Training Versus Strengthening Exercises In

A COMPARATIVE STUDY TO ANALYSE THE EFFECT OF PLYOMETRICS

TRAINING VERSUS STRENGTHENING EXERCISES IN

IMPROVING THE VERTICAL JUMP TEST

IN STUDENT POPULATION

SUBMISSION OF SYNOPSIS FOR THE REGISTRATION OF THE

DISSERTATION FOR MASTER OF PHYSIOTHERAPY

SUBMITTED TO

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

BANGALORE, KARNATAKA.

SUBMITTED BY

OMKAR SINGH

NAVODAYA COLLEGE OF PHYSIOTHERAPY

P.B.No.26, MANTRALAYAM ROAD RAICHUR

KARNATAKA

SEPT - 2007

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

BANGALORE, KARNATAKA

ANNEXURE-II

PROFORMA FOR REGISTRATION OF SUBJECT FOR

DISSERTATION

1 / NAME OF THE CANDIDATE AND ADDRESS / OMKAR SINGH
NAVODAYA COLLEGE OF PHYSIOTHERAPY, MANTRALAYAM ROAD RAICHUR, KARNATAKA
2 / NAME OF institution / NAVODAYA COLLEGE OF PHYSIOTHERAPY, MANTRALAYAM ROAD RAICHUR, KARNATAKA
3 / COURSE OF STUDY AND
SUBJECT / MASTER OF PHYSIOTHERAPY(M.P.T)
PHYSIOTHERAPY IN MUSCULO-SKELETAL DISORDERS AND SPORTS
4 / DATE OF ADMISSION TO COURSE / Sept -2007
5 / TITLE OF THE TOPIC
“ A COMPARATIVE STUDY TO ANALYSE THE EFFECT OF PLYOMETRICS TRAINING VERSUS STRENGTHENING EXERCISES IN IMPROVING THE VERTICAL JUMP TEST IN STUDENT POPULATION ”
6. / RESEARCH QUESTION
Does any difference exists in vertical jump between plyometrics training and strengthening exercise in student population.
6.1 / BRIEF RESUME OF THE INTENDED WORK
Plyometrics is a method of developing explosive power. It is also an important component of most athletic performance. As coaches and athletes have recognised the potential improvements plyometrics can bring to performance, they have integrated it into the overall training program in many sports and made it significant factors in planning the scope of atheletic development.
Plyometrics exercises are defined as eccentric loading immediately following by a concentric Contraction 11,12,13,14. These exercises have been credited with inducing neuromuscular adaptations to the Stretch reflex, Elasticity of muscle and Golgi tendon Organs14,15. 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 plyometrics 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 created22.
Wilk et al22 suggested that muscular performance gains after plyometrics training are attributed to these neural adaptations, rather then to morphologic changes. For this reason plyometrics training may enhance neurons muscular function and prevent knee injuries by increasing dynamic stability17. Plyometric exercises may increase performance and decrease injury risk in competitive athletes10, 18. 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. 19,20
In many programs plyometrics training is defined merely as jump training .The starting position and initiation methods when jumping for height have significant value. Several types of jumps are distinctive including, Squat jumping, counter movement jump, depth jump.
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 along side a weight training program produces optimum results21.
Although the exact reason that plyometrics works may still hold some mystery, it is a fact that the training brings results. Yuriverkhoshansky has stated in the late 1960 that individuals could significantly improve jumping and sprinting ability by progressive jumping exercises. The suggested training and performances of athelets such as Olympic sprint champion, Valeri Borzov help to substantiate those statement. In the early 1980’s researchers, Russ polhemus, Ed Burkhardt, and others offered substantial evidence that combining plyometrics training with a weight. - Training program enhanced physical development far beyond that of weight training programs alone.
Exercise that use the stretch- shortening cycle, or plyometrics, stimulate changes in the neuromuscular system, enhancing the ability of the muscle groups to respond more quickly and powerfully to slight and rapid changes in muscle length. Certain principles of atheletic training apply especially to the stretch - shortening cycle and plyometrics are
·  Progressive overload
·  Specificity
The types of over load available to plyometrics training are
·  Resistive overload
·  Spatial overload
·  Temporal overload
In training with plyometrics exercise just as with other forms of stretch-shortening cycle or athletic training, it is important to follow certain guidelines to ensure safety as well as proper and effective performance. The basic keys for plyometrics techniques are :
·  On going Assessments
·  Landings
·  Foot placement
·  Blocking or thumbs- up rule
·  Follow- through
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 athelete 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 athelets 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 board23.
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 interval24. In resistance training heavy loads (80-90% 1-RM) and low number of repetitions (4-6) are used to improve maximal strength.
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 ability21.
For beginners to strength training, traditional weight training exercises provide as safe, accessible and highly effective way to increase vertical jump power21 .
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 motion21 .
Hence researcher has taken the comparative study to find the effectiveness of plyometrics training versus strengthening exercises in improving the vertical test in student population.
NULL HYPOTHESIS
H0 : There will be no significant difference in pre - test and post-test score of vertical jump test between the groups after giving Plyometric training and strengthening Exercise.
ALTERNATIVE HYPOTHESIS
H1 : There will be a significant difference in the pre test and post test score of vertical jump test in between the two groups after Plyometric training and strengthening Exercise.
6.2 / REVIEW OF LITRATURE
1.  Cheng, CF; Lin, JC and et at (2007)1 conducted a study for 8 weeks to examine the effect of plyometrics training on power and power endurance performance on 20 male basket ball players aged 16-19 years. All subjects performed counter movement jump (CMJ) and continue jump (CJ) on a force platform to measure force, velocity and power production during vertical jumping (VJ). The Wingate anaerobic test was performed on a bicycle ergometer, and the blood lactate concentrations were assessed before and at 5, 30 minutes after the test. Subjects were randomly divided into control and experimental group. All subjects completed the usual preseason basketball on-court training and a weight-training program. Except that, the treatment group completed 8 week Plyometric training. The results have shown the effectiveness of an 8 week combination of weight and Plyometric training improved vertical jump and power performance.
2.  Martel, GREGORY F. and et al (2005)2 conducted 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 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.
3.  ToumiH, Best TM and et al (2004)3, Conducted study over 30 males, to study the effects of Plyometric exercises performed with rapid and slow stretch contraction on jump performance and muscle properties .After the completion of eight week treatment session, results shows, that when plyometrics training is performed with rapid stretch contraction. the counter movement jump height increases and transition phase duration decreases (P<0.05) .
4.  Toumi, Hechmi and et al (2004)4 conducted 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).
5.  Adams K.J. shimp – Bower wan and et al (2001)5 conducted 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.
6.  Matavulj D, KUKOLJ M and et al (2001)6 conducted a study on junior basket ball players to analyze the effects of plyometric training on jumping performance. Three different training regimens were performed. While control group participated only in the regular midseason training activity another two groups performed limited amounts of Plyometric training employing drop jumps from the height of either 50 cm or 100 cms. The result showed that on increase in maximal vertical jump, as well as in maximal voluntary force of hip extensors and rate of force development of knee extensors was observed in both experimental groups, while no significant changes were recorded in control group. They concluded that limited amount of Plyometric training could improve jumping performance in elite junior basket ball players.
7. Impellizzeri FM, Rampinini E and et al (2007)7 Conducted 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.
8.  Young W, MacDonald C and et al (1997)8 Conducted study to evaluate the specificity, validity and reliability of jumping tests on 17 male subjects. The subjects were tested on jumps for height from a standing position and using a 1,3,5 and 7 stride run-up. These jumps were performed using a single and double leg take-off measured by the Yardstick. Selected jumps were also tested using a Board method & repeated for assessment of reliability. The results have shown that the single leg take-off produced significantly higher jumps when the run-up was three or more strides and the Yardstick produced significantly greater jump height then the Board method. They concluded that the Yardstick is the preferred mode of testing to assess jumping ability.
9.  BOBBERT, MAARTEN F and et al (1994)9 conducted a study to analyze the effects of muscle strengthening on vertical jump height. In this study the effects of systematic manipulations of control & muscle strength on vertical height were investigated with a model of the human musculoskeletal system. Model input was STIM (t), stimulation of six lower extremity muscles as function of time; model output was body motion. The model incorporated all features of the musculoskeletal system of human test subjects considered salient for vertical jumping, and the initial body configuration was set equal to that of the test subjects. First, optimal STIM (t) was found for a standard version of the model (experiment A). Subsequently, optimal STIM (t) for the standard model was used to drive a model with strengthened muscles (experiment B). Jump height was now lower then that found in experiment A. Finally, optimal STIM (t) was found for the model with strengthened muscles (experiment C). Jump height was now higher then that found in experiment A. The results have shown that in order to take full benefit of an increase in muscle strength, control needs to be adopted.
6.3 / AIMS AND OBJECTIVES
1.  To find the efficiency of Plyometric training in improving the vertical jump in student population.
2.  To find the efficacy of strengthening exercise in improving the vertical jump in student population.
3.  To compare the effect of plyometrics and strengthening exercises in improving the vertical jump among student population.
7 / MATERIALS AND METHODS
·  Cuff Weight
·  Inch Tape
·  Scale for Measuring jump height
·  Bench and Stool
·  Marker
·  Sports Shoes
7.1 / SOURCE OF DATA
Student Studying in Navodaya College of Physiotherapy Raichur