Biomechanics of judo backward breakfall for different throwing techniques in novice judokas

It is generally accepted that proper learning of the breakfall technique during early judo training is essential for attenuating the risk of judo-related head injury. Therefore, it is critical to understand the kinematics and head injury risks of breakfall motion to design a more safe and effective judo teaching paradigm that results in reduction of injury risk. We aimed to investigate the biomechanics of judo backward breakfalls by comparing osoto-gari and ouchi-gari in novice judokas. Twelve male novice judokas (age: 21.3 years, SD?=?0.6 years; height: 1.74?m, SD?=?0.04?m; body weight: 71.3, SD?=?6.4?kg; body mass index: 23.5, SD?=?2.3) volunteered to participate in this study. The kinematic data of the breakfall motion for both osoto-gari and ouchi-gari were collected using a three-dimensional motion analysis technique (200?Hz). We observed significant differences between the movement patterns for the two techniques, especially in the lower extremity movements. In addition, a significantly greater peak extension momentum (osoto-gari: 1.29, SD?=?0.23?kg?m^2?s^?1; ouchi-gari: 0.84, SD?=?0.29?kg?m^2?s^?1) and lower head position along the vertical axis (osoto-gari: 0.18, SD?=?0.05?m; ouchi-gari: 0.31, SD?=?0.08?m) with a large effect size were found in the breakfall for osoto-gari. Our results suggest that a different paradigm is needed for effectively teaching each breakfall technique that will enable us to substantially lower the risk of judo-related head injuries in novice judokas.     

Kinematic comparison of the seoi-nage judo technique between elite and college athletes

This study sought to identify biomechanical factors that determine fast and skilful execution of the seoi-nage (shoulder throw) technique by comparing kinematics between elite and college judo athletes. Three-dimensional motion data were captured using a VICON-MX system with 18 cameras operating at 250 Hz as three male elite and seven male college judo athletes performed seoi-nage. No significant difference was found in motion phase time of the turning phase between the two groups, indicating that motion phase time is not necessarily a factor contributing quickness in seoi-nage. The maximum relative velocity of the whole body centre of mass along the anterior–posterior direction was significantly greater in the elite athletes (2.74 ± 0.33 m/s) than in the college athletes (1.62 ± 0.47 m/s) during the turning phase (p = 0.023). The overall angular velocity of the body part lines, particularly the arm line, tended to be greater in the elite athletes (p = 0.068). The results imply that the velocity of the thrower relative to the opponent in the forward drive and turning motion reflects high skill seoi-nage. Coaches should recognise the relative forward velocity as a factor that may contribute to a successful seoi-nage when teaching the judo throw technique.     

Analysis of head impacts during sub-elite hurling practice sessions

The reported incidence of head and neck injuries in hurling is 0.12 per 1000 hours, but no previous research has quantified head impact characteristics in this sport. Here, a wireless accelerometer and gyroscope captured head impacts, in 20 senior club level hurling players. Peak linear and rotational acceleration and impact location were recorded during three hurling training sessions, each player participating once. A mean of 27.9 impacts (linear acceleration >10g) per player, per session were recorded; 1314 impacts during a total exposure time of 247 minutes. Only 2.6% impacts had peak linear acceleration of >70g and 6.2% had peak rotational acceleration >7900 rad/s². There were significant differences in the number and magnitude of impacts, quantified by the accelerometer, between three training sessions of differing intensity (?2 0.03–0.09, p < 0.001). This study represents a first step in quantifying head impacts during hurling, demonstrating the feasibility of this technology in the field. The sensors were able to discriminate between sessions of varying intensity. These data can be used to develop athlete monitoring protocols and may be useful in developing innovative helmet-testing standards for hurling. The potential for this technology to provide feedback has clinical utility for team medical personnel.     

Impulsive force on the head during performance of typical ukemi techniques following different judo throws

In this study, eight judo athletes who are major candidates for the Japan national team were recruited as participants. Kinematic analysis of exemplary ukemi techniques was carried out using two throws, o-soto-gari, a throw linked to frequent injury, and o-uchi-gari. The aim of this study was to kinematically quantify the timing patterns of exemplary ukemi techniques and to obtain kinematic information of the head, in a sequence of ukemi from the onset of the throw to the completion of ukemi. The results indicated that the vertical velocity with which the uke’s head decelerated was reduced by increasing the body surface exposed to the collision with the tatami and by increasing the elapsed time. In particular, overall upper limb contact with the tatami is greatly associated with deceleration. In o-soto-gari, the impulsive force on the faller’s head as the head reached the lowest point was 204.82 ± 19.95 kg m · s^–2 while in o-uchi-gari it was 118.46 ± 63.62 kg m · s^–2, z = ?1.75, P = 0.08, and it did present a large-sized effect with r = 0.78. These findings indicate that the exemplary o-soto-gari as compared to o-uchi-gari is the technique that causes more significant damage to the uke’s head.     

对武术馆校武术套路运动员运动损伤的调查研究

为了解我国青少年武术运动员运动损伤的现状及原因,从武术馆校选取青少年运动员进行问卷调查及访谈,并做统计和分析。结果显示:损伤部位分布在踝、膝、髋等关节,大腿、小腿及腰部肌群等部位。损伤类型以肌肉拉伤和关节损伤的比重较大。损伤原因主要与运动员的身体状况、训练内容、运动负荷、比赛及训练安排有关,并提出了针对性的预防措施。     

Kinematic analysis of the double side kick in pointfighting,kickboxing

The double side kick is a frequently used technique in pointfighting on which most offensive kicking techniques are based on. The aim of the study was to identify parameters, e.g., trunk and leg positions, durations and velocities that affect successful technique execution.

44 fighters, male and female, including European and World champions, participated in the research. The participants performed double side kicks to a punching bag with the target at chest level. 10 international experts scored (1–10 points; interrater correlation ICC (3,1): 0.952) videos of the best individual trial for quality of technique execution. Based on the average of the scores participants were categorised into 2 equally sized groups. For kinematic data acquisition, a Vicon 3D-motion capturing system was used. The normalised knee height of the kick leg (KHK), normalised absolute distance to the frontal shoulder (DKS) at the end of both chambering phases, the horizontal velocity during both chambering phases (KEV), the durations of all 6 functional phases and total duration, were analysed.

KHK1, KHK2, DKS1 and DKS2, total duration as well as 4 out of 6 phase durations and KEV1 showed significant differences between groups in two-sided t-test or Mann–Whitney U-test for not normally distributed variables.     

投掷项目运动损伤的预防

研究对投掷运动员运动损伤产生的原因及预防。运用文献资料法、问卷调查法以及数据统计法,对投掷项目的特点以及投掷项目的损伤特点展开研究。总结并分析投掷运动员运动损伤产生的原因,如准备活动不当、技术动作错误、注意力不集中、负荷大而疲劳等原因所造成的损伤,并根据这些易造成损伤的重点问题,提出运动前热身效果、技术动作、运动量大小等一系列的预防措施。     

传统武术对高职院校体育课程建设的应用研究

采用文献资料法,分析传统武术的文化内涵。以武术之礼、武术之美、武术之技击精神以及武术的本土文明特征,指出传统武术在高职体育教学中的应用价值。并通过对台州地方拳种的调研分析对此论点提供支持。     

A systematic review of injuries in recreational field hockey: From injury problem to prevention

ABSTRACT

The purpose of this study was to gather information from scientific literature related to all steps of Van Mechelen’s “sequence of prevention” for injuries applied to youth and adult recreational field hockey players. A systematic review was conducted in Medline via Pubmed and in SPORTDiscus via EBSCOhost. Twenty-six original studies were included. Regarding injury incidence (step 1) results showed several overall injury incidence rates (youth: 1.47 per 1,000 Athlete Exposure (AE) time-loss (TL) injury up to 11.32 per 1,000 AE TL ánd non-time loss (NTL) injury, adults: 2.2 NTL injury per 1,000 AE, 15.2 injury per 1,000 hours of sports participation). Considering games and practices, most injuries were sustained in games (youth: 4.9, adults: 7.87 per 1,000 AE). Considering body parts, highest injury incidence rates were found in body parts in the lower extremities (youth: knee injuries in games (0.33 per 1,000 AE), adults: hamstring injuries in pre-season (0.75 per 1,000 AE)) and injuries in the head/face/eye (youth: 0.66 and adults: 0.94 head/face/eye, 0.71 head/face and 0.63 concussion per 1,000 AE). Regarding aetiology (step 2), no studies were found. Regarding the efficacy of available interventions (step 3 and 4), one study was found among youth players, describing a warm-up programme.     

乒乓球运动员肩关节损伤原因及预防对策

肩关节损伤在乒乓球运动损伤中最为常见,损伤不仅影响运动员运动成绩的提高、运动寿命的减短,甚至给运动员的生理、心理造成严重的影响。本文分析了乒乓球运动员肩关节损伤的原因,并相应提出有效的预防措施,旨在为保证训练的正常进行及提高运动员的运动寿命提供参考。     

Sport-specific biomechanical responses to an ACL injury prevention programme: A randomised controlled trial

Anterior cruciate ligament (ACL) injury prevention programmes have not been as successful at reducing injury rates in women’s basketball as in soccer. This randomised controlled trial (ClinicalTrials.gov #NCT02530333) compared biomechanical adaptations in basketball and soccer players during jump-landing activities after an ACL injury prevention programme. Eighty-seven athletes were cluster randomised into intervention (6-week programme) and control groups. Three-dimensional biomechanical analyses of drop vertical jump (DVJ), double- (SAG-DL) and single-leg (SAG-SL) sagittal, and double- (FRONT-DL) and single-leg (FRONT-SL) frontal plane jump landing tasks were tested before and after the intervention. Peak angles, excursions, and joint moments were analysed using two-way MANCOVAs of post-test scores while controlling for pre-test scores. During SAG-SL the basketball intervention group exhibited increased peak knee abduction angles (p = .004) and excursions (p = .003) compared to the basketball control group (p = .01) and soccer intervention group (p = .01). During FRONT-SL, the basketball intervention group exhibited greater knee flexion excursion after training than the control group (p = .01), but not the soccer intervention group (p = .11). Although women’s soccer players exhibit greater improvements in knee abduction kinematics than basketball players, these athletes largely exhibit similar biomechanical adaptations to ACL injury prevention programmes.     

The predicted risk of head injury from fall-related impacts on to third-generation artificial turf and grass soccer surfaces: A comparative biomechanical analysis

The risk of soccer players sustaining mild traumatic brain injury (MTBI) following head impact with a playing surface is unclear. This study investigates MTBI by performing headform impact tests from varying heights onto a range of third-generation artificial turf surfaces. Each turf was prepared as per manufacturers specifications within a laboratory, before being tested immediately following installation and then again after a bedding-in period. Each turf was tested dry and when wetted to saturation. Data from the laboratory tests were compared to an in situ third-generation surface and a professional grass surface. The surface performance threshold was set at a head impact criterion (HIC) = 400, which equates to a 10% risk of the head impact causing MTBI. All six third-generation surfaces had a >10% risk of MTBI from a fall >0.77 m; the inferior surfaces required a fall from just 0.46 m to have a 10% MTBI risk. Wetting the artificial turf did not produce a statistically significant improvement (P > 0.01). The in situ third-generation playing surface produced HIC values within the range of bedded-in experimental values. However, the natural turf pitch was the superior performer – necessitating fall heights exceeding those achievable during games to achieve HIC = 400.     

Effects of a multifactorial injury prevention intervention in physical education teachers: A randomized controlled trial

Physical education (PE) teachers are at a high risk of musculoskeletal sports or work-related injuries because of the physical activity as inherent part of their profession. Such injuries have a negative impact on work and leisure time activities, and effective injury prevention interventions are needed. The present study aimed at testing the effectiveness of an injury prevention intervention that was developed and optimized according to PE teachers' wishes and values. Fifty-five PE teachers were randomly assigned to intervention or control group. Intervention group teachers engaged in two days of training during which they familiarized with eight injury prevention strategies (seven intrinsic and one extrinsic). A special feature of the intervention was that the way of delivery was based on the self-determination theory in order to stimulate participants' motivation to adhere to the proposed strategies. Prospective registrations during one school year were conducted concerning injuries and preventive behaviours. Results showed that the intervention group teachers had a lower number of injuries per 1000?h time of exposure (TOE) than the controls (INT: 0.49, CON: 1.14 injuries/1000?h TOE, OR: 2.32, 95% CI: 1.06–5.07), and applied a broader variety of strategies including dynamic and static stretching, core stability, balance and strength training, when compared to the controls who mainly engaged in warming-up. In conclusion, with the same amount of time, an injury reduction was found in PE teachers through a more balanced use of provided preventive strategies.     

基于Haddon模型的高校运动伤害事故预防研究

运用文献资料法、逻辑分析法,结合Haddon模型研究高校运动伤害事故的预防。结果显示:高校运动伤害事故的预防具有较高的可能性和必要性,此类事故的致因可依照Haddon模型从"3阶段、3因素"两个维度进行归纳总结。结合致因分析结果,从"3阶段"出发,提出了相应的预防策略,以期为高校运动伤害事故的预防提供参考。     

我国综合性高校留学生武术教学现状研究

通过对我国综合性高校留学生武术教学现状的调查分析,针对研究结果提出:武术教学内容应多样化,以传统套路、太极拳剑为主,其他项目放在课外的校内武术协会或武术社团;教师方面为校内和校外专家聘请相结合;创编适合留学生学习的武术双语教材;为鼓励和激发留学生学习武术的热情,武术管理部门与推广部门的合作,创造类似"CCTV汉语大赛"的"CCTV留学生武术大赛";学校应给留学生武术课以学时学分为保证;改善留学生教学基础设施。     

Impact attenuation of protective boxing and taekwondo headgear

This study aimed to compare the impact attenuation performance of boxing and taekwondo headgear in terms of peak linear and rotational acceleration. To measure the impact attenuation of headgear, a standardized (American Society for Testing and Materials (ASTM) F-2397) martial arts headgear striker was used to impart impacts to a 50th Percentile Male Hybrid III Crash Test Dummy head and neck complex. Two boxing (Adidas and Greenhill) and two taekwondo (Adidas and Nike) headgear, approved by the Association Internationale de Boxe Amateur and the World Taekwondo Federation (WTF), were selected. Each of the selected headgear was fitted to the Hybrid III head and subsequently subjected to five impacts at the front and side with a maximum impact interim time of 60 seconds by the rotating striker at 8?±?0.3?m/s. Linear and rotational acceleration were recorded at 10,000?Hz. There were significant interactions of the impact location and brand on the rotational acceleration, F(3,40)?=?6.7, p?F(1,40)?=?9.07, p?F(3,40)?=?9.9, p?相似文献   

武术国际化发展的对策研究

运用文献资料法、专家访谈法和归纳演绎法对武术国际化发展进行研究,其目的在于探讨加快武术国际化发展的途径。研究结果表明:目前虽然存在影响武术国际化发展的因素,但武术国际化发展是各民族文化相互交融、共同发展的需要,中华武术的改革迎合了国际化发展的需要,加之中国政府支持武术进入奥运会的态度,为武术国际化发展提供了有利条件。     

Modification and Revision of the Scale of Market Demand for Taekwondo Schools

Twenty-six male and female collegiate and semiprofessional/professional soccer players (age = 20.4 ± 2.0 years; height = 172.1 ± 8.2 cm; weight = 70.7 ± 10.8 kg) participated in this study to determine the reliability and validity of a field anaerobic shuttle test (FAST) and the Cunningham and Faulkner (1969) treadmill anaerobic speed test (AST). The relationship between the AST and FAST was also investigated. Intraclass reliability coefficients were acceptable for the FAST (.96) and AST (.97) with no significant difference between the means at T1 and T2 (FAST = 56.0 vs. 55.8 sec; AST = 41.9 vs. 41.4 sec). Poor reliability for the Wingate Anaerobic Test (WAT), .83 (W), .70 (W · kg-1), necessitated correcting the validity coefficients for attenuation, FAST vs. WAT = -.89 (W) and -.71 (W · kg-1); AST vs. WAT = .82 (W) and .74 (W · kg-1). These coefficients provide preliminary evidence that the construct being measured is anaerobic work capacity. The results (FAST vs. AST = -.85) indicate that FAST and AST appear to be measuring the same construct. Further research is needed to substantiate the validity of AST and FAST scores as measures of anaerobic work capacity of collegiate and professional soccer players.     

高校体育专业学生运动损伤的调查分析

对体育专业学生的运动损伤情况进行了调查，探讨学生运动损伤发生的特点及规律，有针对性地提出如何减少与预防运动损伤的措施和建议。     

Increasing hip and knee flexion during a drop-jump task reduces tibiofemoral shear and compressive forces: implications for ACL injury prevention training

Although most ACL injury prevention programmes encourage greater hip and knee flexion during landing, it remains unknown how this technique influences tibiofemoral joint forces. We examined whether a landing strategy utilising greater hip and knee flexion decreases tibiofemoral anterior shear and compression. Twelve healthy women (25.9 ± 3.5 years) performed a drop-jump task before and after a training session (10–15 min) that emphasised greater hip and knee flexion. Peak tibiofemoral anterior shear and compressive forces were calculated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG and participant-specific muscle volumes and patella tendon orientation measured using magnetic resonance imaging (MRI). Participants demonstrated a decrease in peak anterior tibial shear forces (11.1 ± 3.3 vs. 9.6 ± 2.7 N · kg^?1; P = 0.008) and peak tibiofemoral compressive forces (68.4 ± 7.6 vs. 62.0 ± 5.5 N · kg^?1; P = 0.015) post-training. The decreased peak anterior tibial shear was accompanied by a decrease in the quadriceps anterior shear force, while the decreased peak compressive force was accompanied by decreased ground reaction force and hamstring forces. Our data provide justification for injury prevention programmes that encourage greater hip and knee flexion during landing to reduce tibiofemoral joint loading.