm) Flashcards
(27 cards)
Qualitative Motion Analysis
describes how the body looks as it performs a skill
-i.e. position in space, position of the body parts relative to each other, and position of segments of body parts in relation to each other
2 approaches of of qualitative analysis
Composite
Component
Composite Approach (Qual. Analysis)
views the whole body as a system the progresses through phases as it refines movement patterns
- total body approach
- breaks down movements into primary body parts
- i.e. Test of Gross Moto Development #2
Component Approach (Qual. Analysis)
uses the same phase method as composite, but breaks the body down into component sections
- error analysis strategy
- each primary body component is observed
- i.e. throwing a ball; body actions are broken down and observed at the trunk, arms, and action of the feet
Quantitative Motion Analysis
Stems from the simple need for deeper understanding of why the system moves the way that it does
-used in: training elite athletes, PT/AT to quantify injury, biomechanical research
Concepts of Quantitative Motion Analysis (3)
Scalar Quantity
Vector Quantity
Vector Representing Forces
Scalar Quantity
a quantity that possess only a magnitude but has no particular direction. The more massive (heavier) an object, the more resistant it is to motion (harder to move)
- mass
- inertia
Mass
quantity of matter in which the body is composed
Inertia
resistance to having a state of motion changed by the application of force
Vector Quantity
can only be fully specified with a magnitude of appropriate units and precise direction
-weight
Weight
a measure of the force with which gravity pulls on an object’s mass
Vector Representing Forces
arrows are used to represent vector quantities
- Tip points in a certain direction because of a given orientation.
- Tail defines where it began.
- Distance between tip and tail defines the length and path along which it would travel
- direction, orientation, magnitude, point of application, line of action
Direction
the way the force is applied
-i.e. up, down, forward, backward, north, south, positive, negative
Orientation
alignment of the vector in relation to cardinal directions
-i.e. vertical, 45 degrees from horizontal
Magnitude
size of the applied force
-i.e. if the scale is 1 cm= 10 N, then a 10 cm vector represents a 100 N force
Point of Application
point at which the system receives the applied force
-i.e. at the toes, 2 cm from the axis of rotation of the elbow, etc.
Line of Action
imaginary line extending indefinitely along the vector through the tip and tail
-i.e. the path along which the arrow or vector would travel if moved forward or backward
Vector Equality
two vectors are considered equal if they possess the same magnitude and direction
A=B
Communicative Law of Addition
when vectors are added together, the sum is independent of the order of addition
A+B=B+A
Associative Law of Addition
the sum of three or more vectors is independent of the grouping of the vectors for addition.
(A + B) + C = A + (B + C)
Negative of a Vector
a vector that when added to the first gives a sum equal to zero
-i.e. vectors have the same magnitude, but point in opposite directions
A + (-A) = 0
A – B = A + (-B)
Vector Analysis
Can be used to understand the resultant motion of the system that is acted upon by many different sources simultaneously
-resultant
Resultant
a vector that represents the sum of all forces acting upon a system
-i.e. force and direction in which a mass exhibits
Vector Resolution
process used to resolve a single vector into its individual directional component vectors
-i.e. spreading your hand apart after pointing with both hands put together
