ch. 17 plyometric Flashcards
A plyometric movement is a quick, powerful movement consisting of an ________________, followed by an immediate powerful _____________.
Eccentric (AKA counter movement or prestretch)
Concentric muscle action
The eccentric muscle action of a plyometric movement is called this
Counter movement
or prestretch
Both speed and plyometrics rely heavily on ________________ to elicit the desired outcome
Stretch shortening cycle (SSC)
All functional activities are composed of a series of repetitive SSCs, thus it is essential to incorporate exercises that strengthen clients in these areas.
The faster a muscle is stretched the greater the______________ following the stretch, resulting in ________________ output
Concentric force
Increased power output
Response time of the reflex ___________ with training.
Strength of the response caused by stretch in terms of muscle contraction elicited _________ with training.
Pg.412
Does not really change
Increases
During a basketball jump shot _______________ phase is the countermovemnet, beginning at the imitation of the half squat motion and continuing until the bottom of the movement
Eccentric phase
AKA deceleration phase
Involves preloading the agonist muscle groups. During this phase the SEC stores elastic energy and the muscle spindles are stimulated
enhanced coordination, agility, and anaerobic/general conditioning are all benefits of this type of training
plyometric
Errors in alignment will not only cause potential injury but also cause
Increased ground reaction contact time during the amortization phase, resulting in less than optimal concentric force
Ground reaction contact time
Amortization phase
Concentric force
Pg.417
A client doing plyometric training with double leg drills for the first time must
Balance on one leg for 30 seconds without falling
This indicates that the client has enough leg strength to do double leg drills
Before the trainer increases the level of exercises, the client should be able to hold a single leg squat position as described for the balance tests shown in table 17.2
Pg.417
Plyometric training requires significant strength and muscle control, especially during the __________________.
For this reason clients should not be encouraged to perform plyometrics until after having done a resistance training program.
Eccentric phase
This is a quick, powerful movement consisting of an eccentric muscle action, followed by an immediate powerful concentric muscle action
plyometrics
this is called the countermovement or prestretch
the eccentric phase of plyometrics
The ability to achieve high velocity
speed
Both plyometrics and speed rely heavily on this
stretch-shortening cycle
The purpose of this type of training is to use the stretch reflext and natural elastic components of the muscles and tendons to increase the power of subsequent movements and strengthen the muscles and tendons functionally
plyometrics
The purpose of this type of training is to use the same mechanical and neurophysiuologic components in concert with technique and muscular strength to produce larger ground forces thereby allowing clients to run faster
speed training
in this model, elastic energy is stored following a rapid stretch and then released during a subsequent concentric muscle action, thereby increasing the total force production
mechanical model
a primary contributor to force produciton during plyometric exercises, includes some muscular (actin/myosin), but is mainly composed of tendon
series elastic component
when the muscle is stretching in eccentric muscle action this occurs in the SEC
the SEC acts as a spring and is lengthened, storing elastic energy
If the eccentric phase is to long, or requires too great of a motion this occurs
the elastic energy is lost as heat, and no plyometric effect occurs
this involves a change in the force-velocity characteristics of the muscles contractile components caused by stretch
neurophysiological element
The bodies involuntary response to an external stimulus that causes a rapid stretching of the muscle
stretch reflex
The stretch reflex responds at this rate
to the rate that muscle is stretched
The reflex component of plyometric exercise is composed of primarily this type of muscle spindle activity???????
muscle spindle????
This, not this respond to plyometric training
strength of muscle contraction, not the response time of the contraction
enhancement of the stretch reflex
potentiation
Another name for the eccentric phase, which involves preloading the agonist muscle groups
deceleration phase
This is the transition phase, and is the time between the eccentric and concentric phases
amortization phase
These must be kept as short as possible for optimal use of the stretch reflex by the concentric muscle action
amortization phase
This is the bodies response to the events occurring during the eccentric and amortization phases
concentric phase
improved running economy is an additional benefit of this type of training
moderate plyometric training
This may be a compromise for clients who wish to gain the benefits of plyometric training, but for whom plyometric training is not appropriate for
eccentric training
Guidelines for the age plyometrics is safe to begin
as soon as the child is mature enough to follow directions
most important aspect for determining if the client is ready for plyometric training
the client must respond positively to the PTs instructions
The fundamental position that all lower body plyometric exercises originate from and in
the partial, or half-squat position
Feet position in the beginning and end phase of plyometrics
shoulder width apart
describe proper plyometric landing form
feet shoulder width apart
chin slightly tucked
scapulae slightly retracted
trunk parallel to the tibias
knees over/slightly posterior to the toes
heals on the floor
weight should be centered over a solid base of support
pelvic tilt for the body weight squat
anterior
before the PT increases the level of exercises from beginner to intermediate the client should be able to do this
hold a single leg squat position for 30 seconds
recommendations for starting plyometric training (strength): lower body
the clients 1RM squat should be at least 1.5 times their body weight
recommendations for starting plyometric training (strength): upper body
clients weighing 220 pounds should have a 1RM bench press of 1xBW
clients weighing under 220 pounds should have a 1RM bench press of 1.5xBW
This is an alternative measure of prerequisite upper body strength for beginning plyometric training
ability to perform 5 clap push-ups in a row
The body’s ability to control its center of mass in response to forces on the trunk generated by other parts of the body, including the upper and lower extremities
core strength
this is responsible for maintaining balance and postural stability during all activities
core
recommendations for starting plyometric training (speed): lower body
the client should be able to perform 5 reps of 60% BW squats in 5 seconds
recommendations for starting plyometric training (speed): upper body
the client should be able to perform 5 reps of bench press with 60% BW in 5 seconds
Body position during landing
shoulders over the knees and knees over or slightly behind the toes, feet shoulder width apart, with weight shifted to the ball of the foot (heel still on the ground)
Clients weighing more than this much may be at increased risk for injury when performing plyometric exercises
220 lb
4 minimum requirements to begin plyometrics
proper technique for each drill
at least 3 months of resistance training experience
sufficient strength,speed, and balance
no current injuries to involved body segments
required landing surface size of a plyo box
18 by 24 inches
the mode of plyometric training is determined by this
the general parts of the body that perform the exercise
this refers to the amount of effort exerted by the muscles, connective tissues, and joints during performance of an exercise and is controlled both by the type of drill and by the distance covered
plyometric intensity
if intensity is too high this will occur
an increase in the amortization phase which results in negating the plyometric benefirt of the exercise
the number of plyometric training sessions per week depends on these three things (frequency)
age
ability
goals
Frequency and this are inversely proportional
intensity
for youth and adolescent clients, plyometric training may be performed up to this many times per week
2 times per week on nonconsecutive days
Rather than concentrating on frequency, many PT rely more on this between plyometric training sessions
recovery time
Proper work to rest ratio for plyometric training
1:5 to 1:10
typical guideline for days between plyometric training sessions
48-72 hours
Most clients should perform this many plyometric training sessions per week
1 to 3
This is expressed as the number of contacts per workout, but may also be expressed as distance, as with plyometric bounding
plyometric volume
foot?
Number of reps suggested per set up upper body plyo
8-12
a rep of upper body plyo is considered
a catch or throw
Plyometric training should never be longer than this for beginners
30 min
if plyometrics are being incorporated into a workout they should be performed at this time
before any other exercises
what box height should be started with in depth jumps
12 inches
The height of the box should increase by this much until the client can no longer jump to the vertical jump height
6 inches
amount of rest between jumps when assessing for depth box jump height
1 to 2 minutes
What is the distance the ball should travel when assessing the MedBall weight to be used for upper body plyo
10-12 feet
training accomplished in a variety of ways, is the application of maximal force in a minimal amount of time
speed training
application of maximum force at high velocites
speed-strength
If clients are to move more quickly, they must explode when their feet are on the ground
the ability to maintain running speed over an extended duration (typically longer than 6 seconds)
speed-endurance
Helps prevent a client from slowing down during a maximal-speed effort
If you don’t have speed endurance you will be unable to accelerate due to fatigue
during the acceleration phase the body should lean forward approx. this much for the first 13-16 yards
45degree
two leg action phases of sprinting
driving phase
recovery phase
locking the upper arm into place and moving only the lower arm rather than having the action created at the shoulder
allowing the arm to cross the midline of the body
improper arm swing distance
emphasizing the forward motion of the arm swing rather than the backward motion
common errors for arm swing while sprinting
If the arms cross the body’s midline, upper body rotation will occur
Start and end hand position of arm swing during sprinting
shoulder height on the upswing
pass the buttocks on the back swing
speed training focuses on these three areas
form
stride frequency
stride length
During the start, speed is highly dependent on this
stride length
how to determine the clients optimal stride length
length of greater trochanter to the floor
- 3 to 2.5 times this measurement for females
- 5 to 2.7 times this measurement for males
As sprinting speed increases this becomes the more important variable
stride frequency
of the two components of speed training this is likely the more trainable
stride frequency
These types of training drills are used to increase stride frequency
Fast leg drills
sprint-assisted training (running at speeds greater than a client is able to independently achieve)
and resisted sprinting
regardless of the method used, sprint assisted training should not increase speed by more than this percent of the clients maximal speed
10%
This is used to help a client increase stride length, as well as speed-strength, by increasing the clients ground force production during the support phase
*speed strength - application of maximum force at high velocities. Application of force in a minimal amount of time.
resisted sprinting
this is arguably the most important determinant of speed
ground force production during the support phase
This is used especially to improve the acceleration of the sprint
resisted sprinting
Resisted sprinting should not increase external resistance my more than this %
10%
Resisted sprinting should be performed over relatively short distances of…
11-33 yards
training maximum velocity requires these types of distances
longer
Athletes may have this many speed training sessions per week, while non-athletes may benefit from this many sessions per wek
2-4
1-2
proper work to rest ratio of speed training
1:5 to 1:10
3 stages of progression for speed training
low to high volume of low-intensity speed drills
low to high volume of moderate intensity
low to high volume of high intensity
this aspect of speed training typically refers to the number of repetitions and sets performed during a session and is expressed as the distance covered
volume
some athletes may benefit from this type of training, a combination of resistance and plyometric training, by performing plyometrics followed by high-intensity resistance training
complex training
The series of three phases that explains the mechanical and neurophysiological reactions to a plyometric movement. (NSCA CPT, pg. 430)
Stretch-Shortening Cycle (SSC)
The structures that, when stretched, have the ability to store energy that may be released upon an immediate concentric muscle action. (NSCA CPT, pg. 430)
Series Elastic Component (SEC)
The increase in activity of the agonist muscle caused by the reflexive response of the muscle spindles and the release of stored elastic energy. (NSCA CPT, pg. 431)
Potentiation
Elastic energy is stored following a rapid stretch and then released during a sub- sequent concentric muscle action, thereby increasing the total force production. (NSCA CPT, pg. 430)
Mechanical Model of Plyometric Exercise
A change in the force–velocity characteristics of the muscle’s contractile components caused by stretch. (NSCA CPT, pg. 430)
Neurophysiological Model of Plyometric Exercise
A direct effect of a weak core is an
Increased amortization phase time, which will compromise the plyometric effect
Pg. 418
Trainers should require ___________ before starting a client on plyometric activities. Trainers should be well informed of the client’s ____________ and should ensure that the client has had a recent _____________ from a licensed physician.
Formal medical clearance
Medical history
Physical examination
Pg.420
Landing surface should not be so soft that it increases the transition between ___________ and ____________
Eccentric and concentric phase
Pg.420
Clients may progress to harder landing surfaces (true/false)
True
However surfaces such as concrete,tile, hardwood, are not recommended.
Pg.420
These may extended the amortization phase, thus preventing efficient use of the stretch reflex
Excessively thick exercise mats and mini trampolines. (Greater than or equal to 6 inches [15cm])
Pg.420
Following a Needs Analysis, the variable to be included in the plyometric program design are (8)
Mode Intensity Frequency Recovery Volume Program length Progression Warm up
Although commonly viewed as a controlled fall, sprinting may be more accurately described as a series of “______________ where the body is repeatedly launched forward as a projectile”
Pg.428
Ballistic strides
After 13 to 16 yards of acceleration the client should quickly move upright to a less than 5 degree angle lean during maximal speed (with the lean coming from the ground and not the hips)
During the first 13-16 yards of acceleration the focus is on increasing ___________ and ___________
Velocity and stride length
During acceleration the client will have an increased body lean and will be focused more on the _____________ phase and less on the _____________ phase of the spring technique
Driving phase
Recovery phase
The ____________ of speed training is determined by the speed characteristics that the given drill is designed to improve.
Mode
Speed training focuses on three areas:
Form
Stride frequency
Stride length
A clients leg length is 36 inches what is their optimal stride length
2.5 times 36
90 inches
Stride length drills should be performed from ______ to _______ of optimal stride length
60% to 105%
A clients optimal stride length is 90 inches, what distance in inches should stride length be per stride for stride length drills. (It’s a range)
60% of 90 is 54 inches
105% of 90 is 94.5 inches
Stride length drills should be between 54 and 94.5 inches per stride
Which is more trainable stride frequency or stride length
Stride frequency
Stride length is dependent o body height and leg length
Use heavier resistance during resisted sprinting when the goal is to improve the __________ phase
Use lighter resistance when the goal is to improve _____________
Acceleration phase
Maximum velocity
Resisted sprinting is used to help a client increase stride length, as well as speed-strength, by increasing the clients ground force production during the support phase
During resisted sprinting If performance decreases by more than__________, the load being used is too heavy and will have detrimental defects on sprint training
10%
Resisted sprint training targets clients wanting to improve speed-strength. Adding resistance to non athletic clients gait, however, may
Also improve function
Attaching tubing to a 70 year old client during walking may improve his or her ability to walk up hills or may increase confidence in walking. Pushing a sled may help a construction worker.
A more general mode of speed training that most clients can easily perform is
Interval sprinting
A type of interval training
Having clients work on speed drills when they are less recovered may…
Actually be beneficial because it may be more specific to the type of tasks they will have to accomplish
