Sex differences in elbow and wrist joint loading during the cartwheel and round off with different hand positions performed by young gymnasts     

Roman Farana  Gerda Strutzenberger  Timothy Exell  Jiri Skypala  Huw Wiltshire  Gareth Irwin 《Journal of sports sciences》2019,37(13):1449-1456

The aim of the study was to determine if sex differences exist in the key elbow and wrist joint injury risk factors during different cartwheel (CW) and round-off (RO) techniques performed by young male and female artistic gymnasts. Sixteen active young gymnasts (8 males and 8 females) performed 30 successful trials of CW and RO with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3 × 2, technique × sex) and effect-sizes (ES) were used for statistical analysis. In conclusion, female gymnasts exhibited greater normalised peak vertical ground reaction forces (VGRF), elbow and wrist compression forces and elbow internal adduction moments during CW and RO skills compared with male gymnasts. In both sexes, the parallel and reverse techniques increased peak VGRF, elbow and wrist compression forces and the elbow internal adduction moment. Increased elbow flexion resulted in decreased peak VGRF, elbow compression forces and elbow internal adduction moment. Injury risk factors including elbow extension and internal adduction moment with axial compression force suggest that a CW and RO in reverse and parallel techniques can be hazardous especially for young female gymnasts.  相似文献   

Circadian rhythm effect on physical tennis performance in trained male players     

Álvaro López-Samanes  Diego Moreno-Pérez  José L. Maté-Muñoz  Raúl Domínguez  Jesús G. Pallarés  Ricardo Mora-Rodriguez 《Journal of sports sciences》2017,35(21):2121-2128

To determine the effect of circadian rhythm on neuromuscular responses and kinematics related to physical tennis performance, after a standardised warm-up, 13 highly competitive male tennis players were tested twice for serve velocity/accuracy (SVA), countermovement vertical jump (CMJ), isometric handgrip strength (IS), agility T-test (AGIL) and a 10-m sprint (10-m RUN). In a randomised, counter-balance order, tennis players underwent the test battery twice, either in the morning (i.e., AM; 9:00 h) and in the afternoon (i.e., PM; 16:30 h). Paired t-tests were used to analyse differences due to time-of-day in performance variables. Comparison of morning versus afternoon testing revealed that SVA (168.5 ± 6.5 vs. 175.2 ± 6.1 km · h^?1; P = 0.003; effect size [ES] = 1.07), CMJ (32.2 ± 0.9 vs. 33.7 ± 1.1 cm; P = 0.018; ES = 1.46), AGIL (10.14 ± 0.1 vs. 9.91 ± 0.2 s; P = 0.007; ES = 1.23) and 10-m RUN time (1.74 ± 0.1 vs. 1.69 ± 0.1 s; P = 0.021; ES = 0.67) were significantly blunted during the morning testing. However, IS was not affected by time-of-day (P = 0.891). Thus, tennis performance may be reduced when competing in the morning in comparison to early evening. Therefore, coaches and tennis players should focus on schedule the SVA, power, speed and agility training sessions in the afternoon.  相似文献   

我不是软蛋!     

Diego 《当代体育》2008,(8)

多年以来,外籍内线球员在NBA似乎有了固定的模板——传球漂亮,中距离篮子很准,然后他们会自觉或不自觉的远离篮下禁区,他们为自己找到的借口是：我们用头脑打球。可是,傻子都知道,是汉子,就该杀到禁区里面去;是爷们,就捍卫属于自己的篮下三尺领土。  相似文献   

Success in elite cycling: A prospective and retrospective analysis of race results     

Schumacher YO  Mroz R  Mueller P  Schmid A  Ruecker G 《Journal of sports sciences》2006,24(11):1149-1156

The development of peak performances is a main research focus in sports science. It is unclear how many former top junior athletes achieve success in the elite class later. The aim of the present study was to examine the careers of athletes who participated in major junior or adult/elite cycling events using prospective and retrospective analysis of competition results. The official results of major junior (age < or = 18 years) and elite (age > 18 years) cycling races from 1980 to 2004 were analysed. Age-related aspects, career lengths, and success were compared between riders who presented results in both junior and elite races (JUNIOR ELITE) and riders who had no junior race results (ELITE ONLY). Altogether, 27,454 results of 8004 athletes from 108 countries were collected. We found that 29.4% of the elite athletes had participated in junior World Championships, and that 34% of the participants in junior World Championships later participated in major elite competitions. JUNIOR ELITE athletes are significantly more successful in several cycling disciplines and have their first and last elite result at a younger age than ELITE ONLY athletes. No difference was found in career lengths. The data presented here emphasize the importance of long-term training programmes in the development of peak performance in cycling.  相似文献   

拉马库斯&#183;阿尔德里奇 小生怕怕     

Diego 《当代体育》2009,(1)

他并不是天生的篮球神童,甚至到8年级身高长到了6尺7寸时,他在达拉斯Leagoville中学打球还只是被大一点的同伴看做能传球的木桩;他打出了许多怪兽级的比赛：18投16中得到39分,9个篮板,6次盖帽;高中时代他与克里斯&#183;波什的对抗中拿到24分12个篮板,压倒了波什的18分10个篮板;他是个绝对的乖孩子,在课堂上总是恭敬的对老师说着“是的,先生”和“不,先生”,从不喝酒,  相似文献   

Les olympiades mathématiques en roumanie     

T. Roman 《Educational Studies in Mathematics》1974,5(4):425-440

Sans résumé  相似文献   

Gender differences in adolescents’ choice of heroes and admired adults in five countries     

Juan Diego Estrada  Cristina García-Ael  José Luis Martorell 《Gender and education》2015,27(1):69-87

Seven hundred and sixty-eight adolescents from five countries and regions (USA, Spain, Hong Kong, Qatar, and Malaysia), aged 13–19 (M?=?15.78; SD?=?1.28) years, responded to a questionnaire designed to determine who was their most admired famous adult or hero. Male heroes clearly outnumbered admired females (73.3% vs. 26.7%). There was a pattern of same-sex choices, but it was more likely for girls to choose male heroes than for boys to choose females. Over half of the admired adults were athletes, and movie, television, and music stars. Regarding the personally known adults, there was a more balanced choice of males and females, with parents as the most frequent choice. Results suggest that society continues to fail in providing an adequate supply of female role models.  相似文献   

Simulating peers: Can puppets simulate peer interactions in studies on children's socio-cognitive development?     

Roman Stengelin  Daniel B. M. Haun  Patricia Kanngiesser 《Child development》2023,94(5):1117-1135

  相似文献   

Lower extremity power during the squat jump with various barbell loads     

Daniel Jandacka  Jaroslav Uchytil  Roman Farana  David Zahradnik  Joseph Hamill 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(1):75-86

The purpose of this study was twofold: (1) to determine the barbell load that maximised the system power as well as the ankle, knee, and hip joint powers during the squat jump, and (2) to compare the system powers computed from two different methods: the centre of mass (COM) method and the barbell method. Seven male throwers were recruited in this study. The system power (COM method) and the ankle, knee, and hip joint powers were determined with the load incrementally set at 0%, 10%, 30%, 50%, 70%, and 90% of one repetition maximum. The largest system power was observed at the load of 30% (p < 0.008) while the largest ankle and knee powers were observed at 70% and 0% (p < 0.05). The barbell method overestimated the system power (p < 0.001) when compared to the COM method. It was concluded that the barbell method could influence load optimisation in squat jump. The optimal barbell load which maximised the system power did not maximise the ankle, knee, or hip power simultaneously.  相似文献   

Epidemiology of injuries in First Division Spanish football     

Javier Noya Salces  Pedro M. Gómez-Carmona  Diego Moliner-Urdiales  Manuel Sillero-Quintana 《Journal of sports sciences》2014,32(13):1263-1270

Abstract

The aim was to examine the injuries sustained by Spanish football players in the First Division and to compare injury-related variables in the context of both competition and training. The injury data were prospectively collected from 16 teams (427 players) using a specific web-based survey during the 2008/2009 season. A total of 1293 injuries were identified (145 were recurring injuries). The overall injury incidence was 5.65 injuries per 1000 h of exposure. Injuries were much more common during competition than during training (43.53 vs. 3.55 injuries per 1000 h of exposure, P < 0.05). Most of the injuries (89.6%) involved the lower extremities, and overuse (65.7%) was the main cause. Muscle and tendon injuries were the most common types of injury (53.8%) among the players. The incidence of training injuries was greater during the pre-season and tended to decrease throughout the season, while the incidence of competition injuries increased throughout the season (all P < 0.05). In conclusion, the results of this study suggest the need for injury prevention protocols in the First Division of the Spanish Football League to reduce the number of overuse injuries in the muscles and tendons in the lower extremities. In addition, special attention should be paid during the pre-season and the competitive phase II (the last four months of the season) in order to prevent training and competition injuries, respectively.  相似文献