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Rajiv Gandhi University of Health Sciences, Karnataka
Curriculum Development Cell
Confirmation for Registration of Subjects for Dissertation
Registration No
:
Name of the Candidate
: Ms. MARIA ALISHA RODRIGUES
Address
: H. NO- 615 Alison Mansion 3rd Fradilem Navelim
Salcete –Goa.
Name of the Institution
: S. D. M. College Of Physiotherapy, Dharwad.
Course of study and subject
: Masters in Musculoskeletal Disorders and Sports
Physiotherapy.
Date of admission to course
: 15th July 2013.
Title of the topic
:
“A
COMPARATIVE
EFFECTIVENESS
PLYOMETRICS
OF
WITH
STUDY
TO
EVALUATE
PLYOMETRICS
WEIGHT
THE
ALONE
AND
TRAINING
ON
IMPROVING THE AGILITY AND POWER IN LOWER LIMB
PERFORMANCE AMONG COLLEGE LEVEL CRICKET
PLAYERS.”
Brief resume of the intended work
: Attached
Signature of the Student
:
Guide Name
Remarks of the Guide
: Dr. Sunil K M
:
Signature of the Guide
:
Co-Guide Name
Signature of the Co-guide
: -: --
H. O. D. Name
Signature of H. O. D.
: Dr. RAVI SAVADATTI
Principal Name
: Dr. RAVI SAVADATTI
Principal Mobile No.
E-mail ID
: 09845051209
: [email protected]
Remarks of the Principal
Principal Signature
:
:
1
(A)
BRIEF RESUME OF THE STUDY
INTRODUCTION
Success in many sports depends heavily upon the athlete's explosive leg power and muscular
strength. In jumping, throwing, track and field events and other activities, the athlete must be able
to use strength as quickly and forcefully as possible. This display comes in the form of
speed-strength or power.1
Power represents the amount of work a muscle can produce per unit of time. An increase in power
gives the athlete the possibility of improved performance in sports in which the improvement of
the speed-strength relationship is sought.2
Strength training is also an important aspect for athletes in sports. Strength training is synonymous
with the term resistance training and is defined as a specialised form of conditioning that is used to
increase one’s ability to produce or resist force. Strength training uses the principle of progressive
overload to force the body to adapt in order to able to produce and /or resist larger forces. Strength
training is a tool to augment sport performance through improved strength and motor
performance.
Several studies used plyometric training and have shown that it improves power output and
increases explosiveness by training the muscles to do more work in a shorter amount of time.
This is accomplished by optimizing the stretch-shortening cycle, which occurs when the active
muscle switches from rapid eccentric muscle action (deceleration) to rapid concentric muscle
action (acceleration). The rapid eccentric movement creates a stretch reflex that produces a more
forceful concentric muscle action than could otherwise be generated from a resting position. The
faster the muscle is stretched, the greater the force produced, and the more powerful the muscle
movement . 3
Plyometric exercises that exploit the stretch-shortening cycle have been shown to enhance the
performance of the concentric phase of movement and increase power output. PT includes
performance of various types of body weight jumping-type exercise, like drop jumps (DJs),
countermovement jumps (CMJs), alternate-leg bounding, hopping and other SSC jumping
exercises .4
Plyometric drills usually involve stopping, starting, and changing directions in an explosive
2
manner. These movements are components that can assist in developing agility. Agility is the
ability to maintain or control body position while quickly changing direction during a series of
movements. Agility training is thought to be a re-enforcement of motor programming through
neuromuscular conditioning and neural adaptation of muscle spindles, golgi-tendon organs, and
joint proprioceptors.
Agility training objectives and plyometric activities have been used in sports such as football,
tennis, soccer or other sporting events that agility may be useful for their athletes. By enhancing
balance and control of body positions during movement, agility theoretically should improve.5
Illinois Agility Test reliability was established by developing standardized instructions and
implementation methods. The Illinois agility test is found to be reliable measures of agility
between the ages of 18 and 40 yr. Establishing the reliability of these additional measures provides
the clinician with a clinical tool that assesses uniplanar, biplanar, and multiplanar movements, thus
creating a comprehensive assessment of agility.6
Jumping is a complex multi-joint action that demands not only force production but also a high
power output. Numerous investigators have underlined the significance of maximal rate of force
development in the improvement of explosive jumping performance. Plyometric training has been
advocated for sports that require the athletes to have explosiveness and an increased vertical
jumping ability.7
Vertical jumping constitutes an integral component of explosive performance in numerous athletic
activities. As such, jumping ability is crucial in the execution of many athletic skills, such as
rebounding in basketball, spiking in volleyball, and high jumping. Therefore, it is important to
determine the parameters involved in vertical jumping and develop them through proper training
regimens.
The vertical jump test to measure the jumping mechanical power. This test was preferred because
it takes advantage of to potential for using elastic energy storage as well as chemical mechanical
energy conversion. This test has shown to have high validity (compared to the Wingate test, 0.87)
and reliability(test- restest 0.95) coefficients.8,9
Cricket is one of the world’s major team sports in terms of regular international games. It is a
bat-and-ball sport similar to the game of baseball, generally played outdoors on natural grass
fields. At social levels, cricket produces relatively few injuries, but at elite levels injuries are quite
3
common primarily due to higher intensity of matches and Workloads .Today elite sportspeople are
expected to train longer, Harder, and earlier in life to excel in their chosen sport. The Modern
cricketer is no exception. The demands placed on the cricketer are further increased because of the
repetitive nature of the game, often for long periods of time.
The cricket players have to be quick between the wickets (running between wickets to get
maximum runs). These players need to be agile and quick as well as coordinated to take the
catches.10
Weight training has been able to improve vertical jumping performance in most cases by with
lighter more explosive lifts being more effective than the heavier and slower lifts.1
NEED FOR THE STUDY:
Plyometrics is simply a set of drills designed to stimulate the series elastic component over and
over again – preferably during movements that mimic those in the athlete’s sport. A wide variety
of training studies shows that plyometrics can improve performance in vertical jumping, long
jumping, sprinting and sprint cycling.11
Cricketers, like any athlete today, are expected to train harder, for longer, and to commence at an
earlier age, if they are to succeed at the elite level. It is therefore not surprising that physicians are
diagnosing an increasing number of overuse injuries, as the hours of repetitious practice produce a
gradual deterioration in the functional capacity of the body. Training, technique, footwear,
surface, rehabilitation, warm-up and conditioning are all factors which can contribute to overuse
injuries.
Bowling (40%) and fielding and wicket-keeping (33%) accounted for the majority of the injuries,
with batting accounting for 17% of the injuries sustained. Of the bowling injuries, 55% were
lower-limb injuries and 33% were back and trunk injuries. Of the 39 stress fractures, 79% were
overuse bowling injuries, with the younger players sustaining 74% of the stress fractures.
The primary mechanism of injury was the delivery and follow-through of the fast bowler (25%),
running, diving, catching and throwing the ball when fielding (23%) and overuse (17%).
Untrained college level athletes are more prone to these injuries.Hence, we believe that
plyometrics and weight training can be used as a part of training regime to reduce the risk of
sustaining the above injuries. 12
The comparison of plyometric exercises and weight-training protocols has produced controversial
4
results. The combination of plyometric exercises and weight training increased , maintained or
unaffected vertical jumping performance. Adams et al. suggested that this combination may
provide a more powerful training stimulus for the vertical jumping performance than either weight
training or plyometric training alone.1,13,14
There has been no conclusion made regarding the relative effectiveness of plyometric training and
weight training or the combination of both in the development of vertical jump ability.
As far as we know, there have been no studies done to compare plyometric versus plyometric
weight training for agility.
Therefore, the purpose of the present study is to determine how vertical jump performance and
agility are affected by a typical 6-week plyometric training program and a combination of
plyometric and weight training.
RESEARCH HYPOTHESES:
Null hypothesis (H0): There will be no significant improvement in lower limb performance
outcome measures between plyometrics alone and plyometric weight training program.
Alternate hypothesis (H1): There will be significant improvement in lower limb performance
outcome measures between plyometrics alone and plyometric weight training program.
REVIEW OF LITERATURE:-
GD Myer, KR Ford, JL Brent, TE Hewett ,conducted a study to evaluate the effectiveness of
plyometric vs balance training on strength and balance.The results of this study suggest that both
Plyometrics and Balance training are effective at increasing measures of neuromuscular power
and control. A combination of Plyometrics and Balance training may further maximize the
effectiveness of preseason training for athletes.15
In a study conducted by Michael G. Miller et al. on 28 subjects to determine if six weeks of
plyometric training can improve an athlete’s agility . All subjects participated in two agility tests,
T test and Illinois test. The results of this study showed that the plyometric training can be an
effective technique to improve an athlete’s agility.16
Study done by Bartholomeu SA, to determine the effects of plyometrics on vertical jump
5
performance have concluded that relatively small amount of plyometric training is required to
improve performance in these tasks. Just one or two types of plyometric exercise completed 1-3
times a week for 6-12 weeks can significantly improve motor performance.17
Christos Kotzamanidis conducted a study to evaluate the effect of plyometric training on running
performance and vertical jumping in prepubertal boys. . In this study 30 healthy non athletic boys
participated. The finding of this study was that applied plyometric training programme resulted in
an improvement in the vertical jump in preadolescents.18
A study conducted by Parsons L.S. and Jones M.T. using both T-test and Illinois agility test, found
a positive relationship between plyometric training and improvement of both agility tests.19
A study done by Adams K, O'Shea JP, O'Shea Kl and Climstein M, to determine the effect of
6-week plyometric training, squat and squat plyometric programme. The result of this study
contributes to improvements in acceleration, leg strength, muscular power, increased joint
awareness and overall proprioception.14
A study done by Mark Vaczi et al , the aim of the study was to investigate the effects of a short
term in season plyometric training program on power, agility and knee extensor strength. He
conducted this study on male soccer players, this program included two training sessions per week
and maximal intensity unilateral and bilateral plyometric exercises. The results of this study
indicate that plyometric training consisting of high impact unilateral and bilateral exercises
induced remarkable improvements in lower extremity power and maximal knee extensor strength
and smaller improvements in soccer specific agility.20
Avery D. Faigenbaum et al. conducted a study to compare the effects of a six week training period
of combined plyometric and resistance training or resistance training alone on fitness performance
in boys aged 12 to 15years.This study concluded that the addition of plyometric training to a
resistance training program may be more beneficial than resistance training and static stretching
for enhancing selected measures of upper and lower body power in boys.21
According to a study done by Vladan Milic et al on cadet volleyball players , to determine the
effects of a 6 week plyometric training program on the explosive strength of these volleyball
players on single foot and two foot takeoff jumps. The study found a statistically significant
difference in explosive strength in favour of the experimental group. This study also determined
an increase in the explosive strength for the two foot and single foot take off jumps.22
6
A study conducted by Paul E. L to examine the effects of 2 plyometric training programs,
equalized for training volume followed by a four week recovery period of no plyometric training
on aerobic power and vertcal jump performance. The results of this study was 4 week and 7 week
plyometric program are equally effective for improving vertical jump height, vertical jump power
and anaerobic power , and anaerobic power when followed by 4 week recovery period.2
According to a study done by Ioannis G. Fatouros et al. to compare the effects of 3 different
training protocols – plyometric training , weight training and their combination on selected
parameters of vertical jump performance and leg strength. The results of this study showed that all
training treatments elicited significant improvements in all tested variables. However the training
combination group produced improvements in vertical jump performance and leg strength that
were significantly greater than improvements in the other 2 training groups.23
A study done by R Rahimi, N Behpur provides support for the use of a combination of traditional
weight training and plyometric drills to improve the vertical jumping ability and explosive
performance in the leg strength.1
OBJECTIVES OF THE STUDY:
To evaluate and compare the efficacy of plyometrics alone and plyometric weight training on
improving the agility and power in lower limb performance among college level cricket players.
B) PROCEDURE, METHOD AND MATERIALS:
SOURCE OF DATA COLLECTION:
College level male cricket players of SDM Society institutes in Dharwad.
METHOD OF COLLECTION OF DATA:
Subjects will be briefed about the study after their consent will be taken. Subjects will undergo a
physical examination. Each subject will undergo measurements of his vertical jumping
performance and agility. Training in the form of plyometrics and weight training will be done for 2
sessions per week for 6 weeks.1
The outcome measures used are vertical jump height to assess the power and Illinois test to assess
the agility of the subjects.
7
MATERIALS:
Data collection sheet.
Exercise protocol handouts.
Boxes
Consent form.
Stop watch.
Cones.
Measuring tape.
INCLUSION CRITERIA:
Male cricket college level players
Age group between 18-26 years.
Players willing to participate in the study.
EXCLUSION CRITERIA:
Female players
Cricket players on medications like muscle relaxants
Cricket players who are involved in any type of plyometric training at the time of study.
Cricket players with any recent fracture or lower limb injury
STUDY DESIGN: A randomized trial.
STUDY DURATION: 1 year
SAMPLE SIZE: sample size of 80 subjects will be included in the study. They will be allocated
into two study groups i.e. study group A and study group B, using sealed opaque envelopes by a
therapist.
Sample size was decided based on an article by Cristos Kotzamanidis.18
By assuming,
“power of test” = 0.80
8
“effect size”=
“p value”=8.1
“q value”=91.9
Substituiting the above values in the following formula :
N = 2 (Zα + Zβ)2 x pq/(p1 – p2
Where, p1 =14.77
p2=1.43
α=0.05
Zα=1.96
Zβ=0.84
Hence the minimum sample size required in each group is 40.
PROCEDURE:
Participants will be included in the study only after completing the inclusion and exclusion criteria
and a written consent forms will be taken from each participant. The participants will be allocated
in Group A and Group B using sealed opaque envelopes by a therapist. Prior to the study,
procedures and guidelines will be presented orally and in written forms. Plyometrics will be
performed only twice per week for 6 weeks to allow for sufficient recovery between workouts as
recommended by the researchers. During the study all participants will be under direct supervision
and will be instructed on how to perform each exercise.
Training procedureGroup A -, The subjects in the plyometric group performed four plyometric drills – the Depth
jump, the split squat, the Rim jump, the Box to box depth jump.
Depth jump – Stand on the box, toes close to the front edge. Step from the box and drop to land on
both feet. Try to anticipate the landing and spring up as quickly as you can. Keep the body from
''settling'' on the landing, and make the ground contact as short as possible.
Split squat – The split squat is a stable exercise where the member takes up the position with hands
behind the head, take a stride forwards and slightly out to the side, keeping the back straight, drop
the hips directly down to the floor, the front knee should not go past your toes, pause when the
back knee is just above the floor, push up off the front foot to split stance at the start.
9
Rim jump- Spread the feet far apart, front to back, and bend the front leg 90 degrees at the hip and
90 degrees at the knee. Jump up; using arms to help lift, hold the split-squat position. Land in the
same position and immediately repeat the jump.
Box-to-Box depth Jumps- A row of boxes (all the same height, dependent on ability). Stand in a
deep-squat position with feet shoulder-width apart at the end of the row of boxes. Jump to the first
box, landing softly in a squat position. Maintaining the squat position, jump off the box on the
other side and immediately onto and off of the following boxes. Keep hands on the hips, or behind
the head.
Progression of plyometrics ( week 1- week 6)
Week 1- training one and two, intensity 60%
Depth Jump 2 sets of 8 repetitions; box height 50 cm
Split Squat Jump 2 sets of 8 repetitions
Rim Jumps 2 sets of 7 repetitions
Box-to-Box depth Jumps 2 sets of 4 boxes, box height 40 cm
Week 2- training three and four, intensity 70%
Depth Jump 2 sets of 10 repetitions; box height 60 cm
Split Squat Jump 2 sets of 9 repetitions
Rim Jumps 2 sets of 8 repetitions
Box-to-Box depths Jumps 2 sets of 4 boxis, boxheight 50 cm
Week 3- training five – six, intensity 80%
Depth Jump 3 sets of 10 repetitions; box height 70 cm
Split Squat Jump 3 sets of 10 repetitions
Rim Jumps 3 sets of 9 repetitions
Box-to-Box depths Jumps 3 sets of 4 boxes, box height 50 cm
Week 4- training eight and nine, intensity 90%
Depth Jump 3 sets of 10 repetitions; box height 80 cm
Split Squat Jump 3 sets of 12 repetitions
Rim Jumps 3 sets of 11 repetitions
Box-to-Box depths Jumps 3 sets of 4 boxes, box height 50 cm
10
Week 5- training 10 and 11, intensity 70%
Depth Jump 3 sets of 10 repetitions; box height 60 cm
Split Squat Jump 3 sets of 9 repetitions
Rim Jumps 3 sets of 8 repetitions
Box-to-Box depths Jumps 4 sets of 4 boxes, box height 60 cm
Week 6- training 12 – 14, intensity 80%
Depth Jump 3 sets of 10 repetitions; box height 70 cm
Split Squat Jump 3 sets of 10 repetitions
Rim Jumps 3 sets of 9 repetitions
Box-to-Box depths Jumps 3 sets of 4 boxes, box height 50 cm 24
Group B - The plyometric-weight training group performed a combination of the two training
programs (plyometric and weight training program). The plyometrics included the depth jump,
split squat jump, the rim jump and box to box depth jump, progression same as Group A and the
weight training program –that comprised of squat ,leg press and leg extension. The training
programs were designed to overload the leg muscles involved in the vertical jumping motion and
explosive performance.
Progression of weight training
Complex
First
training
sessions
sessions
sessions
sessions
Squat
#
4*8(45%)
4*6
3*6
60sec
50sec
4*8(45%)
4*6
60sec
50sec
4*8(45%)
4*6
60sec
50sec
4*8
3
(30%)
60sec
Leg press
4*8
(30%)
60sec
Leg extension
4*8
60sec
#
(30%)
Second
3
Third
3
(60%)
Fourth
3
(75%)
40sec
(60%)
3*6
(75%)
40sec
(60%)
3*6
(75%)
40sec
sets*reps at (percentage of 1 RM) rest time between sets.1
Testing procedureA vertical jump test was completed from a 2-foot standing position without a step into the jump.
The subjects were allowed to use their hands as they desired. Three test jumps were completed,
and the highest of these was recorded. This test was selected because it has high validity (0.80) and
reliability (0.93) coefficients and because it allows arm movement and a squat motion before the
jump, such as those performed in sports. 25
11
Illinois Agility test - The length of the test was originally set at 30 ft, which was increased slightly
to 10 m for ease of test administration. The course was marked by cones, with four center cones
spaced 3.3 m apart and four corner cones positioned 2.5 m from the center cones. The participant
began the test lying prone on the floor behind the starting line with his arms at his side and his head
turned to the side or facing forward. On the command, the participant ascended to his feet and ran
or moved quickly forward to the first tape mark. Participants were required to touch or cross the
tape mark with their foot. The participant turned around and moved back to the first center cone,
where he weaved up and back through the four center cones. The participant then ran or moved as
quickly as possible to the second tape mark on the far line. Again, participants were required to
touch or cross the end-line tape marks with their foot. Lastly, the participant turned around and ran
or moved as quickly as possible across the finish line. The time to complete each trial was
recorded in seconds.
Prior to training, all subjects will have their baseline agility tested using this test. A maximum of
3mins rest will be given between each repetitions. The test will be explained and demonstrated.
Before testing all participants will be given practice trials to become familiar with the test
procedure. This test will be counterbalanced pre and post testing to ensure that testing effects
would minimize. Subjects will perform the test 3times and the average of the results will be noted.
The time duration will be taken pre and post test using a stopwatch.26
OUTCOME MEASURES
The power of lower extremity: vertical jump height.
Agility: Illinois agility test, to determine ability to accelerate, decelerate, turn in different
directions and run at different angles.
STASTISTICAL TEST:
Paired t –test: for within group comparison for all outcome parameters
Independent t- test: for inter group comparison for all outcome measures.
DOES THE STUDY REQUIRE ANY INVESTIGATION OR INTERVENTION TO BE
CONDUCTED ON PATIENTS OR OTHER HUMANS OR ANIMALS? YES:
ETHICAL CLEARENCE HAS BEEN OBTAINED BY YOU? : YES
12
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Plyometric Training and Recovery on Vertical Jump Performance and Anaerobic Power. J
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24. Stojanovic T, Kostic R. The effect of the plyometric sport training model on development of
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