1. PLYOMETRICS REVIEW
Casey Christy, MA, ATC, CSCS

2. History of Plyometrics
• Jump training became popular in the
1960s when the high performance abilities
of Eastern European Olympians were
attributed to their training methods.
• The term “plyometrics” was coined by Fred
Wilt, an American Track and Field coach, in
1975. It stems from the greek terms plio
and metric which mean “more” and
“measure,” respectively.

3. Benefits
•Plyometrics can be utilized for the
purposes of injury prevention,
enhancing sports performance and
as a form of therapeutic exercise.

4. Benefits
•When used as part of a rehabilitation
program, special care (ie: strength
prerequisites, consultation with
treating physician) must be taken to
ensure the patient’s readiness for
such activity.

5. Athlete Readiness
• Balance Tests
• Beginner athlete should be able to
balance on single leg 30 seconds without
falling.
• Intermediate athlete should be able to
balance doing quarter squat on one leg
for 30 seconds without falling.
• Advanced athlete should be able to
balance doing quarter squat on one leg
for 30 seconds without falling.

6. Athlete Readiness
• General Strength Requirements for high
intensity plyometrics
• Lower Body: Should be able to squat 1.5x
his or her body weight for 1 RM
• Upper Body: Should be able to bench press
1.5x his or her body weight for 1 RM (if body
weight under 220lbs). Bench press body
weight if body weight over 220lbs
• Alternate test method is the athlete should be able to
do 5 clap pushups in a row to assess upper body

7. Athlete Readiness
• A Speed-Strength Test can also be used to
determine readiness for high intensity plyos:
• Lower Body: Should be able to squat 60% of
body weight in 5 seconds or less
• Upper Body: Should
be able to bench press
60% of body weight in 5
seconds or less

8. Safety Concerns
• Landing surface: wrestling mat type ideal
• Age: Younger athletes with open growth
plates should avoid high intensity jumps,
depth jumps, etc
• Maturity: Athlete able to follow directions?
• Size: Those over 220lbs have higher injury
risk, avoid high-volume, high-intensity
plyos, depth jumps with caution (box height
no higher than 18in)

9. Safety Concerns
• Plyos must be supervised by
knowledgeable adult instructor
• Boxes should have non-slip surfaces
• Athletes should wear proper footwear with
ankle and arch support, lateral stability, non-
slip sole
• Prior injury, joint laxity, spinal
dysfunction may affect one’s
ability to do plyos

10. Neuromuscular Principles
•Stretch Shortenening Cycle (SSC):
A combination of stored elastic
energy (mechanical model) and the
stretch reflex (neurophysiological
model) creates a powerful concentric
muscle contraction beyond that which
is possible with only a concentric
contraction.

11. Neuromuscular Principles
•There are two models of the SSC:
•Mechanical Model (rubber band)
•Neurophysiological Model (stretch
reflex)

12. Neuromuscular Principles
•Mechanical model of SSC:
Contractile (myofibrils) and non-
contractile elements (tendon,
sheath, connective tissue) develop
stored elastic energy when quickly
stretched during an eccentric
contraction…

13. Neuromuscular Principles
•The energy is released when
immediately followed by a concentric
contraction. This powerful action is
similar to stretching and releasing a
rubber band.

14. Neuromuscular Principles
•Neurophysiological model of
SSC: The stretch reflex is an
involuntary response to a quickly
stretched muscle. After the
eccentric contraction in which the
muscle spindles are stretched, a
rapid concentric contraction is
possible…

15. Neuromuscular Principles
•The afferent response goes directly
to the efferent motor nerve via the
spinal cord. No other nerves are
involved. The stretch reflex is also
known as a monosynaptic
response, since only one synapse
is involved.

16. Neuromuscular Principles
•The three components of a
plyometric exercise (SSC) are:
•Eccentric contraction
•Amortization phase (time
between the eccentric and
concentric contractions)
•Concentric contraction

17. More about Amortization
•Also known as the transition phase.
•Most crucial phase, duration must be
kept short.
•If the amortization phase is too long,
the stored elastic energy is lost as
heat, prohibiting a powerful
concentric contraction.

18. Pre-Testing
•Vertical Jump pre-test should be
done to get athlete’s base
measurement
•Can re-check after 4-6 weeks of
program.

19. Pre-Testing
•Can also check vertical jump
before each plyometric workout to
determine fatigue. Lower than
normal score indicates athlete may
need additional recovery and plyos
workout should be postponed, or
workout altered.

20. Program Design
•Athletes should have a sufficient base
of strength, agility, flexibility and
proprioception before beginning a
plyometrics program.
•When designing program, begin with
simple, low-intensity exercises and
gradually progress to higher intensity
exercises.

21. Program Design
•Monitor foot contacts carefully:
beginners 60-100 per session;
intermediate 100-150; advanced
120-200.
•Consider how much “plyometric”
activity is already being done in
practice.

22. Program Design
•Perform jumps on a surface that
absorbs impact to prevent injury.
•Allow 48-72 hours between
plyometric sessions to provide for
adequate recovery.

23. Program Design
•Allow 1:5 work to rest ratio for
plyometric exercises (ie: 10 seconds
effort, 50 seconds rest), or if working
muscle endurance, allow 10-15
second rest period.

24. Program Design
•Here are the different types of lower
body plyometric exercises list from
least intensity to highest intensity:
• Jumps in place
• Standing jumps
• Multiple hops and jumps
• Bounds
• Box drills
• Depth jumps

25. Types of Jumps
•Jumps in place are exercises that
involve jumping and landing in the
same spot. Examples include ankle
jumps and squat jumps.

26. Types of Jumps
•Standing jumps are those that
involve jumping in a horizontal,
vertical or lateral direction. An
example would be jumping
horizontally over a barrier in a
forward direction. Standing jumps
involve maximal effort, while
allowing recovery between jumps.

27. Types of Jumps
•Multiple hops and
jumps are repeated
jumps. An example
would be jumping back
and forth over a cone
or other barrier.

28. Types of Jumps
•Bounding is an
exaggerated running
and jumping motion.

29. Types of Jumps
•Box drills include
jumping onto, or off a
box. Box heights can
range from 6in to
42in, and landing
surfaces should be at
least 18in x 24in.

30. Types of Jumps
•Depth jumps involve stepping
down from a box and performing a
vertical or horizontal jump. A sprint
or lateral movement can also be
incorporated immediately after the
depth jump to combine different
movements.

31. Program Design
•High intensity exercises such as
single leg multiple hops, bounding
and depth jumps should only be
performed when the athlete has
sufficient strength, experience and
technique.

32. Program Design
•Box heights will depend on the
athlete’s size, experience and ability.
A 12 or 18in box is typically used for
beginners.

33. Program Design
•Acute inflammation, certain post-
operative conditions or injuries, joint
instability and spinal conditions are
some of the contraindications to
plyometric exercises.
•Consult a physician regarding any
contraindications or limitations.

34. Program Design
•Make sure a thorough warm-up
and stretching program are
completed before performing
plyometrics or agility exercises.
•Power skipping, jumprope, and
ankle jumps in place are good warm-
up exercises.

35. Program Design
•Proceed with caution with those
under the age of 16 and those over
220 pounds. These individuals
require a modified program with
respect to volume and intensity.

36. Program Design
•Follow a slow progression when
adding single leg plyos for any
athlete.

37. Teaching Points
•The hip, knee
and ankle
should be in
alignment with
all jumps.

38. Teaching Points
•Watch knee valgus, especially with
female athletes, and with single leg
exercises. This is a risk factor for
ACL and other injuries and can be
part of a injury prevention program.

39. Teaching Points
•Teach athletes to land in an
athletic position with the chest up,
head up, and back flat (core
training important for this stability),
and bend the knees.
•Teach proper recoil for the next
jump, and to bring the hips through
when performing the next jump.

40. Teaching Points
•Females tend to be more quad
dominant when landing from a jump
which increases ACL risk.
•Teach females to achieve
quad/hams co-contraction by
emphasizing hamstring activation
which protects ACL.

41. Teaching Points
•With single leg exercises, a 30 knee
angle is optimal for ham/quad co-
contraction.
•Teach “sticking landing” first to
emphasize proper landing technique
and body position before doing
higher speed or intensity exercises.

42. Program Design
•Upper body
plyometrics can
involve body
weight (ie: clap
pushups on floor
or standing
against a wall or
medicine ball
exercises).

43. Program Design
•Medicine ball plyometrics include:
•Medicine ball situp with toss to partner
•Standing chest pass
•Power drops (lying supine on a bench
ball is dropped towards your chest, you
catch and lower to chest, then
explosively throw ball back up to
partner)

44. Program Design
•Combination exercises include:
•Medicine ball lunge and torso twist
•Medicine ball box step up and throw
•Depth jump with sprint (no med ball)

45. References:
Baechle, T. and Earle, R. Essentials of Strength Training
and Conditioning, 2nd ed. National Strength and
Conditioning Association. Human Kinetics Publishers.
Chu, D. Jumping Into Plyometrics, 2nd ed.
Gambetta, V. and Odgers, S. The Complete Guide To
Medicine Ball Training. Optimum Sports Training.
Kimball, A. Applied Injury Prevention for Females.
National Strength and Conditioning Association online
course.