Isaac Estevan

Influence of the distance in a roundhouse kick's execution time and impact force in Taekwondo

Taekwondo, originally a Korean martial art, is well known for its kicks. One of the most frequently used kicks in competition is Bandal Chagui or roundhouse kick. Excellence in Taekwondo relies on the ability to make contact with the opponents trunk or face with enough force in as little time as possible, while at the same time avoiding being hit. Thus, the distance between contestants is an important variable to be taken into consideration. Thirty-one Taekwondo athletes in two different groups (expert and novice, according to experience in competition) took part in this study. The purpose of this study was to examine both impact force and execution time in a Bandal Chagui or roundhouse kick, and to explore the effect of execution distance in these two variables. A new model was developed in order to measure the force exerted by the body on a load. A force platform and a contact platform were used to measure these variables. The results showed that there are no significant differences in terms of impact force in relation to execution distance in expert competitors. Significant and positive correlations between body mass and impact force (p<.01) seem to mean that novice competitors use their body mass to generate high impact forces. Significant differences were found in competitive experience and execution time for the three different distances of kicking considered in the study. Standing at a certain further distance from the opponent should be an advantage for competitors who are used to kick from a further distance in their training.

Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo

Effect of Olympic Weight Category on Performance in the Roundhouse Kick to the Head in Taekwondo In taekwondo, kick performance is generally measured using impact force and time. This study aimed to analyse performance in the roundhouse kick to the head according to execution distance between and within Olympic weight categories. The participants were 36 male athletes divided into three categories: featherweight (n = 10), welterweight (n = 15) and heavyweight (n = 11). Our results show that taekwondo athletes in all weight categories generate a similar relative impact force. However, the results indicate that weight has a large impact on kick performance, particularly in relation to total response time.

Effect of stance position on kick performance in taekwondo

Abstract In taekwondo, the stance position can potentially affect kick performance. The aim of this study was to analyse mechanical variables in the roundhouse kick in taekwondo according to three stance positions (0°, 45°, 90°). Nine experienced taekwondo athletes performed consecutive kicking trials in a random order according to these three relative positions of the feet on the ground. Measurements for the mechanical analysis were performed using two 3D force plates and an eight-camera motion capture system. The taekwondo athletes’ reaction and execution times were shorter when starting from the 0° and 45° stance positions than from the 90° position (P < 0.05). Moreover, the ground reaction force was negatively correlated with execution time and positively with velocity of thigh and shank. Our results suggest that the stance position affects the execution technique of taekwondo athletes’ kicks. It is suggested that athletes should not adopt the 90° stance position because it will not enable them to achieve the best performance in the roundhouse kick.

Effects of target distance on select biomechanical parameters in taekwondo roundhouse kick

The aim of this study was to investigate the effects of target distance on temporal and impact force parameters that are important performance factors in taekwondo kicks. Forty-nine taekwondo athletes (age = 24.5 ± 5.9 years; mass = 79.9 ± 10.8 kg) were recruited: 13 male experts, 21 male novices, 8 female experts, and 6 female novices. Impact force, reaction time, and execution time were computed. Three-way repeated measure ANOVAs revealed significant ‘distance’ effect on impact force, reaction time, and execution time (p = 0.001). Comparisons between distance conditions revealed that taekwondo athletes kicked with higher impact force from short distance (17.6 ± 7.5 N/kg) than from long distance (13.1 ± 5.7 N/kg) (p < 0.001), had lower reaction time from short distance (498 ± 90 ms) and normal distance (521 ± 111 ms) than from long distance (602 ± 121 ms) (p < 0.001), and had lower execution time from short distance (261 ± 69 ms/m) than from normal distance (306 ± 105 ms/m) or from long distance (350 ± 106 ms/m) (p = 0.003 and p < 0.001, respectively). In conclusion, target distance affected the kick performance; as distance increases, impact force decreased and reaction time increased. Therefore, when reaction to a simple visual stimulus is needed, kicking from a long distance is not recommended, as longer time is required to respond.

Tactical aspects of a National University Taekwondo Championship in relation to round and match outcome.

Abstract Menescardi, C, Lopez-Lopez, JA, Falco, C, Hernandez-Mendo, A, and Estevan, I. Tactical aspects of a national university taekwondo championship in relation to round and match outcome. J Strength Cond Res 29(2): 466–471, 2015—The aims of this study were to analyze tactical behavior (direct attacks and indirect attacks, in addition to anticipatory, simultaneous, and posterior counterattacks) according to competition round and match, and to compare tactics of competitors (winners and nonwinners) in a university taekwondo championship. The analysis included 334 individual performances from 204 athletes over 169 bouts in the National University Championship. A 2-way repeated measure analysis of variance was conducted with “round” (at 3 levels: first, second, and third) as the within-subject factor and match outcome (at 2 levels: winning and nonwinning) as the between-subject factor. The results of this study show that tactical behavior patterns of winners and nonwinners differ. In addition, these differences vary over the course of a bout (p ⩽ 0.05). Winners perform fewer direct and indirect attacks than nonwinners perform, but execute more anticipatory, simultaneous, and posterior counterattacks. In terms of tactics in each round, there are more frequent direct and anticipatory actions in the third round than in earlier rounds (p ⩽ 0.05). Therefore, coaches should conduct tactical training for athletes in a variety of counterattacks, especially in the third round.

Perfil de habilidades psicológicas en taekwondistas universitarios y su relación con el éxito en competición

Se presenta el perfil de habilidades psicologicas y su poder predictivosobre el exito deportivo en taekwondistas universitarios de competicion. Paraello se evaluo una muestra representativa de 89 taekwondistas (50 hombres y39 mujeres) con edades entre 18 y 34 anos (M = 22,2; DT = 3,34) que competianen el Campeonato de Espana Universitario 2011. Se les administro elInventario Psicologico de Ejecucion Deportiva (IPED) y se tomo como variablede exito deportivo el numero de combates ganados durante el campeonato.Los analisis multivariados mostraron diferencias (p < ,05) en relacion al genero(los hombres informan de mayor auto-confianza, control atencional y afrontamientonegativo) y recibir o no entrenamiento psicologico (mayores niveles encontrol visuo-imaginativo, afrontamiento positivo y control actitudinal paralos que entrenaban psicologicamente), no mostrando diferencias entre expertosy no expertos. En cuanto a los analisis correlacionales se encontraron correlacionespositivas entre control visuo-imaginativo, el nivel motivacional, el controlde afrontamiento positivo y el control actitudinal y el exito deportivo, siendoel control visuo-imaginativo (para la muestra total y los hombres) y el nivelmotivacional (para las mujeres) las habilidades predictoras del exito deportivo.Se discuten los resultados y las implicaciones practicas.

Comparison of Lower Limb Segments Kinematics in a Taekwondo Kick. An Approach to the Proximal to Distal Motion

Abstract In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane) of lower limb segments (thigh, shank and foot), and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years) participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight camera motion capture system. The results showed that the proximal segment reached a lower peak velocity (resultant and in each plane) than distal segments (except the peak velocity in the frontal plane where the thigh and shank presented similar values), with the distal segment taking the longest to reach this peak velocity (p < 0.01). Also, at the instant every segment reached the peak velocity, the velocity of the distal segment was higher than the proximal one (p < 0.01). It provides evidence about the sequential movement of the kicking lower limb segments. In conclusion, during the roundhouse kick in taekwondo inter-segment motion seems to be based on a proximo-distal pattern.

Efectos del apoyo a la autonomía del entrenador en taekwondistas españoles de élite

Resumen es: Tomando como marco teorico la Teoria de la Autodeterminacion, en este estudio se examinaron las relaciones entre el apoyo a la autonomia ofrecido por el ...

MECHANICAL ANALYSIS OF THE ROUNDHOUSE KICK ACCORDING TO HEIGHT AND DISTANCE IN TAEKWONDO

Competition regulation in taekwondo has experienced several changes during the last few years, for example, kicks to the head score more points than kicks to the chest. In addition, some external factors such as the height of target and execution distance seem to affect the kick performance. The aim of this study was to analyse selected biomechanical parameters (impact force, reaction time, and execution time) according to the height and execution distance in two different male groups (experts (n = 12) and novices (n = 21)). Athletes kicked twice from every execution distance (short, normal and long) and towards two different heights of target (chest and head) in a random order. Novices kicked to the head with a longer reaction time than to the chest (p < 0.05) but experts were able to kick with similar performance for both heights. From short and normal distances experts kicked with similar performance; whereas from the normal distance novices had longer reaction and execution time than from the short distance (p < 0.05). In conclusion, in counterattacking situations, experts should perform the roundhouse kick to the head instead of to the chest, because it produces better scores with similar performance; whereas novice athletes should avoid kicking to the head because they are not able to kick with similar performance. Moreover, it is recommended that during counterattacks higher-level taekwondo athletes should intend to kick from normal distances.

The Effect of Color on the Use of Electronic Body Protectors in Taekwondo Matches

This study investigated the relationship between the color protector and success in taekwondo combats in the qualification championships, when electronic body protectors were used. Moreover, it analyzed the confounding effect of a participant being a top-ranked athlete in the 2012 London Olympic Games, in a sample of 462 matches. Results from the entire sample showed a non-significant relationship between the combat outcome and the winner’s color electronic protector. At the level of the tournament, the results showed a significant relationship between wearing a red electronic protector and winning the combat in the Asian and the European qualification tournaments. For gender and weight categories, there was no clear color effect. A significant association was, however, found between wearing red and winning the match in the female featherweight category. The inclusion of electronic body protectors and a counterbalanced seed-condition seem to be effective for controlling the effect of the protector’s color on the outcomes of combats.