Diseño y validación de un cuestionario socio-emocional para jóvenes futbolistas de élite. Desing and validation of a socio-emotional questionnaire for yourh footbal players

Validación de un cuestionario socio-emocional en fútbol

The spanish professional soccer foundations. (Las fundaciones clubes de futbol profesionales en España)

Sports foundations aiming at promoting sports activities partly outline the nonprofit area with specific concern. This study attempts to know the functions, general interests of professional soccer foundations in Spain, to describe their main characteristics and to ascertain if there are significant differences among them, according to their descriptive features. A document survey and analysis was carried out, with an assistance of own establishment of documental database. The findings not only indicate a significant difference between the classification of Spanish soccer foundations and their antiquities, but also manifest the tendency of the existence of physical person in members of founders with regard to its antiquity. The results of the present work implied that there were great dissimilarities of the elaboration of regulations depending on different regions in Spain.

On the Use of Situational and Body Information in Goalkeeper Actions during a Soccer Penalty Kick

Artículo Experimental

Analysis of dehidration and strenth in elite badminton players

Background: The negative effects of dehydration on aerobic activities are well established. However, it is unknown how dehydration affects intermittent sports performance. The purpose of this study was to identify the level of dehydration in elite badminton players and its relation to muscle strength and power production. Methodology: Seventy matches from the National Spanish badminton championship were analyzed (46 men?s singles and 24 women?s singles). Before and after each match, jump height and power production were determined during a countermovement jump on a force platform. Participants? body weight and a urine sample were also obtained before and after each match. The amount of liquid that the players drank during the match was also calculated by weighing their individual drinking bottles. Results and Discussion: Sweat rate during the game was 1.1460.46 l/h in men and 1.0260.64 l/h in women. The players rehydrated at a rate of 1.1060.55 l/h and 1.0160.44 l/h in the male and female groups respectively. Thus, the dehydration attained during the game was only 0.3760.50% in men and 0.3260.83% in women. No differences were found in any of the parameters analyzed during the vertical jump (men: from 31.8265.29 to 32.9064.49 W/kg; p.0.05, women: from 26.3664.73 to 27.2564.44 W/kg; p.0.05). Post-exercise urine samples revealed proteinuria (60.9% of cases in men and 66.7% in women), leukocyturia (men = 43.5% and women = 50.0%) and erythrocyturia (men = 50.0% and women = 21.7%). Conclusions: Despite a moderate sweat rate, badminton players adequately hydrated during a game and thus the dehydration attained was low. The badminton match did not cause muscle fatigue but it significantly increased the prevalence of proteinuria, leukocyturia and erythrocyturia.

Self perception of decision making competence in spanish football players

Background: It is known that competence to make decisions is a fundamental aspect of sport competition. Objective: This study has analyzed the decision profile of a sample of Spanish football players of different levels of expertise. Methods: 690 Spanish football players of national and international level completed the decision making questionnaire, which cover three dimensions ? perceived decision competence, decision anxiety and commitment with decision learning. MANCOVA and ANOVA analysis were carried out to analyse the differences in each dimension based on the level of expertise. Results: Results showed that perception of decision making competence increased and the anxiety decreased with the level of expertise. Conclusions: This study confirmed the usefulness of this questionnaire in the process of training for coaches and sport psychologists.

Time-motion analysis on Chinese male field hockey players

The aim of the study was to evaluate the match work-rate of Chinese field hockey players by analyzing the distance covered at different intensities pooled by specific positions during different periods of matches. Thirty-eight players from twenty-four male field hockey matches at the 11th Chinese National Games were filmed and analyzed.

Time-motion analysis on Chinese male field hockey players

The aim of the study was to evaluate the match work-rate of Chinese field hockey players by analyzing the distance covered at different intensities pooled by specific positions during different periods of matches. Thirty-eight players from twenty-four male field hockey matches at the 11th Chinese National Games were filmed and analyzed.mas

Self-perceptions of decision making competence in Spanish football players

Background: It is known that competence to make decisions is a fundamental aspect of sport competition. Objective: This study has analyzed the decision profile of a sample of Spanish football players of different levels of expertise. Methods: 690 Spanish football players of national and international level completed the decision mak- ing questionnaire, which cover three dimensions ? perceived decision competence, decision anxiety and commit- ment with decision learning. MANCOVA and ANOVA analysis were carried out to analyse the differences in each dimension based on the level of expertise. Results: Results showed that perception of decision making competence increased and the anxiety decreased with the level of expertise. Conclusions: This study confirmed the usefulness of this questionnaire in the process of training for coaches and sport psychologists.

Eccentric Exercise in Treatment of Patellar Tendinopathy in High Level Basketball Players. A Randomized Clinical Trial.

Chronic patellar tendinopathy is a common pathology in sporting population. To date, there is no agreed upon protocol as election treatment. Eccentric exercises have been used with satisfactory outcomes (3). The purpose of this trial was to compare the effects of two eccentric exercise protocols.

Eccentric exercise in treatment of patellar tendinopathy in high level basketball players. A randomized clinical trial

Chronic patellar tendinopathy is a common pathology in sporting population. To date, there is no agreed upon protocol as election treatment. Eccentric exercises have been used with satisfactory outcomes.

Evaluación del rendimiento de jugadores y equipos de fútbol de nivel de élite en diferentes contextos situacionales = Evaluation on Match Performances of Professional Football Players and Teams under Different Situational Conditions = 不同情境条件下高水平足球运动员和运动队的比赛表现分析

El análisis del rendimiento en deportes juega un papel esencial en el fútbol profesional. Aunque el estudio del análisis del juego en fútbol se ha utilizado desde diferentes ámbitos y situaciones, todavía existen diferentes aspectos y componentes del juego que siguen sin estar estudiados. En este sentido existen diferentes aspectos que deben de superar los estudios previos centrados en el componente descriptivo tales como el uso de variables/ indicadores de rendimiento que no se han definido ni estudiado, la validez de los métodos observaciones que no han sido testados con los softwares específicos en fútbol, la aplicación y utilidad de los resultados, así como las limitaciones del estudio de las variables situacionales/contextuales. Con el objetivo de cubrir las citadas limitaciones se han diseñado 6 estudios independientes e inter-relacionados que tratan de estudiar los aspectos anteriormente referidos. El primer estudio evalua la fiabilidad inter-observadores de las estadísticas de juego de la empresa privada OPTA Sportsdata, estos datos son la muestra de estudio de la presente tesis doctoral. Dos grupos de observadores experimentados se requieren para analizar un partido de la liga española de manera independiente. Los resultados muestran que los eventos de equipos y porteros codificados por los inter-operadores alcanzan un acuerdo muy bueno (valores kappa entre 0.86 y 0.94). La validez inter-observadores de las acciones de juego y los datos de jugadores individuales se evaluó con elevados niveles de acuerdo (valores del coeficiente de correlación intraclase entre 0.88 hasta 1.00, el error típico estandarizado variaba entre 0.00 hasta 0.37). Los resultados sugieren que las estadísticas de juego registradas por los operadores de la empresa OPTA Sportsdata están bien entrenados y son fiables. El segundo, tercer y cuarto estudio se centran en resaltar la aplicabilidad del análisis de rendimiento en el fútbol así como para explicar en profundidad las influencias de las variables situacionales. Utilizando la técnica de los perfiles de rendimiento de jugadores y equipos de fútbol se puede evaluar y comparar de manera gráfica, fácil y visual. Así mismo, mediante esta técnica se puede controlar el efecto de las variables situacionales (localización del partido, nivel del equipo y del oponente, y el resultado final del partido). Los perfiles de rendimiento de porteros (n = 46 porteros, 744 observaciones) y jugadores de campo (n = 409 jugadores, 5288 observaciones) de la primera division professional de fútbol Española (La Liga, temporada 2012-13), los equipos (n = 496 partidos, 992 observaciones) de la UEFA Champions League (temporadas 2009-10 a 2012-13) fueron analizados registrando la media, desviación típica, mediana, cuartiles superior e inferior y el recuento de valores de cada indicador de rendimiento y evento, los cuales se presentaron en su forma tipificada y normalizada. Los valores medios de los porteros de los equipos de diferentes niveles de La Liga y de los equipos de diferente nivel de la UEFA Champions League cuando jugaban en diferentes contextos de juego y situaciones (variables situacionales) fueron comparados utilizando el ANOVA de un factor y la prueba t para muestras independientes (localización del partido, diferencias entre casa y fuera), y fueron establecidos en los perfiles de red después de unificar todos los registros en la misma escala derivada con valores estandarizados. Mientras que las diferencias de rendimiento entre los jugadores de los mejores equipos (Top3) y los peores (Bottom3) fueron comparados mediante el uso de diferencias en la magnitud del tamaño del efecto. El quinto y el sexto estudio analizaban el rendimiento del fútbol desde un punto de vista de predicción del rendimiento. El modelo linear general y el modelo lineal general mixto fue empleado para analizar la magnitud de las relaciones de los indicadores y estadísticas de juego con el resultado final del partido en función del tipo de partido (partidos ajustados o todos los partidos) en la fase de grupos de la Copa del Mundo 2014 de Brasil (n = 48 partidos, 38 partidos ajustados) y La Liga 2012-13 (n = 320 partidos ajustados). Las relaciones fueron evaluadas mediante las inferencias en la magnitud de las diferencias y se expresaron como partidos extra ganados o perdidos por cada 10 partidos mediante la variable calculada en 2 desviaciones típicas. Los resultados mostraron que, para los 48 partidos de la fase de grupos de la Copa del Mundo 2014, nueve variables tuvieron un efecto positive en la probabilidad de ganar (tiros, tiros a puerta, tiros de contraataque, tiros dentro del área, posesión de balón, pases en corto, media de secuencia de pases, duelos aéreos y entradas), cuatro tuvieron efectos negativos (tiros bloqueados, centros, regates y tarjetas amarillas), y otras 12 variables tenían efectos triviales o poco claros. Mientras que los 38 partidos ajustados, el efecto de duelos aéreos y tarjetas amarillas fueron triviales y claramente negativos respectivamente. En la La Liga, existió un efecto moderado positive para cada equipo para los tiros a puerta (3.4 victorias extras por cada 10 partidos; 99% IC ±1.0), y un efecto positivo reducido para tiros totales (1.7 victorias extrsa; ±1.0). Los efectos de la mayoría de los eventos se han relacionado con la posesión del balón, la cual obtuvo efectos negativos entre equipos (1.2 derrotas extras; ±1.0) pero un efecto positivo pequeño entra equipos (1.7 victorias extras; ±1.4). La localización del partido mostró un efecto positive reducido dentro de los equipos (1.9 victorias extras; ±0.9). Los resultados obtenidos en los perfiles y el modelado del rendimiento permiten ofrecer una información detallada y avanzada para el entrenamiento, la preparación previa a los partidos, el control de la competición y el análisis post-partido, así como la evaluación e identificación del talento de los jugadores. ABSTRACT Match performance analysis plays an important role in the modern professional football. Although the research in football match analysis is well-developed, there are still some issues and problems remaining in this field, which mainly include the lack of operational definitions of variables, reliability issues, applicability of the findings, the lack of contextual/situational variables, and focusing too much on descriptive and comparative analysis. In order to address these issues, six independent but related studies were conducted in the current thesis. The first study evaluated the inter-operator reliability of football match statistics from OPTA Sportsdata Company which is the data resourse of the thesis. Two groups of experienced operators were required to analyse a Spanish league match independently in the experiment. Results showed that team events and goalkeeper actions coded by independent operators reached a very good agreement (kappa values between 0.86 and 0.94). The inter-operator reliability of match actions and events of individual outfield players was also tested to be at a high level (intra-class correlation coefficients ranged from 0.88 to 1.00, standardised typical error varied from 0.00 to 0.37). These results suggest that the football match statistics collected by well-trained operators from OPTA Sportsdata Company are reliable. The second, third and fourth study aims to enhance the applicability of football match performance analysis and to explore deeply the influences of situational variables. By using a profiling technique, technical and tactical performances of football players and teams can be interpreted, evaluated and compared more easily and straightforwardly, meanwhile, influences and effects from situational variables (match location, strength of team and opposition, and match outcome) on the performances can be properly incorporated. Performance profiles of goalkeepers (n = 46 goalkeepers, 744 full match observations) and outfield players (n = 409 players, 5288 full match observations) from the Spanish First Division Professional Football League (La Liga, season 2012-13), teams (n = 496 matches, 992 observations) from UEFA Champions League (seasons 2009-10 to 2012-13) were set up by presenting the mean, standard deviation, median, lower and upper quartiles of the count values of each performance-related match action and event to represent their typical performances and spreads. Means of goalkeeper from different levels of team in La Liga and teams of different strength in UEFA Champions League when playing under different situational conditions were compared by using one-way ANOVA and independent sample t test (for match location, home and away differences), and were plotted into the same radar charts after unifying all the event counts by standardised score. While differences between the performances of outfield players from Top3 and from Bottom3 teams were compared by magnitude-based inferences. The fifth and sixth study aims to move from the descriptive and comparative football match analysis to a more predictive one. Generalised linear modelling and generalised mixed linear modelling were undertaken to quantify relationships of the performance-related match events, actions and variables with the match outcome in different types of games (close games and all games) in the group stage of 2014 Brazil FIFA World Cup (n = 48 games, 38 close games) and La Liga 2012-13 (n = 320 close games). Relationships were evaluated with magnitude-based inferences and were expressed as extra matches won or lost per 10 matches for an increase of two standard deviations of a variable. Results showed that, for all the 48 games in the group stage of 2014 FIFA World Cup, nine variables had clearly positive effects on the probability of winning (shot, shot on target, shot from counter attack, shot from inside area, ball possession, short pass, average pass streak, aerial advantage, and tackle), four had clearly negative effects (shot blocked, cross, dribble and red card), other 12 variabless had either trivial or unclear effects. While for the 38 close games, the effects of aerial advantage and yellow card turned to trivial and clearly negative, respectively. In the La Liga, there was a moderate positive within-team effect from shots on target (3.4 extra wins per 10 matches; 99% confidence limits ±1.0), and a small positive within-team effect from total shots (1.7 extra wins; ±1.0). Effects of most other match events were related to ball possession, which had a small negative within-team effect (1.2 extra losses; ±1.0) but a small positive between-team effect (1.7 extra wins; ±1.4). Game location showed a small positive within-team effect (1.9 extra wins; ±0.9). Results from the established performance profiles and modelling can provide detailed and straightforward information for training, pre-match preparations, in-match tactical approaches and post-match evaluations, as well as for player identification and development. 摘要 比赛表现分析在现代足球中起着举足轻重的作用。尽管如今对足球比赛表现分析的研究已经相对完善，但仍有很多不足之处。这些不足主要体现在：研究中缺乏对研究变量的清晰定义、数据信效度缺失、研究结果的实用性受限、比赛情境因素缺失以及过于集中在描述性和对比性分析等。针对这些问题，本论文通过六个独立而又相互联系的研究，进一步对足球比赛表现分析进行完善。 第一个研究对本论文的数据源--OPTA Sportsdata公司的足球比赛数据的信效度进行了实验检验。实验中，两组数据收集人员被要求对同一场西班牙足球甲级联赛的比赛进行分析。研究结果显示，两组收集人员记录下的球队比赛事件和守门员比赛行为具有高度的一致性(卡帕系数介于0.86和0.94)。收集人员输出的外场球员的比赛行为和比赛事件也具有很高的组间一致性(ICC相关系数介于0.88和1.00，标准化典型误差介于0.00和0.37)。实验结果证明了OPTA Sportsdata公司收集的足球比赛数据具有足够高的信效度。 第二、三、四个研究旨在提升足球比赛表现分析研究结果的实用性以及深度探讨比赛情境因素对足球比赛表现的影响。通过对足球运动员和运动队的比赛技战术表现进行档案创建，可以对运动员和运动队的比赛表现进行简直接而直观的呈现、评价和对比，同时，情境变量(比赛场地、球队和对手实力、比赛结果)对比赛表现的影响也可以被整合到表现档案中。本部分对2012-13赛季西班牙足球甲级联赛的参赛守门员(n = 46球员人次，744比赛场次)和外场球员(n = 409球员人次, 5288比赛场次)以及2009-10至2012-13赛季欧洲足球冠军联赛的参赛球队(n = 496比赛场次)的比赛技战术表现进行了档案创建。在表现档案中，各项比赛技战术指标的均值、标准差、中位数和大小四分位数被用来展现守门员、外场球员和球队的普遍表现和表现浮动性。方差分析(ANOVA)被用来对西甲不同水平球队的守门员、欧冠中不同水平球队在不同比赛情境下的普遍表现(各项指标的均值)进行对比，独立样本t检验被用来对比主客场比赛普遍表现的差异。数据量级推断(magnitude-based inferences)的方法则被用来对西甲前三名和最后三名球队外场球员的普遍表现进行对比分析。所有来自不同水平球队的运动员和不同水平运动队的各项比赛指标皆被转换成了标准分数，从而能把他们在各种不同比赛情境下的普遍表现(各项比赛指标的均值)投到相同的雷达图中进行直观的对比。 第五和第六个研究目的在于进行预测性足球比赛表现分析，从而跨越之前固有的描述性和对比性分析。广义线性模型和广义混合线性模型被用来对2014年巴西世界杯小组赛(n = 48 比赛场次，38小分差场次)和2012-13赛季西甲联赛(n = 320小分差场次)的比赛中各表现相关比赛事件、行为和变量与比赛结果(胜、平、负)的关系进行建模。模型中的关系通过数据量级推断(magnitude-based inferences)的方法来界定，具体表现为某个变量增加两个标准差对比赛结果的影响(每10场比赛中额外取胜或失利的场数)。研究结果显示，在2014年巴西世界杯小组赛的所有48场比赛中，9个变量(射门、射正、反击中射门、禁区内射门、控球、短传、连续传球平均次数、高空球争抢成功率和抢断)与赢球概率有清晰的正相关关系，4个变量(射门被封堵、传中、过人和红牌)与赢球概率有清晰的负相关关系，其他12个被分析的变量与赢球概率的相关关系微小或不清晰。而在38场小分差比赛中，高空球争抢成功率由正相关变为微小关系，黄牌则由微小关系变为清晰的负相关。在西甲联赛中，每一支球队增加两个标准差的“射正球门”可以给每10场比赛带来3.4场额外胜利(99%置信区间±1.0场)，而所有球队作为一个整体，每增加两个标准差的“射正球门”可以给每10场比赛带来1.7场额外胜利(99%置信区间±1.0场)。其他大多数比赛相关事件与比赛结果的相关关系与“控球”相关联。每一支球队增加两个标准差的“控球”将会给每10场比赛带来1.2场额外失利(99%置信区间±1.0场)，而所有球队作为一个整体，每增加两个标准差的“控球”可以给每10场比赛带来1.7场额外胜利(99%置信区间±1.4场)。与客场比赛相对，主场能给球队带来1.9 /10场额外胜利(99%置信区间±0.9场)。 比赛表现档案和模型中得出的研究结果可以为俱乐部、足球队、教练组、表现分析师和运动员提供详细而直接的参考信息。这些信息可用于训练指导、赛前备战、赛中技战术调整和赛后技战术表现分析，也可运用于足球运动员选材、培养和发展。

Análisis de la actividad física competitiva en jugadores de fútbol de un equipo de excelencia

OBJETIVO: Esta tesis doctoral pretende analizar el rendimiento en fútbol desde un punto de vista físico de los jugadores de un equipo de excelencia (EE). Se entiende como EE a un equipo que presenta un prolongado bagaje de éxitos nacionales e internacionales a lo largo de varios años. MÉTODO: Se utilizó el sistema de registro (AMISCO) de la actividad del jugador de fútbol en competición (distancia total recorrida, distancias a distintas velocidades, y número de sprints) analizando a lo largo de seis temporadas continuada la actividad de jugadores de élite (N=2082), siendo 1051 pertenecientes al EE y 1031 a jugadores de los equipos rivales (ER). RSULTADO: El perfil de actividad (distancia total, distancia en distintas velocidades y nº de sprints) de los jugadores del EE muestran valores inferiores al de los jugadores de los ER. De igual forma ocurre en cada una de las partes del partido, el puesto específico de juego de los jugadores en las distintas temporadas analizadas y en los distintos meses de la temporada. El EE registra una mayor actividad (distancia total recorrida en el partido, distancia recorrida en velocidades altas V>17 km/h y nº de Sprints) cuando juega de local a cuando lo hace como visitante. Asimismo EE muestra demandas superiores de exigencia física en la competición europea (Champions League) frente a la Liga en la distancia total recorrida en el partido y a velocidades bajas (V<17 km/h), mientras que apenas muestra diferencias en los indicadores de exigencia física cuando se enfrenta a los equipos rivales de distinto nivel de rendimiento, exceptuando en la distancia recorrida andando (V=01-11 km/h) con diferencias significativas superiores cuando el nivel del oponente es de Máxima dificultad frente a Elevada dificultad (p<.01) o Media dificultad (p<.01). En función del estilo de juego se registran diferencias en la distancia total recorrida en el partido, en velocidades bajas (V<17 km/h) y en el nº de Sprints (V>24 km/h). Por último, el perfil de actividad del EE no se ve influenciado por el efecto de estar sometido a una alta densidad competitiva (jugar un partido entre semana). Se constata como un jugador de un EE está supeditado no sólo a las exigencias del puesto específico sino también está sujeta a las características propias del jugador al desempeñar el rol o función táctica encomendada. Esta influencia es más evidente en jugadores que ocupan puestos específicos avanzados. CONCLUSION: La presente investigación aporta la caracterización de la actividad de los jugadores de un EE frente al perfil de actividad de sus rivales, mostrando un nivel de respuesta específica y diferente, más estable frente a determinadas variables contextuales y donde la exigencia física en el puesto específico se ve condicionada por las características individuales del jugador, todos estos aspectos pueden ayudar a la hora de planificar el entrenamiento en este tipo de equipos. ABSTRACT OBJETIVE: This doctoral thesis aims to analyze the performance in football from a physical point of view on a team of excellence. METHOD: The registration system (AMISCO) activity soccer player in competition (total distance traveled distances at different speeds, and number of sprints) was used to analyze over six seasons continued activity elite players (N = 2082), with 1051 belonging to Team Excellence (EE) and 1031 players from rival teams (ER). RESULT: The competitive physical response of the US players are analyzed and compared with that of ER. The activity profile (total distance, distance at different speeds and number of sprints) of EE players shown below players ER values. The same occurs in each of the parts of the game, the specific game since players analyzed in different seasons and in different months of the season. The EE recorded increased activity (total distance traveled in the match, distance at high speeds V> 17 km / h and sprints number) when playing a local when it does on the road. EE also shows higher demands physical demands in European competition (Champions League) against the League in the total distance traveled in the party and at low speeds (V <17 km / h), while just shows differences in indicators of demand physics when the opposing teams with different levels of performance faces, except in the distance walked (V = 01-11 km / h) with significant differences when higher level Maximum opponent is facing difficulty High difficulty (p < .01) or Medium difficulty (p <.01). Depending on the style of play differences are recognized in the total distance traveled in the party, at low speeds (V <17 km / h) and the number of Sprints (V> 24 km / h). Finally, the activity profile of EE is not influenced by the effect of being subjected to a high competitive density (play a game during the week). It is found as a player on a team of Excellence is subject not only to the requirements of the specific position but is also subject to the characteristics of the player to play the role or function entrusted tactics. This influence is most evident in advanced players who occupy specific positions. CONCLUSION: This research provides the characterization of the activity of EE players versus activity profile of its rivals, showing a level of response specific and different, more stable against certain contextual variables and where the physical demands on the specific position is conditioned by the individual characteristics of the player, all these aspects can help in planning training in this type of equipment.

Performance variability in basketball players with intellectual impairment: Ankara World Championships 2013 analysis

The aim of the present study was to identify performance variability in basketball for players with intellectual impairment (II) and to compare it with able-bodied (AB) players. Official game statistics from the 13 games played in the Ankara World II-Basketball Championships (2013) were gathered and descriptive data, variability coefficient (VC), maximum scores and its Z-score were calculated from those players who participated at least 10 minutes per game (N = 46; guards = 10, forwards = 21, centers = 15). Results indicated higher performance variability and lower efficiency in shooting percentages and turnovers in II-players comparing with studies in ABplayers. Differences found between game positions indicated similar roles of guards, forwards and centers in II and AB-players. These findings are relevant to understand how II impact on basketball performance, which is a necessary step to develop specific eligibility systems in II-basketball according to the guidelines of the International Paralympic Committee.

Análisis de la incidencia lesional en el fútbol profesional español en la temporada 2008-2009

Se ha descrito en la literatura como el fútbol es un deporte en cuya práctica existe una alta incidencia de lesión. Sin embargo, en España, hasta el momento no se había llevado a cabo ningún estudio que analizara la incidencia de lesión de los jugadores de fútbol profesional. Para poder prevenir lesiones, en primer lugar debemos de identificar la magnitud del problema, así como conocer aquellos factores que pueden influir sobre la producción de lesiones, Éste es principal objetivo de nuestro estudio para, a partir de él, poder diseñar e introducir en la práctica deportiva medidas preventivas con el objetivo de disminuir la incidencia de lesión en el fútbol. Hay que considerar que nos encontramos ante un estudio descriptivo, el cual se caracteriza, por no tener una hipótesis previa. En él nos planteamos como principal objetivo el conocer la influencia de los diferentes factores que influyen en la posibilidad de sufrir una lesión en el fútbol, además de realizar un análisis que describiera las lesiones sufridas, así como sus periodos de recuperación, en el fútbol profesional español, En esta investigación, participaron 27 equipos pertenecientes a la primera y segunda división española (728 jugadores), registrándose durante la temporada 2008- 2009 un total de 2184 lesiones. Para el registro de las lesiones, se utilizó el cuestionario REINLE cumplimentado de forma confidencial por miembros del equipo técnico de los clubes colaboradores, a través de la base de datos LEFUTPRO con acceso vía internet. Como dato general, encontramos que en la práctica del fútbol profesional existe una elevada incidencia de lesión con 8,92 les.*1000h. de exposición, siendo ésta mayor en competición (41,33 les.*1000h.) que en entrenamiento (6,02 les.*1000h.), valores muy acordes a los encontrados en la literatura científica especifica. Se registraron un promedio de 81 lesiones que causaron baja por equipo y temporada, provocando una ausencia media por lesión de 11,3 días. De estas lesiones, el 11,9% de ellas fueron de carácter recidivante, las cuales causaron periodos de baja superiores a las lesiones iníciales, alcanzando un valor promedio de 17,9 días de baja por lesión. El 84,4% las lesiones que se registraron, se localizaron en la extremidad inferior, siendo el muslo, con un 30,5% de todas las lesiones, la región corporal más afectada. A su vez, dentro del muslo, el 53% de las lesiones se localizaron en la región posterior, dentro de la cual, en el 73% de los casos la lesión afectó al bíceps femoral. Además, se encontró una mayor frecuencia de lesión en la pierna dominante (54,4% de las todas las lesiones) frente a la no dominante (36,5% de las todas las lesiones). Desde el punto de vista de la tipología de la lesión, las lesiones de carácter muscular con un 49,1% de los casos, fueron las más frecuentes, seguidas de las lesiones ligamentosas con un 15,1% de los casos. Los mecanismos de producción de lesiones en el jugador sin contacto, fueron más frecuentes (69,1% de todos los casos), que aquellos mecanismos de lesión en los que si hubo contacto (30,9%). En relación al momento de producción de lesión a lo largo de la temporada, se encontró que las lesiones sufridas en entrenamiento fueron progresivamente menos frecuentes con el transcurso de la temporada, mientras que en la competición se fueron incrementando, siendo los últimos meses de la temporada cuando se registraron la mayor parte de las lesiones. A partir de este estudio, proponemos ampliar la investigación en esta línea, concretando algunos de los aspectos que hemos podido identificar a través de nuestros resultados, y que en un futuro puedan tener alguna aplicación práctica en el objetivo común de reducir la incidencia de lesión existente en la práctica deportiva del fútbol. ABSTRACT Football has been described in literature as a sport in which there is a high incidence of injuries. Nevertheless, in Spain, to date, not a single study analyzing the incidence of lesions in professional football players has been carried out. In order to prevent lesions, in the first place we must identify the magnitude of the problem, as well as discover those factors that may influence on the production of lesions, being the latter the main objective of our study, and hence, starting from this point, be able to design and introduce in sports practice preventive measures with the aim of decreasing the incidence of lesions. We must take into consideration that we are before a study characterized by the fact of not having a previous hypothesis. In the present study, our main areas of focus is finding out the different factors that have influence on the possibility of suffering a lesion in this sports practice, as well as carrying out an analysis that describes the lesions suffered in professional football, as well as the necessary recovery periods. 27 teams (728 players), belonging to Spain’s First and Second Football (soccer) Divisions took part in this research. During the 2008-2009 season, a total of 2,184 lesions were registered. To register the lesions, a REINLE questionnaire, of the LEFUTPRO database was used, with access via internet. Each of the participating teams was given a password in a totally confidential manner. In the first place, we found that in the practice of professional football there exists a high incidence of lesions, with 8.92 lesions per 1000 h. of exposure. We found an increase in lesions during competitions (41.33 lesions per 1000 h.) with respect to those occurring during training (6.02 lesions per 1000 h.); these values being in accordance with those found in specific scientific literature. An average of 81 lesions that implied sick leaves were registered per team and season, causing an average of 11.3 days of absence per lesion. Of these, 11.9% of all the lesions studied were recurrent, causing longer sick leave periods than the ones due to the initial lesions and reaching an average of 17.9 days of sick leave per lesion. 84.4% of the lesions registered were located in the inferior extremities, the thigh being the anatomical region, with 30.5% of all the lesions, the most affected body region. In turn, 53% of the lesions to the thigh occurred in the posterior area, and within the latter, in 73% of the cases, the lesion affected the femoral biceps. In addition, we found a greater frequency of lesions in the dominant leg (54.4% of all the lesions), in contrast with the non dominant leg (36.5% of all the lesions). From the point of view of lesion type the most frequent lesions were muscular (49.1% of all cases), followed by ligament lesions (15.1%). Most of the lesions were produced during moments in which the players were not in physical contact at the moment of suffering the injury (69.1%), in comparison with those produced when there was physical contact (30.9%). With relation to the instance in which the injuries were produced along the season, we found that those lesions suffered during training were progressively less frequent as the season wore on, whilst those suffered during competitions gradually incremented, being the last months of the season when most of the injuries were registered. From the research of this study, we propose the need to carry out more research in this same line, focalizing on some more concrete aspects, which, through our results, we have been able to realize that would be interesting to study in greater depth, and that in the future, our results may have a practical application, helping reduce the incidence of injuries that exist in this sport practice.