Chapter 3 - Priciples Of Motion And Stability

Question 1

Discuss newtons laws

Answer 1

1st - apply force to move object
2nd - acceleration IPT mass, weight changes velocity
-> improve performance BC Indiv must find optimal relationship bw force and distance
-> 2 NB phases = prep and application of force through full ROM

3rd - action reaction

Question 2

Explain the relationship bw rotating limbs and projected objects

Answer 2

• Inertia= obj resistance to motion and it’s relation to mass of obj. Depends on mass + limb length
• > limb length incr. = inertia incr. too
• > inertia incr. = incr. energy required to mass obj

Question 3

Discuss open kinetic chain

Answer 3

Max ballistic effort involve movement of body parts w/ sequential movement

Sequence must be timed that applied force of succeeding movement is after previous movement to accelerate and therefore timing is NB

Question 4

Discuss force absorption

Answer 4

Decr. Impact of landing by bend knees = incr. time And distance of landing

To decr. Impact of reaction force = incr. amount time impact occurs or incr. area over which impact occurs

Question 5

Discuss balance and stability

Answer 5

Balance = Ability of object/ person maintain equilibrium

Incr. balance by incr. BOS by lowering COG w/i BOS

Incr. balance decr. Mobility = performer uses BOS wide enough to provide sufficient stability

COG = concentration point of earths grav pull on indiv

Question 6

List and describe 5 ways to use principles to detect and correct errors

Answer 6

1) observe complete skill
- plan before performance - video, notes and pictures

2) analyze phase elements
- focus on specific phases and break down skill to phases
- look at performance of skill in phases

3) use mechanics knowledge in analysis
- observers focus on how mover applies muscular force to generate movements
- questions to elevate skill performance by looking at elements can be modified to make skill proficient

Question 7

List 5 questions that elevates skill performance

Answer 7

Does mover have optimal stability, using all muscles can make contribution to skill

Applying force w/ movements in correct sequence

Applying right force over right amount of time

Applying force in right direction

Manipulating linear / rotatory inertia property

Question 8

Give 3 ways why development is predictable

Answer 8

1 - principles of motion and stability act on all movements and movers
2- movements can be manipulated according to their skill level
3- principles help determine movement patterns likely to produce optimal results