The elite player performance plan: the impact of a new national youth development strategy on injury characteristics in a premier league football academy

The objective of this study was to investigate the injury incidence and patterns in elite youth football at a category 1 Premier League Academy before and after the introduction of a new development strategy, the Elite Player Performance Plan (EPPP). A prospective study was performed over six consecutive seasons encompassing three years before and after the introduction of the EPPP. The findings revealed a most likely moderate increase in total exposure per player per season when the post-EPPP football exposure (640.86 ± 83.25 hours per player per year) was compared with the pre-EPPP football exposure (539.08 ± 71.59). The total injury incidence pre-EPPP was 3.0/1000 hours compared to 2.1/1000 hours post-EPPP (rate ratio 1.43). 6% of all injuries were re-injuries (20.24 ± 33.43 days) but did not result in a substantially longer absence (16.56 ± 15.77 days). The injury burden decreased for the U12-U15 from pre- to post-EPPP, whereas the injury burden increased for the U16-U18 (respectively 125 and 47% higher). These findings suggest that following the introduction of the EPPP there has been a reduction in injuries in the younger age groups U12-U15 but in the older age groups U16-U18 there has been an increase in the severity of the injuries sustained at this club.     

实力展望与备战启示:基于2020年东京奥运周期中日竞技实力分析

运用文献资料、比较分析、逻辑分析等方法,对2020年东京奥运周期中日两国参加世界大赛奥运项目竞赛成绩进行统计,分析东京奥运周期内两国竞技实力,展望东京奥运会两国金牌数目并提出我国备战启示。结果显示:东京奥运周期内中国和日本金、奖牌数量相比里约奥运会均有所增长,两国竞技实力差距先快速缩小后逐渐扩大;中国金牌、奖牌项目分布面较日本更广,中日两国除了重点夺金、夺牌项目以外,其他项目争夺点都较少且实力不稳定;东京奥运会中国可能获得34±5枚金牌,日本可能获得25±5枚金牌;我国备战东京奥运会要坚持改革创新备战、系统保障备战、科技助力备战、聚焦全球备战,促进备战工作由单一化向多元化发展,由个体服务向综合保障发展,由科技服务向科创动力发展,由国内备战向全球备战发展。     

The role of ultrasonography in the diagnosis of anterior cruciate ligament injury: A systematic review and meta-analysis

To evaluate the value of ultrasonography in the diagnosis of anterior cruciate ligament injury (ACL injury) by conducting a systematic review and meta-analysis. A literature search was carried out in the Cochrane Library, Embase, Pubmed databases and included studies prior to April 2017. Based on inclusion and exclusion criteria, studies evaluating ultrasound to diagnose ACL injury were selected. MRI, arthroscopy and clinical-follow were considered the reference standards. The diagnostic accuracy of ultrasound was assessed using a combination of sensitivity, specificity, likelihood ratio (LR), post-test probability, diagnostic odds ratio (DOR) and by summarizing the area under the receiver operating characteristic (SROC) curve. A total of 4 studies involving 246 patients were eventually included in the analysis. In these four studies, the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, post-test probability and DOR were 90.0% (95% CI: 77–96), 97% (95% CI: 90–99), 31.08 (95% CI: 8.75–110.41), 0.11 (95% CI: 0.05–0.24), 89% (3%) and 288.81 (95% CI: 78.51–1062.48), respectively. The area under the SROC curve was 0.98 (95% CI: 0.97–0.99). Our meta-analysis showed that ultrasound can play an important role in the diagnosis of ACL injury. Because of its high sensitivity, high specificity and high diagnostic ability, ultrasound should be a part of the standard diagnostic work-up of an ACL injury.     

从严重受伤到重返冬奥:一位高风险项目运动员的心理康复历程

许多冬季项目都具有比较高的损伤风险,如单板滑雪、高山滑雪和自由式滑雪等。如何帮助这些高风险项目的运动员应对运动损伤的挫折和康复治疗的挑战,是备战北京冬奥会面临的重要课题。研究介绍了心理保障团队如何帮助一位中国自由式滑雪空中技巧受伤运动员LGZ应对康复困难并重返国际比赛的心理康复历程。基于中国运动员心理建设系统,为LGZ的心理康复训练制订了三重目标:1)减少运动损伤的心理应激,积极参与康复治疗,尽早回归正常的训练和比赛;2)提高自我控制能力,形成良好的行为习惯,以平稳的心态参加训练和比赛;3)提升文化素养和精神境界,不断完善自我,促进终生发展。从2017年2月—2018年2月,在历时1年的心理训练中,共对其进行了5种心理干预:提供心理支持、实施表象训练、开展心理讲座、制订比赛预案和提供心理咨询;还通过心理测试来监控运动员的心理状态,并采用运动员个人评价、主管教练评价和竞技比赛表现来评估心理训练的效果。在为期1年的心理训练结束时,这名运动员逐渐克服了运动损伤所带来的焦虑,建立了伤后康复的自信,提高了自我控制的能力,并在平昌冬奥会上取得了她个人的最佳成绩,获得了冬奥会奖牌。这一案例提示我们“术道兼修”的心理训练具有一定成效,也带给我们许多反思。     

The relationship between performance of a single-leg squat and leap landing task: moving towards a netball-specific anterior cruciate ligament (ACL) injury risk screening method

ABSTRACT

Field-based screening methods have a limited capacity to identify high-risk postures during netball-specific landings associated with anterior cruciate ligament (ACL) injuries. This study determined the biomechanical relationship between a single-leg squat and netball-specific leap landing, to examine the utility of including a single-leg squat within netball-specific ACL injury risk screening. Thirty-two female netballers performed single-leg squat and netball-specific leap landing tasks, during which three-dimensional (3D) kinematic/kinetic data were collected. One-dimensional statistical parametric mapping examined relationships between kinematics from the single-leg squat, and the 3D joint rotation and moment data from leap landings. Participants displaying reduced hip external rotation, reduced knee flexion, and greater knee abduction and knee internal rotation angles during the single-leg squat exhibited these same biomechanical characteristics during the leap landing (p < 0.001). Greater ankle dorsiflexion during the single-leg squat was associated with greater knee flexion during landing (p < 0.001). Ankle eversion during the single-leg squat was associated with frontal and transverse plane knee biomechanics during landing (p < 0.001). Biomechanics from the single-leg squat were associated with landing strategies linked to ACL loading or injury risk, and thus may be a useful movement screen for identifying netball players who exhibit biomechanical deficits during landing.     

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.     

The inflammatory response to a wheelchair half-marathon in people with a spinal cord injury - the role of autonomic function

This study investigates the relationship between autonomic function and the inflammatory response to a wheelchair half-marathon in people with a spinal cord injury (SCI). Seventeen wheelchair athletes with a cervical SCI (CSCI, N = 7) and without CSCI (NON-CSCI, N = 10) participated in a wheelchair half-marathon. Blood was taken prior, post and 1 h post-race to determine the concentrations of adrenaline, noradrenaline, extracellular heat shock protein 72 (eHsp72) and interleukin-6 (IL-6). A sit-up tilt test was performed to assess autonomic function at rest. CSCI showed a lower supine ratio of the low and high frequency power of the variability in RR intervals (LF/HF RRI, p = 0.038), total and low frequency power of the systolic blood pressure variability (TP SBP, p < 0.001; LF SBP, p = 0.005) compared to NON-CSCI. Following the race, catecholamine concentrations increased only in NON-CSCI (p < 0.036). The increase in IL-6 post-race was larger in NON-CSCI (p = 0.040). Post-race catecholamine levels explained 60% of the variance in the IL-6 response (r = 0.77, p = 0.040), which was further increased when the resting autonomic function indices were added to the regression model (R² > 81%, p < 0.012). In summary, the dampened acute inflammatory response to a wheelchair half-marathon in CSCI was strongly associated with the autonomic dysfunction present in this group.     

The Japanese and Korean Martial Arts: In Search of a Philosophical Framework Compatible to History

Abstract

The popular discourse about Asian martial arts has often been surrounded by an aura of esotericism, so pervasive that it even influenced the academic discussion to some degree. Moreover, nationalistic motives to promote certain martial arts narratives often prevail. This article focuses on the frequently flawed philosophical and historical discourse surrounding the Asian martial arts. In particular, this study concentrates on the academic discussions of the Japanese and Korean martial arts, and the search for a philosophical framework compatible with historical narratives. The Japanese created a romantic but also nationalistic martial arts narrative that aligned with the ideals of the Meiji Restoration. This romanticized image was naively accepted in the West, often imported along with esoteric ideas of the East. And, as most modern Korean martial arts originated in Japan, the Korean martial arts discussion aligns with that of Japanese martial arts, and this alignment has been a point of heated dispute. Discussions of Korean martial arts reflect a search for a definitive identity of the Korean martial arts community as well as the desire to establish a martial arts tradition independent of those of Japan as well as China. However, the discourse has often been influenced by western, albeit biased and perhaps faulty, historical views, and ideas about martial arts traditions.     

State anxiety and visual attention: The role of the quiet eye period in aiming to a far target

Abstract

In this study, we examined how individuals controlled their gaze behaviour during execution of a far aiming task and whether the functional relationship between perception and action was disrupted by increased anxiety. Twenty participants were trained on a simulated archery task, using a joystick to aim and shoot arrows at the target, and then competed in two counterbalanced experimental conditions designed to manipulate the anxiety they experienced. The specific gaze behaviour measured was the duration of the quiet eye period. As predicted, accuracy was affected by the duration of the quiet eye period, with longer quiet eye periods being associated with better performance. The manipulation of anxiety resulted in reductions in the duration of quiet eye. Our results show that the quiet eye period is sensitive to increases in anxiety and may be a useful index of the efficiency of visual orientation in aiming tasks.