Joint work is not shifted proximally after a long run in rearfoot strike runners     

Jake A. Melaro  Allison H. Gruber 《Journal of sports sciences》2021,39(1):78-83

ABSTRACT

Distal-to-proximal redistribution of joint work occurs following exhaustive running in recreational but not competitive runners but the influence of a submaximal run on joint work is unknown. The purpose of this study was to assess if a long submaximal run produces a distal-to-proximal redistribution of positive joint work in well-trained runners. Thirteen rearfoot striking male runners (weekly distance: 72.6 ± 21.2 km) completed five running trials while three-dimensional kinematic and ground reaction force data were collected before and after a long submaximal treadmill run (19 ± 6 km). Joint kinetics were calculated from these data and percent contributions of joint work relative to total lower limb joint work were computed. Moderate reductions in absolute negative ankle work (p = 0.045, Cohen’s d = 0.31), peak plantarflexor torque (p = 0.004, d = 0.34) and, peak negative ankle power (p = 0.005, d = 0.32) were observed following the long run. Positive ankle, knee and hip joint work were unchanged (p < 0.05) following the long run. These findings suggest no proximal shift in positive joint work in well-trained runners after a prolonged run. Runner population, running pace, distance, and relative intensity should be considered when examining changes in joint work following prolonged running.  相似文献   

Visual function,performance, and processing of basketball players vs. sedentary individuals     

Jesús Vera  Raimundo Jimnez  David Crdenas  Beatriz Redondo  Jos Antonio García 《运动与健康科学(英文)》2020,9(6):587-594

BackgroundAthletes tend to have better visuo-motor performance than do sedentary individuals. However, several basic visual-function and perceptual parameters remain unexplored to date. In this study, we investigated whether differences exist in visual function, performance, and processing between basketball players and individuals without a sport-involvement background.MethodsA total of 33 healthy men with no visual impairment or pathology were divided into 2 groups, depending on the involvement in sport (semi-professional basketball players and sedentary individuals). We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level, and we checked their visual function, performance, and processing through an extended battery of optometric tests.ResultsThe 2 groups differed in resting heart-rate variability parameters (p < 0.001), confirming their dissimilarities in regular time practising sports per week. The basketball players showed a closer breakpoint and recovery nearpoint of convergence, a higher fusional-vergence rate, better discriminability halos, and better eye–hand coordination (all p values < 0.05).ConclusionThese results show evidence that athletes, basketball players in this case, exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds, suggesting an improvement due to the systematic involvement of those skills during basketball practice.  相似文献   

“体教结合”视角下体育运动学校“三集中”办学办训模式发展的困境及其对策——以徐汇区青少年体育运动学校为例          下载免费PDF全文

郑昕波  王春秀 《体育科研》2019,(2):49-55

当前在我国培养高水平竞技体育人才的多种方式中，“体教结合”的“三集中”（集中住、集中学、集中训）办学模式占据着独特的优势和特殊的地位。然而，伴随着高考制度的改革，上海市相关人口政策的相继出台，以及家长对子女未来职业选择的多元化趋势等，青少年体育运动学校的“三集中”式办学的主要矛盾凸显。以徐汇区青少年体育运动学校/徐汇位育体校为研究对象，分析学校“体教结合”的“三集中”办学模式发展的瓶颈问题，并对其产生的原因进行解析，进而提出解决“三集中”办学模式发展困境的若干对策及建议。  相似文献   

Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

Developing Student Metacognition through Reflective Writing in an Upper Level Undergraduate Anatomy Course     

Valerie Dean O’Loughlin  Lauren Miller Griffith 《Anatomical sciences education》2020,13(6):680-693

Incorporating metacognitive strategies in the classroom helps students monitor and adjust their learning strategies throughout the semester, and helps students progress from novice to expert learners in a subject. Journaling (i.e., reflective writing) is one metacognitive task that allows students to contemplate and articulate their skill development as they learn a new subject. The research reported here examines the use of ‘blogs’ (i.e., online journals) in an upper level undergraduate human anatomy course. The blogs both facilitated development of students' metacognitive skills and provided researchers insight into student metacognitive process. Data were examined from 92 students from three successive semesters (spring 2010, 2012 and 2014). Each student reviewed 10 radiology online cases throughout the semester and then reflected on their understanding of anatomy and radiology in an online blog for each case. A total of 927 blogs were examined for this research. The researchers used a grounded theory approach to analyze the blog narratives and develop a codebook based on common themes. The 927 blogs yielded 11,082 statements that were coded with the codebook. As the semester progressed, the blog entries showed that students demonstrated greater self-confidence in their abilities to understand the subject matter, expressed greater enthusiasm for anatomy in general, and they improved their metacognitive skills. This research illustrates that reflective writing in an undergraduate anatomy course not only facilitates improvement in student metacognitive skills, but also provides the instructor with evidence how a student progresses from novice to more experienced learner in anatomy.  相似文献   

The biomechanical characteristics of high-performance endurance running     

Stephen J. Preece  Christopher Bramah  Duncan Mason 《European Journal of Sport Science》2019,19(6):784-792

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.  相似文献   

体育产业促进就业:域外经验与本土启示     

朱凯迪  鲍明晓 《武汉体育学院学报》2019,53(11):10-15

就业是民生之本、安国之策。体育产业作为国家积极培育的新经济增长点和支柱性产业，不仅要在促进国民经济发展中有所建树，也应在促民生、稳就业方面积极作为。从文本分析入手，阐释和总结了发达国家体育产业就业的概况和共性经验。研究表明：发达国家体育产业主要通过促进产业成长释放更多就业岗位、响应社会需求扩充热门体育职业、利用赛事关照弱势群体锻造劳力、扶持中小企业提升就业吸纳水平等措施扩大了就业渠道，带动了社会就业。最后以此为关照，启发体育产业促进就业的本土实践新思路。  相似文献   

基于体育课堂观测的小学生身体活动水平及教师教学行为分析     

李兴盈  汪晓赞 《沈阳体育学院学报》2020,(2):27-33

全球儿童青少年的肥胖发病率逐年增高,身体活动不足,每天参加足够量的身体活动是促进其身心健康发展的基本保障。我国儿童青少年面对繁重的学业和大量的家庭作业,课外体育活动参与的时间大大减少,体育课成为了唯一能促使学生参与中等到大强度身体活动的场所。通过SOFIT工具对上海市黄浦区5所小学的217节体育课的学生身体活动水平和教师教学行为进行了观测,分析发现:上海市小学生体育课中的身体活动水平偏低,能够达到50%以上时间进行中等到大强度身体活动(MVPA)的课时比率非常少。教师用于课堂管理和知识讲解的时间过多,且对促进学生进行MVPA的语言干预不够,这些均影响了学生的课内身体活动水平。建议除对学生的活动时间高度重视外,还应该重视学生课内身体活动强度;体育教师应做到“精讲多练”,推动学生积极的参与体育活动;注重开发优质的体育课程。  相似文献   

公司创业导向的诠释和研究维度   总被引：1，自引：0，他引：1  

郑馨 《科学学与科学技术管理》2007,28(12):59-62

阐述了创业导向的三个分析层面,诠释了公司创业导向的内涵,并分别分析了创业导向的创新性、风险承担性、先动性、竞争积极性、自治性五个维度的特征,建议立足于公司层面,从五个维度对创业导向构念进行研究。  相似文献   

网络学术期刊发展研究   总被引：10，自引：0，他引：10  

吕淑珍 《情报科学》2005,23(12):1827-1830

文章论述了网络学术期刊的发展现状，对期刊上网方式及优势进行了分析，针对目前网络学术期刊存在的问题，提出了今后的发展对策。  相似文献