Mech. Principles test 3

Question 1

6 phases of analyzing sport skills

Answer 1

1) determine the obectives of the skill
2) Note any special characteristics of the skill- rep. non rep. Closed/open
3) Watch elite athletes perform skills
4) divide skill into phases
5) Divide each phase into key elements
6) Understnading the mechanical reason for key elements

Question 2

Nonrepetitive skills

Answer 2

discrete skills
Shifts from one skill to another- swing bat then run
follow through is a deceleration phase
builds momentum from one skill to the next-tumbling
teach each skill separately
add additional skills and teach the rhythm and patterns when combining multiple skills

Question 3

Repetitive skills

Answer 3

skill is continuously repeated,
one complete cycle of skill leads to the next
Swimming

Question 4

Closed skills

Answer 4

skills that are perfomred under predictable environments
No opponent
same required action/movement every time
Easier to train for because you can create a practice environmnent that is the same as comp.

Shooting a free throw, weight lifting-comp.

Question 5

Open skills

Answer 5

skills performed in unpredictable environments
opponent attempts to foild your physical objective
Basketball game
pitches are dif every time in game

Question 6

Phases of skills

Answer 6

prepatory movements and mental set phase
windup/backswing
force-producing movement phase- summation of force
follow through phase

Question 7

Prepatory movements and mental set phase

Answer 7

setting/aligning body before the start of the movement

Does not occur as much in rep. skills

Question 8

Windup/backswing phase

Answer 8

using antagonistic muscles to windup or make use of the stretch shortening cycle prior to the force producing movement phase
pulling arms back before throwing ball

Question 9

force-producing movement phase

Answer 9

actual movement of the skill
forward movement of the arm during overhand throw
Makes use of agonist muscles used during concentric muscle action

Question 10

summation of force

Answer 10

sum of all muscle action produce end result regarding power output

Question 11

follow through phase

Answer 11

deceleration phase/ braking phase
Occurs immediately following force-producing phase
Antagonist muscles eccentrically contract to slow down motion
during rep. skills this phase is shortened to hasten the recovery phase

Question 12

5 steps for identifying and correcting errors in sport skills

Answer 12

observe the complete skill
analyze each phase and its key elements
use your knowledge of sport mechanics in your analysis
select errors to be corrected
decide on appropriate methods for the correction of errors

Question 13

What is the main goal of observing the complete skill

Answer 13

get overall impression of athlete’s performance

Question 14

What should you be doing when observing the complete skill of an athlete

Answer 14

looking for cues beyond the athlete- flight path, rebound, skate marks
and listening for cues- slapping noise on volleyball

Question 15

two ways to approach analyzing each phase and its key elements

Answer 15

start with the result

observe each phase of the skill in sequence

Question 16

What does observing each phase of the skill in sequence entail-steps

Answer 16

preparatory- stance, weight, distribution, head position
backswing- weight transfer, position of implement, flexibility
Force production- approach/actual movement
Follow- through- notice implement immediately afterward, arm and hand action

Question 17

What should you assess while using your knowledge of sport mechanics while analyzing

Answer 17

assess mechanical efficiency

Gravity, friction, drag, air resistance, opposition forces

Question 18

What happens to a spin when you decrease rotary resistance?

Answer 18

spins faster

Question 19

Steps in error correction

Answer 19

separate the phase that contains the error
break the phase into key elements
design a practice/activity useful for teaching correct movement
perform movement slowly, noting key body positions
increase speed, put back into phase
attempt complete skill

Question 20

What is stride length?

Answer 20

amount of forward reaction force from the earth as one pushes back against the earth

Question 21

What is stride frequency?

Answer 21

number of strides per unit of time

Question 22

how do sprinters decrease rotational inertia?

Answer 22

via flexing arms and legs

Question 23

what do sprinters and long distance runners do to muscles not involved in movement?

Answer 23

they relax them

Question 24

What do tense muscles do?

Answer 24

increase metabolic demand and can restrict muscle action

Question 25

In swimming, what is stroke length?

Answer 25

distance each stroke pulls or pushes the water

Question 26

In jumping, what happens when you thrust greater against the earth?

Answer 26

you have a greater propulsion from earth

Question 27

What is the order of kinetic whip?

Answer 27

first larger muscles generate momentum by overcoming inertia of larger body masses via pushing off of the earth
momentum is passed on to smaller muscles

Question 28

What must you have to make kinetic whip work?

Answer 28

windup/backswing

Question 29

When spinning, what happens when you pull legs and arms in? Why?

Answer 29

angular velocity is increased becasue rotational inertia is decreased

Question 30

What is arrresting motion? and ex

Answer 30

When two or more objects collide

catching, landing, slowing down, and stopping

Question 31

Angular momentum equation

Answer 31

decreased RI X increased angular velocity