Efecto agudo del programa Knäkontroll sobre parámetros del rendimiento físico en jugadores de fútbol de categoría juvenil

Soccer is a sport that, due to the high physical demands it requires, entails a high injury risk. Given the magnitude of the problem, researchers have opted to design preventive strategies with the aim of minimizing the incidence of injuries in this sport. These strategies have been structured as warm-up programs. However, evidence on the acute effect of these interventions on parameters of physical performance is scarce. Therefore, the aim of the current study was to assess the acute effect of the Knäkontroll program (level B) on several parameters of physical performance in youth soccer players. A quasi-experimental pre-test and post-test design was used, including the dynamic stability of the lower extremity (Y-Balance Test), the landing kinematics during a vertical jump (Tuck Jump Assessment [TJA]), the ankle dorsiflexion range of motion (ROM-Sport), and the performance of unilateral jumping in the horizontal (Single-Legged Hop Tests) and vertical (Single Leg Countermovement Jump [SLCMJ]) directions as main measures of physical performance. The results showed a significant increase on all physical performance measures after the implementation of the Knäkontroll program, with the exception of the SLCMJ and TJA. In conclusion, the Knäkontroll program may be viewed as a suitable warm-up strategy to be implemented prior to soccer practice. However, the inclusion of additional plyometric exercises might contribute to improve the players’ performance in vertical jumping skills.El fútbol es un deporte que, por la alta exigencia física que requiere, lleva asociado un elevado riesgo de lesión. Dada la magnitud del problema, los investigadores han optado por diseñar estrategias preventivas que ayuden a minimizar la incidencia de lesión en este deporte. Estas estrategias se han organizado como programas de calentamiento previo a la participación en el deporte. Sin embargo, la evidencia sobre el efecto agudo de estas intervenciones sobre parámetros del rendimiento físico es escasa. Por tanto, el objetivo del presente estudio fue analizar el efecto agudo del programa Knäkontroll (nivel B) sobre parámetros del rendimiento físico en jugadores de fútbol de categoría juvenil. Para ello, se utilizó un diseño cuasi-experimental pre-test y post-test, empleando la estabilidad dinámica de la extremidad inferior (Y-Balance Test), la cinemática de la caída en salto vertical (Tuck Jump Assessment [TJA]), el rango de movimiento articular de la dorsiflexión de tobillo (ROM-Sport), la distancia de salto horizontal unilateral (Single-Legged Hop Tests), y la altura de salto vertical unilateral (Single Leg Countermovement Jump [SLCMJ]) como principales medidas del rendimiento físico. Los resultados mostraron un incremento significativo del rendimiento para todas las variables tras la implementación del programa Knäkontroll, a excepción de la altura en el SLCMJ y la cinemática en el TJA. En conclusión, el programa Knäkontroll se presenta como una estrategia adecuada para su aplicación como calentamiento previo a la práctica del fútbol. No obstante, la inclusión de ejercicios (o variantes) adicionales que trabajen el componente pliométrico podría contribuir a la mejora del desempeño en el salto vertical

IS FRONTAL PLANE PROJECTION ANGLE RELATED TO STIFF LANDING PATTERNS? AN ANALYSIS OF DROP JUMP AND TUCK JUMP TASKS

The purpose of this study was to examine the relationship between frontal plane knee projection angle (FPPA) and sagittal (hip and knee flexion) plane landing kinematic measures during a drop jump (DVJ) and a tuck jump assessment (TJA) test in male youth football players. Eighty-one post-pubertal male footballers were recorded performing DVJ and TJA tasks, and FPPA as well as hip (HF) and knee (KF) flexion angles at peak flexion were retrospectively assessed. The main results show that players with greater knee FPPA (valgus) display lower HF values than players with no knee valgus alignment during DVJ landings, but not during TJA. A DVJ pattern which exhibits knee valgus and limited HF angles may increase the risk of knee injury and thus, strategies for hip strengthening and technique modification should be applied to players with this mechanical profile

Competitive Psychological Disposition and Perception of Performance in Young Female Soccer Players

The athletes’ psychological disposition is a factor that is increasingly considered by researchers as a key to sports performance, even as a mediator between the physical, technical and tactical abilities of the athlete and their competitive performance, thus acquiring great relevance in training and in sports performance. The purpose of this study is to analyze the psychological characteristics of young soccer players and their relation to their performance perception, made both by the player herself and by their coaches. The sample is composed of 108 women (M age = 15.53, SD age = 1.05), with ages between 13 and 17 years (13 years, n = 1, 14 years, n = 18, 15 years, n = 36, 16 years, n = 29, 17 years, n = 24), and with a sport practice experience of 7.27 years on average (SD = 2.64). For to address this aim, we used the Psychological Characteristics related to the Sport Performance Questionnaire (CPRD) and the Psychological Skills Inventory for Sports (PSIS). In addition, regarding the evaluation of performance perception, an ad hoc short questionnaire was created, composed by one question addressed to the player and one directed to the coach. The results indicate that the group of players of the under-16 category obtained higher scores in all the psychological dimensions than the U-18 players, showing significant differences in Team Cohesion (p < 0.048). Regarding the degree of congruence between the player’s psychological features, and the player’s and coach’s performance perceptions, the results show statistically significant and negative correlations between the Team Cohesion factor and the athlete’s own outcome perception for the match #1 (rxy = -0.479; p < 0.001), and match #2 (rxy = -0.402; p < 0.01). The results of this study may contribute to establish the differences between different constellations of psychological characteristics according to the categories of competition and their relationship with the perception of performance. This knowledge can be used by sports professionals: coaches, psychologists, physical educators, etc., in order to help athletes to reach their maximum performance

Elite futsal: sex-based differences in players’ flexibility

El objetivo del presente estudio fue analizar las diferencias del perfil de flexibilidad muscular de la extremidad inferior según sexo en jugadores/as españoles de fútbol sala de élite. Un total de 22 deportistas (12 hombres, 10 mujeres) fueron valorados mediante el protocolo ROM-SPORT siguiendo las recomendaciones establecidas por la American Medical Association. Se realizó un análisis descriptivo de diez rangos de movimiento de la extremidad inferior. Una prueba t para muestras independientes se aplicó para observar la existencia de diferencias significativas entre sexos. El análisis estadístico encontró diferencias significativas en el rango de movimiento (ROM) de la rotación interna de la cadera, en el ROM de la rotación externa de la cadera, en el ROM de la abducción de la cadera, en el ROM de la abducción de la cadera con ésta flexionada, en el ROM de la extensión de la cadera y en el ROM de la flexión de la rodilla. Sin embargo, no siempre se encontraron mejores valores para las jugadoras. Los jugadores de élite de fútbol sala presentaron valores superiores de flexibilidad en los músculos aductores, psoas-iliaco y cuádriceps. Por el contrario, las jugadoras presentaron valores superiores en los músculos rotadores de la cadera.The objective of the present study was to analyze the differences in muscle flexibility profile according to sex in elite futsal players. A total of 22 players (12 men, 10 women) were assessed using the basic version of the ROM-SPORT protocol following the recommendations established by the American Medical Association. A descriptive analysis of the values of the ten movements evaluated was performed. A t-test for independent samples was applied to observe the existence of significant differences between sexes. Statistical analysis found significant differences in the range of motion (ROM) of the internal rotation of the hip, the ROM of the external rotation of the hip, the ROM of the hip abduction, the ROM of abduction of the hip with it flexed, in the ROM of the hip extension and in the ROM of the knee flexion. Elite male futsal players have higher flexibility values than female players of the same sport and competitive level in the adductor, ilio-psoas and quadriceps muscles. By contrast, female futsal players have higher values in the rotator muscles of the hip.peerReviewe

Psychological intervention program to control stress in youth soccer players

The influence on the psychological well-being of the players and their sports performance seems to be one of the keys to the current sports practice. The purpose of this study was to determine the effectiveness of a psychological intervention program for stress control in youth soccer players. A total sample of 19 male youth soccer players (age: 16.3 ± 0.99 years; years playing soccer: 10.89 ± 1.56 years) completed the current research. The Psychological Characteristics Questionnaire related to Sports Performance (CPRD) was used to assess stress factors related to sports competition. A program based on Cognitive-Behavioral Therapy was implemented during eight sessions of approximately 50 min each. A pre-post design was used and statistical differences between pre- and post-measures were checked through dependent sample t-tests. The results indicated that the post-test scores were higher than the pre-tests in "Influence of the Evaluation of Performance" and "Mental Skills" factors, which supposes a significant improvement of the stress management related to performance evaluation, as well as the use of psychological resources and techniques. In addition, the post-test scores were also higher in the "Stress Control" factor, although in this case the differences were not statistically significant. Practical indications deriving from the findings of this study can help youth soccer players to manage the stress of competition using a psychological training program

Programa Stop & Go: pruebas de campo para la identificación del riesgo de lesión en jugadores jóvenes de deportes de equipo

The main aim of this study is to describe the battery of questionnaires and field-based tests proposed by the Stop & Go programme for the assessment of the main risk factors for lower extremity injury in youth athletes. The 4 questionnaires and 21 field-based tests that comprise the Stop & Go battery were selected according to scientific criteria (high validity and reliability scores) and can be grouped into three main parts. The first part includes procedures aimed at obtaining information related to the athletes’ personal or individual characteristics (e.g., body composition, maturity status and sports experience). The second part includes a series of questionnaires that assess psychological constructs related to sport performance (e.g., anxiety, stress and motivation). Finally, the third part presents physical tests designed to assess a large number of physical performance measures (e.g., jump height and length, and 30 m sprint time), mechanics of fundamental motor skills (e.g., landing after jumping actions and change of direction), neuromuscular capacity (e.g., muscle stiffness, static and dynamic stability), sagittal integral morphotype, and lower extremity joints range of motion. For those scenarios where there are significant time constraints and limited human and equipment resources, this study also presents a basic or reduced proposal composed of only 6 assessment tests. In particular, this basic proposal brings together those tests that, in the authors’ opinion, could be considered as the minimum necessary for the identification of athletes with a high probability of suffering a lower extremity soft tissue (muscle, tendon or ligament) injury.El objetivo principal del presente estudio es describir la batería de cuestionarios y pruebas de campo del Programa Stop & Go para la valoración de los principales factores de riesgo de lesión de la extremidad inferior en jóvenes deportistas. Los 4 cuestionarios y 21 pruebas de campo que componen la batería Stop & Go fueron seleccionados de acuerdo a criterios científicos (altas puntuaciones de validez y fiabilidad), pudiendo ser estas agrupadas en tres grandes bloques. El primer bloque incluye procedimientos destinados a la obtención de información relacionada con las características personales o individuales de los deportistas (ej.: composición corporal, etapa madurativa y experiencia deportiva). Por su parte, el segundo bloque contiene una serie de cuestionarios que evalúan constructos psicológicos relacionados con el rendimiento deportivo (ej.: ansiedad, estrés y motivación). Finalmente, el tercer bloque presenta pruebas físicas diseñadas para valorar un elevado número de medidas del rendimiento físico (ej.: altura y longitud de salto, y tiempo en el sprint de 30 m), mecánica de las habilidades motrices fundamentales (ej.: aterrizaje tras acciones de salto y cambio de dirección), capacidad neuromuscular (ej.: rigidez muscular, estabilidad estática y dinámica), disposición sagital del raquis y rango de movimiento articular de la extremidad inferior. Para aquellos escenarios donde existan importantes limitaciones de tiempo y escasez de recursos humanos y materiales, este estudio también presenta una propuesta básica o reducida de la batería Stop & Go compuesta por 6 pruebas de valoración. En particular, esta propuesta básica reúne aquellas pruebas que, a juicio de los autores, podrían ser consideradas como las mínimas necesarias para la identificación de deportistas con una alta probabilidad de sufrir una lesión del tejido blando (músculo, tendón o ligamento) de la extremidad inferior

Effect of age category on the flexibility profile in young taekwondo athletes

[ES] El objetivo principal del presente estudio fue conocer el efecto de la categoría de edad sobre el perfil de flexibilidad en jóvenes taekwondistas usando pruebas angulares. Fueron reclutados un total de 17 taekwondistas jóvenes, que se clasificaron según su categoría federativa de edad en cadetes y junior. El rango de movimiento de los principales movimientos de la extremidad inferior fue valorado mediante el protocolo “ROM SPORT”. Se realizó un análisis descriptivo de cada una de las variables cuantitativas, que incluía la media y su correspondiente desviación típica. Una prueba t‐test fue empleada para determinar la existencia de diferencias entre la extremidad dominante y no dominante. Además, la misma prueba estadística analizó la interacción entre los 11 movimientos seleccionados y las categorías de edad. Por último, se calculó el tamaño del efecto de los resultados. Los resultados mostraron diferencias significativas entre ambas categorías en EC (psoas‐ilíaco), RIC (rotadores externos), REC (rotadores internos) y rotación total de la cadera (suma del RIC y REC). Estos resultados no coinciden con otros estudios que han valorado la flexibilidad en este mismo deporte. Los taekwondistas cadetes presentan valores de flexibilidad superiores a la categoría junior en los músculos rotadores internos y externo de cadera y en el psoas‐iliaco.[EN] The main aim of this study was to analyze the effect of the age category on the flexibility profile in young taekwondo athletes, by using angular tests. A total of 17 young taekwondo athletes were recruited, who were classified according to their federative age category. The range of motion of the main movements of the lower extremity was assessed by using the "ROM SPORT" protocol. A descriptive analysis was made of each of the quantitative variables, which included means and standard deviations. A t‐test was used to determine the existence of differences between the dominant and non‐dominant limbs. In addition, the same statistical test analyzed the interaction between the 11 selected movements and age categories. Finally, the effect size of the results was calculated. The results showed significant differences between cadets and juniors categories in EC (iliopsoas), RIC (external rotators), REC (internal rotators) and total rotation of the hip (sum of RIC and REC). These results are not in tune with other studies that have assessed flexibility in taekwondo. Cadet taekwondo athletes had higher values of flexibility than the junior category in the internal and external rotator muscles and in the psoas‐iliac

Effect of age category on the flexibility profile in young taekwondo athletes

The main aim of this study was to analyze the effect of the age category on the flexibility profile in young taekwondo athletes, by using angular tests. A total of 17 young taekwondo athletes were recruited, who were classified according to their federative age category. The range of motion of the main movements of the lower extremity was assessed by using the "ROM SPORT" protocol. A descriptive analysis was made of each of the quantitative variables, which included means and standard deviations. A t-test was used to determine the existence of differences between the dominant and non-dominant limbs. In addition, the same statistical test analyzed the interaction between the 11 selected movements and age categories. Finally, the effect size of the results was calculated. The results showed significant differences between cadets and juniors categories in EC (iliopsoas), RIC (external rotators), REC (internal rotators) and total rotation of the hip (sum of RIC and REC). These results are not in tune with other studies that have assessed flexibility in taekwondo. Cadet taekwondo athletes had higher values of flexibility than the junior category in the internal and external rotator muscles and in the psoas-iliac

Analysis of the flexibility profile in young taekwondo athletes

[ES] El objetivo principal del presente estudio fue determinar el perfil de flexibilidad de la extremidad inferior en atletas jóvenes de taewwondo, así como identificar los deportistas con cortedad muscular. Para ello, un total de 17 taekwondistas jóvenes participaron en el presente estudio; siete deportistas pertenecían a la selección española y diez a la selección Murciana. El rango de movimiento de los principales movimientos de la extremidad inferior fue valorado mediante el protocolo “ROM SPORT” y se realizó un análisis descriptivo de cada una de las variables cuantitativas. Se aplicó la prueba t­test de Student o Wilcoxon dependiendo de la normalidad de los datos. Los valores de ROM de cada movimiento se clasificaron como “normal” o “cortedad” de acuerdo con valores de referencia previamente justificados. Los resultados definen como perfil de flexibilidad en 23º para psoas‐iliaco, 28º para piramidal, 37º para gemelos, 42º para sóleo, 46º para aductores, 46º para rotadores externos, 56º para rotadores internos, 77º para aductores monoarticulares, 80º para isquiosurales, 140º para cuádriceps y 145º para glúteo mayor. La medición individual del ROM identificó cortedad muscular en 11 deportistas en piramidal (64,7%), 13 deportistas en sóleo (76,4%), 8 deportistas en rotadores externos (47%), 14 deportistas en aductores monoarticulares (82,3%), 13 deportistas en isquiosural (76,4%), 4 deportistas en cuádriceps (23,5%) y 12 en glúteo mayor (70,5%). Este perfil de flexibilidad puede ayudar a los profesionales del deporte a marcar objetivos cuantificables en el entrenamiento de la flexibilidad en este deporte. La inclusión de estiramientos o el aumento de la dosis deben de aplicarse sobre las cortedades identificadas en piramidal, sóleo, rotadores externos de cadera, aductores monoarticulares, isquiosural, cuádriceps y glúteo mayor.[EN] The main aim of this study was to determine the flexibility profile of the lower extremity in young taekwondo athletes, as well as identifying athletes with muscle shortness. For this purpose, a total of 17 young taekwondo athletes were assessed; seven from the Spanish team and ten from the Murcia team. The range of motion of the main movements of the lower extremity was evaluated by the "ROM SPORT" protocol and a descriptive analysis of each of the quantitative variables was performed. A Student t‐test or arWilcoxon test was applied depending on the normality distribution of the data. The ROM values of each movement were classified as “normal” or “shortness” according to previously determined reference values. The results define the following flexibility profile: 23º for iliopsoas, 28º for piriformis, 37º for gastrocnemius, 42º for soleus, 46º for adductors, 46º for external rotators, 56º for internal rotators, 77º for monoarticular adductors, 80º for hamstrings, 140º for quadriceps and 145º for gluteus maximus. Individual evaluations identified muscle shortness in pyramidal (11 athletes, 64.7%), soleus (13 athletes, 76.4%), external rotators (8 athletes, 47%), monoarticular adductors (14 athletes, 82.3%), hamstrings (13 athletes, 76.4%), quadriceps (4 athletes, 23.5%) and gluteus maximus (12 athletes, 70.5%). This flexibility profile can help sports professionals to set quantifiable goals for thetraining of flexibility in this sport. The inclusion of stretching exercises or the increase of their doses should be applied for the improvement of the identified shortness in piriformis, soleus, external hip rotators, monoarticular, hamstring, quadriceps and gluteus maximus adductors

Analysis of the flexibility profile in young taekwondo athletes

The main aim of this study was to determine the flexibility profile of the lower extremity in young taekwondo athletes, as well as identifying athletes with muscle shortness. For this purpose, a total of 17 young taekwondo athletes were assessed; seven from the Spanish team and ten from the Murcia team. The range of motion of the main movements of the lower extremity was evaluated by the "ROM SPORT" protocol and a descriptive analysis of each of the quantitative variables was performed. A Student t-test or arWilcoxon test was applied depending on the normality distribution of the data. The ROM values of each movement were classified as “normal” or “shortness” according to previously determined reference values. The results define the following flexibility profile: 23º for iliopsoas, 28º for piriformis, 37º for gastrocnemius, 42º for soleus, 46º for adductors, 46º for external rotators, 56º for internal rotators, 77º for monoarticular adductors, 80º for hamstrings, 140º for quadriceps and 145º for gluteus maximus. Individual evaluations identified muscle shortness in pyramidal (11 athletes, 64.7%), soleus (13 athletes, 76.4%), external rotators (8 athletes, 47%), monoarticular adductors (14 athletes, 82.3%), hamstrings (13 athletes, 76.4%), quadriceps (4 athletes, 23.5%) and gluteus maximus (12 athletes, 70.5%). This flexibility profile can help sports professionals to set quantifiable goals for the training of flexibility in this sport. The inclusion of stretching exercises or the increase of their doses should be applied for the improvement of the identified shortness in piriformis, soleus, external hip rotators, monoarticular, hamstring, quadriceps and gluteus maximus adductors