Dissertations / Theses on the topic 'Soccer players'

The physical demands of soccer players competing in the English Premier League have significantly increased in recent years (Barnes et al. 2014; Bush et al. 2015). Elite soccer players are required to compete on a weekly and often bi-weekly basis during a 9-month competitive season. During periods of fixture congestion, players may participate in three matches within a 7-day period. Previous researchers have reported that some components of performance and physiological measures may still be below a pre-match baseline 72 hours following match-play (Mohr et al., 2003; Andersson et al., 2008; Ispirlidis et al., 2008; Fatouros et al., 2010). Nevertheless, data are sparse for the quantification of player fatigue status during competitive periods. Therefore, the primary aim of this thesis is to evaluate potential indicators of fatigue which may be easily measured and utilised in elite soccer. The aim of the first study (Chapter 4) was to quantify the test-retest reliability of a range of potential fatigue variables in elite soccer players. During the pre-season period, resting perceived ratings of wellness (fatigue, muscle soreness, sleep quality and stress), counter-movement jump height (CMJ), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRRbpm and HRR%), heart rate variability (rMSSD and LnrMSSD) and salivary immunoglobulin-A (S-IgA) were measured during the morning on two consecutive non-training days in thirty-five English Premiership players. Mean values of perceived ratings of wellness (7-13 %CV), CMJ (4 %CV) HRex (3 %CV) and HRR% (10 %CV) were not substantially or statistically significantly different between days. HRV measures’ rMSSD (28 %CV) and Ln rMSSD (10 %CV), perceived ratings of sleep (CV 13%CV) and S-IgA (63 %CV) were statistically significantly different between days. All morning-measured fatigue variables with the exception of S-IgA were reliable enough to allow feasible sample sizes in future pre/post studies. These data indicate that the use of perceived ratings of wellness, CMJ, HRR%, and, to a certain extent, HRV (Ln rMSSD) are reliable enough to monitor the fatigue status of a sample of elite soccer players. The aim of the second study (Chapter 5) was to quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17-days). Total high-intensity running (THIR) distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), CMJ, HRex, HRR% and heart rate variability (Ln rMSSD) were analysed during an in-season competitive period (17 days). Within-subject fluctuations in fatigue (r=-0.51; large; P<0.001), Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were significantly correlated with fluctuations in THIR distance over the study period. Correlations between variability in perceived muscle soreness and sleep quality and HRR% and THIR distance were negligible and not statistically significant. Perceived ratings of fatigue and heart rate variability were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these specific markers show particular promise as simple, non-invasive assessments of fatigue status in elite soccer players during a short in-season competitive phase. The aim of the third study (Chapter 6) was to determine whether the sensitivity of a range of potential fatigue measures studied in Chapter 5 would be improved compared with the training load accumulated over the previous two, three or four days during a short in-season competitive period (17-days). Fluctuations in fatigue (r=-0.28-0.51; “small” to “large”; p<0.05) were correlated with fluctuations in THIR distance accumulation (1-4-day). Changes in HRex (r=0.28; small; p= 0.02) was correlated with changes in 4-day THIR distance accumulation. Fluctuations in Ln rMSSD (r=-0.24; small; P=0.04), and CMJ (r=0.23; small; P=0.04) were only sensitive to changes in THIR distance for the previous day (Chapter 5). Correlations between variability in muscle soreness, sleep quality and HRR% and THIR distance were negligible and not statistically significant for all accumulation training loads. Perceived ratings of fatigue were sensitive to daily fluctuations in acute THIR distance accumulation although sensitivity attenuated over time. Therefore, the present findings indicate that the sensitivity of morning-measured fatigue measures to changes in training load is not improved when compared with training loads beyond the previous days training. The fourth and final aim of the thesis was to quantify the mean daily changes in training load and parallel changes in measures of fatigue across typical in-season training weeks in elite soccer players. The training load of 29 elite soccer players was measured using the ratings of perceived exertion approach. Perceived ratings of wellness (fatigue, sleep quality and muscle soreness), sub-maximal heart rate (HRex), post-exercise heart rate recovery (HRR) and variability (HRV) were also recorded across training weeks in the in-season competitive period. Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness tracked the changes in RPE-TL, being 35-40% worse on post-match day vs pre-match day (P<0.001). Perceived fatigue, sleep quality and muscle soreness improved by 17-26% from post-match day to three days post-match with further smaller (7-14%) improvements occurring between four days post-match and pre-match day (P<0.01). There were no substantial or statistically significant changes in HRex, HRR% and HRV over the weekly cycle (P>0.05). Morning-measured perceived ratings of fatigue, sleep quality and muscle soreness are clearly more sensitive than HR-derived indices to the daily fluctuations in session load experienced by elite soccer players within a standard in-season week. The results of this thesis have shown that simple, ratings of perceived wellness are reliable and sensitive to short training and competition phases and thus may be a suitable strategy for practitioners to use in the attempt to establish fatigue status in elite soccer players. In particular, this thesis has demonstrated that the greatest sensitivity was observed on a daily basis and during typical training weeks and not during short term load accumulation. . Future work is required to quantify whether perceived ratings of wellness and vagal-related heart rate responses are sensitive to changes in training and match load across an entire competitive season in elite soccer players.

Thesis (MSc (Physiotherapy))--University of Limpopo (Medunsa Campus), 2009
Aim: The aim of the study was to review the current management of soccer injuries sustained by professional players and how injury recurrence is prevented among Premier Soccer League (PSL) players in RSA. Study design: Cross sectional study, descriptive survey was followed, as it allowed the researcher to observe and describe the factors that had contributed towards recurrent injuries, as well as a qualitative approach with open ended questions where participant’s expressions encountered during the study, were analyzed. Population: The population of the study included all the medical team members in the PSL teams. PSL has 16 teams. The medical team comprised of any combination of the following members: the team doctor, physiotherapist, masseur, biokineticists, physical trainer, chiropractors and podiatrist. Not all teams have the same combination nor all disciplines mentioned. Sample: Purposive sampling method was used, as the researcher selected main participants with a specific purpose. Each of the PSL teams has 7 members from different disciplines therefore, all available members of the medical team of each PSL teams participated in the study. Data Analysis: Data was analyzed using SPPSS version 13.0.Data collected was loaded onto the statistica program for processing. Frequency tables for all variables are given to demonstrate the distribution of variables. Cross tabulation was also done to establish the relationship between the predictor variables and the response. The Test Statistic CHI-Squared (χ 2 ) was calculated and pvalue of less than 0.05 was determined for the significance. Frequency distribution tables, graphs, and charts were used to analyze the data collected. Content analysis was used for qualitative data. Results: Main findings of the study reflected that the ankle was the most commonly affected body part (69.2%) while the quadriceps and tendon achillies were both less commonly affected v (15.4%). The groin was found to incur most recurring injuries (69.2%). The results revealed that injured players are adequately managed by the medical team (61.5%). Attainment of pain free and full range of movement is the consideration for return to sport however less consideration was given to the persistent biomechanical abnormality. Conclusion: The study confirms that soccer injuries amongst Premier Soccer League (PSL) teams are managed by qualified professionals. The attainment of a free, full range of movement and adequate strength are used as criteria for return to sport and as a measure of preventing injury recurrence. Factors such as players missing out on rich rewards, recognition and regaining position in the team seem to have a great influence as well. Recommendation: The primary recommendation for the player who has had multiple recurrences is to address any underlying reversible risk factors such as poor strength and poor flexibility. A session needs to be held with soccer administrators to advocate the avoidance of factors contributing to recurrent injuries.

Between 65 – 91 % of elite soccer players have at least one injury / year (Hägglund, 2007). Several researches have established models that specify psychological factors that could predict sport injuries. Two examples are Rogers and Landers (2005) stress – coping model and Williams and Andersen´s (1998) stress – injury model. The main purpose of the study was to single out significant psychological factors that could lead to an increased injury risk among soccer players. The participants were 152 male and female soccer players (m = 17, 6) studying at soccer high schools in southwest Sweden. Five questionnaires were used STAI, SAS, LESCA, ACSI – 28 and SSP. Continuously injury record was collected by athletic trainers at the school, during a period of six months. The result suggested that there are four significant predictors that in all could explain 23 % of the injuries. The main factors are life event stress, somatic trait anxiety, mistrust and negative coping. These findings are in unison with for example Williams and Andersen´s (1998) stress – injury model and should be considered by coaches when it comes to preventing sport injuries among their athletes.

The English Football Association (FA) reported female soccer was the nation’s number one team sport for female sport participation (1.38 m). There is no research on physical- and match- performance of female soccer players in England at the elite level and no investigations in to the new re-structure that the English FA made in 2011 for both senior and youth levels. Therefore, the overarching aim of this research thesis was to develop physical performance and match performance profiles of female soccer players in England across senior and youth players at both elite and non-elite levels of play.

The American Dream is founded upon the ideological belief that ‘you can be anything you want to be, regardless of your current class position.’ This belief is contained within the dominant prevailing notion that the U.S. is a meritocracy where power and success are associated with determination and failure with laziness. This thesis challenges whether the American Dream is a relevant, attainable and viable concept for higher education students via the avenue of a soccer scholarship. In so doing, the research presented challenges the perceived wisdom of ‘American exceptionalism’ from a critical theoretical perspective. The research question at the heart of this study is ‘what are the motives of American university students for undertaking a soccer scholarship?’ The adoption of an interpretive paradigm for this study aims to provide an explanation of student decision-making. In the final analysis, this approach reveals what soccer means to the lives of the student-athletes. The central themes of the study were established via a pilot study and categorised as: family, social class, social mobility and career development. Questionnaires were completed by 154 students from two separate Division One universities. Twelve students were then purposively sampled and interviewed using a semi-structured format. To supplement these opinions, interviews were then conducted with a selection of coaches and athletic directors at the respective institutions. Analysis of the responses was contextualised using the framework provided by Csikszentmihayli and Schneider’s (2000) ‘Support/Challenge Questionnaire’. The findings support a common hypothesis that the family is a significant agent in socialising of their children to the cultural values of the American Dream. The findings additionally reveal support for the notion that families are important influences on their child’s sport mobility orientations in the soccer context. An alternative explanation proposed here is that the transmission process is actually a two-way dialogue in which children socialised their parents and vice versa. The family in this study represent a potentially problematic social process for the inculcation of values related to the maintenance of social life. The conclusions presented clearly reveal that the majority of students embarking on a soccer scholarship are motivated by the need to firstly finance their higher education and secondly to take part in a sport they have played since childhood. Students were aware of the uncertainty of the marketplace and the limitations of their own technical ability. As such their participation in the scholarship could be considered to be a pragmatic adaptation of a ‘labour of love.’

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.
Page 52 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 45-47).
Challenges such as player occlusion, fast player motion, small size of players relative to the background make it difficult to track soccer players accurately and consistently throughout a game. To solve these challenges, in this work we present a multi-view approach to tracking soccer players. Here, we formulate tracking as the problem of assigning a label to each pixel in every frame of each camera view, where the label is either the background or one of the players. As a preprocessing step, we utilize the information from the soccer field for camera trajectory estimation and background modeling. Tracking is first carried out independently for each camera view with a layered tracker. Then we integrate the results of layered trackers from multiple views through MCMC inference over tracklet-to- player association. We show that through camera calibration, common background and shared states of the players, inference across multiple camera views significantly alleviates the problem of player occlusion and loss of tracks in some view. As a result, we are able to produce accurate and long tracks for players, enabling further analysis of the game.
by Yixin Li.
M. Eng.

Academy soccer players partake in high volumes of training and match-play, but limited information exists regarding the optimal dietary practices to fuel such demands. Accordingly, the aims of the thesis were threefold: (1) to identify an accurate method of energy intake assessment which quantifies any self-reporting bias bespoke to Academy soccer players, (2) to provide a quantification of the energy intake and energy expenditure of Academy soccer players over a ‘typical’ training week, specifically highlighting any fluctuations in energy balance, (3) to investigate potential strategies to optimise dietary practices of Academy soccer players to reduce any identified energy deficits, whilst also examining the impact on soccer performance variables. Chapter 3 aimed to explore the agreement between researcher observed energy intake and self-reported energy intake in male Academy soccer players using a combined selfreported, weighed food diary and 24 h recall method. Considering the widely reported bias associated with using isolated self-report measures, the accuracy of a combined method was examined. Findings suggested that the combined dietary data collection method is an acceptable alternative to researcher observed approach when assessing energy intake in Academy soccer players, providing that appropriate adjustment was applied for the minor systematic under-reporting. Chapter 4 investigated the energy intake and expenditure of Academy soccer players during a competitive week. The combined method was used to measure energy intake in conjunction with accelerometry to quantify energy expenditure. Findings highlighted that the mean daily energy intake of Academy soccer players was lower than the energy expended during a competitive week, producing significant daily energy deficits. The magnitudes of these deficits were greatest on match and heavy training days. Furthermore, pre-match dietary practices were identified as a concern, reporting inadequate levels of energy intake to fuel match-play. Chapter 5 investigated the physiological and performance effects of increasing prematch energy intake prior to simulated soccer match-play, with the aim of reducing the previously identified significant negative energy balance. Findings demonstrated that Academy soccer players are able to increase pre-match energy intake without experiencing abdominal discomfort, addressing the previously identified energy deficit on such days. Furthermore, whilst increasing habitual energy intake produced limited benefits to physical performance, increased dribbling speed was identified, which may have practical application to match-play. In summary, this research has provided further information concerning the dietary practices of Academy soccer players, a population which has received limited focus, despite substantial implications considering the high demands of training and matchplay in combination with maintaining growth and maturation. Overall findings demonstrate that energy intake remains relatively stable throughout the week, failing to account for the periodised approach to training load. Players are subsequently experiencing significant daily energy deficits in particular during heavy training and match-days. Furthermore, whilst strategies to increase pre-exercise energy intake may help reduce such deficits, limited effects on physiological and soccer-specific performance were identified.

Background: The International Football Federation (FIFA), through their Goal project, renovated Rufaro stadium from natural turf (NT) to artificial turf (AT). This was met with mixed feelings especially with regard to injuries sustained by football players. There is no published scientific data on football injuries in Zimbabwe. Aim: To determine the frequency of injuries on AT and NT among Premier Soccer League (PSL) players in Zimbabwe. Objectives: To determine the attitudes of players regarding the different football playing surfaces, and the incidence, severity and injury types on AT and NT. Methods: The 2013 season's16 PSL teams were selected to complete questionnaires and injury report forms. Injuries recorded during matches on AT and NT were analyzed. Outcome measures were injury incidence (injuries/1000 player hours (Phrs) of exposure)compared for AT and NT using rate ratios (95% confidence intervals). All statistical significance were set at p<0.05. Results: A total of 325 players responded and 295(90.8%) preferred playing on NT. Of these, 250(76.9%) believed that AT was associated with more injuries. A total of 364 injuries occurred during 4455phrs of exposure giving an injury incidence of 81.7 injuries/1000phrs.A total of 69 games (1138.5phrs) on AT revealed an injury incidence of 85.2 injuries/1000phrs while 201 games (3316.5 phrs) on NT revealed an overall incidence of 80.51 injuries/1000-hrs.This analysis showed no statistically significant difference in the incidence of injury between AT and NT surfaces during matches played, [RR= 1.06; 95% CI: 0.84 – 1.34]. With regard to injury severity, the highest incidence occurred on the AT (31.62/1000phrs in the mild category) and the lowest incidence was on the NT (1.81/1000 phrs in the severe category) .The rate ratios for the severity were however not statistically significant. Comparison of the injuries according to body part injured largely revealed insignificant rate ratios. Conclusion: Football players believe that the AT is associated with increased risk of injury. There was no significant difference in injury incidence rates and severity between the AT and NT during the 2013 PSL season in Zimbabwe. The incidence of injury in this study was much higher than comparable European studies and is a need for further studies to explore the underlying reasons for this.

Background: Football (Soccer) is arguably the most popular sport in the international sporting arena. A survey conducted by FIFA (Fédération International de Football Association) (FCPA, 2000) indicated that there are 240 million people who regularly play soccer around the world. Internationally, there are 300 000 clubs with approximately 1.5 million teams. In South Africa, there were 1.8 million registered soccer players in 2002/2003 (Alegi, 2004). Although youth players are predominantly amateurs and have no financial value for their clubs or schools, their continued health and safety are still of vital importance. There are some clubs which contract development players at 19 years of age in preparation for playing in their senior sides and these young players should be well looked after, to ensure a long career playing soccer. Being able to predict injuries and prevent them would be of great value to the soccer playing community. Aims: The main aim of this research was to create a statistical predictive equation combining biomechanics, balance and proprioception, plyometric strength ratios of ND/Bil (Non dominant leg plyometrics/ Bilateral plyometrics), D/Bil (Dominant leg plyometrics/ Bilateral plyometrics) and ND+D/Bil (Non dominant leg + dominant leg plyometrics/ Bilateral plyometrics) and previous injuries to determine a youth soccer player's risk of the occurrence of lower extremity injuries. In the process of reaching this aim it was necessary to record an epidemiological profile of youth soccer injuries over a two season period. It was also necessary to record a physical profile of, and draw comparisons between, school and club youth soccer players. Following the creation of the prediction model a preventative training programme was created for youth soccer players, addressing physical shortcomings identified with the model. Design: A prospective cohort study Subjects: Schoolboy players from two schools in the North West Province, as well as club players from three age groups were used for this study. Players from the U/16 and U/18 teams in the two schools were tested prior to the 2007 season. Players from the U/17, U/18 and U/19 club development teams were tested prior to the 2008 season. The combined total number of players in the teams amounted to 110 players. Method: The test battery consisted of a biomechanical evaluation, proprioceptive and plyometric testing and an injury history questionnaire. The Biomechanical evaluation was done according to the protocol compiled by Hattingh (2003). This evaluation was divided into five regions with a dysfunction score being given for each region. A single limb stance test was used to test proprioception. A Sergeant jump test was utilised using the wall mark method to test plyometric jumping height. A previous injury questionnaire was also completed on all players prior to testing. Test subjects from the schools were tested with the test battery prior to commencement of the 2007 season. The testing on the club teams was undertaken prior to the 2008 season. Injuries were recorded on the prescribed injury recording form by qualified Physiotherapists at weekly sports injury clinics at each of the involved schools and clubs. The coaching staff monitored exposure to training activities and match play on the prescribed recording forms. These training and match exposure hours were used, along with the recorded injuries for creating an epidemiological profile. Injuries were expressed as the amount of injuries per 1000 play hours. Logistical regression was done by using the test battery variables as independent variables and the variable injured/not injured as dependent variable (Statsoft, 2003). This analysis created prediction functions, determining which variables predict group membership of injured and non injured players. Results: There were 110 youth players involved in the research study from seven teams and four different age groups. There were two groups of U/16 players, an U/17 group, three U/18 groups and an U/19 group. The players were involved in a total of 7974 hours of exposure to training and match play during the seasons they were monitored. The average age of the players was 16.6 years. The majority of players were right limb dominant (83.6%) and 65.7% of players failed a single limb stance test. The mean jump height for both legs combined was 33.77cm, with mean heights of 22.60cm for dominant leg jump and 22.66cm for the non dominant leg. In the biomechanical evaluation of the lower leg and foot area, the average youth player presented with adaptation of toes, normal or flat medial foot arches, a normal or pronated rear foot in standing and lying and a normal or hypomobile mid-foot joint. Between 42.7% and 51.8% of players also presenting with decreased Achilles tendon suppleness and callusing of the transverse foot arch. The youth profile for the knee area indicated that the players presented with excessive tightness of the quadriceps muscles, normal patella tilt and squint, normal knee height, a normal Q-angle, a normal VMO: VL ratio and no previous injuries. This profile indicated very little dysfunction amongst youth players for the knee area. For the hip area, the youth profile was described as follows: There was shortening of hip external rotators, decreased Gluteal muscles length, normal hip internal rotation and no previous history of injury. Between 38.2% and 62.7% of players also exhibit shortened muscle length of the adductor and Iliopsoas muscles and decreased length of the ITB (Iliotibial Band). In the Lumbo-pelvic area there was an excessive anterior tilt of the pelvis with normal lumbar extension, side flexion, rotation and lumbar saggital view without presence of scoliosis. Between 58.18% and 65.45% of players presented with an abnormal coronal view and decreased lumbar flexion. Between 41.81% and 44.54% of players also presented with leg length, ASIS, PSIS, Cleft, Rami and sacral rhythm asymmetry. The similarity of the results for these tests in all players contributed to a new variable called 'SIJ dysfunction'. This was compiled from the average of the scores for Leg length, ASIS, PSIS, Cleft, Rami and Sacral rhythm, which was also considered for inclusion in the prediction model. The neurodynamic results of youth players indicated that approximately between 44.54% and 50.91% of players presented with decreased Straight leg raise and prone knee bend tests. The total combined dysfunction scores for the left and right sides were 17.091 and 17.909 respectively, indicating that there were higher levels of dysfunction on the right side than the left. This increased unilateral dysfunction could probably be attributed to limb dominance and increased use of the one leg for kicking and passing during the game. In the epidemiological study on youth players, there were a total of 49 training injuries and 52 match injuries. The total injury rate for youth players was 12.27 injuries/1000 hours, with a total match injury rate of 37.12 injuries/1000 match hours. The combined training injury rate was 7.17 injuries/1000 training hours. 87.13% of injuries were of the lower limb area and the individual areas with the highest percentage of injuries were the Ankle (25.74%), Knee (19.80%), Thigh (15.84%) and Lower leg (14.85%).The totals for youth players indicated that sprains (30.69% of total), strains (27.72% of total) and contusions (27.72% of total) were the most common causative mechanism of injuries. The severity of injuries show 'zero day' (no time off play) injuries to be the most common type (35.64%), followed by 'slight' (1 to 3 days off play) (33.66%) and 'minor' (4 to 7 days off play) (14.85%). School players had higher injury rates than club players but the severity of injuries to club players was higher, with longer absences from play. Non-contact injuries accounted for 52.47% of the total with 46.53% being contact injuries. School players had lower levels of non-contact injuries than club players, which correlated well with lower dysfunction scores recorded for school players during the biomechanical evaluations. This demonstrated that there was a definite relationship between levels of biomechanical dysfunction and the percentage of non-contact injuries in youth players, which formed the premise of the creation of a prediction model for non-contact youth soccer injuries. The next step in the creation of a prediction model was to identify the variables that discriminated maximally between injured and non-injured players. This was done using stepwise logistic regression analysis. After the analysis, ten variables with the largest odds ratios were selected for inclusion in the prediction model to predict non-contact injuries in youth soccer players. The prediction model created from the stepwise analysis presented as follows: P (injury)= exp(-8.2483 -1.2993a + 1.8418b + 0.2485c + 4.2850d + 1.3845e + 1.3004f-1.1566g + 1.8273h-0.9460i-0.5193j) l + exp(-8.2483-1.2993a + 1.8418b+ 0.2485c + 4.2850d + 1.3845e + 1.3004f-1.1566g + 1.8273h-0.94601-0.5193J) a = Toe dysfunction b = Previous ankle injury c = Ankle dysfunction d = SIJ dysfunction e = Lumbar Extension f = Straight Leg Raise g = Psoas length h = Patella squint i = Gluteal muscle length j = Lumbar dysfunction P = probability of non contact injury exp(x) = e x , with e the constant 2.7183 In the ankle area, the toe positional test, previous ankle injury history and combined ankle dysfunction score were included in the prediction model. In the knee area, the patella squint test was included in the model. In the hip area, the Psoas component of the Thomas test was included, along with the Gluteal muscle length test. In the Lumbo-pelvic area, the SIJ dysfunction (average of Leg length, ASIS, PSIS, Rami, Cleft and Sacral rhythm tests), lumbar extension test and lumbar dysfunction scores were included in the prediction model. In the neurodynamic area, the Straight leg raise test was included in the prediction model. The prediction model therefore contained tests from all five the bio mechanical areas of the body. Overall, this model correctly predicted 86.91% of players as either injured or not-injured. The I value (effect size index for improvement over chance) of the prediction model (1=0.67), along with the sensitivity (65.52%), specificity (94.87%), overall correct percentage of prediction (86.91%) and Hosmer and Lemeshow interferential goodness-to-fit value (X 2(8) = 0.7204), all demonstrated this prediction model to be a valid and accurate prediction tool for non-contact youth soccer injuries A second prediction model, for the prediction of hip and groin injuries amongst youth players, was also created. The prediction model created from the stepwise analysis for groin injuries presents as follows: P (Groin injury)^ exp(-116.2 + 33.5383d + 14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) l + exp(-116.2 + 33.5383d+14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) d = SIJ dysfunction k = Previous knee injury m = Previous hip injury e = Lumbar extension f = Straight leg raise n = Limb dominance p = ND/Bil plyometric ratio P = probability of groin injury exp(x) = ex, with e the constant 2.7183 The prediction model for hip and groin injuries included the variables of SIJ dysfunction, previous knee injury, previous hip injury, lumbar extension, straight leg raise, limb dominance and the ratio of non-dominant leg to bilateral legs plyometric height. When all the validifying tests were examined, the I-value (0.64868), sensitivity (66.67%), specificity (98.01%), false negatives (1.98%), false positives (33.33%), Hosmer and Lemeshow goodness-to-fit value (X2(8) = 0.77) and the overall percentage of correct prediction (96.26%) all reflected that this model was an accurate prediction tool for hip and groin injuries amongst youth soccer players. Conclusion: This study showed that it was possible to create a prediction model for non-contact youth soccer injuries based on a pre-season biomechanical, plyometric and proprioceptive evaluation along with a previous injury history questionnaire. This model appears as follows: P (injury)= exp(-8.2483 -1.2993a + 1.8418b + 0.2485c + 4.2850d + 1.3845e + 1.3004f - 1.1566g + 1.8273h - 0.9460i - 0.5193J) l + exp(-8.2483-1.2993a+ 1.8418b + 0.2485c + 4.2850d + 1.3845e + 1.3004f-1.1566g+1.8273h-0.94601-0.5193J) a = Toe dysfunction b=Previous ankle injury c = Ankle dysfunction d= SIJ dysfunction e=Lumbar Extension f = Straight Leg Raise g = Psoas length h = Patella squint i = Gluteal muscle length j = Lumbar dysfunction P = probability of non contact injury exp(x) = ex, with e the constant 2.7183 It was also possible to create a prediction model for non contact hip and groin injuries, which appears as follows: P (Groin injury)= exp(-116.2 + 33.5383d + 14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) l + exp(-116.2 + 33.5383d + 14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) d = SIJ dysfunction k = Previous knee injury m = Previous hip injury e = Lumbar extension f = Straight leg raise n = Limb dominance p = ND/Bil plyo metric ratio P = probability of groin injury exp(x) = ex, with e the constant 2.7183 It was also possible to create a prediction model for non contact hip and groin injuries, which appears as follows: P (Groin injury)= exp(-116.2 + 33.5383d + 14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) l + exp(-116.2 + 33.5383d + 14.5108k + 4.1972m + 1.9330e + 10.7006f-14.4028n + 48.8751p) d = SIJ dysfunction k = Previous knee injury m = Previous hip injury e = Lumbar extension f = Straight leg raise n = Limb dominance p = ND/Bil plyo metric ratio P = probability of groin injury exp(x) = ex, with e the constant 2.7183 Using the hip and groin prediction model, combined with the injury prediction model, injuries in youth soccer players can be predicted. The data for each player should first be substituted into the injury prediction model, to determine the chance of getting injured during the season. The data should then be substituted into the hip and groin injury prediction model, determining the chance of hip and groin injuries during the season. The results from the groin injury prediction model could then be used to exclude groin injuries amongst players. A negative result for the hip and groin injury, which showed a false negative percentage of 1.98%, could be used to determine that an injury that was predicted using the overall injury prediction model, would not be a hip and groin injury. A positive result in the groin injury test could, however, not exclude injuries to other body areas that were predicted by the overall injury prediction model, so the groin injury prediction model could only be used to exclude hip and groin injuries.
Thesis (Ph.D. (Education)--North-West University, Potchefstroom Campus, 2009.

The main purpose of this study was to investigate the relationship among preferred and perceived leadership, their congruence and satisfaction with leadership. The second purpose was to investigate the differences among the offensive, the defensive and the mid-field players of soccer teams in preferred leadership, perceived leadership and satisfaction with leadership. The five leader behaviors which were measured were: training and instruction, social support, positive feedback, democratic behavior, and autocratic behavior. The four aspects of leadership satisfaction, which were measured, were: individual performance satisfaction, team performance satisfaction, training and instruction satisfaction, and personal treatment satisfaction. The subjects of the study were 138 male university soccer players 7 of 9 universities in Ankara Region of Turkey. The athletes consisted of 38 offensive players, 49 defensive players, and 51 mid-field players. Data was collected through Leadership Scale for Sport (LSS) preference version and perception version, and Athlete Satisfaction Questionnaire (ASQ). The study employed hierarchical regression procedures to test the congruence hypothesis derived from the multidimensional model of leadership. Results indicated athlete satisfaction was not dependent on the congruence between preferred and perceived leadership behavior. Additionally, results showed that there were no differences among the offensive, defensive, and mid-field players in preferred leadership, perceived leadership, and satisfaction with leadership. Further research is needed with the multidimensional theory of leadership in varying sport groups and with greater number of participants to identify other situational and behavioral factors associated with athletic performance.

This thesis examined the physical development and match performance of elite youth academy soccer players some of whom were likely to progress to become professional soccer players. Physical characteristics such as standing height, body mass and estimated body fat composition, physical performance and match performance were explored. Furthermore, the relationships between physical performance and match running performance were examined in players from the U9 to U18 age group squads. Finally, the influence of biological maturity on physical characteristics, physical performance and match running performance in these elite youth soccer players was investigated and recommendations are made concerning talent identification and player development. One hundred and eighty-three elite soccer players (chronological age: 8.9 to 18.7 years; age grouping U9-U18) from an English Premier League Academy in the East Midlands were assessed for standing height, body mass, skinfolds, 30 m sprint, slalom and 505 agility, squat jump, counter movement jump with and without arms, Yo-Yo intermittent recovery test (level 1) and Multi-stage fitness test. All physical and performance variables measured in the study developed over time with chronological age except for the sum of 4 skinfold sites and estimated body fat composition (squad mean ± SD, U9 vs. U17: standing height, 139.4 ± 4.8 cm vs. 181.3 ± 5.6 cm; body mass, 33.6 ± 3.9 kg vs. 72.6 ± 5.7 kg; 30 m sprint, 5.26 ± 0.25 vs. 4.15 ± 0.11 s; slalom agility test, 4.83 ± 0.25 vs. 3.96 ± 0.09 s; counter movement jump with arms, 30 ± 3 cm vs. 48 ± 6 cm; the Yo-Yo intermittent recovery test (level 1), 787 ± 333 vs. 2617 ± 573 m). Standing height, body mass, 10, 15, and 30 m sprint times, performance on both agility tests, performance of squat jump and counter movement jump with arms; performance on the Yo-Yo intermittent recovery test (level 1) and on Multi-stage fitness test continued developing until the players reached the U17 squad. Moreover, the highest rate of development in standing height, body mass and all physical fitness tests occurred between the U9-U13 squads. Distance run during match play by 9 to 16 year old boys varied from 4056 (U9) to 7697 (U16) m per match (p < 0.05), and varied from 4675 to 6727 m·hour-1 of a match (p < 0.05). The U11-U16 squads covered a greater distance by high speed running (range: 487-553 mhour-1) compared to the U9 (178 m·hour-1) and U10 (219 m·hour-1) squads (p < 0.05 for all). Similarly, the percentage of time spent in high speed running by the U9 (1.1 %) and U10 (1.3 %) squads was less than that seen in the U11-U16 (2.6-3.0 %) squads (p < 0.05 for all). Chronological age accounted for 43% (p < 0.01), and the Multi-stage fitness test performance explained 7% (p < 0.05) of the variance in total distance covered per hour of a match in the U11-U16 group. Chronological age (p < 0.01) and the Multi-stage fitness test performance (p < 0.05) accounted for 10% and 11% respectively of the variance in percentage of time spent in moderate speed running. Chronological age accounted for 11 % of the variance in the percentage of time spent in high speed running (p < 0.01), whereas 30 m sprint and the Multi-stage fitness test performances explained 15% and 8% respectively of the variance in percentage of time spent in high speed running (p < 0.05 for both). The U9 and U10 squads showed a positive relationship between 20 m sprint time and distance covered in moderate speed running per hour of a match (r = 0.54, p < 0.05). In the U11-U13 squads relationships were evident between performance in 5, 10, 15, 20 and 30 m sprint (r = -0.67 to -0.46), the 3 standing vertical jumps (r = 0.46 to 0.73) and the 2 endurance tests (r = 0.45 to 0.60), and distance covered by moderate and high speed running per hour of a match (p < 0.05 for all). However, in the U14-U16 squads no significant relationships were evident. When stage of genital development was used to categorise players, standing height and body mass in the U12, U13 and U14 squads were positively influenced by biological maturity (p < 0.05 for all). The more mature players in the U13 squad also performed better in counter movement jump without arms and the Multi-stage fitness test (p < 0.05 for both). When stage of pubic hair development was used to categorise players, maturity status showed a positive influence on standing height and slalom agility test performance in the U12 squad (p < 0.05 for both) and on standing height and body mass in the U14 squad (p < 0.05 for both). When estimated chronological age at peak height velocity was used to categorise players, earlier maturing players were heavier (p < 0.01) and performed worse in counter movement jump without arms (p < 0.05) than later maturers in the U9 and U10 squads. Earlier maturers were taller (p < 0.01), heavier (p < 0.01) and possessed a thicker sum of 4 skinfold sites (p < 0.05) and higher estimated body fat (p < 0.01) compared to the later maturers in the U11 and U12 squads. Moreover, early maturers covered a greater distance than late maturers in the multi-stage fitness test (p < 0.05) in the U13 and U14 squads. In the U15 and U16 squads, early maturers were heavier and possessed thicker sum of 4 skinfold sites and higher estimated body fat compared to the late maturers (p < 0.01 for all). Furthermore, early maturers possessed a thicker sum of 4 skinfold sites (p < 0.05), higher estimated body fat (p < 0.01) and covered a shorter distance during the Yo-Yo intermittent recovery test (p < 0.01) compared to later maturers in the U17 and U18 squads. When stage of genital development was used to categorise players, the U12 and U13 players in stage 4 covered a greater distance in high speed running during a match than players in stage 3 (p < 0.05). There was a tendency for this still to be the case when distance was standardised into per hour of a match (p = 0.065). In the U9 and U10 squads, compared to later maturers, earlier maturers were given greater playing time during a match (p < 0.05), and consequently covered a greater distance during match play (p < 0.05). In the U13 and U14 squads, earlier maturers covered more distance per hour of a match and spent a higher percentage of time in high speed running when compared to their later maturing counterparts (p < 0.05 for both). In summary this research has provided the most extensive description yet of the physical characteristics, field test performance and match performance of elite youth soccer players. In addition, for the first time the effect of biological maturity (using 3 different methods of assessment) on a wide range of field tests and on match performance has been reported. The major changes in physical characteristics, field test performance and match performance between 10 and 14 years of age suggest that coaches should avoid as many selection decisions as possible during this age period, that they should take into account the fact that match distances covered at high speeds will be affected by maturity at these ages and that they should be aware that at present, coaches choose to give more mature players additional pitch time which obviously gives them an advantage in terms of playing development. An enhanced awareness of these findings in the coaching community could lead to an improved development and more appropriate selection decisions for elite youth soccer players in England.

Snacking behavior has changed dramatically over the past few decades, with snacking frequency reaching upwards of three times per day and comprising 27% of daily calorie intake. Research has shown that the largest food groupings from snacks are grain-based desserts, sweetened beverages, and salty snacks. Previous studies have also shown that children are influenced by their peers. Youth sports are a very popular venue for children and opportunity for physical activity, with soccer becoming one of the most popular sports among young children in the US. Youth sports, especially soccer, can be a powerful tool for promoting physical activity and healthy eating for overall health and obesity prevention. The goal of this study was to examine the nutrition composition of snacks and beverages offered to young children within a soccer league. The study utilized a cross-sectional observational study of snack foods and beverages offered to children participating in a voluntary youth soccer league in southwest Virginia. Snacks offered to children in the under-five (U5) and under-six (U6) years of age categories were observed during weekly matches using an observational checklist reflecting commonly consumed snack foods and beverages. The checklist included brand name, size of food item/beverage, and number of children (by gender) for each team observed. Undergraduate and graduate nutrition students were trained as observers to assess snacks that were offered, specifically visual item identification and portion size estimation. Food items were then classified into different food and beverage categories, including: sugar-sweetened beverages (SSBs) and 100% fruit juices; water; dairy (beverage); fruits; savory (salty) snacks; grain-based desserts; candy and dairy (food). Nutrition information was gathered for each food item and beverage and entered into a database: calories, carbohydrates, protein, fat, saturated fat, sodium, sugar, fiber, vitamin C, iron and calcium. Descriptive statistics were then computed for all nutrients by all snacks combined and by snack category across all observations. Snacks were also compared to the Smart Snacks in Schools nutrition standards. Across all teams there were a total of 687 items offered to the children: 253 beverages and 434 foods. They offered a mean of 205 calories per child. The most popular beverages were SSBs. The most popular snacks were grain-based desserts (136, 31.3% of all snack foods), followed by fruit (124, 28.5%) and savory snacks (117, 26.9%). No vegetables were served during the observations. Snacks within the savory snack item category provided the most calories per child at 63, followed by grain-based desserts, 58. When offered and served with beverages, snacks offered with fruit had a more favorable nutrition profile with lower mean kilocalories, lower sodium, and lower sugars than snacks without fruit. They were also more likely to meet the Smart Snacks in School nutrition standards: 65.4% compared to 25.6%. Only 44.4% of all snack foods and beverages taken by youth players met the smart snacks standards. Categorically, 67.6% of all grain-based deserts, 100% of all candy and 100% of all dairy beverages taken by youth players did not meet the smart snacks standards. Further research is warranted to identify motivating factors for providing unhealthy snacks and beverages to youth during sporting events. There are several limitations, including generalizability of this sample, however the study provides novel insight into snacks offered to young children during recreational soccer and can help inform future strategies and interventions to promote healthier snacks.
Master of Science

AIM: The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. METHODS: The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test’s ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). RESULTS: Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). CONCLUSION: The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.

Thesis (MSc (Physiotherapy))--University of Limpopo (Medunsa Campus), 2010.
The knee Injuries in Women Soccer Players in South Africa The Knee is a common site for injuries in soccer players. The reasons for the increased rates of knee injuries in women soccer players are not clear, but some theories suggested the reason to lie in the difference in anatomy. This research investigate the prevalence of knee injuries in women soccer players in South Africa and sought to find out whether three of the anatomical factors (Q-angle, pelvic width and Intercondylar notch width) have a role in increasing knee injuries in these individuals. The study design was case –control study. Methodology: Twenty four players of South Africa women soccer team (Under 23) participated in this study. X-rays of the hip were taken and the Q-angles were thereafter measured manually. Association between anatomical factors and knee injuries were determined. The result of this study showed that 17% of the players were having non contact knee injuries. Statistical analysis showed no significant relation between knee injuries among women soccer players and each of the anatomical factors. The P-values of both t-test and ANOVA test were larger than the 0.05 level of significance. The study found that the prevalence of knee injuries among the young women playing for the South African national team U-23 was relatively high. However, this study could not identify significant relationship between the anatomical risk factors and the incidences of knee injuries among the participants.

The majority of the literature on physiological testing and time-motion analysis (TMA) of soccer performance has been conducted on elite senior soccer players. Few TMA studies have focused on young soccer players and currently, there is nothing focusing on global positioning system (GPS) derived data in this cohort. This study aimed to assess in a group of youth soccer players, the reliability of the selected physiological variables, establish a physiological profile of essential performance characteristics, quantify match-related performance such as time motion characteristics, positional roles and physical demands, and examine the relationship between criterion measures acquired from physiological testing and GPS data during match-play. Thirty-four male outfield players (mean ± standard deviation; age 16.5 ± 1.1 years; height 175.2 ± 6.0 cm; weight 65.3 ± 7.2 kg) from three Premier Division 18s soccer teams in the Western Australia State League were recruited and split according to playing position; centre-backs (n=6), fullbacks (n=6), central midfielders (n=7), wide midfielders (n=8) and strikers (n=7). Test-retest reliability and the performance of physiological variables such as peak force, rate of force development (RFD), peak power, vertical jump (VJ) height, agility, aerobic endurance, sprint performance and repeated sprint ability (RSA) were established. The participants from each team were tracked by GPS (GPSports SPI Elite, ACT, Australia) over the entire playing time of four consecutive matches, and in total, GPS data was accumulated from twelve league games for TMA of soccer performance. All variables of the RFD, static jump (SJ), Soccer Specific Agility Test (SSAT), 20 m and 10 m sprint times, and percent sprint decrement of RSA (RSAdec), were associated with low intraclass correlation coefficient (ICC) values, suggesting poor test-retest reliability. No significant differences were revealed by one way repeated measures ANOVA for the mean performance of any of the physiological variables between playing positions with the exception of one criterion measure of the SSAT, while numerous significant main effects across positional groupings were found in the GPS data acquired during match-play (p < 0.05). Paired t tests identified a number of significant main effects among match-related performance between playing halves (p < 0.05). In addition, many large and moderate effect size (ES) values for performance measures between playing positions and halves were detected. Pearson product correlations were used to examine relationships with significant and strong inverse correlations evident between the variables of the 30 m sprint, RSA test and SSAT, and sprint performance during match-play (r = -0.506 to -0.644; p < 0.05). This study showed that the physiological profiles of essential performance characteristics for young soccer players were similar across playing positions. There were numerous significant main effects between playing positions and halves during match-play, and hence, position-specific testing and conditioning protocols may be efficacious in effectively preparing young soccer players for competition. More TMA studies of young soccer players using larger sample sizes are warranted to substantiate the findings of this study.

This research has examined players' and coaches' perceptions of the specific leadership behaviours of soccer coaches. The research was comprised two studies, the first a quantitative study and the second a qualitative study. Both studies focused on researching Yuki's (1989, 1994) 14 specific leadership behaviours. These are: (a) team building and conflict management, (b) developing, (c) supporting, (d) rewarding, (e) recognising, (I) motivating and inspiring, {g) delegating. (h) consulting, (i) problem solving, (j) planning, (k) monitoring, (1) clarifying, (m) informing, and (n) networking. Subjects for Study I were 400 randomly selected soccer players and 40 randomly selected soccer coaches. The ratio between the players and the coaches was 10:1. Results of the MANOVA revealed significant multivariate differences between players' and coaches’ perceptions of coaches' behaviours. The univariate ANOVAs revealed that Coaches' and players' perceptions differed significantly on ten of the 14 specific behaviours. The MANOVA results showed significant multivariate difference between players' perceptions and the coaches' years of experience. The univariate ANOVAs test revealed that players' perceptions differed significantly on eight specific behaviours. The results of Bonferroni adjusted t tests indicated that there was a statistically significant difference between players' perceptions of their coaches' behaviours. Results of the MANOVA revealed significant multivariate difference in players' perceptions of their coaches' behaviours and the level of competition. The univariate ANOVAs test revealed that 13 specific behaviours were statistically significant. Results of the MANOVA showed significant multivariate difference between male and female players. The univariate ANOVAs test indicates that players' perceptions differ significantly on six specific behaviours. Results oft he MANOVA revealed significant multivariate difference between junior and senior players. The univariate ANOVAs test indicated that only delegating is significant at the 0.001 level.

Introduction: In soccer, the long duration of the competitive season and the large number of games require a careful organization of the training load and a maximization of the training stimuli. The presence of close matches (from 7 to 3 days) requires a careful control of accumulated fatigue and the use of training stimuli aimed at improving different aspects of the soccer physical performance. However, to date in soccer, there is little information about the characteristics of tapering during the microcycle, while the knowledge concerning the specificity of the training methods remains confused. Purpose: the aims of the present investigation were threefold: i) to examine the effect of in-week tapering strategy (reduction in training load 24 h before a match) on player preparedness; ii) to compare the physiological response and mechanical profile of different training strategies, and iii) to compare their effects on soccer-related physical performance. Methods: For these training studies three soccer teams were involved, with a total of 41 players. In the first study, a cross-over experimental design was used, and the participants performed two simulated match-week microcycles, with the same workload, except for the experimental week where a further reduction of ~33% of the volume (time) was performed the day before the match. In the second study was used a parallel two-group, work-matched, longitudinal (Baseline-Test Post-test) experimental design. Two different speed endurance training protocols were compared before and after four weeks of training. In the third study, the acute physical and physiological response of two training approaches (speed endurance vs. repeat sprint training) were compared. Results: In the first study, it was found that a further 33% of training-load reduction the eve of the match improved the height of a countermovement jump, sprint time over a 20 m and repeated sprint ability, enhancing preparedness, while Yo-Yo IR1 performance was maintained. The second study showed that 10-seconds sprint was associated with a possibly greater effect on repeat-sprint total time, higher power output, as well as lower blood lactate concentration, compared to 20-seconds sprint. In the third study, we showed that repeated sprint exercise is associated with a higher mechanical load and heart rate response, while speed endurance training is associated with a higher speed average and a higher blood lactate concentration at the end of the exercise. Conclusion: A further volume reduction during tapering provides an improvement of jump and sprint performances. Additionally, the assessment of the sprint duration (during repeated sprint) has shown that short-time sprint generates higher power demand and higher mechanical load. Conversely, long-sprint duration generates higher speed and high level of blood lactate concentration. However, both short and long-sprint duration have a positive effect on soccer-related performances. Therefore, the manipulation of the training load during tapering together with the type of training stimulus led to increasing soccer-physical performance.

This investigation examined the effect of changes in ball properties and cognitive demands on the performance of adolescent male athletes of varying levels of soccer expertise. Participants moved through a course under two conditions: decision and no decision, and with two types of soccer balls, regular and futsal. The experts moved through the courses with both balls significantly faster than the novices and had a lower percentage of control errors with the regular ball but not with the futsal ball. Both groups performed significantly slower under the decision condition, but no differences were found between conditions in the percentage of control errors made. The novices made a significantly smaller percentage of control errors with the futsal ball than the regular ball, although the type of ball had no effect on their performance times. These results suggest that the experts display better soccer skills and cognition than the novices and that the properties of the futsal ball appear to reduce the technical demands for the novices.

In recent times, the performances of the South African senior national team (“Bafana Bafana”) have not matched the impressive off-field advancements in South African professional soccer. At the historic 2010 FIFA World CupTM held in South Africa, Bafana Bafana became the first host nation to be eliminated in the first round of the competition. Such disappointments have compelled stakeholders in South African soccer to call for a re-assessment of all structures and programmes which have an impact on the playing abilities of South African players. Of prime importance is the need to obtain a better understanding of talent development in South African soccer. The aim of this research study was to determine the relevance of selected factors associated with successful talent development in South African male professional soccer players competing in the 2008-2009 ABSA PSL season. In order to accomplish the research aims, the literature relating to talent development concepts and models was examined. The literature review identified seven factors which are relevant to talent development in soccer. The empirical study was exploratory, and it utilized a descriptive, non-experimental approach. Data were collected via a 53-item questionnaire, which was designed to evaluate the identified seven factors. The questionnaire was administered to a sample of 56 South African professional soccer players who played for clubs participating in the 2008-2009 season of the ABSA Premier Soccer League. The results obtained from the sample were analysed in terms of their descriptive statistics and confirmatory factor analysis was performed. The following six factors were statistically confirmed as being associated with the successful talent development of the sample: Training Environment, Motivation and Ambitions, Personal Development, Family Support, Cultural Factors and Coaching. These six factors accounted for 58 percent of the overall variance. The questionnaire had a reliability of 0.84, as measured by the Cronbach alpha coefficient. The study concludes that talent development in South African soccer is a multifactorial and complex process. Although the sample size was not suitable for discriminant analysis, theories such as the relative age effect and the „10-year rule‟ may be applicable to South African soccer. This study also adds to the limited body of knowledge on South African soccer, by identifying and scientifically analysing those factors which are associated with successful talent development. As success on the international stage becomes a priority in South African soccer, the identified factors serve as a sound scientific basis in the formulation of improved structures and strategies for perfecting the abilities of young soccer players, and increasing the competitiveness of Bafana Bafana.

Introduction: College soccer begins in August and ends in November, allowing athletes less than 4 months to condition and play all regular season matches. A consistent consequence of this condensed season structure is an elevated risk of training distress. In turn, training distress can lead to impaired performance and an increased likelihood of injury. Thus, it is important to identify signs of symptoms of distress early so that appropriate adjustments to training volume can be made. Simple, noninvasive techniques, which can be implemented by coaching staff, are ideal. This study investigated whether heart rate recovery was effective as an indicator of training distress in collegiate soccer players. Methods: 26 women and 17 men were enrolled in the study. Data were collected at 4 time points, measuring shuttle run time, heart rate recovery time, resting heart rate values, and MTDS questionnaire score. Heart rate recovery time was defined as the duration it took an athlete to reach 60% heart rate maximum from peak heart rate following the shuttle run. Results: Shuttle run times were prolonged in the beginning and end of season compared to the two mid-season tests (p < 0.001); heart rate recovery times differed at each time period (p=0.003); freshmen deviation from baseline was greater compared to all other grades (p=0.001). Although not statistically significant, resting heart rate values trended up at the end of the season for both genders. Conclusions: Heart rate recovery did not detect training distress in athletes; shuttle run times and resting heart rate appeared to be possible variables that should be taken in to consideration for further research and possibly assist in tailoring training session for optimal performance.

Knee injuries are extremely prevalent in high pivoting sports such as soccer, with non-contact anterior cruciate ligament (ACL) injuries being the most common. Female athletes are up to eight times more likely to experience ACL injuries compared to males. The purpose of this study was to investigate the possible reasons why females are so much more likely to experience ACL injuries and identify methods which can be used to prevent such injuries. A review of textbooks and articles regarding the anatomy and biomechanics of the knee was conducted followed by a review of articles on the topic of anatomical, biomechanical, neuromuscular, and hormonal differences between males and females. This investigation identified multiple risk factors under each category which place females at an increased risk of ACL tear. A later review of the diagnosis and treatment showed that ACL injuries are the most well understood of the major ligament tears which occur in the knee. Treatment options include non-operative methods and surgical methods, depending on the patient and extent of the injury. Finally, a review of the literature regarding prevention programs demonstrated that it is possible to decrease the risk of ACL injury in females through neuromuscular and biomechanical training.

Background: Soccer players, independent of positions, perform high-intensity movements such as agility for short periods and have longer periods of low-intensity and rest during a soccer game. Agility is considered to be dependent on perceptional and decision-making factors and physical factors related to changes in directions. Most research has displayed no differences in different preplanned agility test within playing positions. However, no studies have been done on reactive agility within different positions on the soccer field. Aim: The purpose of the study was to compare if soccer players ́ reactive – and preplanned agility performance differs between their positions in the team. The study will also examine the level of correlation between results from reactive agility and preplanned agility. Methods: Thirty male soccer players, 17-19 years old, were tested in reactive agility and preplanned agility. The subjects were divided into three groups depending on their playing position, including defenders (n=10), midfielders (n=10) and forwards (n=10). Mean scores for both agility tests were analyzed with a one-way analysis of variance (ANOVA) and the criterion level for significance was set at 5 % (p ≤ 0.05). Correlations were performed to study the relationship between reactive agility and preplanned agility. Following limits were used to determine the strength of the value of Pearson correlation; r=.10 to .29 small, r=.30 to .49 medium, r=.50 to 1.0 large. Results: No statistical significant differences between defenders, midfielders and forwards in neither reactive agility (p=0.624) or preplanned agility (p=0.481) were perceived. There was a small correlation (r=0.24) between all studied results from the reactive – and preplanned agility test. When positions were correlated within the two test, the highest correlation between reactive agility and preplanned agility was found in midfielders with a medium correlation (r=0.47) while small correlations appeared within defenders (r=0.28) and forwards (r=-0.11). Conclusions: The findings of this thesis showed no statistical significant differences between playing positions in reactive agility nor in preplanned agility. The impact of the soccer players’ integration with different soccer coaches could be an explanation to the reactive agility results where some coaches may focus on developing perceptual skills more than other coaches. The absence of differences in preplanned agility may suggest that the physical abilities needed to perform the Zig-Zag test did not differ among defenders, midfielders or forwards. It can also be suggested that reactive agility and preplanned agility are two independent variables who do not share characteristics. Future research should focus on incorporating a more valid reactive agility test for soccer players and study larger samples who are specialized in their positions.

Purpose: To determine the effects of acute caffeine ingestion on female soccer players repeated-sprint performance, time to exhaustion, heart-rate, and rating of perceived exertion. Additionally, to investigate if habitual caffeine consumption effects supplementation results. Methods: Using a randomised double-blind research design, 18 females from the Women’s National League ingested two-tablets containing either caffeine (400 mg) or placebo (lactose) 1 hour before completing an indoor multiple-sprint test (12 x 30 metre; separated by 35 seconds rest), and a multi-stage fitness test (Yo-Yo Intermittent Recovery Test Level 2). Participants attended two-testing sessions 7-days apart and consumed either placebo or caffeine on the first session, and the opposite on the second testing session. Sprint-times were recorded using dual-beam photocells, time to exhaustion was measured in seconds and metres covered using interval recording on paper. Heart rate was monitored continuously, while RPE was measured after every third-sprint and every-minute during the multi-stage fitness test. Results: Sprint 3, 4, and 5 in the multiple-sprint test showed significant results (three sprints p=0.001, sprint 3: caffeine 7.58±1.36, placebo 7.61±1.33, sprint 4: caffeine 7.54±1.35, placebo 7.60±1.31, sprint 5: caffeine 7.56±1.36, placebo 7.60±1.32), while sprint 8 and 9 showed a tendency for faster times. Time to exhaustion was significantly improved with caffeine (p=0.0001, caffeine 428±209 seconds, placebo 345±122 seconds), heart-rate was not significantly different between trials as no interaction effect was found between trials (p=0.183), RPE overall wasn’t statistically different between trials (all values were p > 0.005) with sprint 12 providing the only significant different rating of perceived exertion score (p=0.003, placebo 16.3±0.8, caffeine 15.7±0.9). Finally, habitual caffeine consumption wasn’t statistically different between conditions (time to exhaustion p=0.92, rating of perceived exertion p > 0.005, heart-rate p > 0.01, and multiple sprints p > 0.004). Conclusion: Caffeine supplementation improves female soccer performance by means of increased time to exhaustion, tendency to improve multiple-sprint performance, and doesn’t affect heart-rate. Caffeine does not affect rating of perceived exertion, however, due to the increase in performance seen it is thought that unchanged RPE allows the body to work at higher intensities for longer. Finally, habitual caffeine consumption does not affect results as long as an abstention period of 48 hours is undertaken prior to matches. Take home message: Caffeine in a 400mg dose positively effects female soccer performance and minimal health risks or negative effects are associated with this supplementation. Caffeine produces a huge positive increase in endurance capacity, such as time to exhaustion, while also increasing the ability to perform at higher intensities for longer, reduced perception of effort.

This study examined the effects of a sports drink on the performance of young soccer players. Ten competitive young male soccer players, ages 10 and 11, performed two experimental trials while consuming 32 ounces of either a sports drink (G)- Gatorade or a placebo (P)- Crystal Light in a double-blind, crossover design. Both trials consisted of a 15-minute warm-up period, a pre and post exercise test protocol and a 40-minute indoor scrimmage with a five-minute half time. The assigned fluid was consumed just prior to the warm-up, pre-test protocol, scrimmage and post-test protocol as well as during the half time of the scrimmage. The exercise tests included six activities such as shooting velocity, dribbling, passing, jumping, backward running, and sprinting in order to measure skill, agility, power, and speed. The results showed that due to the interaction of the 40-minute scrimmage and the consumption of Gatorade, the post-test shot velocity measurement was significantly (p<0.01) lower for P while G remained similar to the pre-test measurement. Also, there was a significant (p<0.05) decrease in the number of jumps completed for both P and G during the post-test jumping exercise when compared to the pre-test measurement. However, there were no significant difference of treatment, time and/or their interaction for the dribbling, passing, backward running, and sprinting. Many possible reasons may account for this lack of effect. 1) Muscle glycogen may not have been substantially depleted, possibly because the prescribed exercise during the trial was not intense or long enough. 2) Prior to the experimental trials, muscle glycogen stores were sufficient where no additional CHO was necessary (due to the subjectâ s diet on the day of the trial or the short fast prior to the experimental trials). 3) Alternative mechanism, such as increased lactate production or dehydration and not muscle glycogen depletion, may be the cause of impaired skills. 4) A childâ s increased fat utilization allows for less of a need for manipulation of glycogen stores.
Master of Science

The aim of the study was to document the epidemiology of injuries sustained by South African high school soccer players. Subjects for the study were selected from all the high schools (n = 10) in Tembisa (Gauteng, South Africa). A cohort of 227 high school soccer players, representing all the players in the Tembisa schools, was followed over one playing season. All practice and match hours were recorded and specific injury report forms were completed by all the coaches. All injured players were then referred to the principal investigator (JR) for detailed examination to document injuries. Factors such as pre-season training, warm-up, stretching, playing surface, environmental factors, and the use of protective equipment were also recorded. In this study, 63% of all the players sustained an injury during the season (seasonal incidence). The overall incidence of injuries was 9.04/1000 hours of play. The incidence in matches was 274 times higher than in practice. More than half (57%) of the injuries were classified as moderate. The highest incidence of injury per player position was in goalkeepers (13.7/1000 hours play). The lower extremity accounted for most injuries (88.8%), principally the ankle (42.4%) and the knee (27.1%). The most common type of injury was a ligamentous sprain (68%), followed by musculotendinous strains (15.8%). There were only two joint dislocations, and no fractures. All the participants in this study played on gravel pitches and on no occasion was a first-aid kit available. The majority of players were not aware of appropriate stretching, warm-up, and strapping techniques to prevent injuries. None of the players engaged in any form of pre-season training. In two of the schools (20%) the soccer coaches had formal training with coaching certification. Although the injury rate in high school soccer players in this study is only slightly higher than that reported · by others, it is clear that scientifically based measures of injury prevention (pre-season training, warm-up, stretching, and strapping) need to be implemented in these schools. In addition, proper sports and first-aid facilities should be provided, and coaches should receive formal continuous training.

Bakgrund: Fysisk smärta kan försämra både fysisk och psykisk förmåga samt leda till flertalet komplikationer. Smärta är ofta sammankopplat med skador. Skador är vanliga bland idrottare, och skaderisken ökar ju högre nivå man spelar på. Då skador är så pass vanliga bland idrottare på hög nivå så kan man anta att detsamma gäller med smärtkänningar. Eftersom smärta kan påverka en negativt på så många sätt så kan det vara intressant att undersöka smärta bland idrottare på hög nivå. Syfte: Syftet med studien var att undersöka upplevelsen av smärta samt relationen till smärta hos kvinnliga fotbollsspelare på hög nivå i Sverige. Metod: 68 från 4 olika lag i division 1 och 2 deltog i studien. De var mellan 14-30 år gamla och hade spelat på hög nivå mellan 1-13 år. En enkät användes för att samla datan och SPSS användes för att analysera den med deskriptiv statistik. Resultat: 50 % av spelarna skattade deras smärtutsträckning före, under och efter träning och match med 3 eller mer på en skala mellan 1-5, där 1 är "ingen utsträckning" och 5 är "hög utsträckning". Resultaten varierade angående vilken influens smärta haft på försktighet, förmåga, potential, känslor och koncentration. Spelarna kände dock att smärta haft störst påverkan på deras förmåga att spela och deras emotionella välmående. 42.65 % av spelarna fortsatte som vanligt när de upplevde smärta under träning och 44.12 % av dem fortsatte men tog det lugnare, medan 83.83 % fortsatte som vanligt när de upplevde smärta under match. Samtliga av deltagarna var av uppfattningen att det kan vara skadligt på olika sätt att spela trots att man känner smärta. Slutsats: De flesta av spelarna var negativt påverkade av smärta i någon grad. Även om de var övertygade om att det kan leda till problem om man spelar trots smärta så fortsatte de flesta att spela när de fick smärtkänningar under träning och match.
Background: Physical pain affects mental performance as well as many physical factors and is often associated with injuries. Injuries are common among athletes and a higher level of play coheres with a higher prevalence of injuries. Since injuries are so common among high-level athletes, it is reasonable to assume that pain is also connected to the high level of play. Also, since experiencing pain has its side-effects, it is interesting to investigate physical pain among high-level athletes. Purpose: The purpose of the study was to investigate the presence and experience of pain among high-level female soccer players in Sweden, as well as their relationship to pain. Method: 68 players between 14-30 years old who had played at a high level for 1-13 years participated in the study. A questionnaire was used to collect the data and SPSS was used to analyse it with descriptive statistics. Results: 50 % of the players rated their pain extent before, during and after practices and games with 3 or more on a scale from 1-5, where 1 is “no extent” and 5 is “high extent”. The results were scattered regarding the influence pain had on carefulness, ability, potential, emotions and concentration, but the players felt that pain had the biggest influence on their ability to play and their emotional wellbeing. 42.65% of the players continue as normal when experiencing pain during practice and 44.12% of them continue but take it easier, while 83.82% continue as normal when experiencing pain during game. All of them thought that playing and practicing with pain could lead to future complications in some way. Conclusion: Most of the players struggled with pain to varying degrees. Even though being convinced that playing with pain can lead to complications, they kept on playing when they experienced pain themselves.

Thanks to the technological innovation of electronic motion recording methods, the use of quantitative data in sport to measure performance has increased significantly in recent years, enough to represent a new specialty of statistical studies. The most relevant literature concerning quantitative models for evaluating the price of a football player is examined. Through OLS, an empirical analysis is conducted that can understand and predict what are the performance variables that can determine a player's trading price. The data relate to the exchanges that took place in the top Italian football championship (Serie A) between 2017 and 2019. The variables that determine the price change due to the role, therefore there is a strong specialization by role. The performance does not fully explain the price changes of the players. Furthermore, the higher investments are not necessarily proportional to the sporting results of the team.

The aims of this thesis were to examine the relationships between relative age, maturity status, and physical phenotypes on the selection, playing position allocation, and development tempo of a broad sample of elite youth soccer players’ that best represents UK development programs governed by the Elite Player Performance Plan (EPPP). The first research study (Chapter 4) aimed to establish the short-term reliability (STR) and smallest worthwhile changes (SWC) for a battery of field tests commonly used to assess elite youth soccer players’ physical and somatic phenotypes. On two occasions, the within-practitioner STR of three anthropometric measures (stature, seated height and body-mass) were assessed to estimate age at peak height velocity (APHV). In addition, within-player STR of the Multi-Stage Fitness Test (MSFT), 10 and 20 m sprints were assessed using 45 elite youth soccer players (age: 13.5 ± 1.5 years; body-mass: 49.2 ± 10.3 kg; stature: 177.7 ± 6.4 cm). In addition, within-player STR was established for T-Test and counter-movement jump (CMJ) performance using 21 senior amateur soccer players (age: 24 ± 5.3 years; body-mass: 84.3 ± 7.1 kg; stature: 177.7 ± 6.4 cm). The within-practitioner STR (coefficient of variance [CV], (95% confidence interval [CI])) and SWC were established for anthropometric measures (stature: CV = 0.4 % [CI = 0.3 to 0.5 %], SWC = 2.3 cm; seated height: CV = 1.1 % [0.9 to 1.4 %], SWC = 1.1 cm; body-mass: CV = 0.7 % [0.6 to 0.9 %], SWC = 2.3 kg) and APHV (CV = 0.8 % [0.7 to 1.0 %], SWC 0.1 year) respectively. Within-player physical fitness reliability and SWC were also established for CMJ (CV = 5.9 % [4.6 to 9.0 %], SWC = 0.6 cm), T-Test (CV = 1.7 % [1.3 to 2.4 %], SWC = 0.08 s), 10 m sprint (CV = 2.7 % [2.2 to 3.4 %], SWC = 0.03 s) and 20 m sprint (CV = 4.9 % [4.1 to 6.4 %], SWC = 0.06 s) performances. This battery of anthropometric and physical fitness field tests observed a high level STR and produced SWC values that will permit talent development (TD) practitioners to implement SWC % to assess changes in player growth, maturity and physical fitness. Research study 2 (Chapter 5) aimed to quantify the relative-age effect (RAE) and examine differences in physical phenotypes owing to the RAE of 731 (U11 to 18) elite youth soccer players sampled from 17 UK soccer development centres. Chi-squared analysis identified a clear un-even birth distribution across all age groups, demonstrating an over-representation of players born in the first quartile (Q1) (U11 to 12: 39%; U13 to 14: 46%; U15 to 16: 57%; U17 to 18: 42%) in comparison to Q4 (U11 to 12: 13%; U13 to 14: 8%; U15 to 16: 8%; U17 to 18: 14%) of the selection year that significantly differed to the distribution expected from National census data (all ≤ 0.001). Small to moderate differences in player stature and body-mass were identified for U11 to 14 players, whereby players born in Q1 were both heavier (ES = 0.48 to 0.57) and taller (ES = 0.62 to 1.06) than players born in Q4. U11 to U12 and U17 to 18 players born in Q1 were generally (ES = 0.37 to 0.70) more mature than their relatively younger (Q4) counterparts. There were no significant differences in agility (P = 0.108 to 0.643), 10 m (P = 0.122 to 0.886) and 20 m (0.090 to 0.911) sprint times between Q1 and Q4 players. However, relatively younger (Q4) U15 to U16 players showed small to moderate (ES = 0.34 to 0.49) inferiority in MSFT performance that continued for Q2 (Q2 vs. Q4: P = 0.041, ES = 0.91). The obvious birth distribution bias identified within this chapter favours the selection of players who are born earlier in the selection year, who possess enhanced maturity related anthropometric and aerobic performance characteristics. Study 3 (Chapter 6) assessed the contribution of relative age, maturity and physical phenotypes upon soccer playing position allocation (goalkeeper [GK], central-defender [CD], lateral-defender [LD], central-midfield [CM], lateral-midfielder [LM], and forward [FWD]) in 465 elite-youth soccer players (U13 to U18`s). U13 to 14 CD were identified as being relatively older than LD (ES = 0.72). CD and GK were generally taller (U13 to 14: ES = 0.49 to 1.19; U15 to 16: ES = 0.72 to 1.48; U17 to 18: ES = 0.96 to 1.58) and heavier (U13 to 14: ES = 0.64 to 1.40; U15 to 16: ES = 0.24 to 1.57; U17 to 18: ES = 0.51 to 1.32) than other players at each developmental stage and were advanced maturers at U13 to 14 (ES = 0.63 to 1.22). Position specific fitness characteristics were distinguished at U17 to 18, where LD and LM were faster than their central counterparts (10m: ES = 0.72 to 0.83; 20m: ES = 0.94 to 1.07). In summary, relative age, maturity and anthropometric characteristics appear to bias the allocation of players into key defensive roles from an early development stage, whereas position-specific physical attributes do not become apparent until the latter stages (U17 to 18) of talent development in outfield players. Study 4 (Chapter 7) assessed the development tempo of anthropometric and physical fitness characteristics according to players decimal age and maturity offset (YPHV) of 969 (U9 to U18) UK elite youth soccer players using battery of 7 field tests. Segmented regression analysis established that estimated stature increases were highest between 10.7 (CI = 10.2 to 11.2) to 15.2 (CI = 14.8 to 11.2) years, and between -3.2 (-3.5 to -2.9) to 0.8 (0.5 to 1.1) YPHV, with estimated annual growth rates of 7.5 (CI = 7.0 to 7.9) and 8.6 (CI = 8.3 to 9.0) cm·year-1 identified for decimal age and YPHV, respectively. Estimated rate of body-mass developmet was also increased (7.1 [CI = 6.6 to 7.6] kg·year-1) between 11.9 (CI = 11.5 to 12.3) to 16.1 (CI = 15.5 to 16.7) years of age, whereas when modelled against somatic maturity, body-mass increases continued at 7.5 (CI = 7.2 to 7.7) kg·year-1 from -1.6 (CI = -2.1 to -1.1) to ~4.0 YPHV, without plataeu. Estimated CMJ development tempo decreased from 2.5 (CI = 2.2 to 2.8) to 1.3 (CI = 0.7 to 1.9) cm·year-1 circa- PHV (0.6 [-0.4 to 1.6] YPHV). Estimated T-Test performance gains ceased from 15.8 (CI = 15.2 to 16.4) years of age onwards, but when modelled against somatic maturity status, improvements slowed by ~43% at 0.4 (CI = -0.1 to 0.9) YPHV. Players estimated endurance capacity increased by 169 (CI = 158 to 179) and 185 (CI = 173 to 198) m·year-1, until 16.4 (CI = 15.9 to 17.0) years and 2.1 (CI = 1.6 to 2.5) years post PHV, respectively. Estimated 10 and 20m sprint performance increased until 11.8 (CI = 11.2 to 12.5) years of age, or -1.8 (CI = -2.5 to -1.0) YPHV, before development tempo increased (31-43%) until 15.8 (CI = 15.3 to 16.3) years, or 1.2 (CI = 0.1 to 2.3) to 1.3 (CI = 0.8 to 1.8)YPHV. Findings identified that model strength for stature and body-mass was slightly higher in YPHV (r2 = 0.89) versus decimal age (r2 = 0.81). However these trends were not apparent for the development of physical fitness attributes. In addition, Chapter 7 revealed that players estimated sprint performance development markedly increased (31 to 43%) between 11.8 years and 15.8 years, or 1.2 to 1.3 YPHV. This data will provide practitioners with a guide to help forecast players’ rate of anthropometric and physical fitness characteristics development at an early stage of their development. Findings here’s suggest that TD practitioners should systematically use estimates of maturity offset to reduce the premature deselection of equally talented but slower players who may reach the same sprint capacity in adulthood, but are slightly later maturers versus there team-mates. In summary, the standardised battery of field-tests used within this thesis observed high levels of STR. There was a clear birth distribution bias that favours the selection of players’ for UK elite soccer development centres, who are born earlier in the selection year. It is likely that transient anthropometric advantages afforded to relatively older players within younger age categories act as a major contributory factor that bias the premature selection and role allocation of these players in to key defensive (GK and CD) roles, before the development of position-specific physical attributes become apparent during the latter stages (U17 to 18) of the EPPP in outfield players.
Likely to be of particular importance to TD practitioners, players’ estimated sprint performance development increased across decimal ages (11.8 to 15.8 years) spanning PHV (-1.8 to 1.3 YPHV), justifying research to further examine the intricacies between training prescription and maturity on sprint speed development. Monitoring player maturity will enable a better understanding of maturity related anthropometric and performance gains, and is likely to improve sensitivity of training prescription and physical phenotype development forecasting. Emphasising the necessity for systematic and consistent monitoring of player growth and maturity that will likely inform talent identification and development processes, and reduce the biases associated with relative age and anthropometric advantages upon talent selection and positional role allocation.

Several studies conducted on home advantage in sport have focused on game location and performance outcome. The purpose of this study was to examine three components of home advantage, such as the effect that game location has on self-efficacy, a critical psychological state, and assertive play, a critical behavioral state. Participants (N = 21) from one mid-sized, midwest, Division I soccer program completed the Modified State Sport-Confidence Inventory (MSSCI) prior to six home conference games and six away conference games. In addition, all 12-conference games were observed and coded according to four assertive behaviors of soccer players. Data were analyzed using a permutation test and Spearman's Rho with a level of significance set at .05. Results indicated there was no significant difference in self-efficacy between home and away games and no significant difference in assertive play between home and away games. No significance relationship was found for self-efficacy and assertive play. Possible limitations along with recommendations for the future are discussed.
School of Physical Education

The aim of this study was to investigate how timing training by Interactive Metronome ® (IM) affects motor timing and rhythmicity in soccer players. Twenty-four female soccer players (age 19 ± 2.8) participated, and were randomly assigned to either a control or an IM training group. All participants took part in a functional magnetic resonance imaging (fMRI) session before the start of the training period, to find out what brain areas are activated during different tempos. The fMRI outcomes indicate that some of the active areas are the inferior parietal cortex (BA 40), frontal/SMA and precentral cortex and postcentral (BA 6) and inferior frontal cortex (BA 45). Pre- and post-measurements of motor timing deviation and variability was made. The result shows that after four week of IM training a significant improvement of motor timing was found for the IM group in comparison to the control group. The findings indicate that timing training can improve timing ability in healthy sport perpetrators.

The purpose of this study was to investigate elite soccer players' attentional focus during their best performances, better understand the strategies they use to enter or re-enter optimal attentional states, and explore potential attentional differences according to soccer positions, performance tasks, and game situations. No previous studies have explored elite soccer players' attentional skills from a naturalistic and qualitative perspective in such detail. The growing interest in soccer among Canadians provided further justification for this study. Data collection consisted of individual semi-structured interviews with eight elite soccer players from five main soccer positions, namely goalkeeper, defender, wing, midfielder, and forward. Cross-case thematic analysis indicated positive thinking and pre-performance routines as important sources of optimal focus. Attentional focus varied according to soccer positions and performance tasks. Information processing, sport expertise, and attentional systems theoretical frameworks informed the discussion of results. Applied and theoretical implications were drawn and future studies were recommended.

The purpose of this dissertation was to better understand position specific physical qualities and how they relate to high speed running performance throughout the course of a competitive collegiate soccer season. The amount of literature devoted to female soccer players is scarce when compared to the vast amount of literature associated with male soccer players. The objectives of this dissertation were: 1) to determine if playing position has an influence on physical qualities such as speed, change of direction ability, countermovement jump performance, relative strength, rate of force development, and intermittent endurance capacity, 2) investigate the differences between high and lower caliber players as defined by minutes played per match when considering the physical qualities mentioned previously, 3) and finally to assess the influence of physical qualities and playing position on high speed running performance throughout the course of a competitive season. Data from 57 Division I Women’s Collegiate soccer players from a single institution were used. The influence of playing position and caliber of play on physical qualities were assessed using both laboratory and field based testing assessments. It appears that attacking based players (forward, wide midfielder, and attacking midfielder) were faster compared to defensive based players (central defensive midfielder, central defender, and goalkeeper) when assessed during 20 m sprint assessments and change of direction ability assessments. The only variable to differentiate between caliber of play was the Yo-Yo Intermittent Recovery Test – Level 1 (YYIRT1), indicating that higher caliber players possess greater intermittent endurance capacity compared to lower caliber players. Playing position was the major contributor when assessing high speed running performance during competition, explaining almost 70% of the variance. These findings highlight the impact of tactical factors on physical performance during competition and the need for position based assessments to better identify relevant physical qualities with respect to playing position in Division I Women’s Collegiate Soccer players. Further research is needed with a wider range of players from various levels to determine if these findings exist across all levels or are unique to the institution used during these investigations.

Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES)
Hamstrings muscle injury is the most frequent soccer-related injury in amateur and professional soccer players. Despite various interventions, the risk of hamstrings re-injury remains high. Several scientific studies examined the potential risk factors and their contribution to the occurrence of hamstrings injuries in male soccer players. The aim of the study was to investigate the relationship between selected physical characteristics, such as time-to-peak torque, hip abduction peak torque, hamstrings-to-quadriceps strength ratio, and hamstrings flexibility and the occurrence of hamstrings injuries in amateur male soccer players. A prospective, quantitative cross-sectional study design was utilized in this study. A total of 89 amateur male soccer players aged 18-35 years were recruited from the Cape Town Football District to perform functional assessments before injury occurred, which included anthropometric measurements, an evaluation of lower extremity isokinetic muscle strength (both knee and hip) and hamstrings flexibility tests. Instruments used to measure the anthropometric data were a calibrated Seca balance beam scale and stadiometer, a skinfold caliper, a sliding caliper, an anthropometer (All Harpenden, UK) and a metal tape measure. The Biodex Pro System 4 isokinetic dynamometer was used to measure lower extremity isokinetic muscle strength and a goniometer to measure hamstrings flexibility. Descriptive statistics included means and standard deviations, and inferential statistics included Pearson product-moment correlation to determine the relationship between selected physical characteristics and the occurrence of hamstrings injuries. Multivariate logistic regression via the forward stepwise method was utilised to predict potential physical characteristics (risk factors) for hamstrings injury in amateur male soccer players. Statistical significance was a p value of below 0.05. The prevalence of hamstrings injury was 4.3 %, with the multivariate logistic regression analysis indicating that time-to-peak torque was a significant predictor of the occurrence of hamstrings injury (OR = 1; p = 0.027). In conclusion, time-to-peak torque was a significant predictor of the occurrence of hamstrings injury. The players with hamstrings injuries produced a significantly slower time-to-peak torque, which has relevance for soccer players and coaches in addressing this common injury at all levels of competition.

2012/2013
Twenty professional soccer players (N=20) in the Italian soccer first league - Serie A - were randomly divided into 2 equal groups: Experimental group (Group 1) and Control group (Group 2). Both groups received the same physical and tactical conditioning as the weekly program. Ten players (experimental group) received integrative training based on a specific autonomic-biofeedback protocol to improve central and peripheral efficiency of the nervous system. Pre- and post- assessment were conducted with a psychophysiological assessment and a cognitive task (visual search task) to measure the improvements. This dissertation reviews evidence in support of the notion that heart rate variability are associated with individual differences in cognitive performance: heart rate variability might serve as a peripheral index of the integrity of central nervous system networks that support goal-directed behavior. It is examined evidence about the relationship between higher levels of resting heart rate variability and superior performance on cognitive tasks. By providing a common neural basis for these diverse functions, the neurovisceral integration model may serve as a unifying framework within which to examine associations among these various self-regulatory and adaptability processes. The results showed that is possible to improve through this evidence-based mental training approach based on the autonomic nervous system biofeedback central abilities as visual searching and stress control in professional soccer players.
XXVI Ciclo
1981

Background: Three epidemiological studies conducted in Rwanda have highlighted that many people at different levels in the community of soccer do not implement accepted control measures for reducing the risk of injuries. However, little is known about what soccer community members themselves know about injury prevention. Purpose: The aim of this study was to identify perceptions of factors influencing the implementation of soccer injury prevention strategies in Rwanda.

Thesis (MScSportSc)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Talent identification and early selection into a professional soccer academy has been reported to be very important for the long term development of footballing expertise (Le Gall et al., 2010). This awareness of the need for early identification of gifted youngsters has led to an increased number of soccer centres of excellence and academies throughout the world. Traditionally, identification and selection of promising individuals into youth soccer academies has been linked to a coach’s subjectivity and preconceived image of the player. Once this method is used in isolation it can result in tedious misjudgements in talent identification - hence the emphasis on science-based approaches. Through soccer-specific research, a number of anthropometric and physical parameters have been linked to successful performance in soccer. The primary aims of the study were to explore the anthropometric, somatotype and functional fitness characteristics of young academy soccer in South Africa and Zimbabwe and to distinguish variables that can be relevant for Talent Identification. The study followed a quantitative non-intervention design with a sample of convenience. A total of 74 young soccer players (Age 15.9±0.81) from South African (n = 41) and Zimbabwean (n = 33) soccer academies were purposively sampled. The following anthropometric variables were measured following the International Society of the Advancement of Kinanthropometry (ISAK) protocol: body mass and height; skinfolds – (triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh, medial calf); Girths – (arm relaxed, arm flexed and tensed, waist, gluteal, and calf); bone breadths – (biepicondylar humerus and biepicondylar femur). Functional fitness variables that were measured include: lower back muscle flexibility (sit and reach test), upper body flexibility (shoulder flexibility), leg power using (vertical and horizontal jumps), overhead throw (2kg medicine ball throw), speed tests (10, 20, and 40m sprint tests), agility (Illinois test) and aerobic fitness (Hoff test). There were no statistically significant differences in age, body mass, height, fat mass, body mass index, lower back flexibility, right shoulder flexibility, 20m sprint, and endurance capacity (p>0.05). Statistically significant differences were found in percentage body fat (p>0.05), sum of 8 skinfolds, fat free mass, somatotype, left shoulder flexibility, upper and lower body power, 10m and 40m sprints (p<0.01). South African players were found to have higher %BF and sum of skinfolds and then Zimbabwean players. It was concluded that Zimbabwean players performed significantly better than South Africans in agility, 10m, 40m sprints, vertical jump, horizontal jump and overhead throw and had better future chances of success in soccer. Goalkeepers were taller and heavier, while midfielders and defenders were found to be lighter and shorter. Goalkeepers were the most agile group, while forwards were the fastest group. Agility, power and speed were the most important variables that can be used during talent selection and coaches should purposefully work to develop these characteristic during training sessions. Height and weight are relevant in allocating positional roles to players and not in Talent Identification.
AFRIKAANSE OPSOMMING: Talentidentifisering en vroeë seleksie in ʼn professionele sokkerakademie blyk baie belangrik te wees vir die langtermyn ontwikkeling van sokker vaardighede (Le Gall et al., 2010). Hierdie behoefte vir die vroeë identifisering van talentvolle jong spelers het aanleiding gegee tot ʼn toename in sokker sentra van uitnemendheid en akademies wêreldwyd. Tradisioneel is die identifisering en seleksie van belowende individue vir toelating tot ʼn jeug sokker akademie aan ʼn afrigter se subjektiwiteit en voorafopgestelde idees van die speler gekoppel. Wanneer die metode in isolasie gebruik word kan dit dodelike mistastings in talent identifisering teweeg bring – daarom die klem op wetenskaplik gebaseerde benaderings. Deur sokker spesifieke navorsing is daar alreeds ʼn aantal antropometriese en fisieke parameters aan suksesvolle prestasie in sokker gekoppel. Die primêre doelwitte van die studie was om die antropometrie, somatotipe en funksionele fiksheidskenmerke van jong sokker akademie spelers in Suid-Afrika en Zimbabwe te ondersoek en om veranderlikes wat relevant vir talentidentifisering kan wees te onderskei. Die studie het ʼn kwantitatiewe, nie-intervensie ontwerp met ʼn gerieflikheidsteekproef gevolg. ʼn Totaal van 74 jong sokkerspelers van Suid-Afrika (n = 41) en Zimbabwe (n = 33) sokker akademies is doelgerig geselekteer (ouderdom 15.9 ± 0.81 jaar). Die volgende antropometriese veranderlikes is ooreenkomstig met die International Society of the Advancement of Kinanthropometry (ISAK) protokol gemeet: liggaamsmassa en -lengte; velvoue (triseps, subskapulêr, biseps, iliokristale vou, supraspinalis, abdominale, quadriseps, mediale gastroknemius); omtrekke (arm ontspanne, arm in fleksie en gespanne, middel, gluteale, en kuit); been breedtes (biepikondelêre humerus en biepikondelêre femur). Funksionele fiksheidsveranderlikes wat gemeet is was: laerug spierlenigheid (sit en reik toets), boonste ekstremiteit lenigheid (skouer lenigheid), beenkrag (vertikale en horisontale spronge), oorhoofse gooi (2kg medisyne balgooi), spoedtoets (10, 20, en 40m spoedtoetse), ratsheid (Illinois toets) en aërobiese fiksheid (Hoff toets). Geen statisties betekenisvolle verskille is in ouderdom, liggaamsmassa, -lengte, vetmassa, liggaamsmassa indeks, laerug lenigheid, regterskouer lenigheid, 20 meter spoed en uithouvermoë kapasiteit (p>0.05) tussen SA en Zimbabwe spelers gevind nie. Statisties betekenisvolle verskille is wel in persentasie liggaamsvet (p<0.05), som van agt velvoue, vetvrye massa, somatotipe, linkerskouer lenigheid, boonste en onderste ekstremiteit liggaamskrag, 10m en 40m spoed (p<0.01) gevind. Suid-Afrikaanse spelers het ʼn hoër persentasie liggaamvet en som van velvoue as die Zimbabwiese spelers gehad. Daar is tot die gevolgtrekking gekom dat Zimbabwiese spelers betekenisvol beter as Suid-Afrikaanse spelers in die meeste fiksheidstoetse gevaar het en waarskynlik beter kanse vir sukses in sokker het. Doelwagters was groter en swaarder, terwyl middelveld spelers en verdedigers ligter en korter was. Doelwagters was die ratste groep, terwyl voorspelers die vinnigste groep was. Ratsheid, krag en spoed is as die belangrikste veranderlikes geïdentifiseer wat tydens talentidentifisering gebruik kan word en afrigters moet doelbewus daaraan werk om hierdie eienskappe tydens oefensessies te ontwikkel. Lengte en gewig is relevant in die toekenning van posisionele rolle aan spelers en nie in talentidentifisering nie. Hierdie is die eerste studie waarin die antropometriese en funksionele fiksheidsprofiele van jong sokkerspelers in Suid-Afrika en Zimbabwe met mekaar vergelyk word. Dit baan die weg vir ander navorsers om hierop uit te brei deur sokkerspelers van ander lande in Afrika te toets en by te dra tot die kennis van sokkerspelers in Afrika. Hierdie navorsing skep ook die basis vir afrigters en oefenkundiges in Afrika om die bydrae wat die wetenskap maak ten opsigte van liggaamsamestelling en funksionele fiksheid beter te verstaan om talentidentifisering in sokker te verbeter.

The purpose of this project was to review anterior cruciate ligament (ACL) literature and develop a performance evaluation and injury risk assessment (PIER) for female soccer players. A strategy guide for decreasing injury risk and enhancing performance was developed in hopes to bring awareness to the athletic community about ACL injury for female soccer players.