Alfonso Gutiérrez-Santiago

The temporal structure of judo bouts in visually impaired men and women

Abstract The aim of this study was to determine the temporal structure of judo bouts in visually impaired men and women (n = 117 judokas in the senior category; 92 men and 25 women). We developed a data recording system based on the temporal parameters of judo and applied it to a broad sample of international bouts (n = 219; 184 between men and 35 between women). The descriptive analysis of frequency of occurrence revealed that most of the bouts ended before the time-up bell sounded (81% men/74% women). Other defining features are shown in the following mean values (for men/women): the total bout time was 266/242 s; the total time paused was 158/172 s; the total time spent in standing combat was 82/54 s (P = 0.008), while that of floor combat was 60/84 s (P = 0.021); each bout had 6.9/5.7 paused sequences with a duration of 19.6/21.1 s, and 12.4/11.7 active sequences with a duration of 22/19.7 s. The sequential analysis by means of T-patterns (THEME) confirmed that the temporal structure of judo is not the same for men and women, thereby highlighting the need for a range of training methods matched to the needs of visually impaired competitors.

Effects of two different exercise programs on gait parameters in individuals with Parkinson's disease: A pilot study

To date, little attempt has been made to compare or evaluate the effects of different physical exercise programs on gait disorders in people with Parkinsons disease (PD). This pilot study is aimed at obtaining preliminary data of the effects of two different exercise programs on gait parameters in people with PD by means of a biomechanical three-dimensional motion analysis. Twenty-five individuals with idiopathic PD participated either in a land-based (LB) or in a LB plus water-based (LWB) exercise program for 16 weeks. The efficacy of both exercise programs was quantified by means of a biomechanical gait analysis from which spatiotemporal and sagittal plane kinetic (gait speed, stride length, cadence, stride time, simple support time, double support time) and kinematic (angles of the hip, knee, and ankle joints) variables were recorded. Once the intervention ended, significant changes were observed in stride length and single/double support time variables in all the patients. The intergroup analysis revealed the existence of significant differences only in the gait Speed and hip Angle parameters. Few significant improvements in the amplitude of lower limb joints were found. These results suggest that land-based and land-plus-water-based exercise programs can be considered as a useful physical rehabilitation alternative, both equally capable of improving gait impairment on Parkinsons disease.

Sequences of errors in the Judo throw Morote Seoi Nage and their relationship to the learning process

The aim of this study was to identify the most common technical errors, and their behavioural sequences, in the judo throw Morote Seoi Nage. Participants (n = 46; 29 men and 17 women) were physical education students who were systematically observed by means of video recordings taken over a period of five academic years. The results, derived from descriptive statistics and a sequential analysis of T-patterns obtained with the software package THEME v.5, showed that a sub-optimal knee bend produces a throw around the side rather than over and towards the front of the shoulder. Furthermore, an inadequate hip and trunk position, caused by prior incorrect placement of the left foot, leads to a failure of weight bearing, which itself is the cause of the side throw. As regards the teaching and learning of judo, these findings enable us to propose motor drills to correct the errors detected, and movement sequences that will ensure a successful throw. Recommendations are also made about the use of feedback.

Knowledge of Error in Relation to the Teaching and Learning of the Osoto-Gari Judo Throw

The aim of this study was to determine the most frequent technical errors, and their associated behavioural sequences, in the judo throw osoto-gari, proposing improvements to the way in which judo is taught and learnt. Inexperienced students (n=55, 30 males and 25 females; M=24.8 years, SD=2.3) from the Faculty of Educational and Sports Science at the University of Vigo (Spain) were recorded on digital video while performing the technique. The results of this systematic observational study based in descriptive statistics and the sequential analysis of temporal patterns were obtained via the THEME v.5 software, revealing a series of typical errors when learning the osoto-gari. Specific sequences of errors were identified being able to propose motor tasks and teaching-learning processes to ensure that novices successfully learnt the osoto-gari technique. Recommendations about the use of feedback are also provided.

Knowledge of Errors in the Teaching-Learning Process of Judo-Techniques: Osoto-Guruma as a Case Study

Abstract The aim of this article was to suggest some changes in the teaching-learning process methodology of the judo osoto-guruma technique, establishing the action sequences and the most frequent technical errors committed when performing them. The study was carried out with the participation of 45 students with no experience regarding the fundamentals of judo (21 men and 24 women; age=24.02±3.98 years old) from the Bachelor of Science of Physical Activity and Sport Science at the University of Vigo. The proceeding consisted of a systematic observation of a video recording registered during the technique execution. Data obtained were analyzed by means of descriptive statistics and sequential analysis of T-Patterns (obtained with THEME v.5. Software), identifying: a) the presence of typical inaccuracies during the technique performance; b) a number of chained errors affecting body balance, the position of the supporting foot, the blocking action and the final action of the arms. Findings allowed to suggest some motor tasks to correct the identified inaccuracies, the proper sequential actions to make the execution more effective and some recommendations for the use of feedback. Moreover, these findings could be useful for other professionals in order to correct the key technical errors and prevent diverse injuries.

T-Pattern Detection in Judo Combat: An Approach to Training Male Judokas with Visual Impairments According to Their Weight Category

This study aimed to describe the temporal structure of judo combat for the different weight categories in men with visual impairments so that coaches can adapt traditional judo training methods to this specific population. Observational methodology was used in 184 combats (n = 92 male senior judokas with visual impairments). A T-Patterns study (THEME) and a descriptive and inferential statistical analysis were carried out. The results showed that most of the observed combats ended before regulation time was over (81%). The different weight categories must be taken into account in order to establish adequate training patterns for this population. Special attention must be paid to Work Sequence Time in Stand-up Judo (WSSQT) since this parameter showed significant differences (p = 0.001). The mean values obtained in the studied combats indicate that visual disability accounts for the shorter work sequences and longer pause sequences observed in this group of judokas. These results confirmed that the temporal structure of judo combat in male athletes with visual impairments is different from that of fully-sighted ones. Given all that, a different approach to training each group of judokas becomes necessary, since the temporal structure of the combat is different in each case.

An Accurate and Rapid System to Identify Play Patterns in Tennis Using Video Recording Material: Break Point Situations as a Case Study

Abstract The goal of this study was to present an accurate and rapid detection system to identify patterns in tennis, based on t-pattern analysis. As a case study, the break point situations in the final matches of the clay court tournaments played during the seasons 2011 and 2012 between the tennis players Novak Djokovic and Rafael Nadal were chosen. The results show that Nadal achieves a higher conversion rate with respect to Djokovic in the break point situations, independent of the outcome of the match. Some repetitive patterns of both players were revealed in break point circumstances. In long rally sequences (higher than seven hits), the Spanish player won more break points, both serving and receiving, as a result of unforced errors of his opponent’s backhand. In medium rally sequences (between four and seven hits), other factors such as the type, direction or serve location have shown to play an important role in the outcome of the point. The study also reveals that Djokovic frequently commits double faults in these critical situations of the match. This is the first time that t-patterns have been used to analyze the sport of tennis. The technique is based on computer vision algorithms and video recording material to detect particular relationships between events and helps to discover the hidden mechanistic sequences of tennis players.

Injury assessment of common nage-waza judo techniques for amateur judokas

There are few detailed publications that allow performing associations between the technical aspects and the occurrence of injuries. The purpose of this study was to apply a methodology based in recording material to assess the injury risk factors. Common nage-waza judo techniques during regular training of amateur judokas were used as a case study. Novice students (n=193; 100 men and 93 women) from the University of Vigo during five academic years (2003 to 2008) were filmed during the ordinary training period of the technical execution of ten nage-waza techniques. The obtained data were evaluated using descriptive statistics and tpatterns analysis. Thus, it was possible to identify the presence of typical inaccuracies during execution of the technique uncovering the main temporal sequence of errors allowing us to link our findings with the injury occurrence. In order to narrow the unexpected causes of accidents regarding poor technique performance in regular training, this research provides the hidden temporal sequence of errors of common throw techniques, helping professionals to correct the key technical errors in order to prevent diverse type injuries. The methodology developed here could be easily extended to other martial sports.

Determinação de feedback no judô por meio de T-patterns

O objetivo de esta investigacao baseia-se na proposta de mudancas metodologicas no ensino/aprendizagem da tecnica de judo Deashi-harai, assinalando os erros tecnicos mais comuns durante a sua execucao, assim como as suas sequencias. Realizou-se um estudo observacional, onde participaram 50 estudantes da Universidade de Vigo sem conhecimentos previos de Judo, foram filmados executando a tecnica em estudo depois de uma formacao previa de quatro meses. Os resultados obtidos foram avaliados atraves de estatistica descritiva e analise de T-patterns. Identificamos: a) uma diversidade de defeitos na execucao da tecnica; b) umas sequencias de erros em cadeia que afetam consideravelmente o desequilibrio, a posicao do pe direito, a acao de varrimento e a acao dos bracos. Estes resultados permitem-nos propor tarefas motrizes baseadas nos erros detetados, em sequencias de movimentos que garantam o exito na projecao e recomendacoes sobre a utilizacao do feedback.

Determinación del feedback en el judo a través de T-patterns

O objetivo de esta investigacao baseia-se na proposta de mudancas metodologicas no ensino/aprendizagem da tecnica de judo Deashi-harai, assinalando os erros tecnicos mais comuns durante a sua execucao, assim como as suas sequencias. Realizou-se um estudo observacional, onde participaram 50 estudantes da Universidade de Vigo sem conhecimentos previos de Judo, foram filmados executando a tecnica em estudo depois de uma formacao previa de quatro meses. Os resultados obtidos foram avaliados atraves de estatistica descritiva e analise de T-patterns. Identificamos: a) uma diversidade de defeitos na execucao da tecnica; b) umas sequencias de erros em cadeia que afetam consideravelmente o desequilibrio, a posicao do pe direito, a acao de varrimento e a acao dos bracos. Estes resultados permitem-nos propor tarefas motrizes baseadas nos erros detetados, em sequencias de movimentos que garantam o exito na projecao e recomendacoes sobre a utilizacao do feedback.