Fatigue increases ankle sprain risk in badminton players: A biomechanical study     

Alexis Herbaut  Julien Delannoy 《Journal of sports sciences》2020,38(13):1560-1565

ABSTRACT

Ankle sprains are the most common injury in regular badminton players and usually occur at the end of a match or training. The purpose of the present study was to examine the influence of fatigue produced by badminton practice on the lower limb biomechanics of badminton players. It was hypothesized that fatigue induces ankle kinematic and lower leg muscle activity changes which may increase the risk of ankle sprain. Ankle kinematics, ankle kinetics and muscles activities of 17 regular badminton players were recorded during lateral jumps before and after an intense badminton practice session. Post-fatigue, ankle inversion at foot strike and peak ankle inversion increased (+2.6°, p = 0.003 and +2.5°, p = 0.005, respectively). EMG pre-activation within 100 ms before foot landing significantly decreased after fatigue for soleus (?23.4%, p = 0.031), gastrocnemius lateralis (?12.2%, p = 0.035), gastrocnemius medialis (?23.3%, p = 0.047) and peroneus brevis (?17.4%, p = 0.036). These results demonstrate impaired biomechanics of badminton players when fatigue increases, which may cause a greater risk of experiencing an ankle sprain injury.  相似文献   

Screening for risk of low energy availability in athletic and recreationally active females in Ireland     

Danielle M. Logue  Sharon M. Madigan  Mirjam Heinen  Sarah-Jane McDonnell  Eamonn Delahunt  Clare A. Corish 《European Journal of Sport Science》2019,19(1):112-122

ABSTRACT

Introduction: Low energy availability (LEA) results in physiological adaptations, which can contribute to unfavourable health outcomes. Little information exists on risk of LEA in active individuals competing in different sports or levels of competition. The aims of this study were to (1) identify risk of LEA in females competing at different levels of competition and (2) investigate associations between risk of LEA, illness and dietary habits. Methods: The validated questionnaire, ‘Low Energy Availability in Females Questionnaire’ was distributed online (November 2016–February 2017) to assess risk of LEA. Twenty-nine additional questions collected information on demographics, illness history and dietary habits. Participants were considered at risk of LEA if they attained a score of?≥?8 and were grouped into: (i) international; (ii) provincial/inter-county; (iii) competitive; and (iv) recreationally active. Chi-square and logistic regression analyses were used to explore differences between those at risk or not at risk of LEA. Results: Risk of LEA was identified in 40% (n?=?331) of 833 participants and was 1.7 and 1.8 times more likely in international and provincial/inter-county athletes compared to those who were recreationally active (International: odds ratios (OR) 1.68, 95% confidence intervals (95%CI) 1.12–2.54; Provincial/inter-county: OR 1.83, 95%CI 1.20–2.77). In participants at risk of LEA, missing >22 days of training during the previous year due to illness occurred 3 times more frequently (OR 3.01, 95%CI 1.81–5.02). Conclusion: Risk of LEA was widespread in this heterogeneous sample. Awareness of LEA and the development of appropriate energy management strategies to ensure athlete health across levels of competition are required.  相似文献   

生活方式干预对心血管疾病危险因素的影响——美国HELPS项目成果     

Peter H. Brubaker  罗曦娟  Chelsea Boltj  Shuchang Du 《北京体育大学学报》2017,40(6):48-53

摘要：心血管疾病（CVD）一直是全世界最主要的死因。由于CVD等慢性疾病对健康的威胁越来越大，有必要开展生活方式干预项目以控制这些疾病的危险因素。本研究的目的是评估美国的重要慢病干预项目—HELPS治疗型生活方式改变（TLC）项目对减少CVD危险因素和其他慢性疾病的有效性。方法：140位大学教职工参加为期12周的HELPS TLC项目，干预前后用配对t检验对其体重、BMI、腰围（WC）、6分钟步行距离（6MWD）、空腹血脂和血糖进行测定和比较。结果：干预后6MWD显著增加，总胆固醇（TC）和WC显著下降。对“高危”参与者进一步分析显示：BMI（-1.5±0.5，-3.9%）、TC（- 22.8±4.0，-9.0%）、LDL（- 14.1±4.9，9.3%）和血糖（-6.9±2.2，-6.1%）均显著下降；男性腰围（-4.5±0.8，-10%）显著减小，女性未见显著改变（-1.5±0.5，-4.0%）。此外，体重的变化与TC（r=0.43）、LDL（r=0.35）和血糖（r=0.44）的变化均显著相关。结论：参加12周的生活方式干预项目可以使CVD危险因素减少，特别是在CVD“高危”个体中。HELPS TLC项目的远期效果还待进一步深入研究。  相似文献   

Writer identification approach based on bag of words with OBI features     

Amal Durou  Ibrahim Aref  Somaya Al-Maadeed  Ahmed Bouridane  Elhadj Benkhelifa 《Information processing & management》2019,56(2):354-366

Handwriter identification aims to simplify the task of forensic experts by providing them with semi-automated tools in order to enable them to narrow down the search to determine the final identification of an unknown handwritten sample. An identification algorithm aims to produce a list of predicted writers of the unknown handwritten sample ranked in terms of confidence measure metrics for use by the forensic expert will make the final decision.Most existing handwriter identification systems use either statistical or model-based approaches. To further improve the performances this paper proposes to deploy a combination of both approaches using Oriented Basic Image features and the concept of graphemes codebook. To reduce the resulting high dimensionality of the feature vector a Kernel Principal Component Analysis has been used. To gauge the effectiveness of the proposed method a performance analysis, using IAM dataset for English handwriting and ICFHR 2012 dataset for Arabic handwriting, has been carried out. The results obtained achieved an accuracy of 96% thus demonstrating its superiority when compared against similar techniques.  相似文献   

Cultural Identification and Religious Identification Contribute Differentially to the Adaptation of Australian Adolescent Muslims     

《Int J Intercult Relat》2016

Australian Muslims are generally perceived as a devalued group in Australia and the public attitudes towards them are generally negative. This context raises questions about belonging and adaptation among Australian adolescent Muslims. The current study investigated how adolescent Muslims relate to their heritage culture, religion, and Australian culture, and which of these three factors is most important to adolescent Muslims’ psychological and socio-cultural adaptation. The study employed a mixed-method design. A total of 321 high school Muslim students (149 males and 172 females) aged between 14 and 18 years completed self-report questionnaires, and a subset sample of 18 students in the same age range, evenly split between males and females, participated in semi-structured interviews. The study revealed a hierarchical pattern of identification among Australian adolescent Muslims, with attachment to their religion being the most important, followed by heritage culture identification and being Australian in third place. Australian adolescent Muslims’ religious identification was perceived overall as more crucial to their socio-cultural and psychological adaptation, than their heritage culture identification or Australian identification. There was an overall modest contribution of Australian identification to adolescent Muslims’ adaptation. This might be connected with the relatively less attachment they show to their Australian identity due maybe to perception of being the target of prejudice, an issue that can be addressed by implementation of prejudice reduction strategies.  相似文献   

Key somatic variables associated with,and differences between the 4 swimming strokes     

Alan M. Nevill  Yassine Negra  Tony D. Myers  Senda Sammoud  Helmi Chaabene 《Journal of sports sciences》2020,38(7):787-794

ABSTRACT

This study identified key somatic and demographic characteristics that benefit all swimmers and, at the same time, identified further characteristics that benefit only specific swimming strokes. Three hundred sixty-three competitive-level swimmers (male [n = 202]; female [n = 161]) participated in the study. We adopted a multiplicative, allometric regression model to identify the key characteristics associated with 100 m swimming speeds (controlling for age). The model was refined using backward elimination. Characteristics that benefited some but not all strokes were identified by introducing stroke-by-predictor variable interactions. The regression analysis revealed 7 “common” characteristics that benefited all swimmers suggesting that all swimmers benefit from having less body fat, broad shoulders and hips, a greater arm span (but shorter lower arms) and greater forearm girths with smaller relaxed arm girths. The 4 stroke-specific characteristics reveal that backstroke swimmers benefit from longer backs, a finding that can be likened to boats with longer hulls also travel faster through the water. Other stroke-by-predictor variable interactions (taken together) identified that butterfly swimmers are characterized by greater muscularity in the lower legs. These results highlight the importance of considering somatic and demographic characteristics of young swimmers for talent identification purposes (i.e., to ensure that swimmers realize their most appropriate strokes).  相似文献   

基于系统动力学的客滚船航行安全仿真     

郭国平  徐元春  吴兵 《上海海事大学学报》2017,38(2):12-16

为保障客滚船航行安全,在分析客滚船航行安全影响因素的基础上,构建客滚船航行安全因果关系图,并运用Vensim-DSS构建客滚船航行安全仿真模型.对渤海上的某一客滚船的航行安全进行仿真,分析安全投入增加对客滚船航行安全水平的影响,得出结论:客滚船航行安全系统是一个复杂的动态系统,其航行风险主要是由人、货物、自然环境、交通环境、硬件设施和管理等6个因素交叉耦合导致的,其中人、货物和自然环境对客滚船的航行安全水平影响显著.这可为客滚船航行安全风险管理及防控方面的研究提供参考.  相似文献   

学校体育场地设施对社会开放的安全风险规避研究     

彭英  唐刚  位可娜 《北京体育大学学报》2017,40(2):79-86

摘要：为科学预测和控制学校体育场地设施对社会开放的安全风险，运用文献资料法、访谈法、案例分析法、问卷调查法和数理统计法对学校体育场地设施对社会开放过程中出现的安全风险因素进行研究。基于90个开放案例的事故树分析，识别出开放过程中的物、人、制度和环境4大类，共30个安全风险因素；通过巴雷托分析法和风险矩阵分析法评估出运动场地、运动器材设施，锻炼者、管理者4类关键安全风险因素11个；针对关键安全风险因素，提出引入第三方管理，分时、分类、分阶段开放，与社区合作、加强社区居民的管理，多元主体协同供给体育指导、咨询服务等事前风险预防措施；引入开放风险保险制度，设立开放风险专项基金制度的事后风险转移措施。以期能解决学校体育场地设施对社会开放过程中面临的实际问题，推进学校体育场地设施资源共享，促进全民健身事业的发展。  相似文献   

关于二手房贷款风险控制的对策研究     

张建江 《山西广播电视大学学报》2011,16(4):74-76

城市土地资源的稀缺性使得成熟地段的新房交易数量急剧减少,二手房的交易量稳步攀升,二手房贷款逐渐升温。但我国二手房贷款市场存在的问题还很多,深入地分析和探索这些问题,寻找解决的办法和对策,对于稳定二手房交易有着十分重要的意义。  相似文献   

Dialectics of design: how ideas of ‘good design’ change     

《普罗米修斯》2012,30(1):29-39

This paper advances a first‐pass theory of change in the styling of objects of domestic utility. It is based on the idea that the expressive potential of design for the maker, the user and the designer exists in tension with other desirable properties of the designed artefact. Respectively these are mass availability, conformity to professionally‐defined ideas of good taste, and the demands of function and marketability. The theory is illustrated by reference to the emergence and subsequent dilution of three design movements; Arts and Crafts, Art Nouveau and certain versions of Modernism.  相似文献