Lecture 6: Plyometric Training

Question 1

Mechanical Model

Answer 1

series elastic component (SEC)

Question 2

-SEC

Answer 2

elastic energy is stored during an eccentric action, then released during an immediate concentric muscle action

• contributes to total force production by naturally returning muscles/tendons to their un-stretched configuration
• if concentric action does not occur immediately or the eccentric phase is too long the stored energy is lost as heat

Question 3

PED

Answer 3

parallel elastic component

-epimysium, perimysium, endomysium, & sarcolemma exerts a passive force with unstimulated muscle stretch

Question 4

Neurophysiological Model

Answer 4

Potentiation fig. 16.2

Question 5

Potentiation

Answer 5

change in force velocity characteristics of the muscle’s contractile components due to the stretch reflex (muscle spindles)
-if concentric muscle action does not occur immediately after the pre-stretch the potential energy is lost

Question 6

Muscle Spindles

Answer 6

proprioceptive organs that detect a quick stretch and respond by increasing muscular activity (involuntary protective response)
-creates a breaking effect, allowing for a powerful concentric action

Question 7

Stretch Shortening Cycle (SSC)

Answer 7

• incorporates both the energy storage capabilities of the SEC and the stimulation of the stretch reflex to facilitate a max increase in muscle recruitment of a minimal amount of time
• Plyos use SSC that ultimately increase the power of subsequent movements in the shortest possible time

Question 8

SSC phases

Answer 8

1) eccentric
2) amortization
3) concentric

Question 9

Eccentric Phase

Answer 9

• stretch of agonist muscle
• elastic energy is stored in the SEC
• muscle spindles are stimulated

Question 10

Amortization phase

Answer 10

• pause between phases
• type Ia afferent nerves synapse with alpha motor neurons
• alpha motor neurons transmit signals to agonist muscle group

Question 11

Concentric Phase

Answer 11

• shortening of agonist muscle
• elastic energy is released from the SEC (mechanical)
• alpha motor neurons stimulate the agonist muscle group (neurophysiological)

Question 12

SSC combines…

Answer 12

mechanical and neurophysiological mechanisms

• is the basis of plyos
• rapid eccentric muscle action stimulates the stretch reflex and storage of elastic energy which increase force produced during subsequent concentric action

Question 13

Highest Jump

Answer 13

1) Approach Jump
2) Countermovement Jump
3) Static Squat Jump

Question 14

Lower Body Plyos

Answer 14

Jumps in place 
standing jumps
multiple hops and jumps 
bounds
box drills
depth jumps

Question 15

Jumps in Place

Answer 15

• jump and land in same spot without rest
• emphasis on vertical
• amortization phase: between jumps
  ex) squat jump, tuck jump, split-squat jump, pike jump

Question 16

Standing Jumps

Answer 16

emphasis on horizontal vertical component

• max effort with recovery between reps
• ex) vertical jump, jump over barriers

Question 17

Multiple Hops and Jumps

Answer 17

combo of jumps in place and standing jumps

• repeated movements
• ex) double single leg hop, lateral barrier hop, zigzag hop

Question 18

Bounds

Answer 18

• exaggerated movements with much horizontal speed
• measured by distance and/or # of reps performed
• Distance >30m
  ex) skip, power skip, backwards skip, alternate leg bound

Question 19

Box Drills

Answer 19

• increased intensity multiple hops and jumps by use of a box
• using one, both, or alternating legs
  ex) leg push-off, lateral push-off, side to side push-off, jump on/off, lateral box jump

Question 20

Depth Jump

Answer 20

• use of gravity and athlete’s weight to increase intensity
• jump vertically and horizontally or to another box
• use one or both legs
  ex) single leg depth jump, depth jump to another box, depth jump with lateral movement, depth jump with standing long jump

Question 21

Upper body plyos

Answer 21

not used as often as lower although still a variety

-good for rapid, powerful upper body movement spots (ex-throwing)

Question 22

Examples of upper body plyos

Answer 22

Med Ball throw’s and catches (chest pass, two-hand overhead throw, two hand side to side, single arm throw, power drop)
-push-ups (depth push-up)

Question 23

Trunk Plyos

Answer 23

• stretch reflex is not sufficiently involved during many trunk exercises
• to counteract this exercise movements must be shorter and quicker to allow stimulation of the stretch reflex

Question 24

Program design factors

Answer 24

Intensity- depends on drill performed
Frequency- 1-3 times per week
Recovery- 48-72hrs b/w session
Volume- repsxsets, # of foot contacts, or distance covered
Program Length- 6 to 10 weeks
Progression- low to moderate volumes of low intensity to moderate intensity to high volume
Warm-up- general warm-up, stretching, specific warm-up

Question 25

Plyos for young and old

Answer 25

• not a concrete age to start at
• high intensity lower body drills are contraindicated
• progression should be from simple to complex
• min of 2-3 days recovery for youth and 3-4 days for older
• volume and intensity for older should be decreased

Question 26

Plyos for seniors

Answer 26

-can be done- be careful with depth jumps and one footed contact to to problems with BMD and balance problems

Question 27

Safety considerations and other problems

Answer 27

insufficient strength/speed/balance/base, inadequate warm-up, improper progression, poor training area, poor equipment, not correct volume or intensity, weight, previous injuries, depth of jump

Question 28

Strength Base Required

Answer 28

1RM squat at least 1.5x body weight
1RM bench press at least body weight for larger athletes and 1.5x body weight for smaller athletes
-Ability to do 5 clap push-ups

Question 29

Proper landing technique

Answer 29

centre of gravity in line with base of support

• shoulders over the knees
• flexion of the ankles, knees, and hips
• landing surface should have adequate shock absorbing properties

Question 30

Safety for depth jumps

Answer 30

no greater than 1.2m

• recommended- 41-107cm
• normal 76-81cm
• for people over 220lbs no greater than 46cm

Question 31

Speed Base Required

Answer 31

• able to perform 5 reps of squat with 60% body wt in 5s or less
• able to perform 5 bench press with 60% of body weight in 5s or less

Question 32

Balance Base Required

Answer 32

beginners: 30s single leg
intermediate: 30s single leg in 1/4 squat
advanced: 30s single leg in 1/2 squat