The effect of match fatigue in elite badminton players using plantar pressure measurements and the implications to injury mechanisms

[EN] The purpose of this study was to investigate the differences in plantar pressure under the lead and trail foot between two lunge tasks to the net in the dominant (LD) and non-dominant (LND) directions, and to explore how fatigue affects the plantar pressure patterns whilst performing movements before and after a competitive match. Peak and mean pressure were measured with the Biofoot-IBV in-shoe system from five repetitions of each task, with sensors positioned under the calcaneus, midfoot and phalanges on the lead and trail foot. Data were collected pre and immediately post playing an official 1st national league competition match. The study was conducted with a sample of thirteen 1st league badminton players. A 2x2 repeated ANOVA found significant differences between the two tasks and between pre and post match (fatigued state). Players also had different foot pressure distributions for the LD and LND tasks, which indicated a difference in loading strategy. In a fatigued state the plantar pressure shifted to the medial aspect of the midfoot in the trail limb, indicating a reduction in control and a higher injury risk during non-dominant lunge tasks.SIGeneralitat Valenciana ACIF121/2015Universidad Católica de Valencia San Vicente Márti

Effect of concurrent training on trainability performance factors in youth elite golf players

[EN] Background. Due to the early specialization of golf players, examining the within session sequence of training should be considered to enhance performance and prevent injury risk. The present study analyzed the effects of an 18-week concurrent training developed before or after a specific golf session in adolescence elite golfers on several performance factors. Methods. Sixteen right-handed male golfers, were randomly divided into two groups: After golf specific training (AG) (n = 8, age: 16.77 ± 0.58 years) and before golf specific training (BG) (n=8, age: 16.93 ± 0.59 years). AG and BG players followed a concurrent physical conditioning program (CT) after or before the golf specific training, respectively. Body mass, body fat, muscle mass, jumping ability (CMJ), ball speed (Sball), golf movements screens (GMS), power in a golf swing-specific cable woodchop (Wmax) and the perceived training load (TL) in golf specific training (TL-G) and TL in CT (TL-CT) were measured on three separate occasions. Results. BG demonstrates a lower TL-CT than AG (p < :001, η2 p = 0:90) along the training program without effects on TL-G, achieving significant percentage of change on CMJ (9.38%; p=:165; d D0.73), GMS (50.52%; p=:41, d =0.91), Wmax (16.93%; p=:001; d =2.02) and Sball (1.82%; p=:018; d = 0.92) without interaction effects on anthropometric measures. Conclusions. Performing CT sessions before the regular golf training can improve specific performance factors with a lower perceived TL than the same training carried out after the regular golf training.S

An exploration of the effect of proprioceptive knee bracing on biomechanics during a badminton lunge to the net, and the implications to injury mechanisms

[EN] The aim of this study was to determine changes in knee biomechanics during badminton lunges due to fatigue, lunge strategy and knee bracing. Kinetic and kinematic data were collected from sixteen experienced right-handed badminton players. Three factor repeated measures ANOVAs (lunge direction – fatigue – brace) were performed with Least Significant Difference pairwise comparisons. In addition, clinical assessments including; Y-balance test, one leg hop distance and ankle dorsiflexion range of motion were performed pre and post fatigue. The knee showed significantly greater flexion during the forehand lunge compared to backhand. In contrast, the internal rotation velocity and the knee extension moment were greater during backhand. Knee angular velocity in the sagittal plane, peak knee moment and range of moment in the coronal plane and stance time showed significantly lower values post fatigue. In addition, the peak knee adduction moment showed significantly lower values in the braced condition in both the fatigued and non-fatigues states, and no significant differences were seen for peak vertical force, loading rate, approach velocity, or in any of the clinical assessment scores. There appears to be greater risk factors when performing a backhand lunge to the net compared to a forehand lunge, and proprioceptive bracing appears to reduce the loading at the knee.SIThis work was supported by Generalitat Valenciana ACIF projects [Grants number ACIF2016/121 and BEFPI 2017/014] and Valencia Catholic University ‘San Vicente Mártir’ pre-competitive grants for research groups

Inteligencia emocional, percepción de apoyo a la autonomía y relaciones en el deporte

El objetivo del presente estudio fue analizar las relaciones entre las percepciones de los deportistas de su inteligencia emocional, el apoyo a la autonomía prestado por el entrenador y la relación con éste. Para la medida de las variables se utilizaron dos traducciones al español de escalas en inglés: el Brief Emotional Intelligence Scale (BEIS-10) para medir la inteligencia emocional y Coach-Athlete Relationship Questionnaire (CART-Q) para medir las relaciones con el entrenador, y la versión en español de la escala S-SCQ para medir la percepción de apoyo a la autonomía. La muestra estuvo compuesta por un total de 327 estudiantes de educación secundaria de varios institutos públicos practicantes de deporte extraescolar. Se analizó la estructura factorial de las escalas mediante análisis de ecuaciones estructurales y la fiabilidad a través del coeficiente α. Asimismo se calculó la correlación test-retest para el BEIS-10. Los resultados confirmaron la fiabilidad de las escalas y las correlaciones altas y positivas entre las tres variables analizadas, teniendo un papel mediador la percepción de apoyo a la autonomía. Así pues se apoya la relación de la inteligencia emocional de los deportistas con variables relacionadas con su bienestar

2015 Badminton World Championship: Singles final men’s vs women’s behaviours

[EN] The purpose of the current study was to identify players’ behaviours and to assess differences between genders at final singles matches of 2015 Badminton World Championship, focusing on time events, shots and court movements. Final men’s (MS) and women’s (WS) singles matches of 2015 Yakarta World Championship were analysed (150 points and 967 actions). Official videos from Badminton World Federation were used to carry out the post-event analysis. Variables analyzed were: ‘timing factors’, type of ‘shots’ and players’ trajectories executed during the match. Descriptive (mean and % of distribution) and comparative analysis between gender and result of events (successful vs. unsuccessful) were carried out. Generally speaking, time-related variables show higher figures in the men’s final than in the women’s. Smash, net and lob shots occur more frequently in the men’s final, whereas clear, drop and drive shots are used more often in the women’s final. The hitting of the shuttlecock without any previous movement redominates over the rest or movements for both genders. In the training field, these findings may be used by coaches in order to improve athletes’ performance. In research field, it could be a new way to obtain information that had not been previously taken into account.SIThis research has been made possible thanks to funding from the Generalitat Valenciana through the scholarship for hiring research personnel in training of VALi+d programme

Badminton World Championship stress zones and performance factors: The key to success through log-linear analysis

[EN] The main purpose was to analyse the frequency and effectiveness of different kind of shots and players’ footwork performed by single men badminton players on World Championship depending on court zone. 18 matches were randomly selected and evaluated with a total of 1,273 points and 5,710 play actions. The most stressed court zone is Z5 and Z8 (middle zone) followed by Z10 (deep and lateral zone), while the most successful areas are Z8 (left middle zone) and Z10. When analysing footwork depending on distance covered by players, large footwork is performed mostly to Z1 and Z2. Hitting the shuttlecock with no previous movement is the most common situation from Z4 and Z5. When gathering in three court zones, the most stressed one is middle zone with similar values for Net and deep court zone. On the contrary, the most successfully gathered court zone is deep one, followed by middle and Net zones.SIGeneralitat Valenciana ACIF projects [Grant number 2016/121], Universidad Católica de Valencia “San Vicente Mártir” project, Estudios en el deporte de élite desde los Mixed Methods, técnicas de análisis de estudios comparativos [UCV2017/230/002

Emotional intelligence, perception of autonomy support and relationships in sport

[ES] El objetivo del presente estudio fue analizar las relaciones entre las percepciones de los deportistas de su inteligencia emocional, el apoyo a la autonomía prestado por el entrenador y la relación con éste. Para la medida de las variables se utilizaron dos traducciones al español de escalas en inglés: el Brief Emotional Intelligence Scale (BEIS-10) para medir la inteligencia emocional y Coach-Athlete Relationship Questionnaire (CART-Q) para medir las relaciones con el entrenador, y la versión en español de la escala S-SCQ para medir la percepción de apoyo a la autonomía. La muestra estuvo compuesta por un total de 327 estudiantes de educación secundaria de varios institutos públicos practicantes de deporte extraescolar. Se analizó la estructura factorial de las escalas mediante análisis de ecuaciones estructurales y la fiabilidad a través del coeficiente α. Asimismo se calculó la correlación test-retest para el BEIS-10. Los resultados confirmaron la fiabilidad de las escalas y las correlaciones altas y positivas entre las tres variables analizadas, teniendo un papel mediador la percepción de apoyo a la autonomía. Así pues se apoya la relación de la inteligencia emocional de los deportistas con variables relacionadas con su bienestar.[EN] The purpose of the current study was to analyze the relationship between athletes’ perceptions of their emotional intelligence, autonomy support provided by the coach and the relationship with it. For the measurement of the variables used three translations into spanish of scales in English, the Brief Emotional Intelligence Scale (BEIS-10) to measure emotional intelligence, Coach-Athlete Relationship Questionnaire to measure relations with the manager and Sport Climate Questionnaire scale to measure perceived autonomy support. The sample consisted of 327 secondary school students from various public schools extracurricular sports practitioners. The factor structure of the scales was analyzed by structural equation analysis and reliability through the alpha coefcient. Te test-retest correlation for the BEIS-10 was also calculated. Te results confrmed the reliability of the scales and high and positive correlations between the three variables, having perception of autonomy support a mediating role. It is supported the relationship between the athletes’ emotional intelligence with variables related to their well-beingS

Effect of vibration vs non-vibration foam rolling techniques on flexibility, dynamic balance and perceived joint stability after fatigue

[EN] Foam roller and vibration techniques are currently used to assist in recovery after fatigue. The main purpose of this study was to determine the effects of the use of a foam roller with and without vibration on dynamic balance, ankle dorsiflexion, hamstring and lumbar spine flexibility, and perceived knee and ankle stability after an induced fatigue protocol. 24 healthy recreationally active participants (17 males and 7 females) were recruited to a randomized cross over trial consisting of: no treatment (NT), foam roller treatment (FR) and vibration foam roller treatment (VFR). The assessments included; the Sit & Reach test, Y balance test, and post-treatment perceived knee and ankle stability. Measurements were taken after a standardised warm up (baseline), and repeated following an exercise-induced muscle fatigue protocol consisting of repeated lunges until volitional fatigue. The three treatment conditions were assessed on three separate days in a randomized order. A 3×3 repeated measures ANOVA was used to investigate differences between the three treatments over the three time points, and a one factor repeated measures ANOVA was used to determine any differences between treatments using the Global Rate of Change scale when considering perceived stability. FR and VFR treatment conditions both showed a greater ankle dorsiflexion ROM (p<0.001), greater posteromedial and posterolateral reach distances (p<0.001) and a better knee and ankle perceived stability (p<0.001) when compared to the NT condition. A trend toward significance was observed in the hamstring and lumbar spine flexibility (p=0.074) in both treatment conditions when compared to the NT condition. However, no differences were seen between the FR and VFR treatment conditions. Both foam roller treatment conditions seem to assist in exercise-induced muscle fatigue recovery with improvements in range of motion, balance and perceived stability.SIUniversidad Católica de Valencia San Vicente MártirGeneralitat Valencian

Players’ On-Court Movements and Contextual Variables in Badminton World Championship

[EN] This study aimed to analyze the elite badminton players’ on-court movements related to contextual variables (game, round, and match status). A total of 18 matches of the Jakarta 2015 World Championship (1,273 points and 5,710 play actions) were examined by univariate and bivariate analyses. Significant differences were found when comparing the players’ on-court movements related to game, round, and match status (p < 0.05). All movements were executed more frequently in game 2, with the exception of diagonal large backward left (DLBL), diagonal short backward left (DSBL), diagonal short backward right (DSBR), and longitudinal short backward (LSB). The results obtained related to the round showed that longitudinal large backward (LLB) was the most frequent footwork in R1/16 and R1/2, diagonal short forward left (DSFL) was the most frequent one for R1/4, and transversal short right (TSR) was the most used movement for the final round. According to match status, no movement (NM) was the most common situation before hitting the shuttlecock at any moment during the match. This study shows how contextual variables modulate the elite players’ on-court movements. This information could be valuable for coaches and players, allowing them to better understand the players’ behavior in a competition, which could be used to design more specific training tasks and prepare match strategies in order to improve the players’ performance in competitions.SIGeneralitat Valenciana ACIF2016/121Universidad Católica de Valencia San Vicente Márti

Validación de una unidad de movimiento inercial con un codificador lineal para evaluar fuerza y potencia

[EN] The object of this study was to find out the evaluation and reliability of an inertial movement unit (IMU), based on the TITAN (rO2 Sport Technology and Consulting, Valencia, Spain) system, measuring the variables of sports performance. A linear encoder T-Force (Ergotech System, Murcia, Spain) was used to compare data obtained. 10 voluntary subjects with previous experience of strength training in the study participated. They carried out a total of 200 times bench press in concentric phase, 50% and 70% of individual body weight. The variables analyzed were: maximum speed, maximum acceleration, maximum strength and maximum power peak. Models of linear regression with an independent variable (T-Force data) and a dependant variable (TITAN data) were applied. The assumed independence of error was contrasted by way of a Durban-Watson trial. Partial self correlations were calculated with a significant level p≤0.05. The existence of interclass correlations between the averages of both apparatus,ranging between 0.95 and 0.99 was conformed. In conclusion, the TITAN system could be a valid system to measure maximum velocity, maximum acceleration, maximum strength and maximum power peak during the bench press trial. Therefore, this system based on IMU, could be a valuable tool for the evaluation of strength and power training in the execution of this movement.[ES] El objetivo de este estudio fue descubrir la evaluación y la confiabilidad de una unidad de movimiento inercial (IMU), basada en el sistema TITAN (rO2 Sport Technology and Consulting, Valencia, España), que mide las variables del rendimiento deportivo. Se utilizó un codificador lineal T-Force (Sistema Ergotech, Murcia, España) para comparar los datos obtenidos. Participaron 10 sujetos voluntarios con experiencia previa en entrenamiento de fuerza en el estudio. Realizaron un total de 200 veces press de banca en fase concéntrica, 50% y 70% del peso corporal individual. Las variables analizadas fueron: velocidad máxima, aceleración máxima, fuerza máxima y pico de potencia máxima. Se aplicaron modelos de regresión lineal con una variable independiente (datos de T-Force) y una variable dependiente (datos de TITAN). La supuesta independencia del error fue contrastada mediante un juicio de Durban-Watson. Las autocorrelaciones parciales se calcularon con un nivel significativo p≤0.05. Se confirmó la existencia de correlaciones entre clases entre los promedios de ambos aparatos, que oscilaban entre 0,95 y 0,99. En conclusión, el sistema TITAN podría ser un sistema válido para medir la velocidad máxima, la aceleración máxima, la fuerza máxima y el pico de potencia máxima durante la prueba de press de banca. Por lo tanto, este sistema basado en IMU, podría ser una herramienta valiosa para la evaluación del entrenamiento de fuerza y potencia en la ejecución de este movimiento.S