Análise de capacetes no TKD

Br J Sports Med. 2013 Jan 24. [Epub ahead of print]

Safety performance evaluation of taekwondo headgear.

O'Sullivan DM, Fife GP, Pieter W, Shin I.

Source

Department of Physical Education, Chung-Ang University, Anseong, Republic of Korea.

Abstract

BACKGROUND:

With over 20 years of taekwondo concussion research highlighting the high incidence of injury, previous studies recommend an investigation of headgear impact attenuation performance.

OBJECTIVE:

To examine impact attenuation differences between the anterior, posterior and sides of selected taekwondo headgear brands.

DESIGN:

Between-groups.

SETTING:

Biomechanics laboratory.

METHODS:

Five different commercially available taekwondo headgear were selected for impact testing. A 50th percentile Hybrid II Dummy Crash Test head and neck was fitted with the selected helmet and was bolted to a 25 kg steel torso-like structure. Each headgear model was impacted eight times to the anterior, posterior and sides by a 6.75 kg bowling ball at three heights to produce 52.25, 85 and 144 J strikes.

MAIN OUTCOME MEASUREMENTS:

Resultant head linear acceleration.

RESULTS:

Two-way (Helmet×Location) mixed analysis of variance with repeated measures on the second factor was performed to determine the differences between headgear by location of impact. There was a two-way (Helmet×Location) interaction for acceleration (η(2)=0.368).

CONCLUSIONS:

Taekwondo headgear manufacturers and sport governing bodies must consider improving the design of especially anterior helmet properties.

Genética e judô

Int J Sports Physiol Perform. 2013 Jan 23. [Epub ahead of print]

ACTN3 R577X Polymorphism is not Associated with Elite Judo Athletic Status.

Rodríguez-Romo G, Yvert T, de Diego A, Santiago C, Díaz de Durana AL, Carratalá V, Garatachea N, Lucia A.

Source

INEF, Universidad Politécnica de Madrid, Spain.

Abstract

We compared ACTN3 R577X genotype/allele frequencies in the majority of all-times best Spanish judo male athletes (n=108) and 343 ethnically-matched non-athletic men. No between-group differences were found in allele (P=0.077) or genotype distributions (P=0.178). Thus, the R577X polymorphism was not significantly associated with the status of being an elite judo athlete, at least in the Spanish population. The contribution of genetics to sports-related phenotype traits is undeniable with some genotypes, of which ACTN3 R577X is currently the leading candidate, partly allowing to distinguish individuals predisposed to either 'endurance' or more 'power' sports. However, few athletic events can be categorized as 'purely' power or endurance-based. Although genetic testing (i.e. of ACTN3 R577X) is already being marketed to predict sports talents and potentials of young children, its usefulness is still questionable, at least in competitive judo.

Prevenção de quedas em crianças

Br J Sports Med. 2013 Jan 17. [Epub ahead of print]

Prevention of fall-related injuries in 7-year-old to 12-year-old children: a cluster randomised controlled trial.

Nauta J, Knol DL, Adriaensens L, Klein Wolt K, van Mechelen W, Verhagen EA.

Source

Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.

Abstract

INTRODUCTION:

To counteract the recently observed increase in forearm fractures in children worldwide, an educational programme to improve fall skills was developed. In this 8-week programme children learned basic martial arts falling techniques in their physical education classes. In this study, the effectiveness of this educational programme to improve fall skills was evaluated.

METHODS:

A cluster randomised controlled trial was conducted in 33 primary schools. The intervention group received the educational programme to improve falling skills during their physical education (PE) classes whereas the control group received their regular PE curriculum. At baseline (October 2009) and follow-up (May 2010), a questionnaire was completed by the children about their physical activity behaviours. Furthermore, fall-related injuries were registered continuously during an entire school-year.

RESULTS:

A total of 36 incident injuries was reported in the intervention group, equalling an injury incidence density (IID) of 0.14 fall-related injuries per 1000 h of physical activity (95% CI 0.09 to 0.18). In contrast, 96 injuries were reported by the control group corresponding to an IID of 0.26 (95% CI 0.21 to 0.32). However, because intracluster correlation was high (ICC=0.46), differences in injury incidence were not statistically significant. When activity level was taken into account, a trend was shown suggesting that the 'falling is a sport' programme was effective in decreasing falling-related injury risk, but only in the least active children.

DISCUSSION AND CONCLUSION:

Although results did not reach significance because of strong clustering effects, a trend was found suggesting that a school-based educational programme to improve falling skills may be more beneficial for the prevention of falling-related injuries in children with low levels of habitual physical activity.

Para reflexão

O problema era a "pegada na perna". Fizeram as restrições e o percentual de ippon despencou. Com certeza é muito mais bonito verem as lutas terminarem com duas punições a uma do que ver alguém ser projetado de tê-guruma : )
Agora fizeram uma reunião de uma tarde e mudaram de novo as regras.
Como a charge indica, tem sempre algo atrás das mudanças, que muitas vezes não passam pela melhoria do judô (nem para quem assiste e muito menos para quem luta).

Análise técnica e tática e respostas fisiológicas ao boxe

Int J Sports Physiol Perform. 2013 Jan;8(1):84-91.

Amateur boxing: activity profile of winners and losers.

Davis P, Wittekind A, Beneke R.

Source

Centre for Sport and Exercise Science, University of Essex, Essex, UK.

Abstract

An activity profile of competitive 3 × 2-min novice-level amateur boxing was created based on video footage and postbout blood [La] in 32 male boxers (mean ± SD) age 19.3 ± 1.4 y, body mass 62.6 ± 4.1 kg. Winners landed 18 ± 11 more punches than losers by applying more lead-hand punches in round 1 (34.2 ± 10.9 vs 26.5 ± 9.4), total punches to the head (121.3 ± 10.2 vs 96.0 ± 9.8), and block and counterpunch combinations (2.8 ± 1.1 vs. 0.1 ± 0.2) over all 3 rounds and punching combinations (44.3 ± 6.4 vs 28.8 ± 6.7) in rounds 1 and 3 (all P < .05). In 16 boxers, peak postbout blood [La] was 11.8 ± 1.6 mmol/L irrespective of winning or losing. The results suggest that landing punches requires the ability to maintain a high frequency of attacking movements, in particular the lead-hand straight punch to the head together with punching combinations. Defensive movements must initiate a counterattack. Postbout blood [La] suggests that boxers must be able to tolerate a lactate production rate of 1.8 mmol · L-1 · min-1 and maintain skillful techniques at a sufficient activity rate.

Kung fu e obesidade em crianças e adolescentes

Res Sports Med. 2013 Jan;21(1):37-51. doi: 10.1080/15438627.2012.738444.

Self-perception and attitude toward physical activity in overweight/obese adolescents: the "martial fitness" study.

Tsang TW, Kohn MR, Chow CM, Singh MF.

Source

a Exercise, Health & Performance Faculty Research Group, Faculty of Health Science , The University of Sydney , Sydney , Australia.

Abstract

This randomized, placebo-exercise controlled trial found that 6-months of Kung Fu training improved enjoyment of physical activity more than the placebo-exercise intervention, while both groups improved perceptions of behavioral conduct and changed strategies for physical activity. Importantly, family support for physical activity declined in subjects who had more visits to health care professionals, which is worrisome, as this represents another risk factor for sedentary behavior in this vulnerable cohort that must be overcome for successful, sustained behavioral change. Programs supporting positive attitudes of both adolescents and their families toward physical activity will be necessary to optimize exercise adoption and adherence as a means to combat the obesity epidemic in childhood and adolescence.

Protocolos de exercício no TKD e luta em competição

Int J Sports Med. 2013 Jan 7. [Epub ahead of print]

Taekwondo Exercise Protocols do not Recreate the Physiological Responses of Championship Combat.

Bridge CA, McNaughton LR, Close GL, Drust B.

Source

Sport and Exercise Research Group, Edge Hill University, Ormskirk, United Kingdom.

Abstract

The aim of this study was to determine the external validity of Taekwondo-specific exercise protocols. 10 male international Taekwondo competitors (age 18±2 years) took part in a championship combat and an exercise protocol that simulated the activity pattern of Taekwondo combat. Heart rate and venous blood samples were obtained in both settings. Despite similarity in the activity profiles, the championship Taekwondo combats elicited higher (p < 0.05) heart rate (188±8 bpm), plasma lactate (12.2±4.6 mmol.L ^{− 1}), glucose (10.3±1.1 mmol.L ^{− 1}), ­glycerol (143.4±49.4 µmol.L ^{− 1}), ­adrena­line (2.7±1.7 nmol.L ^{− 1}) and noradrenaline (14.3±9.4 nmol.L ^{− 1}) responses than the ­Taekwondo exercise protocol (heart rate: 172±4 beats.min ^{− 1}; plasma lactate: 3.6±2.7 mmol.L ^{− 1}; glucose: 5.9±0.8 mmol.L ^{− 1}; glycerol: 77.7±21.3 µmol.L ^{− 1}; adrenaline: 0.6±0.2 nmol.L ^{− 1} and noradrenaline: 3.0±1.1 nmol.L ^{− 1}). This discrepancy in the physiological responses appeared to be mediated by a reduced stress response in the Taekwondo exercise protocol. These findings suggest that Taekwondo-specific exercise protocols are not appropriate to study the physiological demands of Taekwondo. ­Strategies designed to increase the stress response in this setting may be necessary to improve the external validity of this experimental framework.