LEWIS: Plyometrics

Question 0

Type of training designed to improve

Answer 0

Power

Question 1

Plyometrics involves high intensity, explosive

Answer 1

Muscular contractions

Question 2

Plyometric exercises involve bounding, jumping or hopping to make muscle groups work

Answer 2

Eccentrically before a powerful concentric contraction

Question 3

focuses on engaging the

Answer 3

Stretch reflex

Question 4

The stretch reflex is a protective mechanism that

Answer 4

Prohibits over stretching of muscle fibres

Question 5

Any tendency to over stretch is detected by specialised receptors in muscles called

Answer 5

Muscle spindles

Question 6

When muscle spindles are suddenly activated, a nerve impulse is sent to the spinal chord which results in the immediate contraction of the

Answer 6

Muscle being over stretched

Question 7

Eccentric contractions occur when the muscle lengthens as it develops tension - these contractions occur during

Answer 7

Downward movements

Question 8

Concentric = shortening

Occurs during

Answer 8

Upward movements

Question 9

Plyometrics contraction involves an

Answer 9

Initial rapid eccentric movement

An explosive concentric movement

Question 10

A muscle that is eccentrically stretched before a concentric contraction will

Answer 10

Contract more forcefully and more rapidly

Question 11

Plyometrics works as a form of power training because, when a quick stretch is detected in the muscles, an involuntary protective stretch reflex occurs to prevent over stretch and injury - the stretch reflex increases the activity in the muscle undergoing the stretch allowing it to

Answer 11

Act more forcefully

Result = powerful braking effect and the potential for a powerful concentric muscle action

Question 12

If the concentric muscle action does not occur immediately after the pre-stretch, the potential energy produced by the stretch reflex response is

Answer 12

Lost

Question 13

The sequence of the 3 phases is called the

Answer 13

Stretch-shortening cycle

Question 14

3 phases:

Answer 14

1)Eccentric muscle action - elastic (potential) energy is generated and stored in the elastic tissues of the muscle

2)Amortisation - short time between end of eccentric and start of concentric
The shorter this phase the more powerful the subsequent muscle contraction Will be

3)concentric muscle action/Actual muscle contraction, involves an upward concentric contraction which results in improved muscular performance

Question 15

By utilising the stretch-shortening cycle, movements can be made

Answer 15

more powerful and explosive

Question 16

Questioned suitability because there is a

Answer 16

Risk of injury

Question 17

As a precaution to reduce injury it is suggested that performers attempting to introduce Plyometrics do so with a

Answer 17

substantial strength-training background

Question 18

Injuries are more likely to occur if there are

Answer 18

Depth jumps from TOO great a height
Improper landing
Inappropriate landing surface

Question 19

Landing surface=important

Should possess adequate

Answer 19

Shock-absorbing properties, e.g. Grass, rubber mats or suspended floor

Question 21

Plyometrics can improve performance in

Answer 21

Vertical jumping
Long jumping
Sprinting
Sprint cycling

Question 22

plyometric training uses muscles’ elastic properties and proprioceptors (muscle spindles and GTO) to generate maximum force by:

Answer 22

increasing the recruitment of muscle in a minimal amount of time

Question 23

The eccentric contraction immediately preceding a concentric contraction significantly increases the force generated concentrically as a result of the storage of elastic potential energy. This extra energy is released as

Answer 23

kinetic energy during the concentric phase

Question 24

3 mechanism by which plyometric training improves performance:

Answer 24

• Enhanced muscle spindle activity
• Desensitisation of the GTO
• Enhanced neuromuscular efficiency

Question 25

Enhanced muscle spindle activity: (SET THE MUSCLE TO A PRESET LENGTH) when muscle spindles are stretched the muscle spindles are also stretched. This causes the spindles to send nerve impulses that result in reflex contraction of the stretched muscle. This reflex enables the muscle to

Answer 25

rapidly return to its preset length

Question 26

Desensitisation of the GTO: Repeated plyometric exercises desensitise the GTO by increasing the degree of stimulation needed for the GTO to inhibit muscle contraction. This means that:

Answer 26

the muscle can produce more force

Question 27

Enhanced neuromuscular efficiency: May promote better coordination of contracting agonists and synergists, thus improving the efficiency of the CNS, Making use of the stretch reflex, inhibiting the GTO and enhancing the ability of the nervous system to react to the lengthening muscle optimises the

Answer 27

force produced by the concentric contraction

Question 28

Plyometrics improves jumping ability, running economy and power output but not:

Answer 28

improved strength