Technical-Tactical Actions Used to Score in Taekwondo: An Analysis of Two Medalists in Two Olympic Championships

Biomechanics research on laterality effect between dominant and non-dominant during double roundhouse kick in the competitive taekwondo

Background

The Double Roundhouse Kick (DRK) is one of the major scoring tools and athletes employ the leg of the dominant side (DS) or the non-dominant side (NS) for always attacking in an alternating state. The purpose is to examine the discrepancies in the biomechanical characteristics of the DS and NS of the leg of the DRK skills of sub-elite taekwondo athletes.

Methods

Using the Vicon, Kistler, and Daedo brand Electronic Body Protector (EBP), collection of the DRK data (attack time, joint angle, joint angular velocity, joint moment, ground reaction force, etc.) of 12 sub-elite taekwondo athletes (19.6 ± 2.0 yr, 180 ± 7.3 cm, 70 ± 9.8 kg) with the DS leg and NS leg. The measured data analyses via Visual3D, and statistical methods using nonparametric tests paired with samples based on the Wilcoxon signed-rank test (The significance level is set as significant for P<0.05, and very significant for P<0.01).

Results

(i) There is no statistically significant discrepancy between the DS and NS at the time of hit (P>0.05) and shift of the center of gravity (P>0.05). (ii) Attacking leg (AL): the maximum knee flexion angle (Knee-MFA) (P<0.05) and the peak linear velocity of attack of the foot in the vertical hitting direction (P<0.01) on the DS was greater than that on the NS during the first hit phase (P1). (iii) Supporting leg (SL): the peak hip extension moment (P<0.05) on the DS was reported to be higher than that of the NS during the second hit phase (P2). (iv) Symmetry Index (SI): In the P1, the vertical ground reaction force (vGRF) of the SL leads to SI = 10.19 %, and in the P2, the vGRF of the SL results in SI = 18.48 %.

Conclusions

The DRK requires more and more symmetry between the DS and NS. The Knee-MFA of the AL and the line of attack speed of the foot in the vertical striking direction of the SL exhibited significant discrepancies. The DS has higher striking speed, athletes need to improve the striking speed of the NS leg in training, achieving more scoring opportunities in the game. Both the DS and NS revealed strong symmetry in the peak SI of the ground reaction force of the SL stirrup; however, weak symmetry was attained in the peak SI of the vGRF of the SL landing cushion.

Repeated High-Intensity Technique Training and Repeated Sprint Training Elicit Similar Adjustment in Physiological Responses But Divergent Perceptual Responses and Combat-Related Performances in Adolescent Taekwondo Matches

PURPOSE

This study investigated the effects of 4 weeks of repeated sprint training (RST) versus repeated high-intensity technique training (RTT) on the physiological responses (ie, blood lactate), mean and peak heart rate, rating of perceived exertion, technical-tactical performance, and time-motion variables during simulated taekwondo combats.

METHODS

Twenty-four taekwondo athletes (18 male and 6 female; age: 16 [1] y) were randomly and equally assigned to RST (10 × 35-m running sprints interspersed by 10-s rest) or RTT (10 × 6-s bandal-tchagui kicking executions interspersed by 10-s rest) groups in addition to their regular training. Both groups performed simulated combats before and after training.

RESULTS

Delta lactate and peak heart rate were attenuated following training (P < .001 and P = .03, respectively), with no differences identified between RTT and RST conditions. Rating of perceived exertion decreased after training only in the RTT (P = .002). Time fighting and preparatory activities increased following training (P < .001), with higher values observed following RTT than RST (P < .001). Nonpreparatory time decreased after training (P < .001), with more pronounced reductions observed following RTT when compared to RST (P < .001). The number of single attacks decreased only following RST (P < .001), whereas combined attacks increased only after RTT training (P < .001).

CONCLUSIONS

Similar adjustments in the physiological responses to combat were observed following 4 weeks of either RST or RTT, but RTT elicited more favorable perceptual responses and combat-related performance. This highlights the importance of specificity of training and its effective transfer to combat.

Application of the Polar Coordinate Technique in the Study of Technical-Tactical Scoring Actions in Taekwondo

The objective of this study was to design, validate and update an observation tool to analyse the technical-tactical actions by which taekwondo players win points. An ad hoc observational tool was developed for subsequent use in HOISAN software by viewing seven finals (14 viewings) in the Rome 2019 Grand Prix, collecting data (1,382 technical/tactical actions) from both winners and losers (women, n = 3; men, n = 4). An observational methodology based on a nomothetic, follow-up and multidimensional (N/F/M) observational design was used. In the statistical analysis, to check the validity of the generalizability analysis, the Category/Observer (C/O) and Observer/Category (O/C) models were employed, and to determine reliability between observations (intra- and interobserver), the Pearson, Spearman, Kendall's tau-b and Cohen's kappa correlation coefficients were applied. One point were awarded for every penalty given against the opponent. Two points were obtained for a circular technique to the trunk protector (in winners) or by scoring a point for a punch plus a penalty against the opponent, three points in melee actions, anticipatory actions with the left side (winners), or after a punch action, and circular technique (losers). Four and five points were only obtained by winners, in a direct attack with the right leg, turning (five points) or simultaneous (four points). The results of this study provide information on the most effective technical-tactical actions in taekwondo for scoring points in a contest.

Diseases That Occur Prior to Spontaneous Intracerebral Hemorrhage: Identification of Predisposing and Risk Factors Using Lag Sequential Analysis

Spontaneous intracerebral hemorrhage (sICH) has many predisposing/risk factors. Lag sequential analysis (LSA) is a method of analyzing sequential patterns and their associations within categorical data in different system states. The results of this study will assist in preventing sICH and improving the patient outcome after sICH. The correlations between a first sICH and previous clinic visits were examined using LSA with data obtained from the Taiwan National Health Insurance Research Database (NHIRD). In this study, LSA was employed to examine the data in the Taiwan NHIRD in order to identify predisposing and risk factors related to sICH, and the results increased our knowledge of the temporal relationships between diseases. This study employed LSA to identify predisposing/risk factors prior to the first occurrence of sICH using a healthcare administrative database in Taiwan. The data were managed using the clinical classification software (CCS). All cases of traumatic ICH were excluded. Ten disease groups were identified using CCS. Hypertension and dizziness/vertigo were identified as two important predisposing/risk factors for sICH, and early treatment of hypertension resulted in a greater survival rate. Five disease groups were found to have occurred prior to other diseases and affected mostly the elderly, resulting in subsequent sICH. The results of this study also showed that nutritional status and tooth health were highly associated with the occurrence of sICH owing to a poor state of the digestive system. In conclusion, there are many diseases that influence the risk of a subsequent sICH. This study demonstrated that LSA is a very useful tool for future study of healthcare administrative databases.

Comparison between the KPNP and Daedo Protection Scoring Systems through a Technical-Tactical Analysis of Elite Taekwondo Athletes

Background: In the last two decades, the use of technology has been incorporated into taekwondo, changing the rules of the sport to employ a more objective scoring system. The current electronic Protection Scoring Systems (PSS) include sensors that register the number and power of the hits scored, but these may interfere with athlete’s techniques and tactics. This study aimed to analyze the technical-tactical differences in elite taekwondoists using two different PSS. Methods: We systematically observed 112 combats involving 224 athletes, and their actions were registered and analyzed using contingency tables. Results: Eight hundred twenty-seven effective actions were tagged, and differences were found in the types of kicks performed using different PSS. For the total sample, there were differences between PSS in technical actions (X2 = 36.08(10); p < 0.01; V = 0.21), tactical actions (X2 = 10.73(3); p < 0.05; V = 0.11), and hitting side (X2 = 30.97(1); p < 0.01; V = 0.19). In men, the differences in techniques and tactics between different PSS were found in technical actions (X2 = 27.15(10); p < 0.01; V = 0.25), guard position (X2 = 14.94(1); p < 0.01; V = 0.18), and hitting side (X2 = 11.07(1); p < 0.01; V = 0.16), while in women, significant differences were found in technical actions (X2 = 37.03(8); p < 0.01; V = 0.32), tactical actions (X2 = 24.45(3); p < 0.01; V = 0.26), guard position (X2 = 3.95(1); p < 0.05; V = 0.10), hitting side (X2 = 19.27(1); p < 0.01; V = 0.23), and laterality (X2 = 16.32(3); p < 0.01; V = 0.21). Conclusions: The present study evidenced a difference in the technical-tactical behavior of elite taekwondoists as a result of the PSS used in combat, with more marked differences in female athletes. These findings also suggest the need to adapt and review the PSS to effectively score in the same way.

Big Data Analysis of the Key Attributes Related to Stress and Mental Health in Korean Taekwondo Student Athletes

In the present study, we used big data analysis to examine the key attributes related to stress and mental health among Korean Taekwondo student-athletes. Keywords included “Taekwondo + Student athlete + Stress + Mental health”. Naver and Google databases were searched to identify research published between 1 January 2010 and 31 December 2019. Text-mining analysis was performed on unstructured texts using TEXTOM 4.5, with social network analysis performed using UCINET 6. In total, 3149 large databases (1.346 MB) were analyzed. Two types of text-mining analyses were performed, namely, frequency analysis and term frequency-inverse document frequency analysis. For the social network analysis, the degree centrality and convergence of iterated correlation analysis were used to deduce the node-linking degree in the network and to identify clusters. The top 10 most frequently used terms were “stress”, “Taekwondo”, “health”, “player”, “student”, “mental”, “exercise”, “mental health”, “relieve”, and “child.” The top 10 most frequently occurring results of the TF-IDF analysis were “Taekwondo”, “health”, “player”, “exercise”, “student”, “mental”, “stress”, “mental health”, “child” and “relieve”. The degree centrality analysis yielded similar results regarding the top 10 terms. The convergence of iterated correlation analysis identified six clusters: student, start of dream, diet, physical and mental, sports activity, and adult Taekwondo center. Our results emphasize the importance of designing interventions that attenuate stress and improve mental health among Korean Taekwondo student-athletes.

Analysis of Different Key Behavioral Patterns to Score in Elite Taekwondoists According to the Weight Category and Gender

Traditionally, research in taekwondo has focused on athletes' overall performance considering the entire sample of the tournament or analyzed selected bouts while ignoring behavioral differences of athletes according to their gender and weight category. Thus, the aim of this study was to analyze the behavioral patterns used to score points in the London Olympic Games according to gender and weight category [fin (FW), feather (FTW), light (LW), and heavy (HW)] of the athletes. A total of 24,940 actions were analyzed by using observational methodology, a mixed method methodology where lag sequential and polar coordinate analysis were applied. Different patterns could be seen in the actions performed prior to score between the weight categories for both genders. To score one point, females FW performed dodges, LW used indirect attacks and HW used direct attacks, posterior counterattacks, dodges and blocks. After scoring one-point, female athletes used a variety of actions, defensives like dodges (FW/LW) and blocks (LW), and offensives like simultaneous counterattacks (FW, FTW, LW) and posterior (FTW) as well as direct (FTW, HW) and indirect (FW) attacks. No patterns were found in males when scoring one-point, only LW competitors performed a sequence characterized by the performance of dodges followed by indirect attacks prior scoring while simultaneous counterattacks occurred after score one point. To score two points, similar patterns were found for all weight groups among female competitors. Females performed openings prior to scoring (LW/HW), while anticipatory (FW/FTW) and posterior counterattacks (LW) occurred after scoring, followed by cuts (FW), direct attacks (LW) and openings (HW). In males, FTW and HW used counterattacks prior to scoring (posterior and simultaneous), while FTW and LW also used counterattacks after scoring (anticipatory and simultaneous). Prior to scoring three points different patterns were found according to the weight category, while FW females used cuts and openings, LW used dodges and posterior counterattacks. After scoring three points, FW continued to use cuts, openings and posterior counterattacks while FTW used indirect attacks and HW used simultaneous counterattacks. On the contrary, similar behavior was found in males. FW and LWs used simultaneous counterattacks prior to scoring while they used defensive actions such as openings (FW) and dodges (LW) after scoring. Male FTW used also posterior counterattacks after scoring. Prior to scoring four points females reported different key behaviors. FW used anticipatory counterattacks and LW direct attacks whereas after scoring, FTW used dodges and openings. Similarities were found in males to score four points. LW and HW performed blocks prior scoring, FW and HW performed also direct attacks while FTW performed posterior counterattacks prior score. After scoring, defensives actions were performed such as dodges (LW) or cuts (FW, FTW, HW) and indirect attacks (LW, HW). This is one of the first studies analyzing behavioral patterns in taekwondo according to the weight category and gender of the athletes. The observed relationships identified different behavioral patterns according to the weight category for each gender and demonstrate the necessity to individualize trainings according to the athlete's characteristics (weight and gender). It is suggested that coaches and psychologists train athletes to improve their decision-making according to the successful patterns extracted in this study.

Design, validation, and testing of an observational tool for technical and tactical analysis in the taekwondo competition at the 2016 Olympic games

Observational methodology uses validated observational tools to collect information in sports with multiple variables that interact in the sporting context. Given the importance of data quality for observational tools, the purpose of this study was to design, validate, and test the reliability of a mixed observational instrument combining field formats and category systems for analyzing technical and tactical actions in an Olympic taekwondo (TKD) tournament. The instrument collects information of six criteria and 25 categories of the tactical and technical actions, kicking zone, laterality, kicking leg, guard, and score. A total of 2 374 actions were analyzed from 10 bouts involving 12 competitors in the 2016 Rio de Janeiro Olympic Games. The coefficients derived from the generalizability analysis (G coefficients) were used to check the accuracy, validity, and reliability of the tool created, while lag-sequential and polar-coordinate analysis were used to determine technical and tactical patterns of TKD athletes. The results showed optimal G coefficients and provide us with objective, valid, and reliable information on the bout situation analyzed, allowing us to extrapolate the data from our results to the sample population. The lag-sequential and polar-coordinate analyses showed that the competitors scored one point through direct attacks with linear techniques to the chest and performed circular actions with the back leg before and after scoring one point. Three points are scored by indirect attacks and subsequent counterattacks with spinning kicks to the trunk and head (using linear and circular techniques). These results reveal technical and tactical implications derived from the latest modifications of the regulations of this sport, as well as the need to adapt athletes' training for the next Olympic Games.

Talent and Creativity of Taekwondoists Winners of the 2016 Summer Olympics

Athletic talent and creativity are important for winning bouts in combat sports. The aim of the current study is to analyze technical–tactical actions performed by athletes of the 2016 Summer Olympics according to the outcome (winners and losers) of a given bout. A total of 2374 actions were analyzed. In this mixed-methods study, we used a nomothetic follow-up and multidimensional design. The results showed that winners scored one point through direct attacks to the chest. After scoring, athletes kicked with the back leg. In addition, they performed direct attacks prior to score one point, while cuts occurred after scoring. Three points were scored by spinning techniques and actions to the head, after which they kicked with the front leg. Cuts occurred prior to scoring three points, while direct attacks occurred after scoring. The creativity to score points emerged as a necessary characteristic of taekwondo athletes to win a bout. These results showed technical–tactical implications derived from the last modifications of the regulations of this sport, as well as the necessary adaptation of the athletes’ trainings in preparation for the next Olympic Games. It is suggested that coaches and psychologists train athletes in better decision-making and creative strategic planning in accordance with the successful patterns extracted in this study.

Serving Patterns of Women's Badminton Medalists in the Rio 2016 Olympic Games

The aim of the present study was to describe and identify the serving performance profiles of medalists during an elite women’s badminton tournament taking notational and temporal variables into account. The sample was composed of the 14 matches (n = 1,052 rallies) played by the three medalists during the 2016 women’s singles Olympic Games badminton event (Rio, Brazil). The independent variable studied was serving player (medalist/opponent); while the dependent variables were related to notational analysis: serve type, set, and point won by the server/receiver; and the time-related variables: number of strokes per rally, rally time, rest time, and frequency of strokes. The main results showed that: (i) temporal parameters were similar for total match duration but shorter for rally time, and longer for rest time and with more strokes per rally than found in previous research; (ii) the serve effectiveness showed neutral values when analyzing serving by all the players, medalists, and opponents (around 50%); (iii) the two-step cluster analysis identified how successful players used the serve when playing short rallies with backhand short and flick serves (cluster 1), and forehand long serves (cluster 2); and during long rallies with the use of the backhand short serve, forehand short serve and forehand long serve (cluster 3). On the other hand, medalists and their opponents used forehand long serves during set 1 with durations of 8.80 s (cluster 5); and the opponents showed an independent performance using the forehand short serve during sets 1 and 2 (cluster 4); and (iv) the classification tree analysis (Exhaustive CHAID) identified the importance of different serving patterns with the gold medal player using more backhand and forehand flick serves, and the main use of backhand short serves during sets 1 and 2 in all the tournament stages. The bronze medalist used more forehand long serves during all sets, and the silver medalist showed a mixed performance of serves using the forehand short serve, the backhand short serve and the forehand long serve. The current findings may help coaches and players to manage different serving and playing patterns during training and matches according to the serve and rally requirements.