Description of the finger mechanical load of climbers of different levels during different hand grips in sport climbing

Abstract

Currently, direct empirical evidence exists about the amount of mechanical load that climbers apply to each finger during several hand grips specific to sport climbing, but not yet in a specific hanging position.

The objectives of this study are a) to draw and build a solid and rigid support that simulates the real action of a hand grip in a hanging position in sport climbing, to enable the measurement of the mechanical load endured by the fingers in a hanging position and in addition, b) to describe the distribution of mechanical load among fingers as a function of the level of climbing during different hand grips in a hanging position.

Thirty young male participants took part in the initial phase of reliability of the measurements, while another 64 male climbers participated in the subsequent study phase to check the relations between independent and dependent variables. The level of on sight climbing and the total practice experience were used to define the groups. The research task consisted of performing hanging positions on the created support in order to measure the mechanical load endured by the fingers in the three most characteristic hand grips in climbing (crimp, half crimp and slope). It has been concluded that the performance level of the climbers had no influence on the production of a pattern of differentiated finger mechanical load during the research task.     

Connective tissue adaptations in the fingers of performance sport climbers

Abstract

This study investigates the changes of the connective tissue in the fingers of performance sport climbers resulting after a minimum of 15 years of climbing. Evaluation was performed by ultrasonography on the palmar side of the fingers (Dig) II–V to measure the thickness of the A2 and A4 annular pulleys, the flexor digitorum superficialis (FDS) and profundus (FDP) tendons and the palmar plates (PP's) of the proximal interphalangeal (PIP) as well as distal interphalangeal (DIP) joint in sagittal and axial direction. Totally, 31 experienced male sport climbers (mean age 37y, 30–48y grade French scale median 8b, range 7b+ to 9a+) participated in the study. The control-group consisted of 20 male non-climbers (age 37y, 30–51y). The A2 and A4 pulleys in climbers were all significantly thicker (A2 Dig III 62%, Dig IV 69%; A4 Dig III 69%, Dig IV 76%) as compared to non-climbers pulleys. All PP's of the DIP joints were also significantly thicker, particularly at Dig III and IV (76 and 67%), whereas the PP's at PIP joints were only scarce significant for three joints. Differences of the diameter of the flexor tendons were less distinct (1–21%) being significant only over the middle phalanx. High load to the fingers of rock climbers after a minimum of 15 years of climbing years induced considerable connective tissue adaptions in the fingers, most distinct at the flexor tendon pulleys and joint capsule (PP) of the DIP joints and well detectable by ultrasound.     

Body fat measurement in elite sport climbers: Comparison of skinfold thickness equations with dual energy X-ray absorptiometry

Abstract

The aim of this study was to compare equations for estimating percentage body fat from skinfold thickness in elite sport climbers by assessing their agreement with percentage body fat measured using dual-energy X-ray absorptiometry (DXA). Skinfold thickness was measured in a convenience sample of 19 elite sport climbers [9 women and 10 men; mean age 31.2 years (s = 5.0) and 28.6 years (s = 3.6), respectively]. Percentage body fat was estimated using 17 different equations, and it was also measured by DXA. A significant inter-methods difference was observed for all equations, except for Durnin's equation in men (inter-methods difference: ?0.57% and ?0.29%; 1.96 s: 5.56 and 5.23 for Siri's and Brozek's equation, respectively) and women (inter-methods difference: ?0.67% and ?1.29% for Siri's and Brozek's equation, respectively), and for Wilmore's equation using Siri's body fat equation in women (inter-methods difference: ?1.86%). In women, the limits of agreement were lower when using Durnin's equation compared with Wilmore's equation (1.96 s: 3.86% and 5.13%, respectively). In conclusion, of the 17 studied equations, Durnin's equation was the most accurate in estimating percentage body fat in both male and female elite climbers. Therefore, Durnin's equation could be used to assess percentage body fat in elite sport climbers if more accurate methods are not available. The generalizability of the results is limited by the fact that the sample was not selected at random.     

Motor unit activation strategy during a sustained isometric contraction of finger flexor muscles in elite climbers

The aim of the study was to evaluate, by an electromyographic (EMG) and mechanomyographic (MMG) combined approach, whether years of specific climbing activity induced neuromuscular changes towards performances related to a functional prevalence of fast resistant or fast fatigable motor units. For this purpose, after the maximum voluntary contraction (MVC) assessment, 11 elite climbers and 10 controls performed an exhaustive handgrip isometric effort at 80% MVC. Force, EMG and MMG signals were recorded from the finger flexor muscles during contraction. Time and frequency domain analysis of EMG and MMG signals was performed. In climbers: (i) MVC was higher (762 ± 34 vs 512 ± 57 N; effect size: 1.64; confidence interval: 0.65–2.63; P < 0.05); (ii) endurance time at 80% MVC was 43% longer (34.2 ± 3.7 vs 22.3 ± 1.5 s; effect size: 1.21; confidence interval: 0.28–2.14; P < 0.05); (iii) force accuracy and stability were greater during contraction (P < 0.05); (iv) EMG and MMG parameters were higher throughout the entire isometric effort (P < 0.05). Collectively, force, EMG and MMG combined analysis revealed that several years of specific climbing activity addressed the motor control system to adopt muscle activation strategies based on the functional prevalence of fast resistant motor units.     

广东省高校学生户外运动状况调查

采用文献资料法、问卷调查法、相关分析法、数理统计法等方法,对广东省10所高校学生参与户外运动的项目、态度、时间、频率、经费投入、安全保障、制约因素等问题进行调查研究,目的是了解大学生参与户外运动的开展现状,促进高校户外运动的发展和户外运动课程的开发.     

Fingertip force and electromyography of finger flexor muscles during a prolonged intermittent exercise in elite climbers and sedentary individuals

Abstract

The aim of this study was to characterize forearm muscle fatigue identified by the decrease in electromyogram median frequency and/or fingertip force during intermittent exercise. Nine elite climbers (international competitive level, USA 5.14a on sight) and ten non-climbers were instructed to maintain a fingertip force of 80% of their maximal voluntary contraction force on a dynamometer mimicking a rock climbing grip during a 5 s effort/5 s rest cycle for 36 repetitions (i.e. 6 min of exercise). Elite climbers lasted twice as long as non-climbers (climbers: 3 min; non-climbers: 1 min 30 s) before the force could no longer be maintained (i.e. the failure point). After this moment, fingertip force decreased and stabilized until the end of the exercise around 50% maximum voluntary contraction force in non-climbers and 63% in elite climbers. Electromyogram median frequency showed a greater decrease in non-climbers than in elite climbers before the failure point. No change in median frequency was observed after the failure point in elite climbers or in non-climbers. These results confirm that elite climbers are better adapted than non-climbers for performing the intermittent fingertip effort before the failure point. After this point, the better fingertip force of elite climbers suggests different forearm muscle properties, while the electromyography results do not provide any indication about the fatigue process.     

校园体育文化对培养学生人文素质的作用

通过献资料法和实践观察法，分析了校园体育化对培养学生适应社会生活的自我意识、遵守社会明规范、追求社会生活的理想目标、人际交往的适应性、创造性思维个性特征、自我发展的调控能力等人素质的作用．     

陕西省农民体育的现状

采用文献法、问卷法、访问法等研究方法,全面分析了陕西省农民体育的现状,为研究我国农村体育和广泛开展农民健身活动提供参考。     

竞技运动在学校体育中的地位

我国在总体概念的体育分类体系中的竞技性问题一直是争论的焦点,究其原因主要是“竞技”这一术语在定义上的模糊,特别是学校体育承担着培养高水平运动员的任务,这种分类体系的矛盾更为明显．直接影响到学校体育的定位。随着时代的发展,竞技运动市场化的强化,用“职业运动”来代替“竞技体育”的时机基本成熟。体育的分类体系中引入“职业运动”这一术语对正确认识体育的内涵,将产生较大帮助。     

体育院校开设体育经纪人专业的构想

通过分析国内外体育经纪人培养的现状，指出在我国体育院校开设体育经纪人专业的紧迫性；同时就我国体育院校开设体育经纪人专业的可行性进行了探讨，指出政策保证、市场发展、体育院校的专业优势等都是体育院校开设体育经纪人的条件，并提出了开设体育经纪人专业的指导思想。     

中小学校园体育文化建设的内容与要求

体育物质化、体育精神化、体育规范化和体育智能化，是中小学校园体育化建设的4个方面。在分析以上4方面的内涵和特点的基础上，针对中小学校园体育化所处的特定环境和对象的特殊性，相应提出了不同的建设要求。     

思维滥觞及体育、竞技在科教文中的地位

体育(PE)和竞技(Sport)思维滥觞体现在体育和竞技语词、概念双脱落，认为身体化即体育，金字塔大体育，不计特性和本质，“历史因果链条”说，“家族相似”说。指出体育(PE)和竞技(Sport)在教科中的地位。     

我国学校社区体育一体化发展的思路与途径

为了解我国学校社区体育一体化发展基本思路和途径，采用文献资料法、系统分析法和逻辑分析法等研究方法，对我国学校社区体育一体化发展的基本思路和有效途径进行了综合分析。研究表明：应建立和完善一体化体育组织网络；确保一体化保障体系的运行。应通过加强全民健身宣传、深化素质教育、利用网络优势、开放体育校本课程、发挥地方政府实施管理的纽带作用、推广“俱乐部型”体育课模式、增进学校和社区的沟通等有效的途径加以实现。     

完善高校体育俱乐部教学的对策

通过对华南师范大学公共体育课实施体育俱乐部式教学改革近3年来的状况进行调查分析，阐明了高校体育俱乐部教学模式的特点，指出了学生自我健身意识不高、俱乐部管理不完善等问题，并提出改进的相应对策。     

优秀攀岩运动员肘关节屈伸肌等速肌力测试研究

利用德国Isomed2000等速肌力测试系统对优秀攀岩运动员左右肘肘关节进行等速测试,探析攀岩运动员肘关节屈伸肌群的生物力学特征,为运动训练科学选材及康复提供理论依据。结果：优秀攀岩运动员屈伸峰力矩（PT）随测试速度的增大而减小,且屈伸峰力矩屈肌大于肘伸肌;最大功率随测试速度的增大而增加,左右侧做功无明显差异,表明两侧肌力平衡;屈或伸的向心/离心（ECC/CON）随给定运动速度的增加而增大,屈肌的向心/离心（ECC/CON）比值小于1.0。     

Differences between violent and non-violent adolescents in terms of sport background and sport-related psychological variables

Abstract

To date, neither theoretical approaches nor empirical findings allow clear predictions about the influence of sport engagement on youth violence. The present study uses a typological approach to investigate groups of adolescents with different characteristics of violent behaviour and cognition regarding their sport background and psychological variables associated with violent behaviour. A sample of 2438 Swiss adolescents aged 12–18 years completed five self-report questionnaires on sport engagement, violent behaviour and cognition, self-concept, wellbeing, and stress perception. After in-depth data cleaning and method checking, the data of 832 participants were clustered using the Ward method. Five reliable clusters based on violent behaviour and cognition can be identified: non-violent adolescents, adolescents at risk, violence supporters, psychological harassers, and violent adolescents. Harassers are most engaged in sports and are over-represented among elite athletes. Violent adolescents are over-represented in game sports with body contact, whereas non-violent adolescents are involved in individual sports with a focus on aesthetic factors. Results further reveal that non-violent adolescents scored highest on general self-concept and relationship to parents, whereas harassers scored highest on general sport abilities. Moreover, harassers and violent adolescents have the least favourable values on different scales of wellbeing and stress perception. Given the cross-sectional nature of the study, no conclusion about selection or socializing processes can be drawn. Further in-depth consideration is needed to advance our understanding of the relationship between sport, psychological dimensions, and violence.     

辽宁省部分城市实施全民健身计划现状的调查研究

通过文献资料、问卷调查、数理统计等方法,对辽宁省部分城市居民有过3年以上参加体育锻炼经历的人群进行调查统计,旨在为辽宁省各城市推进全民健身计划的有效实施提供理论依据,为群众体育的发展提出相应建议。     

Exploring the covariates of sport participation for health: an analysis of males and females in England

Increasing sport participation has been identified as a key vehicle for achieving World Health Organisation guidelines for health-enhancing physical activity (HEPA). A policy challenge is to promote this changed behaviour. Making use of the Active People Survey, a zero-inflated ordered probit model is used to identify the covariates of sport participation for males and females with respect to the related decisions to either participate in sport or not, and to participate at either lower or higher than desired intensity. To inform current policy emphases, the Active Places Survey is also used to examine the causal impact of facility provision on these behaviours. Results indicate that females are more likely to adopt less intensive activity even with time available. Families could place most constraints on females, but also reduce the intensity of male participation. Education has a greater association with higher intensity female activity. The largest effects are identified for sport club membership and facility satisfaction. Both of these affect male intensity of activity most. The main policy challenges facing sport in contributing to HEPA are shown to involve retaining male intensity of participation when ageing and encouraging greater female intensity of participation, with more appropriate matching of facilities.     

课外体育锻炼对大学体育后进生身体自尊及生活满意感的影响

以身体自尊、一般自尊和一般生活满意感3个量表为研究工具,采用集体课外锻炼和自行课外锻炼的分组方式,同时辅以认知干预,对35名体育后进生进行为期8周的干预实验,为考察结合认知干预的两种不同课外锻炼方式对大学体育后进生的影响,实验前后进行量表测试,并对测试数据进行差值多元方差分析及LSD多重比较.结果显示:不同课外锻炼方式在因变量身体自尊、一般自尊和生活满意感上的主效应均非常显著;两干预组与对照组之间实验效果存在显著性差异;两干预组的效果也存在差异.结论:不同形式的课外锻炼能不同程度提高大学体育后进生的身体自尊及生活满意感水平,且自行课外锻炼方式对大学体育后进生干预效果最佳.     

澳门社区体育的发展模式

对建立符合澳门地区社会水平与澳门实际情况的“社区体育发展模式”进行了研究。研究认为：(1)在构建澳门社区体育发展模式的过程中，首先应完善社区体育组织体系。建立组织网络系统，充分发挥各级社区体育组织的功能作用，提高组织管理水平，建立一支稳定的、具有一定专业水平的社区体育指导队伍；(2)目前澳门劳工阶层与平民大众因受各种因素、条件的影响和限制，不能积极参加或无法参加社区体育活动：(3)体育场地设施的建设与使用，未能配合到社区体育的发展。对现有的体育资源，应予充分利用和开发；(4)加强与其它体育形态的合作，在互补的基础上相互支持，以求共同发展。