RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
KARNATAKA BANGLORE
ANNEXURE-II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1 / Name of Candidate and Address / DEVANSHIBEN SATISHKUMAR TRIVEDI
PLOT NO.880/A-2, “NATAVAR NIVAS”,
BEHIND MAHILA COLLEGE, MUNIDERI,
BHAVNAGAR-364001, GUJARAT.
2 / Name of Institution / SHREE DEVI COLLEGE OF PHYSIOTHERAPY,
MAINA TOWERS, BALLALBAGH,
MANGALORE- 575003.
3 / Course of Study and Subject / MASTERS OF PHYSIOTHERAPY,
2 YEAR DEGREE COURSE,
(MUSCULOSKELETAL DISORDERS AND SPORTS)
4 / Date of Admission to the Course / 31st OCTOBER, 2011.
5 / Title of Topic / “THE EFFECT OF PLYOMETRIC TRAINING AND STRENGTH TRAINING AMONG MALE COLLEGE VOLLEYBALL PLAYERS – A COMPARATIVE STUDY.”
6 / BRIEF RESUME OF THE INTENDED WORK
6.1 NEED FOR THE STUDY:
Plyometric is a method of developing explosive power. It is also an important component of most athletic performance. As coaches and athletes have recognized the potential improvements plyometric can bring to performance, they have integrated it into the overall training program in many sports and made a significant factor in planning the scope of athletics development.
Plyometric exercises are defined as eccentric loading immediately following by a concentric contraction.1,2,3,4 These exercises have been credited with inducing neuromuscular adaptations to the stretch reflex, elasticity of muscle and golgi tendon organs.4,5 The stretch reflex is initiated during the eccentric loading phase and can facilitate greater motor unit recruitment during the ensuing concentric contraction. The series and parallel connective tissue components of muscle also store elastic energy, which can generate additional force if a muscle recoils quickly in the form of concentric contraction. Lastly the golgi tendon organs usually have a protective function against excessive tensile load in the muscles; however, after plyometric training, golgi tendon organ desensitization is thought to occur, allowing the elastic components of muscles to undergo greater stretch. When stretch reflex and stored elastic energy are combined a more powerful concentric force is created.6
Wilk et al suggested that muscular performance gains after plyometric training are attributed to these neural adaptations, rather than to morphologic changes. For this reason plyometrics training may enhance neurons, muscular function and prevent knee injuries by increasing dynamic stability.7 Plyometric exercises may increase performance and decrease injury risk in competitive athletes.8,9 During most functional activities, the knee joint is subjected to high abduction and adduction moments, and therefore, a theorized relationship exists between these movements and knee injury.10,11
Plyometrics is the most commonly used training method to increase vertical jump power. It “bridges the gap between strength and speed”. Studies are showing that a plyometrics programs that runs alongside a weight training program produces optimum results.12
Countermovement vertical jump height has been used as a test protocol to measure successful depth- jump performance. In 1974, Sergio Zanon suggested a protocol, an athlete is made to carry out a standing high jump after flexing his legs and maximum height is reached with his hand on a graduated board. The highest reading of three jumps is registered. The athletes is made to carry out the same operation, landing on the same point from a height which is progressively higher by 20-40-60cms (depth jump test), and from each different height of fall, the maximum height is reached and subsequent jump is read off of the graduated board.13
Also, the vertical jump results along with the subject’s weight were used as variables in an equation to convert the data into Watts, a true measure of power that allows a fair comparison between participants (Sayers, Harackiewicw, Harman, Frykman, & Rosenstein, 1999). The Sayers formula (Sayers et al., 1999) is as follows: Peak Power (W) = 60.7 × [jump height (cm)] + 45.3 × [body mass (kg)] – 2055.14
The other functional measurement used is standing broad jump in assessing the general gains in lower extremity power.15
Resistance exercises are any form of active exercise in which a dynamic or static muscle contraction resisted by an outside force, applied either manually or mechanically.
In resistance training, dosage includes intensity, volumes, frequency and duration of exercise and rest interval.16
The principle fitness component of vertical jumping is power. Power is a combination of strength and speed. So, a weight training program that improves maximal strength can improve the power and increase vertical jump ability.
For beginners to strength training, traditional weight training exercises provide as safe, accessible and highly effective way to increase vertical jump power.
Improvements in dynamic weight training relate directly to improvement in power and increase vertical jump ability. An example of a dynamic weight training exercise is the jump squat. Lighter loads (30%1-RM) are used and the resistance is accelerated explosively through full range of motion.12
Hence there is need for the study to find the effectiveness of plyometrics training versus strength training in improving the vertical jump test, standing broad jump test and peak power in male college volleyball players.
RESEARCH QUESTION:
Is there any significant difference in pre-training and post-training value of vertical jump test, standard broad jump test and peak power between the groups after giving Plyometric training and strength training?
NULL HYPOTHESIS:
There will be no significant difference in pre-training and post-training value of vertical jump test, standard broad jump test and peak power between the groups after giving Plyometric training and strength training.
ALTERNATE HYPOTHESIS:
There will be a significant difference in the pre-training and post–training value of vertical jump test, standard broad jump test and peak power in between the two groups after Plyometric training and strength training.
6.2 REVIEW OF LITERATURE:
A study to compare the effects of 3 different training protocols-plyometric training, weight training, and their combination on the vertical jump performance, anaerobic power and muscular strength. Forty-eight male college students were divided into 4 groups: a plyometric training group, a weight training group, a plyometric plus weight training group, and a control group. The vertical jump, the fifty-yard run and maximal leg strength were measured before and after a six-week training period. Subjects in each of the training groups trained 2 days per week for 6 weeks, whereas control subjects did not participate in any training activity. The results showed that all the training treatments elicited significant (P<0.05) improvement in all of the tested variables. However, the combination training group showed signs of improvement in the vertical jump performance, the 50 yard dash, and leg strength that was significantly greater.17
A study to compare the effect of three modified plyometric depth jump and periodised weight training on the following functional tests: one-legged vertical jump, two-legged vertical jump, 30-meter sprint, standing broad jump, and 1 RM of the seated single leg press. Sixty-four untrained participants (18-28yr) were randomly assigned to one of the following groups: hip depth jump, knee depth jump, ankle depth jump, weight training, or a control. Experimental groups trained two days a week for 12 weeks. Statistically significant improvements were observed among the plyometric groups for functional tests of power and the weight training group for functional tests of strength and speed. Results indicate that modified plyometric depth jumps offer a greater degree of specificity related to power training in athletes.15
A study on 19 females volley ball Players aged 15 + for 6 week to examine the effects of aquatic Plyometric training (APT) on vertical jump and muscular strength. APT or flexibility exercises testing of leg strength was performed at base line and after 6-weeks, and VJ was measured at baseline and after 2, 4 and 6 weeks. Results showed that similar increase in VJ was observed in both groups after 4 flexibility exercises weeks. (P<0.05). They concluded that combination of APT and volley ball training resulted in larger improvement in VJ then in the flexibility exercises.18
A study to determine if six weeks of plyometric training can improve an athlete’s agility. Subjects were divided into two groups, plyometric training and a control group. All subjects participated in two agility tests: T-test and Illinois Agility Test, and a force plate test for ground reaction times both pre and post. After the completion of 4 weeks, both groups increased vertical jump (P=0.01) no difference (P>0.05) was observed between groups. They concluded that plyometrics and weighted plyometrics exercises both results in significant, but similar improvement in vertical jump in strength trained post testing. The plyometric training group had quicker post test times compared to the control group for the agility tests and also reduced time on the ground in the post test compared to the control group. The results of this study show that plyometrics training can be an effective training technique to improve an athlete’s agility.19
A short training study on 22 male hand ball players aged 17 – 24 to compare the changes in central and peripheral properties of the leg extensors derived from maximal resistance training and combined resistance + plyometric training program. After the 3 week of training only combined training increased maximal voluntary force, squat jump and counter movement jump performance (P<0.05). Results showed that at the end of 6 week training programs, The two training groups increased maximal isometrics force and squat jump performance (P<0.05).20
A study to compare the effect of 4- weeks plyometrics and weighted plyometrics training on vertical jump on the 14 Strength trained women aged 25 + 4 years wt. = 63+ 10 kg. with a minimum 1 year of strength training experience, were randomly assigned to either plyometrics (P, n=7) or a weighted plyometrics (WP, n=7) training group. After the completion of 4 weeks, both groups increased vertical jump (P=0.01) no difference (P>0.05) was observed between groups. They concluded that plyometrics and weighted plyometrics exercises both results in significant, but similar improvement in vertical jump in strength trained women.21
A study to establish the validity and reliability of vertical jump force test (VJFT) for the assessment of bilateral strength asymmetry in a total of 451 athletes. The VJFT consists of countermovement jumps with both legs simultaneously: one on a single force platform, the other on a leveled wooden platform. Jumps with the right or left leg on the force platform were alternated.. Results have shown significant correlations between VJFT and both the isokinetic leg extension(r=0.48; 95 % confidence interval, 0.26-0.66) test and the isometric leg press test (r=0.83;0.70-0.91). VJFT test-retest intraclass correlation coefficient was 0.91 (0.85-0.94), and typical error was 2.4%. They concluded that the assessment of bilateral strength asymmetry with the VJFT is valid and reliable, and it may be useful in sports medicine.22
A study to cross validate the three jump power equation using vertical jump and reach test, develop a more accurate equation from a large heterogeneous population, analyze gender differences and jump protocols, and assess Predicted Residual Sum of Squares (PRESS) as a cross-validation procedure. One hundred eight college-age male and female athletes and nonathletes were tested on a force platform. They performed three maximal effort vertical jumps each of the squat jump (SJ) and countermovement jump (CMJ) while simultaneously performing the vertical jump-and-reach test. Results showed SJ data yielded a better power prediction equation than did CMJ data because of the greater variability in CMJ technique. The following equation was derived from SJ data: Peak Power (W) = 60.7 × (jump height [cm]) + 45.3 × (body mass [kg]) - 2055. This equation revealed greater accuracy than either the Lewis or previous Harman et al. equations and underestimated peak power by less than 1%, with a SEE of 355.0 W using SJ protocol.14
6.3  OBJECTIVES OF THE STUDY:
1.  To find the efficacy of Plyometric training in improving the vertical jump, standing broad jump and peak power in male college volleyball players.
2.  To find the efficacy of strength training in improving the vertical jump, standing broad jump and peak power in male college volleyball players.
3.  To compare the effect of plyometrics and strength training in improving the vertical jump, standing broad jump and peak power in male college volleyball players.
7. / MATERIALS AND METHODS:
7.1 SOURCE OF DATA:
1. Volleyball male players from different colleges.
7.2 METHOD OF COLLECTION OF DATA:
Study design: Experimental Method
Sample size: 50 Subjects [ 25 in each group ]
Sample method: 50 male college volleyball players will be chosen based on inclusion and exclusion criteria. 25 players selected in each group using purposive sampling technique.
INCLUSION CRITERIA:
·  Male college volleyball players.
·  Participants did not perform either plyometric or weight training of their lower extremity for a period of at least six months prior to the study.
·  Playing volleyball for at least since 6 months.
·  Age between 18-28 years.
·  Willingness to participate in the study.
EXCLUSION CRITERIA:
·  Any history of Cardio Respiratory Disorders.
·  Any history of Orthopedic and Neurological Impairments.
·  Any systemic disorders.
STATISTICAL TEST:
The collected data will be analysed by mean standard deviation paired and unpaired t-tests.
OUTCOME MEASURE:
·  Vertical jump height efficiency in centimeters,
·  Standing broad base (horizontal jump measurement) in centimeters,
·  Peak power by formula of Sayers et al,
Power = 60.7*(jump height in cm)+45.3*(body mass in kg)-2055
Of the male college volleyball players before and after undergoing Plyometric training or strength training.23
METHODOLOGY:
For all participants, vertical jump height efficiency, standing broad base and peak power will be measured. After randomizing the subjects into two groups (n=25), Warm up exercises will be given for both the groups in the form of Jogging and calisthenics for 10 mins. After training the cool down exercises will be given for both the groups in the form of stretching for 5 mins. The subjects of one group (n=25) will be given Plyometric training for 8 weeks, 3 session per week. The protocol for plyometric training is as follows :
PLYOMETRIC EXERCISES / 1ST PHASE
(2 weeks) / 2ND PHASE
(2 weeks) / 3RD PHASE
(2 weeks) / 4TH PHASE
(2 weeks)
DEPTH JUMP / 3*10(20)30 / 3*12(30)30 / 3*11(40)30 / 3*12(50)30
CMJ / 3*10( - )30 / 3*12( - )30 / 3*11( - )30 / 3*12( - )30
LATERAL JUMP / 3*10( - )30 / 3*12( - )30 / 3*11( - )30 / 3*12( - )30