Thesis (Ph. D.)--Oregon State University, 2007. / Includes bibliographical references (leaves 121-129).

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.

The main problem in analysing soccer is the existence of a large number of interacting variables. Far fewer difficulties exist for cricket, baseball, racket ball games or even American football, where the actions may be broken down into a series of discrete events which are relatively easy to record and assess. Despite the considerable interest which soccer matches provoke, and the many varied post-game discussions on its strategy which often result, little research has actually been conducted into the strategical aspect of play. This study is an attempt to examine patterns of play at professional level and more specifically, to investigate whether successful attacking patterns can be identified which are commonly used by all teams. The study concentrates on the analysis of patterns of play in soccer, by examining the suitability and accuracy of the two methods of obtaining objective data on patterns of play; the live match analysis technique and the video recording technique with subsequent analysis. The results show that both techniques produce the same results; however, the former is more convenient. Data for five league teams playing home and away matches and for an international team playing five home matches during the season 1987-1988 have been obtained and analysed. Analysis of patterns of play for the five league teams shows that there were similarities and dissimilarities between the top and the poorer teams. The distinct patterns of play identified for each team in both home and away matches were few in number. Top teams had the same number of successful patterns of play in home and away matches. The poorer teams also had the same number of successful patterns in home and away matches but they were fewer In number. Top teams applied the same strategies when they played at home or away whilst the poorer teams applied different strategies when playing at home or away. These findings led to another investigation which compared the patterns of play of the league teams with those of an international team. The international team and the poorer league teams had the same number of successful patterns of play in home matches but they were fewer in number than those of the top league teams. Successful patterns of play appeared more often for the international and league teams in those matches they won. The number of free attacking moves and set pieces in a match did not give any indication of success for the international and league teams. A team wins when it has a greater number of shots on target and a greater proportion of attacks producing shots regardless of whether the team is playing at league or international level. The final part of the study examines the defensive strategies employed against the successful attacking patterns of play of the five league teams. The results indicate that both the top teams and the poorer teams had distinct successful defensive strategies which were similar in home and away matches but the defensive strategies of the poorer teams were, of course, less successful than those of the top teams. These findings clearly indicate that there are similarities in employing defensive strategies in home and away matches for all teams, but the defensive strategies of the top and the poorer teams were markedly dissimilar. It is clear that close marking is a crucial element of the best defensive strategies (i.e. teams who marked their opponent players most frequently, succeeded in nullifying successful attacking patterns of play).

Made available in DSpace on 2014-06-11T19:34:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-04Bitstream added on 2014-06-13T20:47:59Z : No. of bitstreams: 1 rosa_lm_dr_guara.pdf: 2031104 bytes, checksum: 1dc34b7fa7a828565c82d7d8dada586b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O controle postural é um fator determinante na execução de gestos funcionais que necessitam de um alto desempenho da coordenação motora, como por exemplo, nas atividades esportivas. Neste presente trabalho foi abordada a modalidade esportiva do futebol, e de forma mais específica, o gesto técnico do chute. Neste sentido, o objetivo deste trabalho foi de investigar o equilíbrio dinâmico durante o chute futebolístico por meio de um sistema de análise com uma tarefa controlada. O sistema proposto neste estudo foi constituído por um dispositivo disparador vertical de bola, um alvo de acerto, e por um controle cinemático da bola por meio de cinemetria. A amostra foi constituída por cinco atletas profissionais de futsal, os quais realizaram a tarefa de vinte e cinco chutes ao alvo com a bola em movimento vertical. Para análise dos dados foi proposta a identificação do comportamento gráfico das curvas médias da trajetória, deslocamento e velocidade do centro de massa (CM) e do centro de pressão (COP) desenvolvidas durante a execução da tarefa controlada do chute. Os resultados apresentaram as mesmas tendências de comportamento gráfico de curvas médias da trajetória, deslocamento e velocidade do CM inter-sujeitos nas fases pré-chute, chute e pós-chute, além de coerência gráfica das curvas médias intra-sujeito. Entretanto, não foram encontradas tendências de comportamento gráfico das curvas médias do COP inter-sujeito, assim como, coerência das curvas médias intra-sujeito. Diante dos resultados deste trabalho, a análise do CM demonstrou ser uma ferramenta eficaz para análise do equilíbrio dinâmico em atletas praticantes de futebol durante a realização da tarefa controlada do chute. / Postural control is a determining factor in the execution of functional movements that require high performance motor coordination, such as in sports. This work broached soccer, more specifically the technical movement of the kick. In this context, the objective of this study was to investigate dynamic balance during the kick in soccer, through a system of analysis with a controlled task. The system proposed in this study consisted of a vertical trigger device on the ball, a target, and kinematic control of the ball using a cinemetry method .The sample consisted of five professional indoor soccer players, who made twenty-five kicks at the target with the ball moving vertically. Data analysis was proposed to describe the behavior graph for the average curves of trajectory, velocity and displacement of center of mass (COM) and center of pressure (COP) developed during the controlled kick execution. The results showed the same behavior graph tendencies for average curves of trajectory, velocity and displacement of the inter-subject COM in the pre-kick, kick and post-kick, and graphic coherence of intra-subject average curves. However, there were no behavior graph tendencies for average inter-subject COP curves, and no coherence for the average intra-subject curves. Based on the results of this study, the analysis of CM demonstrate to be an effective tool for analysis of dynamic balance in athletes playing soccer during the course of the controlled task of the kick.

No description available.

Orientador: Tamotsu Hirata / Banca: João Alberto de Oliveira / Banca: José Elias Tomazini / Banca: Renato José Soares / Banca: Luis Mochizuki / Resumo: O controle postural é um fator determinante na execução de gestos funcionais que necessitam de um alto desempenho da coordenação motora, como por exemplo, nas atividades esportivas. Neste presente trabalho foi abordada a modalidade esportiva do futebol, e de forma mais específica, o gesto técnico do chute. Neste sentido, o objetivo deste trabalho foi de investigar o equilíbrio dinâmico durante o chute futebolístico por meio de um sistema de análise com uma tarefa controlada. O sistema proposto neste estudo foi constituído por um dispositivo disparador vertical de bola, um alvo de acerto, e por um controle cinemático da bola por meio de cinemetria. A amostra foi constituída por cinco atletas profissionais de futsal, os quais realizaram a tarefa de vinte e cinco chutes ao alvo com a bola em movimento vertical. Para análise dos dados foi proposta a identificação do comportamento gráfico das curvas médias da trajetória, deslocamento e velocidade do centro de massa (CM) e do centro de pressão (COP) desenvolvidas durante a execução da tarefa controlada do chute. Os resultados apresentaram as mesmas tendências de comportamento gráfico de curvas médias da trajetória, deslocamento e velocidade do CM inter-sujeitos nas fases pré-chute, chute e pós-chute, além de coerência gráfica das curvas médias intra-sujeito. Entretanto, não foram encontradas tendências de comportamento gráfico das curvas médias do COP inter-sujeito, assim como, coerência das curvas médias intra-sujeito. Diante dos resultados deste trabalho, a análise do CM demonstrou ser uma ferramenta eficaz para análise do equilíbrio dinâmico em atletas praticantes de futebol durante a realização da tarefa controlada do chute. / Abstract: Postural control is a determining factor in the execution of functional movements that require high performance motor coordination, such as in sports. This work broached soccer, more specifically the technical movement of the kick. In this context, the objective of this study was to investigate dynamic balance during the kick in soccer, through a system of analysis with a controlled task. The system proposed in this study consisted of a vertical trigger device on the ball, a target, and kinematic control of the ball using a cinemetry method .The sample consisted of five professional indoor soccer players, who made twenty-five kicks at the target with the ball moving vertically. Data analysis was proposed to describe the behavior graph for the average curves of trajectory, velocity and displacement of center of mass (COM) and center of pressure (COP) developed during the controlled kick execution. The results showed the same behavior graph tendencies for average curves of trajectory, velocity and displacement of the inter-subject COM in the pre-kick, kick and post-kick, and graphic coherence of intra-subject average curves. However, there were no behavior graph tendencies for average inter-subject COP curves, and no coherence for the average intra-subject curves. Based on the results of this study, the analysis of CM demonstrate to be an effective tool for analysis of dynamic balance in athletes playing soccer during the course of the controlled task of the kick. / Doutor

Magister Scientiae (Physiotherapy) - MSc(Physio) / Literature has described soccer as the most popular sporting code in the world. South Africa heralds a registry of 1.8 million players. The purpose of the study was to conduct a detailed analysis of soccer injuries sustained in South African professional soccer team over one competitive season. The study utilized a questionnaire to collect quantitative data assessing age of players injures, playing position, site of injury, mechanism of injury, injury management, physiotherapy access and prevention measures which was administered by a physiotherapist at competitive matches. The study defined injury as any injury sustained during competitive matches where a player received medical attention. The study sample consisted of 26 male soccer players ranging from 17-39 years with a mean age of 23.77 years (SD=5.233). Injury prevalence was reported as 58% with a significance (p<0.05) in the ages of players injured compared to the non-injured. The majority of injuries were sustained by the 20-24 year old players coupled with midfielders being the most predominant position encountering injury (40%). The lower limbs were the most affected (67.1%) with the knee being reported as the most affected joint (21.4%). Defenders and midfielders were significantly more likely to sustain a lower limb injury compared to goalkeepers and forwards who were seen to incur more trunk injuries. The majority of injuries were the result of being tackled (27.2%). A significance was reported with mechanism of injury and playing position (Fisher’s Exact=41.118, p<0.05). Injurymanagement was predominantly self treatment followed by physiotherapy treatment (30%). The main contributor to the decrease in physiotherapy treatment received by players the absence of the service at the club (65.7%) and financial reasons (54.3%). The results of the study confirm that many SouthAfrican professional soccer players are prey to sustaining injury during one competitive soccer season. The study highlighted the need to start prevention efforts at club level in order to curtail the high injury prevalence at professional levels.

Orientador: Carlos Norberto Fischer / Banca: Afonso Antonio Machado / Banca: Gustavo Lima Isler / Resumo: Além de ser uma modalidade esportiva que envolve relações de cooperação e oposição, o futebol também é um ambiente de rica disponibilidade e aplicação de informações acerca do que ocorre nas partidas. Ao encontro disso, o presente trabalho centra inquietações em busca do entendimento das ocorrências do jogo de futebol e da relação destas com o resultado final das partidas. Dessa forma, o objetivo do estudo consiste em apontar indicadores e variáveis que apresentam maior influência nos resultados das partidas de futebol. A relevância do estudo pauta-se no fato de permitir a análise de vários indicadores (posse de bola, passes, finalizações, entre outros) da modalidade ao mesmo tempo, permitindo a identificação de alternativas que aumentem as chances de êxito. O estudo se caracteriza como uma pesquisa quantitativa, de caráter descritivo. Para atingir os objetivos, será utilizada como amostra os dados estatísticos referentes às 380 partidas da temporada 2015/2016 da Premier League, o campeonato Inglês, dados estes coletados junto ao website do jornal Inglês "Daily Mail". Também foram coletados dados referentes aos valores de mercado dos jogadores das equipes, obtidos no website do "Transfermarkt", especializado em determinação financeira de elencos. Como ferramentas auxiliares para o processo de análise dos dados coletados serão utilizados alguns recursos computacionais, mais especificamente, a planilha eletrônica e o aplicativo Weka, um programa que implementa vários algoritmos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Besides being a sport that involves cooperation and opposition relations, football is also an environment of rich informations availability and application about what occurs in the matches. To that, the present work focuses concerns looking for the understanding of the games occurrences and their relation with the final match results. In this way, the study's aim consists in pointing indicators and variables that show higher influence on football matches results' occurrence. The relevance of the study is based on allowing the analysis of many indicators (ball possession, passes, shots, among others) of the sport at the same time, allowing the alternatives' identification to increase chances of success. The study is characterized as a quantitative research, of described character. To reach the aim proposed, will be used as the sample the statistic data from the total of 380 Premier League, (English Football League) matches in the season 2015/2016, data obtained through accesses to Daily Mail's website (english periodic). The data related to the teams' market value were collected in the Transfermarkt' website, specialized in squads financial determination. As auxiliary instruments for the collected data analysis' process, some computational resources will be used, specifically, a spreadsheet and the Weka app, a program that implements many algorithms of data mining area. As initial analysis' results, numbers show that better conversion of the total shots in goals takes to a hig... (Complete abstract click electronic access below) / Mestre

Athletes participating in professional soccer are at an increased risk for long-term neurologic disease due to exposure of repetitive head trauma (MacKay et al., 2019). Recent studies have confirmed cases of dementia and chronic traumatic encephalopathy in retired professional soccer players who played during 1966 (McKee et al., 2014; Hales et al., 2014; Bieniek et al., 2015; Ling et al., 2017; Grinberg et al., 2016). It is suspected that repetitive sub concussive impacts from heading may be a contributing factor to the development of chronic neurological deficits (Matser et al., 1998; Witol & Webbe, 2003). It is unknown if current soccer players are at similar risk of brain trauma. Differences of soccer balls, rules changes, and evolution of the game, may have influenced total frequency and impact magnitude of heading. A comparison of frequency and impact magnitude of heading between 1966 and 2018, highlights the potential risk of chronic neurodegeneration in professional soccer players. Ten 1966 and ten 2018 FIFA World Cup matches were randomly chosen for video analysis. Total frequency of headers were documented for each game. Header exemplar reconstructions were completed in the laboratory using a 1966 Slazenger Challenge and 2018 Telstar 18 ball. A pneumatic linear impactor and projectile launcher were used to hit the ball and impact a Hybrid III head form to measure dynamic head response. A finite element model was then used to determine heading magnitudes as measured by Maximal Principal Strain (MPS). The study revealed there were no significant differences in overall frequency of headers between the 1966 and 2018 games. The year 2018 had significantly higher frequency of headers in the medium MPS category while, 1966 had significantly higher frequency in the high category. There were no significant differences of linear acceleration, angular acceleration, and MPS values when comparing the 2018 dry and 1966 dry ball at the same velocity and location. Current athletes who are heading the 2018 Telstar 18 are sustaining similar frequency and magnitudes of heading as athletes in 1966 under the same velocity and impact locations.

Background: There is growing participation in soccer at all levels of sport. Soccer increases the physical and psychological demands on players, which subsequently increase the risk of injuries. There are limited prospective epidemiological studies in Africa, and studies that have been conducted to date often fail to incorporate standardised injury definitions or reporting methods. Therefore, there is an urgent need to conduct epidemiological studies within the context of low to middle-income countries, where resources may be limited, and taking into consideration exposure times to design appropriate preventive measures. Aim: The purpose of the study was to explore the nature and incidence of soccer-related injuries in first division players in Rwanda, and to establish intrinsic risk factors for injuries. Methods: A prospective cohort study was conducted for two seasons. Eleven teams (326 players) and 13 teams (391 players) were followed for the seasons 2014-2015 and 2015-2016. Anthropometric and musculoskeletal screening composed of flexibility tests, strength and endurance, balance and proprioception tests, and lower limb function tests were conducted as well as training and match exposure were recorded. Team medical personnel recorded the location, type, duration and mechanism of time-loss injuries following the suggestion of the International Federation of Football Associations (FIFA). The primary outcome was the incidence of overall, training and match injury as well as body part, type, patterns and severity of injuries. Multivariate model using the Chi-squared Automatic Interaction Detection (CHAID) was used to assess intrinsic predictors of injury. Significance was accepted as p<0.05. Results: There were 455 injuries and approximately 46% of the players were injured in each of the two seasons. The team weighted mean incidence of match injuries was significantly lower during season one (14.2 injuries/ 1000 hours) compared to season two (21.9 injuries/ 1000 hours) (t(22)= -2.092, p=0.048). No difference was observed in the team-weighted incidence for overall and training injuries between the two seasons. There was increased injury incidence with increased acute: chronic training and match workload ratios. Lower extremities were the most frequently affected over the two seasons (80% of all injuries), with the knee joint most commonly injured (28% off all injuries) followed by the ankle joint (25% of all injuries). Ligament strains were the most common form of injury followed by muscle strains and contusions. The most common mechanisms of injury were collisions between players and receiving a tackle. About three quarters of the reported injuries were mild or moderate in severity and injuries to the Achilles tendon lead to the longest median lay-off time. The greatest incidence of injuries was sustained between the 46thand 60thminute of match play. A score of 11cm or less on the Sit and Reach test, more than one year in the current club and a timed hop of more than 2.5 seconds were all associated with injury. Conclusions: The rate of injuries found in this study is lower compared to the studies that reported injuries in adult male at either professional or amateur level. The patterns of training and match injuries, location, type and severity of injuries are similar to previous studies. Flexibility and balance, and coordination emerged as being significant predictors of increased risk of injury. More studies with emphasis on intrinsic and extrinsic factors are needed to attain wider knowledge concerning injuries among soccer players in Africa. Prevention intervention is necessary to minimise the of lower limb injuries.