Understanding Human Patterns (LOIL 1)

Question 1

state what it is meant by the key term - kinesiology

Answer 1

kinesiology is the study of how the body produces and controls force to generate movement, resist movement and stabilise the body

Question 2

state what it is meant by the key term - biomechanics

Answer 2

biomechanics is the study of the structure and function off biological systems by the means of mechanics

Question 3

what can a body be considered during the flight of a jump ?

Answer 3

a body can be considered a projectile during the flight of a jump

Question 4

what is height of jump measured as ?

Answer 4

the height of jump is measured as the height of the BCOM during the flight phase

Question 5

how is the body moving during the flight phase of a jump ?

Answer 5

everything is related to the BCOM and the body can be considered as a projectile

Question 6

state the 3 determinants of projectile motion

Answer 6

1. height of release
2. angle of release
3. velocity of release

Question 7

what does projectile angle determine ?

Answer 7

projectile angle determines the shape of the trajectory, all other things being equal

Question 8

what does Vy determine, and what does Vx determine ?

Answer 8

Vy determines the height and time of flight

Vx determines the range of flight

Question 9

what is take off velocity determined by ?

Answer 9

take off velocity is determined by the power generated by leg extensor muscles during the concentric phase of take off

Question 10

state the equation for power (3 points)

Answer 10

power = work / time

power = (force x distance) / time

power = force x velocity

Question 11

as the speed of contraction increases, what happens ?

Answer 11

as the speed of contraction increases, the amount of force produced decreases (F-V curve)

Question 12

at what point is peak power produced ?

Answer 12

peak power occurs at 1/3 of maximum shortening velocity

Question 13

state what it is meant by the key term - stretch shortening cycle

Answer 13

if a concentric contraction is preceded by active stretching, more force is produced during the concentric phase

Question 14

the SS cycle works on the basis of what 4 parameters ?

Answer 14

1. energy storage
2. more time to develop force
3. stretch reflex
4. muscle potentiation

Question 15

how does the SS cycle increase jump height ? (3 points)

Answer 15

1. during the countermovement jump, the extensor muscles of the lower limbs are stretched in the eccentric phase
2. this should enhance their power output during the concentric phase
3. assuming the same shortening velocities of the muscle fibres during the take off, this will produce a higher power output and hence a higher jump

Question 16

what is sprinting ?

Answer 16

sprinting is a high power activity

Question 17

what are the 3 methods of training to develop power ?

Answer 17

1. heavy resistance training
2. explosive power training
3. mixed-methods training

Question 18

ultimately, 3 key elements must be considered when attempting to increase power output. explain these 3 elements

Answer 18

1. it is essential that the overall muscular strength is maximised because of its direct relationship with the ability to express high rates of force development and power outputs
2. it is important to develop the ability to express high forces in very short periods of time, which are reflected by the rate of force development
3. it is important to develop an ability to express high forces as the velocity of shortening increases

Question 19

state 2 ways in which you can increase the amount of force a muscle can produce

Answer 19

1. muscle hypertrophy

2. increase the level of activation

Question 20

state 2 ways in which you can increase the velocity of muscular contraction

Answer 20

1. muscle hypertrophy

2. increase the level of activation

Question 21

which training method produces the most peak force ?

Answer 21

1. heavy resistance training

2. explosive/ballistic strength training

Question 22

how does changeover evict force enhancement ?

Answer 22

if changeover does not occur quickly, some of the energy stored in the stretch reflex will be lost as heat, and the muscle may start to fatigue

Question 23

state 2 ways in which force enhancement is maximised

Answer 23

1. larger stretch

2. faster changeover

Question 24

there is no optimal size of the stretch. explain this using 4 points

Answer 24

1. too small and more energy could have been stored
2. too large and speed of changeover is likely to decrease
3. stretch occurs in the MTU
4. if muscle fibres are stretched onto the descending limb of the F-L curve, force output will be reduced and the risk of injury will increase

Question 25

what is power measured in ?

Answer 25

Watts (W)

Question 26

what is a Watt (W) ?

Answer 26

1 Watt (W) is equal to 1 joule per second