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University of St Mark & St JohnA Training Intervention Comparing the Effectiveness of Front and Back Squats in the Development of Lower Limb Power and Flexibility.Jonathan RowtcliffDissertation submitted in part-fulfilment of the requirements for BSc (Hons) Health, Exercise and Physical Activity.2014ContentsPageTitlei-iiContentsiiiList of Tables and FiguresivStatement of OriginalityvAcknowledgementsviAbstract1.11-3Introduction1.24Aims1.34Hypotheses1.44Limitations1.55Glossary of Terms, Acronyms and Definitions2.06Literature Review2.16Search Terms2.26Introduction2.37-8Concepts, Physiology and Kinematics of Power during Exercise2.49-12Factors that Affect Muscular Power2.513Exercises and Loads to Maximise Power Potential in Training2.613-15Importance of Power in Team Sports2.716-17Summary3.018Methodology and Materials3.118Study Design3.218Subjects3.319Equipment List3.419-20Protocol3.521Testing Procedures3.621Statistical Analysis3.722Confidentiality4.023Results4.123Introduction4.223Group Differences4.324-26Force and Power Improvements4.427Correlations between Flexibility and Force4.528Male and Female Differences4.629-30Summary5.031Discussion5.131Introduction5.231Biomechanical and Kinematic Differences between Front and Back Squats5.332-33Correlations between Flexibility and Force5.434Male and Female Differences5.534-35Summary6.036Conclusion6.137Recommendations7.038-46Reference List7.147-48Appendices 1: Medical History & Par-Q49-50Appendices 2: Ethical Approval Form51-52Appendices 3: Consent Form53Appendices 4: Example of Data Recording Sheet54Appendices 5: Male Pre Test Values55Appendices 6: Female Pre Test Data56Appendices 7: Male Post Test Data57Appendices 8: Female Post Test DataList of Tables and FiguresFigure 1Technique and bar position during the back squat.Figure 2Technique and bar position during the front squat.Figure 3The ATP-PC, Glycolytic and Aerobic energy systems and their contribution of ATP production during activities of varying durations.Figure 4Speed-Strength Continuum and Percentage of 1 RMFigure 5Correlation between sit and reach flexibility and force production during leg dynamometer test for all participants (n=32).Figure 6Mean Values and Standard Deviations of Male and Female Flexibility Pre and Post Intervention.Figure 7Male and Female Mean and Standard Deviations of Peak Power Output from the Countermovement Depth Jump Measure.Figure 8Differences between Genders and Peak Power Output/Mass Means and Standard Deviations.Table 1Mean physical characteristics of participants in both front and back squat groups. (± standard deviations).Table 2List of Equipment Used throughout Research.Table 3Significance Values of Improvement from Pre-Post Measures.Table 4Significance of Improvements Between FSG and BSG Post-Intervention.Table 5Means, Standard Deviations (±) and Difference between Pre and Post Measures.Table 6Correlation and Significance of Correlation between Pre and Post Measures for the Front Squat Group.Table 7Correlation and Significance of Correlation between Pre and Post Measures for the Back Squat Group.Statement of OriginalityI confirm that I have fully acknowledge all sources of information and help received and that where such acknowledgement is not made the work is my own.Signed: ………………………...........Dated: ……………………….............AcknowledgementsI wish to thank my family, friends, teammates and girlfriend, Katie, as well as my housemates for their much needed support and encouragement throughout the course of my dissertation and right the way through university life. Without their continuous support, my time at University wouldn’t have been half as enjoyable.I would like to thank the members of the Hockey Team for their help not only during my dissertation, but also as I learnt to play Hockey properly. I also owe a big thanks to the sports science lab technicians for putting up with my continuous pestering to use the facilities.Finally, I would like to thank my dissertation tutor as well as all the lecturers who aided me through university life to achieve the grades that I have over the past 3 years.AbstractINTRODUCTION: Lower limb power plays a significant role in any sporting performance or daily activity that causes energy expenditure. The squat exercise is one of/if not the most common and popular exercise integrated into a programme of exercise. The aim of this study was to investigate the effectiveness of front and back squats in developing leg power and flexibility. METHOD: Male and female University Hockey players (N=32), volunteered to take part in a 6-week, high –velocity squat intervention, to discover whether front squats are most effective at developing leg power. Participants were randomly assigned to one of two groups, Front Squat Group (FSG) (N=16); and Back Squat Group (BSG) (N=16). BSG performed Back Squats (Figure 1) at a load that maximises power performance (60% 1-RM) whereas FSG performed Front Squats (Figure 2) of the same intensity (60% 1-RM). RESULTS: The results indicate that although both squat methods are effective at developing leg power, there are no statistically significant differences between the front and back squat (0.476 for CMDJ and 0.759 for Leg Dynamometer Force). The results also displayed no significant correlations (Figure 5) between flexibility and force but did establish that females had a greater range of lower extremity ROM than males (females, pre= 21.4±4cm, post= 25.5±4.5cm, males pre= 14±6cm, post= 17±6cm). DISCUSSION: Both methods of squatting should be integrated into a training programme to maximise muscular force and power potential. CONCLUSION: It was concluded that neither front nor back squats are more effective at developing leg power despite both causing significant improvements in force, power and flexibility performance between pre and post measures.1.1: IntroductionPower is one of the dominant motor abilities, not only in sport and exercise but also in everyday life. No movement or action, whether in sport or daily living can be made without expressing some form of muscular power (Lopez-Segovia et al., 2011). Power is defined as the ability of the muscles to exert a maximal amount of exertion as quickly as possible. It is the combination of strength and speed and involves rapid eccentric and concentric muscular contractions in movements such as jumping, hopping, throwing, kicking, and sprinting (Sporis et al., 2010). These movements, although seen frequently in everyday life, are most common in sports performances. Due to the importance of power in almost every sport, it is necessary for athletes and performance coaches to have an awareness of specific exercises that can improve power performance. Every team invasion sport requires varying levels of power in different muscles. This very factor alone is the reason why every training programme is different and specific to certain individuals. Hockey requires players to be fast and agile whilst sprinting, whereas rugby players are required to be more powerful and strong in order to break through the defensive line. This variation in sporting performance needs of individuals, allows each training programme to be individualised and sport specific. Displays of power are also essential for day to day living and it is not uncommon for people to train to improve power for recreational benefits and an improved quality of life.Many researchers have attempted to define the term ‘power’ and the effects certain training protocols have, upon the development of power in athletes and recreationally active individual’s (Petrovic et al., 2012). There is also a broad range of literature that compares the effects of load on peak power and force (Cormie et al., 2007; Harris et al., 2007; Hori et al., 2007; Stone et al., 2003; McBride et al., 2002; Baker et al., 2001; Garhammer, 1980). Nonetheless, no previous research compares the effectiveness of front squats in the development of power and more interestingly, very few studies compare various squatting techniques with each other. Current research shows comparisons have been made, between training protocols and variations of exercise kinematic (Gullet et al., 2009; Stoppani, 2010) as well as providing normative data for comparison (Taylor et al., 2010; Patterson and Peterson et al., 2004). Although the literature surrounding power and the squat exercise is vast, there are very few studies that focus upon female athletes and less frequent again, is research that compares the differences in power performance between males and females. It is also clear that there is a lack of empirical evidence that correlates power and level of flexibility; especially when focussing on a particular sport, for example, field hockey.Many health, fitness and performance practitioners consider the squat to be one of, if not the most popular and effective exercises performed. It is an exercise that is efficient in aiding weight loss and improving athletic performances amongst other benefits. It can be performed whilst loaded or as a bodyweight exercise depending on exercise and performance goals (Lutz et al., 1993; Palmitier et al., 1991). There are a number of different squat techniques that can be performed which can initiate varying levels of muscular activation. The squat, a compound, multi-joint movement, stimulates a range of muscles and muscle groups from the quadriceps and hamstrings to the spinal erectors, abdominal and core stabiliser muscles. The back squat is however, the most widely used squat in sport and exercise. It requires the performer, when bearing a load, to have the barbell just above the posterior deltoids (trapezius) during the ascending and descending phases (Stoppani, 2010; Gullet et al., 2009; Baechle and Earle, 2008) With the barbell being in this position it enables the performers to load the barbell up significantly higher than many other exercises. Figure 1 illustrates the correct technique and barbell position during the back squat. The weight is slightly above the posterior deltoid muscle on the trapezius. The descent of the movement requires the performer to slowly flex the knees and hips until the thighs are parallel to the floor (Figure 1 Phase 2) (Baechle and Earle, 2008; Bean, 2008; Marsh, 2008; Delavier, 2001). The hips and knees are then extended until the athlete reaches the start position (Figure 1 Phase 1). The back should be kept flat (straight) and heels kept on floor throughout the exercise with the knees aligned over feet (Baechle & Earle, 2008; Bean, 2008; Marsh, 2008; Delavier, 2001). The front squat, (Figure 2) is possibly the second most common squat method integrated into training programmes. The key difference between the front squat and back squat is the position of the barbell (Figure 2 Phase 1). Where the back squat is performed with the barbell/load on the posterior plane of the body, hence ‘back’ squat, the front squat is performed with the weight on the anterior (front) plane of the body. The elbows should be kept parallel to the ground which aids in keeping the barbell resting on the clavicle and anterior deltoids (Baechle & Earle, 2008; Bean, 2008; Marsh, 2008; Delavier, 2001). During the ascending and descending phases, the movements are similar to the back squat. Despite the dominance of the squat exercise in health, fitness and sport performance literature, and its universal use by athletes and the general public in exercise programmes, there is a surprising lack of knowledge surrounding which squat technique is better. Gullet et al., (2009), compared the biomechanical differences between the front and back squat, however, no known research is present comparing the effectiveness of these squat methods in developing leg power and flexibility.12Figure SEQ Figure \* ARABIC 1: Techniques and Bar Position during the Back Squat.12Figure SEQ Figure \* ARABIC 2: Technique and Bar Position during the Front Squat.1.2: AimsThe aims of this study are:To discover which squat (front or back) was more effective at developing leg power over a six-week training programme.To find out whether level of flexibility is positively correlated to the production of power in lower limbs (i.e. legs).1.3: HypothesesIn order to fulfil the aims it was hypothesised that:-It was hypothesised that front squats would be a more effective and safer exercise in developing leg power.The greater the lower limb flexibility level of an individual then the more power they would be able to exert from the leg muscles.It was also hypothesised that males, in general, would exhibit greater PPO/Mass values compared to women.1.4: LimitationsThe limitations of the study are variables in which the researcher has no control over and are identified below.There is no control over the participant’s diet and fluid intake. However recommendations were made to the subjects.Previous injuries that the subjects may have suffered.The study relied on volunteers and so may only appeal to those with a more extrovert personality.Exercise habits of participants outside of trial.Effort level of subjects during pre and post testing and the exercise intervention.No control group was used to ensure that the measures tested were the cause of any changes.Changes/adaptations may occur in training periods longer than 6 weeks.1.5: Glossary of Terms, Acronyms and Definitions.TermDefinitionAerobicExercise with oxygen (air)AnaerobicExercise without oxygen (without air)ATP (Adenosine TriPhosphate)A molecule that supplies energy to the body and musclesATP-PC (Adenosine TriPhosphate-Phosphocreatine)Short term Energy systemFatigueTiring of muscles and/or physiological systems during long periods of exercise.PPOPeak Power OutputPeriodizationA method of splitting up a training programme to maximise performance.PlyometricRepeated explosive movements i.e jumpingStretch Shortening CycleWhere muscles are stretched prior to an explosive movement/contraction i.e countermovement jumps2.0: Literature Review2.1: Search TermsThe studies within this review were identified using the following electronic databases: Sport Discus (1984-2014); Google Scholar (2004-2014); Europe PubMed Central (2000-2014) and Medline (1952-2014). The search terms used to locate the articles were as follows: Leg power; Power training; Squats; Squat Techniques; Front squats; Back squats; Front vs Back squats; Improving leg power; Lower limb power; Training for power; Muscular Force; Exercises to improve leg power; Muscular contraction; Production of muscular power.2.2: IntroductionThe purpose of this review is to identify any concepts or gaps missing from previous literature and highlight key physiological adaptations when training for an improvement in power. It will enlighten health, fitness and performance professionals of the various concepts, within strength and power and effective training methods. Reference will also be made to the importance of power within sports, specifically team invasion sports. Physical activity is imperative when leading a healthy lifestyle. A lack of exercise can cause a number of health related issues, which affect not only the individual, but also costs the NHS millions each year. Physical inactivity is recognised as the “fourth leading risk factor for global mortality causing an estimated 3.2 million deaths globally” (WHO, 2014). In the U.K. over a quarter of all adults, as of 2012, were classed as obese (26% BMI 30-40) (NHS, 2014). Being overweight or obese significantly increases the risk of diabetes (Type 2), heart disease, strokes, cancers (breast and colon) as well as leading to depression (NHS, 2014). In order to reduce the risk of suffering with such health problems, people can be physically active in a variety of ways. Participation in exercise can be for personal benefit (recreation) i.e. enjoyment, social or competitively i.e. within a sporting context. Exercise significantly improves quality of life as well as developing various components of fitness like strength, power and speed.Power is one of, if not the most dominant motor ability seen both in everyday life, as well as in sporting competitions. Almost every movement in sport and daily living will express some form of muscular power (Petrovic et al., 2012). Most sports are dependent, particularly in competitions, on displays of muscular strength and power (Baker, 2001; Haff, 2001). Many of these sports require lower body power in order to execute a variety of actions such as, sprinting, stopping, changing direction, kicking and jumping (Thorlund, 2009; Hoff & Helgerud, 2004; Wisloff, 1998). Both sportspersons and coaches are becoming increasingly more interested in the term power in their training regime.Researchers have attempted to lineate similarities between power, strength and speed (Lopez-Segovia et al., 2011). Whilst others have attempted to discover whether various exercise and loading techniques are effective in developing muscular power (Balsalobre-Fernandez et al., 2013;Loturco et al., 2013; Cormie et al., 2007; Harris et al., 2007; Hori et al., 2007; Stone et al., 2003; McBride et al., 2002; Baker et al., 2001; Toji et al., 1997; Garhammer et al., 1980). Other research has delineated differences between stable and unstable exercises and the effects upon muscular power (Behm & Colado, 2012; McBride et al., 2010; McBride et al., 2006; Anderson & Behm, 2004).2.3: Concepts, Physiology and Kinematics of Power during ExercisePower is the ability of the muscles to exert a maximal muscular contraction instantaneously in an explosive burst of movement. It is a combination of speed and strength and is generally measured in Watts (W) (Katch et al., 2011; Baechle & Earle, 2008). Displays of power are seen throughout everyday activities and in sporting/athletic competitions e.g. Usain Bolt in the 100m, Cristiano Ronaldo jumping over 1 metre in height in football and Bradley Wiggins winning the Tour De France. “Power development is paramount to optimal neuromuscluar function” (Kraemer & Newton, 2000). Kawamori & Haff, (2004), consider muscular power to be a principle determinant of athletic performance requiring an explosive production of force such as throwing, jumping and kicking (Kawamori & Haff, 2004; Cronin & Sleivert, 2005). Traditionally, coaches, athletes and those who exercise for recreational benefits, focused upon training for absolute muscular strength or muscular endurance. However, recently there has been a heightened interest in more functional training in order to optimize athletic performances and improve quality of life (Katch et al., 2011; Bean, 2011; Lopez-Segovia et al., 2010; Marques, 2010; Baechle and Earle, 2008; Shepherd, 2006; Cronin and Sleivert, 2005).As with every musculo-skeletal movement that requires energy in the form of ATP (Adenosine Tri-Phosphate), muscles require an immediate energy source to generate powerful movement. There are three energy systems within the human body and all play a difference role. The ATP-PC (Adenosine Triphosphate-Phosphocreatine) system can only sustain ATP (Adenosine TriPhosphate) metabolism for 0-10 seconds before the muscles fatigue. Following the fatigue of the ATP-PC system the short term glycolytic system will resume energy metabolism. However this system is much slower and can only sustain energy production for 10-60seconds before the aerobic energy system takes over (Figure 3) (Katch et al., 2011).Figure 3: The ATP-PC, Glycolytic and Aerobic energy systems and their contribution of ATP production during activities of varying durations.As previously stated, many researchers have attempted to distinguish differences between exercises and loading techniques in the training of muscular power. Many of these exercises have been functional multi-joint compound exercises like the squat, power clean and certain jump protocols (Gullet et al., 2009). The squat, a common leg muscle exercise, activates muscles such as quadriceps, hamstring and glutei, as well as initiating core stabilising muscles such as the spinal erectors and abdominal muscles (Baechle & Earle, 2008; Delavier, 2001; Escamilla, 2001; Escamilla et al., 2001; Escamilla et al., 2001). Lutz et al., (1993) and Palmitier et al., (1991), explained that differences in the loading of the squat depend entirely on the goals of the performer, whether it be for specific sports performance or recreational and health purposes. List et al., (2013) investigated the biomechanics of the back squat whilst Gullet et al., (2009), compared the biomechanical differences between the front and back squat. Both studies concluded that the back squat added additional stress upon the vertebrae and knee joints. It was concluded, that the front squat, although it couldn’t be as heavily loaded and being a more difficult exercise to perform, is a safer exercise and should be incorporated gradually into any exercise programme. List et al., (2013), also concluded that despite the general consensus among health and fitness practitioners, emphasis shouldn’t be placed upon restricting knee kinematics during the squat. It was found that this restriction in keeping knees behind the toes increases the likelihood of back injury and causes greater compression forces upon the knee joint.2.4: Factors that Affect Power Production of MusclesThe rate of force and power exerted by the muscles can vary largely depending on a number of physiological factors. Gender, age, activity levels, somatotype, lifestyle, exercise experience, specific limb length and joint angles can all affect the amount of power muscles can exert (Katch et al., 2011; Wilmore et al., 2008; Bouchard et al., 2007). Whilst there is a wealth of diverse research assessing power performance and loading to maximise power potential, very few studies focus upon female participants. However, research comparing the responses of male and females during various exercise protocols has been combined in a number of studies (Nikolaidis., et al 2012; Tsolakis et al., 2012; Paradisis et al., 2012; Pradas et al., 2010; Witmer et al., 2010; Stone et al., 2008; Youdas et al., 2007; Cotterman et al., 2005; Chui et al., 2003; Jensen & Ebben, 2003; Schmidtbleicher, 1996). Exceptions to this are McCurdy et al., (2010), Terblanche & Venter, (2009), Forte et al., (2008), Rixon et al., (2007) and Duthie et al., (2002), who all reported findings based on female athletes alone. Similarly to Witmer et al., (2010), Duthie et al., (2002) and Rixon et al., (2007), considered the effects that a PAP protocol (Post-Activation Potentiation) on maximal force and power production in the short term. This was accepted by a number of researchers which could have significant implications for fitness and performance professionals when designing an exercise programme to develop power (Witmer et al., 2010; Hodgson et al., 2005; Robbins, 2005). Rixon et al., (2007), found similar findings to the study by Duthie et al., (2002) whereby a period of heavy squats (90% 1-RM and 3-RM respectively) prior to power movements significantly inhibits jump heights and power outputs in well trained women. Contrastingly, Witmer et al., (2010), found that, in a study of males (N=12) and females (N=12), found that the performance of heavy resistance exercises prior to a series of power movements (vertical jumps) can elicit significant performance improvements. However, note should be made that not all participants showed signs of improvement, highlighting significant individual differences between athletes. Mangus et al., (2006) showed similar performance enhancements in CMJ after a series of heavy squat exercises. Likewise, Mangus et al., (2006), made specific reference to individual differences as only 50% of participants displayed performance improvements in CMJ. However Mangus et al., (2006), only used male participants so differences between male and female athletes are unclear. As shown in the previous studies, squats are an extremely popular exercise when attempting to develop lower limb strength and power. Youdas et al., (2007), compares the activation of muscle fibres in males (n=15) and females (n=15) during a single leg squat (SLS) on both a stable and labile surface (Youdas et al., 2007). The results convey that males are more effective at initiating their hamstring muscles during SLS (stable and labile), with a H:Q ratio (Hamstring:Quadricep) three and a half times larger than females. Contrastingly, women were more quadriceps dominant, specifically during the labile SLS (14% more EMG (Electromyographic) activity). Therefore the research suggests that the single leg squat may not be as effective at developing quadriceps power in males. Similarly, a study conducted by McCurdy et al., (2010), compared lower extremity EMG activity in 11 highly trained female athletes (Football, Softball and Track athletes). They found that the 2-leg squat produced higher mean and mean peak power than the SLS, as well as a higher Q:H (Quadricep:Hamstring) ratio. However, this study has neglected to incorporate males and so no comparisons between the sexes can be made (McCurdy et al., 2010). Therefore, future studies could predict that males activate hamstrings more effectively during the squat and SLS exercises whilst comparing male and female data previously recorded. Cotterman et al., (2005), attempted to compare muscle force production between using the smith machine (SM) and free weights (FW) between males and females. It was found that the SM squat 1RM was greater than the FW squat. This may suggest that SM squats are more efficient when developing quadriceps hamstring muscles, as it would reduce compression forces upon the spine and knees. On the other hand, the FW squat stimulates greater core activation in order to maintain balance, which would explain the reduction in force production (Anderson & Behm, 2004).McBride et al., (2006), studied the effects that performing isometric squats on stable and unstable surfaces has on force output and muscular activity. It was discovered that performance of isometric squats on an unstable surface significantly reduces peak force, rate of force development and agonist muscle activity (McBride et al., 2010; McBride et al., 2006). It has been well established that stable exercises are the most effective at developing strength and power. However, training using unstable exercises is extremely effective at enhancing core activation, improving balance as well as being of great benefit to physiotherapists and injury rehabilitation professionals (Behm & Colado, 2012; Sparkes & Behm, 2010;; McBride et al., 2006; Anderson & Behm, 2004; Behm et al., 2002).A study by Shetty, (2002), looked at alternative performance models for the assessment of lower limb power specifically in anaerobic type sports. The study used untrained college students (n=19) and found a positive correlation (r=0.47) between height of jump and power produced. This correlation was greater than a correlation (r=0.19) found by Viitasalo (1988). These findings are consistent with Considine and Sullivan (1973), who found positive correlations of r=0.51 (Pearson’s Correlation). It was concluded that variances in the subjects age, sex and level of training, could be key determinants in the varying significance of jump height and power output in the lower limbs. This research highlights that there are differences not only between males and females but also age and exercise experience.The level or experience of exercise and lifestyles of the participants will also have an effect on maximal power outputs. A number of studies have documented the training level of the athletes that have been tested upon (Loturco et al., 2013; Balsalobre-Fernandez et al., 2013; List et al., 2013; Marques et al., 2011; Ayed et al., 2011). Not only is the level of training an important factor in the performance of power activities, but also the type of training. For example the performance needs of a hockey or team sport player, is vastly different from the performance needs of an Olympic weightlifter or field athletes. Similarly, an elite level athlete will display greater level of performance in the same test measures, as an athlete in the cognitive or grass root level of performance. Caruso et al., (2009) and Sharma et al., (2012), both look at whether there are any correlations between anthropometry and front squat or power performance in American footballers and professional Indian hockey players. Caruso et al., (2009), concluded that anthropometric measures are an important factor in determining front squat ability. Similarly, Sharma et al., (2012), found that height and body weight were positively correlated with lower limb power. This could be due to the limb length and subsequently a more advantageous joint angle.In order for athletes to generate the maximum amount of muscular power in competition, it is important, as with any exercise programme, to perform a warm up. The exercises selected by coaches and athletes alike, can have a huge effect on the athletes performance if the warm up protocol is not carefully considered. Yamaguchi et al., (2006), studied the effects of extensive stretching on lower power performance. They found a 5.5±0.9% decrease in countermovement jump heights after a period of extensive stretching. Whilst it is generally accepted that stretching should be performed during a warm up to improve muscle elasticity, extensive static stretching shouldn’t be performed prior to activities requiring maximal power outputs. Tsolakis and Bogdanis, (2012), also found that stretching prior to power movements significantly reduces the muscular peak power in 20 international fencers (10 males and 10 females). The fencers were put through two warm up protocols and as expected, female range of motion (ROM) was significantly greater than male ROM. However, the males CMJ (Countermovement Jump) performance was greater despite there being no significant differences between male and female percentage change. When combined with research by Witmer et al., (2010), Rixon et al., (2007), Mangus et al., (2006) and Duthie et al., (2002), clear conclusions can be made as to which exercises can be integrated into a warm up protocol to maximise peak power output.Age is another significant factor to consider in relation to peak power outputs. Both Taylor et al., (2010), and Patterson and Peterson, (2004) look to distinguish normative data in terms of power output and vertical jump heights, in children aged 10-15 and young adults respectively. Korff et al., (2014), studied the age and activity related differences in the mechanics underlying maximal power production in young and older adults. Results convey an age related decline in muscular power which can be attributed to joint specific factors and that activity level can be a modifier of coordination during exercise. Absolute maximum power was significantly higher in young adults compared with both older sedentary adults and older active adults.Ayed et al., (2011), looked at the differences between white and black young footballers their abilities to perform maximal muscular contractions. Results convey that there are some differences in peak power production between white and black young footballers. The white players demonstrated a greater PPO (Peak Power Output) (W and W/Kg), optimal breaking force and optimal velocity than the black players. However, the black group (BG) performed significantly better in the jump and sprint measures. Furthermore, it was found that 33% of the variance of PPO of BG was explained by qualitative factors relating to cycling skill, muscle composition and socioeconomic and training statue.2.5: Exercise and Loads to Maximise Power Potential in TrainingMany researchers have attempted to discover the most effective training loads in order to maximise power performance in various exercises/movements (Cormie et al., 2007; Harris et al., 2007; Hori et al., 2007; Stone et al., 2003; McBride et al., 2002; Baker et al., 2001; Toji et al., 1997; Garhammer, 1980). The effectiveness of load on peak force and power in jump squats, power cleans and regular squat has also been reported by Cormie et al., (2007); Harris et al., (2007); Hori et al., (2007) Stone et al., (2003); Baker et al., (2001) and Garhammer, (1980). However there is very little empirical evidence that compares the success that different exercises have upon improving power performance.Cormie et al., (2011b) found through various studies, that differences in exercise selection require different loading in order to maximise power production. When performing weightlifting or strength based exercises (i.e. the squat, bench press), a load ranging between 50% and 90% of 1-RM is most effective at developing power. On the contrary, when performing ballistic, plyometric exercises, effective loading can range from 0 to 50% of single repetition maximum. These findings correlate with findings by Cormie et al., (2007), where it was discovered that performance of power cleans and squats should be performed with a load of between 50-60% of 1-RM. It was also concluded that, the loads used should replicate the specific requirements of different sports. Cormie et al., (2011a), also found that maximal power production is influenced by a number of morphological factors including fibre type, tendon properties and neural factors affecting muscular recruitment. Specific loading of exercises to enhance muscular power has been shown to demonstrate similar benefits as traditional strength training, both in short and long term performance (Loturco et al., 2013; Witmer et al., 2010; Hodgson et al., 2005; Robbins, 2005). These findings concur with a study performed on 7 high-level and elite hurdlers by Balsalobre-Fernandez et al., (2013). These results are somewhat useful in providing a base level of data. However due to the small sample size used (n=7) and the fact that only top level athletes were represented, results are not transferable to the general population. In contrast to this, Loturco et al., (2013), tested upon 45 members of the Brazilian Special Forces, in order to identify whether optimal power training zones produce similar performance improvements to traditional strength training (Loturco et al., 2013). Although the sample size will enable this data to be more accurate and transferable to the population, it similarly to Balsalobre-Fernandez., (2013), focuses upon highly trained individuals. This may present difficulties in accurately prescribing appropriate training loads for the general population. Similarly to Witmer et al., (2010), Mathews et al., (2003) and Smith et al., (2001), state that post-activation potentiation (PAP) can be used to elicit performance improvements, by including resistance exercises into a warm up protocol (Mathews et al., 2003; Smith et al., 2001). This research demonstrates a need for health and performance coaches to individualise complex training programmes to gain optimum results for the performer. Various studies agree with Mathews et al., (2003), and Smith et al., (2001), that heavy back squats significantly improve vertical jump performance and consequently are an efficient exercise at developing leg power (Rixon et al., 2007; Gourgoulis et al., 2003; Young et al., 1998). On the other hand, there was no significant improvement in vertical jump performance after a period of heavy back squat lifting (Hanson et al., 2007; Rixon et al., 2007; Mangus et al., 2006; Scott & Docherty, 2004; Jensen et al., 2003; Jones et al., 2003).Strength EmphasisPower EmphasisSpeed EmphasisFigure 4: Speed-Strength Continuum and Percentage of 1 RM (Bain, 2012).As studied previously by Cormie et al., (2011a), Cormie et al., (2011b), plyometric or ballistic, high intensity training has been proven to improve power performance in athletes of varying ages, genders and exercise experiences. Plyometric training involves repeated maximal bursts of high velocity movements. Plyometric training involves the stretch shortening cycle (eccentric-concentric muscle contraction) within the muscles to elicit a repeated exertion of maximal force. Vaczi et al., (2013), found in a study on 24 male football players, that short term plyometric training should be incorporated into the in-season training sessions as an effectual method of improving leg power and subsequently football performance. This would suggest that the improvements seen could be replicated by higher level athletes, as the participants were considered beginner athletes. Similarly, Makaruk et al., (2010), studied the effects of plyometric training upon maximal power output and jumping ability on 44 non training students. They found that plyometric training elicited a significant improvement to power output, when performing a CMJ (counter-movement jump) and DJ (depth jump).2.6: The Importance of Power in Team Sports“Power is one of the dominant motor abilities in most sport games and individual sports. No movement or action in sports activities can be made without expressing some sort of muscular power” (Petrovic et al., 2012).There has been a rise in the emphasis placed on improving power, amongst athletes within team and individual sports. “Many sports depend heavily upon muscular strength and power especially at competition level” (Baker, 2001; Haff, 2001). Over the past 10 years many researchers have attempted to discover the effects that power has on sport specific performance across a wide range of sporting activities and athletic events. Power is needed for a variety of different tasks during a sporting activity, such as sprinting, accelerating, changing direction, stopping, jumping, throwing and hopping.As previously stated, most researchers studying the effects of training for power to improve sporting performance, are aimed at male athletes (McMaster et al., 2013; Vaczi et al., 2013; Sander et al., 2013; Sharma et al., 2012; Petrovic et al., 2012; Lopez-Segovia et al., 2011; Ayed et al., 2011; Caruso et al., 2009; Burr et al., 2007; Hoffman et al., 2005). Sharma et al., (2012) and Burr et al., (2007), both assess the lower limb power of hockey players and attempt to predict hockey playing potential as a result of lower limb power efficiency. Although hockey doesn’t involve much jumping and throwing (unless you are a goalkeeper, in which case, jumping is crucial), power in the upper and lower limbs is essential. As previously researched, lower limb power is directly related to sprinting and acceleration, which are dominant in most sports, especially hockey (Sharma et al., 2012). It is vital to be able to move quickly and swiftly across the hockey pitch as well as stop and change direction; retaining balance as efficiently and effectively as possible(Wisloff, 1998; Hoff and Helgerud, 2004; Thorlund, 2009. Findings conclude that strength and power specific training is directly and positively correlated to an improvement in acceleration and sprint times in various athletes (Sander et al., 2013; Vaczi et al., 2013; Lopez-Segovia et al., 2011). However, much of this research focuses upon high level athletes and so cannot be justified as an accurate measure of the whole population. These participants are very highly trained and these gains may not occur in a beginner athlete. The subjects may also be in a particular stage of training that maximises certain motor abilities throughout the athlete’s season i.e. periodisation. For example, instead of training every component on a weekly basis, the athlete will train specific components (i.e. strength, power, speed, rehabilitation exercises), in order to maximise their competition performance.However, this research can only be attributed to male performers as none of the studies look at the relationship between power and female sport performance. One researcher (Terblanche et al., 2009) looks specifically at the effects that backward training can have on the speed, agility and power of young female netball players (n=17). The research found that backward training did in fact have a positive effect upon agility, speed and power performance. However as the research was conducted on just 17 well trained athletes it is hard to make any general conclusions. It was also focused upon young adults (age=19-20yrs) and so presumptions are limited in respect to older athletes.2.7: SummaryThese findings therefore highlight a greater need for research to be conducted on the general population and the effective methods of improving power not only for performance but also daily activities (Petrovic et al., 2012). Moreover, further research needs to be conducted, particularly on female athletes, comparing both males and females. This will determine whether certain exercises are better at improving certain musculo-skeletal functions such as power.It is clear from the literature that participating in regular training and physical activity will improve ‘quality of life’ and/or athletic performance depending on personal goals. However, there is a transparent lack of literature that compares the effectiveness of certain exercises, in relation to improving certain components of fitness. Despite the vast literature surrounding power performance and training to maximise muscular power, there is little empirical evidence that compares specific exercises in terms of effectiveness in developing power. Therefore, the aims of this study are:To compare the front and back squat in terms of power development in the lower limb muscles. To discover which squat (front or back) is more effective at developing leg power over a six-week training programme.To find out whether level of flexibility is positively correlated to the production of power in lower limbs. The following hypotheses where identified by the researchers:The front squat would be the more efficient exercise despite being able to load back squats (Figure 1) with a heavier resistance due to the more horizontal body position adopted in comparison to the front squat (Figure 2).It was hypothesised that the greater the lower limb flexibility of an individual, the more power they could exert.Finally, it was hypothesised that males would generate a greater peak power to mass ratio during the countermovement depth jump measure.3.0: Materials and Method3.1: Study DesignTwo experimental groups were used to compare the effectiveness of the front squat and back squat in developing leg power over a six week mesocycle. Each week the subjects were required to follow a pre-designed training intervention, focusing on either front squats or back squats. The first experimental group (FG) performed high- velocity front squats at the optimal power load (60% of 1-RM) (Cormie et al., 2010; Cormie et al., 2007). The second experimental group (BG) performed high-velocity back squats at a load that optimizes power output (60% of 1-RM) The following tests were performed pre and post the training intervention which lasted six weeks. The 1RM tests and load percentages were calculated at the end of the two week technique practice.3.2: SubjectsBoth Males (n=16, age 20.5±1.3yrs, body-mass 73.97±8.79kg, stature 177.56±6.74cm) and Females (n=16, age 19.25±1.44yrs, body-mass 63.03±10.22kg, stature 161.44±4.33cm) University students (n=32, age 19.88±1.48yrs, body-mass 68.50±11.81kg, stature 169.5±9.90) participated in the study. All participants belonged to the same English University based in the South West and were all part of the universities male and female BUCS hockey teams. The subjects all attended the same S&C training sessions each week except from hockey specific training. Prior to the start of the study the participants underwent a physical examination and cleared of any medical disorders (appendix 1) that may have prevented them from full participation. The study was approved by the Research Ethics Committee (appendix 2). All participants were informed of the procedures and aims of the research prior to the study. The participants were made aware of their rights to withdraw from the experiment at any point, confidentiality of data and of the risks and benefits that the training intervention may bring about. Written informed consent (appendix 3) was obtained from the subjects prior to the start of the study.Table 1: Mean physical characteristics of participants in both front and back squat groups. (± standard deviations).GroupGenderAgeWeightHeightFront SquatMales20.75 (0.9)74.26 (10.8)177.2 (6.8)Females18.86 (1.5)66.9 (16.4)161.8 (4.0)Back SquatMales20.25 (1.6)73.7 (7.0)177.9 (7.1)Females19.63 (1.4)59.16 (3.5)161.1 (4.8)Overall19.88 (1.5)68.5 (11.81)169.5 (9.9)3.3: EquipmentHardwareModelManufacturerPlace of ManufacturerAssociated Software (if applicable)Seca Medical ScalesScales and StadiometerSeca MedicalBirmingham, UKN/AMulti-Frequency Body Composition AnalyserMC-180MATanita CorporationTokyo, JapanHealth Monitor V2.7.8Jump Mat SystemSmart JumpFusion SportCoopers Plains, AustraliaFusion ProConcept 2 DynamometerConcept 2Concept 2 Inc.Vermont, USAN/ASit and ReachN/ACranleaN/AN/ABarbell and Weight PlatesN/AJordanN/AN/ASPSS for MacSPSS 22.0IBM Inc.N/AStatistical Package for Social SciencesWindows Microsoft Office ExcelMicrosoft Excel 2007Microsoft CorporationN/AMicrosoft Office3.4: ProtocolPilot StudyThe aim of the pilot study was to familiarise the researchers with the design protocol and to mitigate any limitations of the procedures in place. Six subjects consented to participate in the pilot study which tested anthropometric characteristics (Multi-Frequency Body Composition Analyser, MC-180MA – Tanita Corporation, Tokyo, Japan), hamstring flexibility and CMDJ (countermovement depth jump) (Smart Jump – Fusion Sport, Coopers Plains, Australia) height for power measurements. The pilot study lasted for two weeks and participants were tested before and after the two week training period. The original protocol started with the testing of anthropometrics followed by a sit and reach test. The participants were then required to perform a CMDJ to measure leg power. However a study by Tessier et al (2013), reported that the CMJ may not be an accurate measure of leg power. However, Burr et al (2007) found that “All 4 of the jumping protocols used are reliable and provide acceptable measures of leg power if used consistently for a population” (Burr et al., 2007). In order to mitigate any issues with reliability, a second test of power was introduced using a Concept 2 Leg Dynamometer (Concept 2 – Concept 2 Inc, Vermont, USA). Additionally, a study performed by Yamaguchi et al., (2006), clarified the effects of static stretching on muscular performance and found that extensive static stretching decreases maximal power performance. This allowed for adjustments to be made to the design of the testing protocol. In order to save time, the study highlighted a need to pre design data recording sheets/excel spreadsheets. This also enabled for more coherent testing procedures where the data can be analysed instantaneously. The results of the tests were (if sought by individuals) explained to the subjects and compared to vertical jump and power norms for young adults identified in research by Patterson and Peterson, (2004).Main StudyThe subjects were required to complete a total of two weeks prior to the start of the study practicing the techniques of both front and back squats, to ensure that all participants were confident performing the movements. The first week was spent practicing the back squat and the second week the front squat. At the end of each week the participants had to find a weight that they could squat for a maximum of one repetition (1RM). The subjects were randomly divided into two groups: front squat group (FSG - N = 16 (8 males and 8 females), age 19.8±1.51yrs, stature 169.49±9.62cm, body mass 70.58±13.92kg); back squat group (BSG - N = 16, age 19.93±1.48yrs, stature 169.50±10.49cm, body mass 66.43±9.24kg). The training protocol lasted 6 weeks, with the subjects training twice a week (micro-cycle) each at the same times on the same days each week (Thursday 11-1pm). The study training sessions took part on the rest days between regular training sessions for the players. The study lasted for a total of 10 weeks. All participants would perform a standardized warm up protocol prior to their respective squat training. Following the warm up, participants would perform three sets of five front squats (FSG) or back squats (BSG) using Olympic standard barbells. The participants all loaded the barbell with 60% of their 1RM (single repetition maximum) (Cormie et al., 2007).3.5: Testing ProceduresThe subjects were required to perform several tests in order to compare the effectiveness of the training interventions used. To attain the physical characteristics of the participants various anthropometric measurements were taken. Height and weight was recorded using Seca Medical Scales and Stadiometer (Seca Medical, Birmingham, UK). Following these measurements the subjects were required to undergo body composition analysis (Multi-Frequency Body Composition Analyser, MC-180MA – Tanita Corporation, Tokyo, Japan) for accurate measurements in body fat percentage, muscle percentage, BMI and BMR calculations. The data was recorded onto a data recording sheet by the participant to keep the results confidential. Following the anthropometric measurements, participants were asked to perform countermovement jumps (CMDJ) (Smart Jump – Fusion Sport, Coopers Plains, Australia). This data was directly entered onto a pre-designed Microsoft excel spreadsheet by the researcher. A second test of leg power was incorporated to ensure the validity and reliability of the data. Subjects were required to perform a seated squat motion on a Concept 2 Dynamometer (Concept 2 – Concept 2 Inc, Vermont, USA). Subjects performed three on both CMDJ and the dynamometer to increase validity. Finally, participants tested their level of hamstring and lower spine flexibility by performing a sit and reach test. Flexibility was measured last, due to findings by Yamaguchi et al., (2006) which suggest that static stretching prior to exercise can decrease maximal power output during performance. 3.6: Statistical Analysis (Reliability measures)The statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS for Mac version 22.0, SPSS/IBM Inc). Means and standard deviations represented central tendency and the spread of data. The means and standard deviations were also double checked using Microsoft Office Excel 2007 for Windows to mitigate any human errors occurring during data input on SPSS. Independent T-tests were used to compare variances in each measure between front squat and back squat groups. This allowed for the researchers to identify if there were any statistically significant improvements between groups. In order to investigate the differences between pre and post measurements, Dependent (paired) T-test were used for each group (FSG & BSG). In addition to this, a bivariate correlation was performed in order to find any relationship between force/power production and level of lower limb flexibility.Finally, graphs were produced to convey the means and standard deviations of the measures tested. The graphs convey variances in pre and post Flexibility, CMDJ PPO, CMDJ PPO/Mass and Force/Power production between FSG and BSG. In order to ascertain gender differences, error bar graphs were also produced in order to best convey the central tendency and spread of data of pre and post results.3.7: ConfidentialityAll data has been kept confidential and stored on a password protected Dell Laptop. Once collected, collated and presented, all data will be destroyed. Original copies will either be given to the corresponding participant if requested, or otherwise destroyed.4.0: Results4.1: IntroductionThe mean load lifted by the Back Squat Group was 71.25±21kg which was 53% heavier than that of the Front Squat Group (46.56±11.65kg). The normalized Back Squat (Figure 2) 1-RM values for males were 90±10kg and for females, 52.5±6.54kg. The Front Squat Group had normalized Front Squat (Figure 3) 1-RM values of 56.25±6.9kg (males) and 36.87±5.3kg (females). This data highlights that individuals are able to lift significantly higher loads during the back squat.4.2: Key Theme 1: Between Group DifferencesTable 3: Significance Values of Improvement from Pre-Post Measures.Significance (2-tailed)Pre/Post MeasureFront SquatBack SquatFlexibility0.0000.000CMDJ PPO0.0000.000Force/Power0.0000.000CMDJ PPO/Mass0.0010.000Table 4: Significance of Improvements between FSG and BSG Post-Intervention.Post Intervention MeasuresSignificance (2-tailed)Sit and Reach Flexibility0.830CMDJ PPO0.476Force/Power Dynamometer0.759CMDJ PPO/Mass0.566Both FSG and BSG showed significant statistical (p=<0.05) improvements in all measures (Flexibility= 0.000, CMDJ PPO= 0.00, CMDJ PPO/Mass= 0.001 (0.000 for BSG), force= 0.000) (Table 3). The results suggest that both methods of squatting are equally as effective at developing power and improving flexibility over a 6-week period (statistical significance = p=<0.05) (Flexibility=0.830, CMDJ PPO=0.476, Power/Force=0.759, CMDJ PPO/Mass=0.556) (Table 4).4.3: Key Theme 2: Force/Power ImprovementsTable 5: Means, Standard Deviations (±) and Difference between Pre and Post Measures.Squat GroupMeasureFlexibility (cm)PPO (Watts)Force/Power (Kg)PPO/Mass (W/Kg)FrontPre17.56 (±8.77)2511.86 (±611.42)133.93 (±32.72)35.43 (±4.13)Post20.81 (±9.08)2621.53 (±620.35)141.10 (±32.19)36.92 (±4.45)Difference+ 3.25+ 109.67+ 7.17+ 1.49BackPre18.00 (±10.80)2271.05 (±528.33)131.56 (±27.14)33.82 (±4.09)Post21.62 (±11.91)2473.37 (±538.38)137.89 (±25.98)36.03 (±3.96)Difference+ 3.62+ 202.32+ 6.33+ 2.21Table 5 portrays a larger mean increase in Back Squat group CMDJ PPO (202.32w) than for FSG (109.6694w). However, the FS group produced a mean of 2621.53±620.35w which was 148.16w higher than the BSG (2473.37±538.39w). The BSG also experienced greater mean improvements in CMDJ PPO/Mass (2.21w/kg). However, the FSG displayed greater average force generation during the Force Dynamometer test measure (141.10±32.19kg), an improvement of 7.17kg from 133.93±32.72kg in the pre test measure.Table 6: Correlation and Significance of Correlation between Pre and Post Measures for the Front Squat Group.PREPOSTPre SRPre PPOPre ForcePre PPO/KgPost SRPost PPOPost ForcePost PPO/KgSR - Pearson Correlation Sig. (2-tailed) N1160.0660.809160.0850.75416-0.2130.428160.944**0.000160.760.780160.1860.49116-0.2210.41016PPO - Pearson Correlation Sig. (2-tailed) N0.0660.80916116.562*.02316.599*.01416.037.89116.988**.00016.589*.01616.646**.00716Force - Pearson Correlation Sig. (2-tailed) N0.0850.75416.562*.02316116.506*.04616.076.77816.561*.02416.981**.00016.499*.04916PPO/Kg - Pearson CorrelationSig. (2-tailed) N-0.2130.42816.599*.01416.506*.04616116-.243.36516.570*.02116.481.05916.946**.00016SR - Pearson CorrelationSig. (2-tailed) N0.944**0.00016.037.89116.076.77816-.243.36516116.053.84516.175.51616-.229.39416PPO - Pearson CorrelationSig. (2-tailed) N0.760.78016.988**.00016.561*.02416.570*.02116.053.84516116.593*.01516.655**.00616Force - Pearson Correlation Sig. (2-tailed) N0.1860.49116.589*.01616.981**.00016.481.05916.175.51616.593*.01516116.470.06616PPO/Kg - Pearson Correlation Sig. (2-tailed) N-0.2210.41016.646**.00716.499*.04916.946**.00016-.229.39416.655**.00616.470.06616116**. Correlation is significant at the 0.01 level (2-tailed). *. Correlation is significant at the 0.05 level (2-tailed).Table 7: Correlation and Significance of Correlation between Pre and Post Measures for the Back Squat Group.PREPOSTPre SRPre PPOPre ForcePre PPO/KgPost SRPost PPOPost ForcePost PPO/KgSR - Pearson Correlation Sig. (2-tailed) N116-.582*.01816-.485.05716-.379.14716.990**.00016-.471.06516-.489.05516-.198.46316PPO - Pearson Correlation Sig. (2-tailed) N-.582*.01816116.853**.00016.892**.00016-.634**.00816.968**.00016.837**.00016.799**.00016Force - Pearson Correlation Sig. (2-tailed) N-.485.05716.853**.00016116.764**.00116-.543*.03016.793**.00016.994**.00016.622*.01016PPO/Kg - Pearson CorrelationSig. (2-tailed) N-.379.14716.892**.00016.764**.00116116-.431.09616-.431.09616.764**.00116.908**.00016SR - Pearson CorrelationSig. (2-tailed) N.990**.00016-.634**.00816-.543*.03016-.431.09616116-.520*.03916-.540*.03116-.243.36416PPO - Pearson CorrelationSig. (2-tailed) N-.471.06516.968**.00016.793**.00016-.431.09616-.520*.03916116.771**.00016.854**.00016Force - Pearson Correlation Sig. (2-tailed) N-.489.05516.837**.00016.994**.00016.764**.00116-.540*.03116.771**.00016116.617*.01116PPO/Kg - Pearson Correlation Sig. (2-tailed) N-.198.46316.799**.00016.622*.01016.908**.00016-.243.36416.854**.00016.617*.01116116**. Correlation is significant at the 0.01 level (2-tailed). *. Correlation is significant at the 0.05 level (2-tailed).4.4: Key Theme 3: Correlations between Flexibility and ForceTables 6 and 7 convey the correlations between all measures pre and post interventions for front squat (Table 6) and back squat groups (Table 7). Table 6 indicates that although there are no statistically significant correlations, the data is sporadic and data points show positive and negative correlations. There were some correlations present, between force and power measures (leg dynamometer and countermovement depth jump), but this is to be expected as they are both measures in power.Table 5 depicts the correlations and significance values of Pearson’s Correlation for the BSG. Conversely to the front squat group, slight significant correlations can be found between flexibility and force/power output. However, as table 7 shows, the correlations are negative which signify that as one measure increases, the other decreases. This represents findings that improvements in flexibility are not directly correlated to increases in force generation as it was hypothesised.Figure 5: Conveys the correlation between flexibility and force production for all participants (n=32).When both FSG and BSG group post flexibility and force data were correlated, there is a slight positive correlation. This positive correlation however, is insignificant as the previous tables (Table 6 & 7) depict significance values above 0.05 (sig. p=0.05). The trend line illustrates the mean increase in force and correlation to flexibility. The data point 0,0 was included to allow the trend line to pass through zero.4.5: Key Theme 4: Male & Female DifferencesGender of ParticipantsSit & Reach Flexibility (Cm)Figure 6: Mean Values and Standard Deviations of Male and Female Flexibility Pre and Post Intervention.Gender of ParticipantsPeak Power Output (Watts)Figure 7: Male and Female Mean and Standard Deviations of Peak Power Output from the Counter-Movement Depth Jump Measure.It is evident that the females have a greater level of lower limb flexibility (pre= 21±4cm, post= 25.5±4.5cm) than males (pre= 14±6cm, post= 17±6cm) during the sit and reach test (Figure 6). Figure 7 however, illustrates that males demonstrated superior results when measuring for power and force output. Male CMDJ PPO increased from 2750±200w to 2900±150w (+ 150w). Interestingly, females CMDJ PPO also improved by 150w from 2050±300w (pre) and 2200±300w (post).Gender of ParticipantsPeak Power Output/Mass (W/Kg)Figure 8: Differences between Genders and Peak Power Output/Mass Means and Standard Deviations.Figure 8, portrays the difference in power to weight ratio between males and females during the countermovement depth jump (CMDJ) in Watts/Kg body weight. During the pre test measurements males generated a mean of approx 37±1.5W/Kg, which was 4.5W/Kg higher than female pre test CMDJ data (32.5±2W/Kg). However, females displayed a similar mean improvement in PPO (W)/Mass (Kg) (1.75w/kg) to males (1.75w/kg) between pre and post training intervention (males = 38.75±1.75w/kg, females = 34.25±2.25w/kg) (Figure 8). Males improved PPO/Mass by approximately 4.7% from pre test value, whereas females improved their PPO/Mass by 5.4%.4.6: SummaryFrom the results, it can be concluded that there are no statistically significant differences between the effectiveness of front and back squats in improving leg power over a 6-week training period. Both methods of squatting significantly improve power and force output, as well as improving lower limb flexibility. The data determines that males can generate more peak power on average as well as having a better PPO/Mass ratio than females. However, females did present similar improvements in power and force production as well as being more flexible and having a greater lower limb motion range.5.0: Discussion5.1: IntroductionThe purpose of this study was to identify whether front squats at an intensity of 60% 1RM, were more effective at improving force production in the lower limbs, over a six-week training period. The data from this training intervention display that there are no significant differences between front and back squats in developing lower limb power (power/force=0.759 and CMDJ PPO=0.476 (p=<0.05)). The results convey that over a 6 week training period both front and back squats performed at 60% of 1RM are equally effective at developing lower limb power. Furthermore, it shows that there are no significant correlations between force production and lower limb flexibility, despite there being a slight positive correlation overall. Finally, the graphs convey differences in means, standard deviations and mean improvements between FSG and BSG and differences across males and females in pre and post testing conditions.5.2: Key Theme 1: Biomechanic and Kinematic Differences between Front and Back SquatTable 1 indicates the significance values of pre and post measures between front and back squat groups from the independent samples t-test. It was clear that both squat groups considerably improved all of the test measures (sig. p =<0.05). It was found however that the front squat was slightly less significant in improving CMDJ PPO/Mass (0.001) compared to BSG (0.000). However, due to the absence of a control group, it is uncertain how reliable these data are when compared to a non-squat group. There are currently no known studies that have compared the effectiveness of loaded squat techniques in improving power. This presents issues when attempting to compare the data to other studies to ascertain similar findings, although literature investigating the most effective load to develop power is extensive.Data from the independent samples t-test, suggest that no significant differences exist between front squat and back squat at improving lower limb flexibility and leg power. Table 2 conveys the significance values between front and back squat groups in improving leg power and flexibility, in the sit and reach test. The sit and reach flexibility test displayed the greatest insignificance level (0.830) whereas the CMDJ PPO conveyed the most significant improvement (0.476). However, statistical significance was set at p=<0.05 and so none of the measures were significantly different between FSG and BSG. Table 2 reinforces that neither front nor back squat were more effective at improving leg power and flexibility. These results concur with previous studies that compared the level of muscular stimulation between heterogeneous squatting methods by the use of electromyography (EMG) (Gullet et al., 2009).Interestingly, the BSG showed a greater mean improvement in CMDJ PPO (+202.32) from 2271.05±528.33 (Table 3). In comparison, the FSG elicited a greater increase in Force/Power output (+7.17) from the dynamometer measure (pre=133.93±32.72, post=141.10±32.19). These results could reflect the biomechanical differences between performance of the front and back squat. Back squats allow the performer to lift heavier loads due to the position of the barbell on the upper back/posterior deltoids (Gullet et al., 2009). This barbell position also encourages the performer to lean forwards more, thus allowing for greater flexion at the hips, knees and ankle joints and altering the centre of mass (COM). The change in COM between front and back squat may be the cause of the larger improvements seen in CMDJ PPO. It has been well documented that training on unstable surfaces or whilst activating more stabilising muscles to maintain balance, can significantly reduce power generation (Behm & Colado, 2012).5.3: Key Theme 2: Correlations between Flexibility and Force GenerationPrevious studies have found that extensive stretching prior to power exercises (i.e. jumping, hopping and throwing) can have a detrimental effect on the force and power produced by the muscles (Yamaguchi et al., 2006; Tsolakis and Bogdanis, 2012). This research however attempted to distinguish a link between level of flexibility and amount of force generated by the leg muscles. Table 4 conveys the bivariate correlations between the pre and post sit and reach test (SR) with the power/force measures (CMDJ PPO, Force/Power Dynamometer, CMDJ PPO/Mass) in the front squat. The back squat correlations are presented in Table 5.It is clear from Table 4 that no correlations exist between level of flexibility and force or power produced in FSG. However, it is evident that a number of significant positive correlations occur between PPO, Force and PPO/Mass. This is to be expected, due to the similar nature of the measures (all measures of lower limb power). This transmits that if force were to improve it would not be a direct result of an improvement in flexibility and vice versa. Pearson’s correlation denoted a positive or a negative correlation (depending on whether the figure is positive (above value of 0) or negative (-)). The significance value however, depicts how meaningful the Pearson correlation is (sig. p=0.05). If the significance value were to be greater than 0.05, then no statistically noteworthy correlation is present. Conversely, if the significance (2-tailed) value is less than 0.05 (p=<0.05) then there is a statistically significant correlation.Table 5 displays the bivariate correlation analysis and significance levels between measures and the back squat. Pre flexibility and pre PPO (CMDJ) values indicate a significant negative correlation -0.582 (sig. 0.018) which suggests that flexibility is negatively correlated to peak power output. This denotes that as flexibility increases, peak power output decreases or vice versa. This negative correlation is also present in the post measures data between the same variables (-0.520, sig. = 0.039). It can be concluded that flexibility is not linked to improvements in force production, particularly in the lower limbs. However, a certain level of flexibility is necessary in the generation of force and power from muscle. This, as a greater range of motion, will allow the muscles to activate the stretch shortening cycle, which has been proven to aid in power movements (Earp et al., 2014). For example, in hockey when a player goes to take a shot, prior to striking the ball the player must make a back swing. If the player had poor flexibility then they wouldn’t be able to back swing very far, which would inhibit the amount of maximum power that they could produce. This is replicated across a variety of sports i.e. football when striking a ball to shoot. This is concurrent with research in racket sports, where researchers have attempted to distinguish the joint angle at which is most powerful, during various tennis shots (Tanabe and Ito, 2007; Akutagawa and Kojima, 2005).Figure 5 expresses the slight positive relationship (trend line) between sit and reach flexibility and force from leg dynamometer, in both front and back squat groups. The trend line portrays a slight positive correlation between the two measures. However, as tables 4 and 5 imply, this positive correlation is insignificant (p value >=0.05). This could be due to both male and female data being incorporated into the graph. It is thought that this slight correlation is caused by a greater range of motion at the hip and knee joints (Gaudreault et al., 2013).5.4: Key Theme 3: Male and Female DifferencesFigures 6-8 depict the varying performance differences between males and females during the pre and post test measures, attained from the dependent (paired) samples t-tests. Figure 6 conveys that females have a greater level of lower limb flexibility. Although these differences could be down to training diversity, it is much more likely that they are due to the physiological variations between males and females (Zapartidis et al., 2011). It could be predicted from this data that females may possess a greater ability to generate power due to having greater range of motion (ROM). However, due to varying levels and distributions of muscle and fat mass, this may not necessarily be the case.Furthermore, Figure 7 portrays the mean peak power output differences between male and female pre and post measures during the countermovement depth jump. Similarly to previous research, male peak power output is significantly higher than that of the female participants for both pre and post measures (pre PPO = males 2750±200w, females 2050±300w) (Balsalobre-Fernandez et al., 2013). Fascinatingly, an increase of 150w was experienced by both males (5.5% increase) and females (7.3% increase) (post PPO = males 2900±150w, females 2200±300w). These variances are most likely due to differences in the hormone levels of males and females (Katch et al., 2011; Baechle and Earle, 2008; Bean, 2008; Wilmore et al., 2008). This rejects recent research which suggests that the greater the level of flexibility, the greater the amount of force a muscle group can exert (Gaudreault et al., 2013).Similarly, Figure 8 also conveys the mean PPO/Mass (W/Kg) ratio of males and females in the pre and post measures of the countermovement depth jump. It is evident from the graph that males possess a greater power to mass ratio (37±1.5W/Kg) when compared to females (32.5±2W/Kg). This data shows that per kilogram of body mass, males can on average, generate 37 watts of power.5.5: SummaryThe aim of this study was to identify whether there were any significant differences between the effectiveness of performing front squats and back squats in developing lower limb power. It is evident that there are no significant differences between front and back squats in developing lower limb power. There were however, significant improvements between pre and post measures, indicating that squats are effective at improving leg power over a 6-week training period. However, no control group was used therefore the resulting improvements cannot be confidently ascertained to the specific training intervention.Male and female variances were evident in term of flexibility and power due to physiological gender differences. Overall, males improved their peak power output/mass by 4.7% which is 0.7% lower than the female improvement of 5.4%. Males were also able to generate more force during the dynamometer testing even though the females were on average more flexible. This rejects the hypothesis that there will be a positive correlation between level of flexibility and force/power generation. Females recorded a greater range of motion and flexibility during the sit and reach measure pre (21.3±7.7cm) and post (25.5±7.8cm) intervention. However males generated more force (pre 152.65±24.1kg, post 158.5±23.4kg), despite having a lower average level of flexibility.This research provides a vital exercise comparison to the health and fitness industry as well as strength and conditioning practitioners. It will allow athlete development coaches to effectively plan and deliver training sessions, aimed at improving lower limb power.6.0: ConclusionIn conclusion, the research provided little significant data whilst attempting to discover whether front squats were more effective at developing lower limb power. It also failed to differentiate any significant correlations between lower limb flexibility and power/force production. Positively, however, it corroborated with previous research that males can generate more power per mass (Watts/Kg 0.067) than females of a similar age and level of fitness. This could have substantial value for exercise and performance coaches, as well as athletes, whilst eradicating any confusion surrounding the effectiveness of front and back squats. This research will enhance an athlete’s awareness that both front and back squats are effective when developing leg power. Furthermore, coaches can clearly identify the differences in flexibility and leg power in university students (age = 19.87±1.5yrs) when compared to the general population or normative data (Patterson & Peterson, 2004, and Taylor et al., 2010). Comparisons between male and female hockey players were also represented, adding to the sparse body of knowledge surrounding female athletes and power performance. With the presented information, both coaches and athletes will profit from an enhanced knowledge surrounding the effectiveness of certain exercises in improving specific components of fitness.6.1: RecommendationsThe study presents an effort to distinguish whether the front squat is more effective at developing lower limb power in young adults during a 6 week training intervention. Although no significant differences were observed between front and back squats, it is advised that both types of squatting should be integrated into a training programme. However front squats, if not already used frequently, should be slowly incorporated into a programme of exercise, to ensure correct technique and safe, effective lifting. Specific consideration should be made to ensure an appropriate load and tempo is used to develop power. 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Vol. 12, No. 1: 130-137.7.1: AppendicesAppendix 1: Medical history & Par-QForename(s)GenderMale/FemaleSurnameD.o.BDate/Month/YearBefore undertaking in any physical activity it is very important that you complete a Par-Q in order to see if there are any reasons as to why you may not be able to participate in physical activity. It also allows your trainer to choose appropriate exercises and intensities with regards to your health and fitness. It also informs them of any medical problems you may have and lets them act in accordance to your best interests.Please answer the following questions honestly and to the best of your knowledge. All information gathered will be kept in confidentiality. Please circle the box that reflects your answer.YesNoDo you have any heart problems?If Yes, Please expand:YesNoDo you have a history in your family of heart problems?If Yes, Please expand:YesNoDo you have any respiratory/breathing disorders or problems? If Yes, Please expand:YesNoDo you suffer from any back pain or joint/bone problems? If Yes, Please expand:YesNoDo you suffer from any chronic health problems? If Yes, Please expand: (include diabetes, epilepsy, osteoporosis)YesNoHave you ever had chest pain or dizziness during exercise? If Yes, Please expand:YesNoHave you had or currently undergoing any medical operations/treatments? If Yes, Please expand: (include cancer, major injuries and degenerative diseases)YesNoAre you pregnant now or given birth in the past 6 months? YesNoAre you taking any medication prescribed by a medical professional? If Yes, Please expand: Drug Name:Used for:YesNoHas your GP or any medical professional ever told you of any reasons as to why you cannot participate in regular physical activity? If Yes, Please expand:YesNoAre there any reasons you can think of that may affect your participation in regular physical activity?If Yes, Please expand:Client NameDateClient SignatureTrainer SignatureAppendix 2: Ethical Approval FormName of Applicant Module CodeName of supervisor / module leaderFacultyTitle of project*Please see attached proposalTimeframe of researchProvide a brief timetable of the proposed research, particularly indicating data collection phase(s). Ethical approval is for a limited time period: if the research changes, or extends beyond this period, the applicant should ensure that ethical issues are reconsidered using the procedures specified in section 4.3 of the Ethics Policy.*Please see attached proposalPurpose of researchProvide a summary of the research, written in terms easily understandable by a non-specialist*Please see attached proposalJustification for the researchIndicate the contribute to knowledge, policy, practice and/or peoples’ lives that the research is anticipated to make*Please see attached proposalParticipants in the researchProvide details of the participants in the research. Where appropriate, this should include specification of the population to be studied and sampling procedures to be used*Please see attached proposalRecruitment proceduresThis should explain the means by which participants in the research will be recruited. If any incentive and/or compensation (financial or other) is to be offered to participants, this should be clearly explained.*Please see attached proposalInformed consentExplain the information that will be provided to potential participants, and procedures for gaining consent*Please see attached proposalMethodsOutline the methods of data collection and analysis*Please see attached proposalConfidentiality, anonymity, data storage and disposalProvide explanation of any measures to preserve confidentiality and anonymity, including specific explanation of data storage and disposal plans. (Note that there may be need to store data for some years after completion of the project.) *Please see attached proposalEthical considerations Outline the ethical dimensions to the proposed research, both those which may be seen as ‘positive’ and ‘negative’. Where potential risks to participants’ or researchers’ physical, psychological or emotional wellbeing may be present, explain any steps that will be taken to minimize these. *Please see attached proposalPublished ethical guidelines to be followedIdentify the professional code(s) of practice and/or ethical guidelines relevant to the subject domain of the research. Your supervisor/module leader should be able to provide guidance. *Please see attached proposalSignature of applicantSignature of Module Leader, Programme Leader / Head of Department / Chair of Faculty Ethics CommitteeI declare that I have read the Ethics Policy and will follow the guidelines therein:I confirm that this project has been approved for the stated period:Signature:Date:Signature:Date:Note that a Certificate of Ethical Approval does not connote an expert assessment of the research or of the possible risks involved, nor does it detract in any way from the ultimate responsibility of researchers for all research undertaken by them, and for its effects on human subjects.Appendix 3: Consent FormForenameEmergency ContactForenameSurnameSurnameContact Number(s)Home:Mobile:Contact Number(s)Home:Work:Mobile:Address Postcode:City/TownRelationCountyGeneral StatementThe purpose of this form is to ensure that you, the client, are fully aware of any risks that may occur and to make you aware of the benefits/changes that may occur during your exercise programme. In order to measure any progressions it is necessary to undertake a few tests prior to exercise. These tests may include:Height/Weight measurementsBody composition measurementsLung/respiratory measurementsBlood pressure measurementsHeart rate measurements (resting and during exercise)These tests are not compulsory and only done completely by choice. Any data collected will be kept confidential and are only used as a guide for your trainer in order to best compensate for your exercise needs.During this exercise programme a wide variety of equipment is likely to be used in order to reach certain goals and to prevent any tedium or reversibility of any gains seen. Likely pieces of equipment are listed below:Cardio Machines – treadmill, rower, cross trainer, stepper, stationary bike, EFX, AMT.Weight Machines – leg press, leg extension, lat pull down, chest press, shoulder press, ab/adductor machine, cables, shoulder retraction, calf raise and smith machine.Free Weights – dumbbells, kettle bells, barbellsOther – resistance bands, medicine ball, fit ball, body weight exercises, TRX system, swimming pool, skipping rope, benches.Please read the following document carefully as it is for your best interests and if at any stage you are unsure of something please do not hesitate to ask.Risk AssessmentI am aware that in a gym or exercise environment there are going to be a variety of risks that may affect the health and safety of myself and others. I understand that all exercises undertaken during this exercise programme are at my own risk and that although my trainer will endeavour to ensure my health and safety it is also my responsibility to be act safely and in accordance with general safety rules and regulations. I understand that I may suffer from some injuries due to exercise and that if I perform the exercises incorrectly I am increasing my chances of injuring myself. I hereby state that I have been cleared by a medical professional to participate in regular physical activity.Equipment UseDuring the course of this exercise programme I understand that the use of various types of equipment may be used in order to achieve the goals that I have set out with my trainer. I am fully aware of the implications that may arise if this equipment is misused or mistreated. I understand that any mistreatment of equipment may result in serious injury and that by disobeying my trainer’s instructions I am putting both myself and others at risk. I acknowledge that and misuse of equipment is at the discretion of the trainer and that I will be asked to leave the area immediately. Any cost of damaged equipment will be paid by the culprit. If any equipment is already damaged/broken prior to use it is my responsibility to inform the trainer. If I see any misconduct of equipment I will inform my trainer immediately.Benefits of ExerciseI am fully aware that this programme of exercise is intended solely to aid in achieving my aims and objectives. I accept that these benefits may change my physical appearance. The potential benefits of this exercise programme have been identified to me by my trainer and I willingly undertake the exercise programme in the knowledge of these changes.SummaryI have read and fully acknowledge all that is expected of me during this exercise programme. I am fully aware of all the risks and benefits associated with exercise and physical activity. I have understood the document and have asked any questions that I may have had. By signing this legal document I understand that I am agreeing to everything stated and that I am willing to do what my trainer says in order to reach my goals.Client NameDateClient SignatureTrainer SignatureAppendix 4: Example of data recording sheetLocation: Marjon Sports Science LabDate: / / 2014Time: :Technicians: Jonathan Rowtcliff?????????????Subject Details???Name:D.O.B:Age:Male/Female???Par-Q: Passed/Referred???Consent Form Completed: Y/NAnthropometricsBMR:????SideMuscle Mass (Kg)Weight:Muscle Mass:?LegsLeft??Right?Height:Body Fat %:?ArmsLeft??Right?BMI:Fat Free Mass:?Torso????????????????Appendix 5: Male Pre Test ValuesSit and ReachAttempt 1 CMJAttempt 2 CMJAttempt 3 CMJAverage CMJStDev CMJDynamometer Power Output (Kg)?Flexibility (cm)ppoppo/massppoppo/massppoppo/massppoppo/massppoppo/massAttempt1Attemp2Attemp3MeanStDev242757.436.912924.739.142869.938.412850.538.1685.11.13144146173154.316.1323264.135.363156.434.192937.131.823119.233.79166.61.8017118819918614.172278.635.881694.526.682157.233.972043.432.18308.24.85110120116115.35.082216.733.532222.933.622551.138.592330.235.25191.32.89104100101101.62.022349.237.952836.545.822629.342.472605.042.08244.53.95151160180163.614.8263255.440.792983.937.39297137.233070.138.47160.62.01173137163157.618.5143113.843.822945.241.452856.140.192971.741.82130.81.84169172176172.33.5123176.537.502963.234.982864.833.823001.535.43159.31.88160176182172.611.3132916.640.172756.837.972654.736.562776.038.23132.01.81149152156152.33.512937.238.292832.136.92288137.562883.437.5952.50.681601651671643.692934.836.002735.533.562583.431.692751.233.75176.22.16125131133129.64.1162358.436.172349.136.022165.833.212291.135.13108.61.661571631661624.5122764.939.642459.835.262485.635.632570.136.84169.12.4212813514813710.123133.336.533221.437.563331.038.843228.537.6599.01.151821871801833.6363122.345.512668.038.892509.736.582766.740.33318.04.631391431351394152394.434.452298.733.072167.631.182286.932.90113.81.63145152158151.66.5Appendix 6: Female Pre Test Values?Sit andReach TestAttempt 1 CMJAttempt 2 CMJAttempt 3 CMJAverage CMJStDev CMJDynamometer Power Output (Kg)?Flexibility (cm)ppoppo/massppoppo/massppoppo/massppoppo/massppoppo/massAttempt1Attempt2Attempt3AverageStDev212781.244.712468.539.682454.239.452568.041.28184.822.97134161133142.6615.88242286.341.561175.021.361963.935.701808.432.88571.7010.39737274731241651.726.132137.033.811785.128.241857.929.39250.723.96978981898174127.438.683850.036.083821.635.813933.036.86168.941.58113124121119.335.68131985.630.831853.228.771822.328.291887.029.3086.741.34120132134128.667.5782453.238.392261.335.382142.533.522285.635.76156.772.4599101108102.664.72201923.733.05179330.801682.428.901799.730.92120.782.07142139135138.663.51292157.335.022033.433.001983.232.192057.933.4089.611.45123124129125.333.21342354.537.732138.434.262065.533.102186.135.03150.292.40135140141138.663.21171725.330.751662.729.631548.327.591645.429.3389.751.59828588853281875.531.951568.126.711427.724.321623.727.66229.033.9097102103100.663.21151959.134.071973.234.311858.332.311930.233.5662.661.08111110116112.333.21192125.434.172234.535.922045.932.892135.234.3294.681.521301261311292.64122231.634.702128.333.092103.132.702154.333.5068.091.051081091131102.64351448.226.911352.625.14126423.491354.925.1892.121.71939910197.664.16241786.3430.641649.228.281822.131.251752.630.0691.261.561101121171133.60Appendix 7: Male Post Test Values?Sit and Reach Attempt 1 CMJAttempt 2 CMJAttempt 3 CMJAverage CMJ?StDev CMJDynamometer Power Output (Kg)Flexibilityppoppo/massppoppo/massppoppo/massppoppo/massppoppo/massAttempt1Attempt2Attempt 3AverageStDev272963.239.303102.641.142814.437.322960.139.25144.101.97152178167165.6613.05363473.538.253266.135.972955.532.553231.735.59260.672.871801921981909.16112349.935.442513.337.902311.134.852391.436.07107.321.61115119121118.333.05111967.130.172425.337.192571.439.432321.235.60315.294.83110108116111.334.1642714.044.712531.841.712797.646.082681.144.17135.882.231601581561582293362.141.053567.243.552931.535.793286.940.13324.423.96181188179182.664.72152931.639.833374.545.852726.937.053011.040.91331.044.49176180171175.664.50153419.641.443142.238.082512.330.453024.736.66464.925.63165180185176.6610.40132777.138.673298.345.932812.739.172962.741.26291.144.05154156159156.332.5133297.242.593018.839.002667.534.462994.538.68315.524.071661711701692.64113442.140.883197.237.972744.532.593127.937.14353.934.20128138140135.336.42182583.438.502497.637.222166.332.282415.736.00220.233.281631781691707.54132861.340.242745.238.612533.135.622713.238.16166.442.34135142144140.334.7243573.440.423248.636.742935.933.213252.636.79318.793.601901871781856.24413361.846.433334.446.053105.442.893267.245.12140.791.94142148141143.663.78202840.238.642795.338.032504.134.072713.236.91182.452.48150160163157.666.80Appendix 8: Female Post Test Values?Sit and ReachAttempt 1 CMJAttempt 2 CMJ?Attempt 3 CMJ?Average CMJ?StDev CMJ?Dynamometer Power Output?(Kg)Flexibilityppoppo/massppoppo/massppoppo/massppoppo/massppoppo/massAttempt1Attempt2Attempt3AverageStDev262869.146.572674.543.412532.341.112692.043.70169.062.74156141143146.668.14262057.135.831886.332.861879.532.741940.933.81100.621.7580818481.662.08271770.227.101964.930.091818.527.841851.228.35101.361.521019810099.661.52204369.843.613923.639.154042.840.344112.141.03231.012.30120137128128.338.50162051.030.472063.930.661924.428.562013.129.9177.111.14125136142134.338.62122491.839.932374.238.042002.932.092289.636.69255.154.08102118106108.668.32252115.435.432062.034.541859.431.142012.333.70135.092.2715115713614810.81332218.036.662216.436.631938.732.042124.335.11160.792.651301281381325.29382511.838.702204.333.962126.132.752280.735.14203.893.14137149148144.666.65241982.933.551854.631.381699.128.751845.531.22142.132.401049589967.54342061.835.671801.631.171874.632.431912.633.09134.192.32103111105106.334.16192169.636.222248.937.541944.032.452120.835.40158.182.641161201181182251963.532.452493.641.212212.336.562223.136.74265.204.38148144139143.664.50162384.137.72233236.891924.930.452213.635.02251.423.97117123116118.663.78391619.429.121638.729.471569.128.221609.128.9435.950.64100103111104.665.68281789.028.712085.233.471887.630.291920.630.82150.852.421141171201173 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