|Year : 2021 | Volume
| Issue : 1 | Page : 8-12
Relationship between Explosive Strength and Agility among College Level Football Players: A Pilot Study
S Priya1, Mallya Umananda2, KM Devika1
1 Laxmi Memorial College of Physiotherapy, Mangalore, Karnataka, India
2 Department of Orthopaedics, A. J. Institute of Medical Science, Mangalore, Karnataka, India
|Date of Submission||17-Aug-2020|
|Date of Decision||19-Jan-2021|
|Date of Acceptance||31-May-2021|
|Date of Web Publication||31-Jul-2021|
Dr. K M Devika
Laxmi Memorial College of Physiotherapy, A J Tower, Balmatta, Mangalore, Karnataka
Source of Support: None, Conflict of Interest: None
Context: For a successful performance, influence of certain biomechanical factors enhances learning and mechanical effectiveness of performance in football. For a player, dynamic strength ability gives acceleration to the body which affects explosive strength and physical abilities.
Aims: The aim of the study was to find out the relationship between explosive strength and agility among college level footballers.
Settings and Design: A pilot study was conducted among college level football players from different colleges of Dakshin Kannad.
Materials and Methods: Twenty male college level football players (21.25 ± 2.0 years) participated in this study, wherein each participant took part in two kinds of testing sessions: countermovement jump and t-test. Explosive strength was assessed using My Jump application, and agility was assessed using t-test.
Statistical Analysis Used: Karl Pearson correlation coefficient test was used for analysis.
Results: There was a significant moderate negative correlation between explosive strength and agility among college level football players (r = −0.536 and P = 0.015) and was statistically significant.
Conclusions: The present study concluded that there was a moderate negative correlation between explosive strength and agility among college level football players. Greater the explosive strength, lower is the time taken to perform t-test.
Keywords: Agility, Change of direction, College level football players, Explosive strength
|How to cite this article:|
Priya S, Umananda M, Devika K M. Relationship between Explosive Strength and Agility among College Level Football Players: A Pilot Study. Indian J Phys Ther Res 2021;3:8-12
|How to cite this URL:|
Priya S, Umananda M, Devika K M. Relationship between Explosive Strength and Agility among College Level Football Players: A Pilot Study. Indian J Phys Ther Res [serial online] 2021 [cited 2021 Oct 21];3:8-12. Available from: https://www.ijptr.org/text.asp?2021/3/1/8/322916
| Introduction|| |
Football (Soccer) is one of the most popular sports worldwide and highly dependent on various physical, technical, tactical, and psychological factors. It has been estimated that more than 240 million elite players participate in football., Football involves intense physical contact, short, fast, and noncontinuous movements. Common explosive movements in football are kicking, tackling, jumping, running, sprinting, and changing direction.
These movements are produced by simultaneous activity of many muscles, segments, and joints.,, Some of them act as antagonists and limit the performance. When there is increased antagonist activity, net moment produced will be less which results in minimal performance. For a better performance, the player should demonstrate higher agonist activation.
Howard et al. and Cerrah et al. reported that all of the muscle group in lower extremity are active during explosive movements such as kicking, jumping, and sprinting. Muscular strength is needed for most explosive performance. To produce these movements for a short period, body requires specialized muscle fibers. Fast-twitch fibers are large muscle fibers which produce high force, quick contraction speed, and easily fatigable. These fibers are considered for power activities.,,
The strength produced by the muscles during explosive movements should be assessed for better results. The basis for explosive strength is in speed strength. Due to inadequate lower limb training, Indian college level footballers exhibit lower jumping performance. Studies have reported that 8% of college level football players discontinue the game because of injury which results from poor lower extremity strength.
Agility is the ability to change body position and direction rapidly and precisely. To improve the ability of an athlete to give responses to change in situation, term agility should be considered along with the strength. One of the factors that influence change of direction (COD) performance is the nature of muscle contraction.
The lower limb strength required for kicking, running, and jumping in footballers is lower. Furthermore, Indian college footballers showed lesser speed in sprinting than basketball players.
Stojanovic et al. found a significant negative correlation between all COD and jump tests. Greater the explosive strength, lesser is the time taken to perform COD. It seems that agility and explosive strength are interrelated with one another, and it is an important fitness parameter in football.,
Physical fitness is a major component in the playing ability and performance in football. Compared to elite football players, college players were deficient in certain fitness components. Lack of poor playing technique, practice environmental facilities, nonavailability of sophisticated instruments, and seasonal overtraining are some of the reasons. For a player, dynamic strength ability gives acceleration to the body which affects explosive strength and physical abilities such as COD, and it may improve intramuscular coordination. The findings may throw more light on the role of muscular strength capacities in determining the performance of explosive movements among college level athletes. By finding the relation between explosive strength and agility, we can design a proper training regimen to avoid poor performance which results in lower extremity injuries.
| Materials and Methods|| |
The present study was a pilot design conducted on twenty male college level football players from Dakshin Kannad. Inclusion criteria of the study were (i) male players, (ii) players free from injury, (iii) practicing at least 2 h/weeks, and (iv) who are not participating in specific agility training apart from their regular session. Individuals were excluded if they had any: (i) history of low back pain, (ii) history of lower extremity injury, (iii) history of surgery, and (iv) elite players.
Players between the age group of 15 and 25 years were screened using inclusion and exclusion criteria. The study was approved by the Institutional Ethical Committee. Written consent and patient information sheet were obtained from all players. The procedure of the study was explained to the players. Outcome measure used for assessing explosive strength was countermovement jump (CMJ) using My Jump application and for agility was t-test.
Players participated in two separate tests with 5 min of interval. Explosive strength was assessed by performing countermovement using My Jump application. After a short period of warm-up exercise, weight of the player was recorded in the application. Starting from a standing position with their legs straight during the flight phase of the jump, players performed each CMJ with hands on their hips. The examiner manually selects the initial contact frame, the take-off frame from the floor, and the final landing frame during jump. Players were instructed to land on the ground with both feet and ankle in dorsiflexion. Players can jump as high as possible. Three trials were taken, and height was recorded in centimeters. My Jump app for CMJ height has got perfect agreement between force platform (intraclass correlation coefficient [ICC] – 0.997) and good validity for CMJ height (r = 0.995, P < 0.001).
T-test was used to determine the player's ability to change the position and direction during the game. The players should start at Cone A. On the command of the timer, the player sprints to Cone B and touches the base of the cone with their right hand. They then turn left and shuffle sideways to Cone C and also touch its base with their left hand. Then, shuffling sideways to the right to Cone D and touching the base with the right hand. Then, they shuffle back to Cone B touching with the left hand and run backward to Cone A. The stopwatch is stopped as they pass Cone A. The test was repeated when any player who cross one foot in front of the other, fail to touch the base of the cone, and/or fail to face forward throughout. Time taken to finish the test was recorded. Three trials were given, and mean of these trials was taken as the final value. The reliability of t-test was 0.90 (95% confidence interval: 0.82–0.94) and interclass correlation of the t-test was ICC = 0.97.
Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 16.0. package (Chicago, IL, USA). Data were expressed in mean and standard deviation. Karl Pearson's correlation coefficient was used to find the relationship between explosive strength and agility. P < 0.05 was considered statistically significant.
| Results|| |
Demographic profile of players is presented in [Table 1]. A total of twenty college level football players aged between 18 and 25 years were included in the study.
CMJ scores showed a negative correlation with t-test scores (P = 0.015). A significant moderate negative correlation (r = −0.536) was found between explosive strength and agility among football players [Table 2].
|Table 2: Descriptive statistics of explosive strength and agility among the players|
Click here to view
| Discussion|| |
The present pilot study was done to find the correlation of explosive strength and agility among college level football players. There was a moderate negative correlation exists between explosive strength and agility in college level football players.
Football is a physically demanding sport that requires a high degree of skill, technical expertise, and teamwork. In the present times, competitions at college level are very tough and closely contested. Awareness about the proper playing techniques, injury prevention, and nutrition are lacking, and seasonal overtraining is seen in these players. For attaining top position in competitions, a proper preseason evaluation and regular training are required along with their academics.
The explosive strength refers to player's ability to exert or produce maximum amount of force within a short span of time interval. A study was done by Alexander to find the relationship between muscle strength and sprint kinematics in elite sprinters and found a strong correlation between sprint performances and concentric knee extension torque in elite sprinters. Similar result was found in another study conducted by Dowson et al. to find the relationship between isokinetic muscle strength and sprint running performance in different sports. Another study was done by Shimokochi et al. to find out the relationships among performance of lateral cutting maneuver from lateral sliding and hip extension and abduction motions, ground reaction force, and body center of mass height. The finding of the study showed that for a sudden COD is needed to lower the center of mass. For that team players squat and maintain that position to activate the gluteus maximus muscle, thereby they can kick the ground strongly and perform CODs. In the present study, there exists a moderate negative correlation between explosive strength and agility among college level football players.
In football, the team requires fast and exceptional movers in forward, backward, and lateral directions within a short time. These changes of direction movements in response to moving ball is called agility. Keogh et al. found that, in field sports, speed during COD is an important determinant of performance. In the present study, players with greater strength performed t-test within less time, but when comparing with test results of Hoffman, the t-test result shows poor performance (>11.50) in college level football players.
A series of concentric contractions takes place before the execution of COD movement. This allows the players to produce more force and move quicker while playing., An appropriate evaluation ought to be done to gauge the ability to perform straight and COD runs with high efficacy. Several studies have been reported the relationship between CMJ-drop jump and sprint and power skills.,,
According to Pandey and Chaubey, stronger players would have more ability to produce force, for example, greater vertical jump height. According to NCAA, the average college level football player jumps between 29 and 31 inches.
This study reveals that college students who participate in football are deficient in physical performance. A moderate negative correlation was found between explosive strength and agility among this population. In this study, the players exhibit a lower range of jump height when compared to normal.
However, literature also shows studies with contradicting results. A study was conducted by Hermassi et al. to find out the relationship between maximal strength of lower limb, anthropometric characteristics, and fundamental explosive performance in handball players. The findings of the study showed that a player who has great strength shows poor in sprinting or COD performance.
In one of the studies done by Kulkarni et al., it was observed that players who performed vertical jump or agility drills were not able to produce high muscular force even they generated the fastest ball kick velocity. Therefore, increase in strength should translate into increased power for a better professional performance. These findings provide the coaches and trainers to make some modifications in their training strategy.
Another study was conducted by Cronin and Hansen to check the strength and power predictors of sports speed and found that there is no relation between extension strength and knee flexion and single-sprint performance. Similarly, another study was done, and authors concluded that there is only low correlation between CMJ and 20 m COD test.
The present study found that player who jumps maximum height takes only a few seconds to finish the test (t-test) and vice versa. These findings will benefit the college level players, coaches, and trainers in their available training sessions. Consequently, they do not have to train both attributes separately.
Apart from isolated strength training, players can focus on potential training modifications such as multidirectional and loaded vertical jump training as well as agility drills. Thus, the training can be more effective.
Higher participation and high risk of injuries are seen in school, college level, and recreational football players. Regular and proper training and practice sessions are less for this population. This showed that a properly designed training regimen is essential for good performance.
Limitations of the study were players had different training duration, type and intensity of exercise training, and frequency of session. An overall physical performance of a player is determined not only by the tested components. Other physical performances such as flexibility and endurance are not included in this study. There was a difficulty in recording takeoff and/or landing frame while using My Jump application.
More studies using electromyography can be used to study the muscle activity of lower limb, abdominal, and trunk muscle during training sessions. More studies can be done using My Jump application in different sports. Influence of height and weight on explosive and agility performance can be done.
| Conclusions|| |
The present study found a moderate negative correlation between explosive strength measured by CMJ (cm) and agility by t-test (s) in college level football players. Players with high value of CMJ show a significant better performance in agility t-test and vice versa. Apart from isolated strength training, agility training might be helpful to improve player's capacity to decelerate in minimal time and to reaccelerate rapidly toward another direction.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]