首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
The concepts of having fun and being aware of feeling states are presented as two critical factors in ski racing. First, the positive motivational characteristics of 'fun' are outlined. It is suggested that fun is not only a concept for young athletes but elite ones as well. Preliminary data based on a questionnaire, completed by the United States Alpine Ski Team and approximately 150 ski coaches, are represented. Second, the discussion on feelings refers to the mental programming of tactile sensations and determining one's emotional arousal (feeling state) prior to, and during, competition. Practical suggestions are made with regard to the psychological states and their effects on ski racing.  相似文献   

2.
Alpine ski racing is one of the most popular sports in many countries; nevertheless, selection disadvantages and severe injuries result in high dropout rates. In this review we summarize existing knowledge about the specific challenges associated with selection bias and injuries, and their effects on talent development in ski racing.

The relative age effect (RAE) appears in all age categories of national Austrian and international alpine ski racing. Relatively younger athletes seem to only have a chance for selection if they are early maturing. Talent selection processes should consider both the biological maturity status as well as the relative age; additionally, a competition system based on a rotating cut-off date might contribute to a reduction of RAE. Youth and adolescent ski racers report lower injury rates compared to World Cup athletes. The knee was the most affected body part in relation to traumatic injuries. The most frequently reported overuse injuries were knee pain (youth) and low back pain (adolescent level). Athlete-related modifiable risk factors were core strength, neuromuscular control, leg extension strength and limb asymmetries. Based on these findings, prevention measures should be expanded to contribute to long-term injury prevention. In future research more multi-disciplinary, longitudinal studies should be performed.  相似文献   


3.
The purpose of this study was to examine whether differences in construction between the compact ski, the racing ski and the soft ski influence the behavioural and electromuscular responses of the user. Eight qualified male ski instructors performed two 'shuss' trials and three different basic turns. Six muscles (M. biceps femoris, M. gastrocnemius lateralis and medialis, M. rectus femoris, M. vastus lateralis and M. tibialis anterior) were studied, using a conventional but portable electromyographic (EMG) registration with telemetric synchronization, active electrodes and a six-channel portable data recorder. Muscle contractions were continuously registered and visualized in raw EMG form and linear envelopes. The differences between the mean rectified EMG data of dynamic contractions while skiing and the mean rectified EMG data of the maximal voluntary contraction were used in the primary analysis of data, from which the participation levels of the muscles investigated could be calculated for each type of ski. Based on this comparison, differences between the effects on muscle activity of the three types of skis were unimportant. In a second phase, the normalized linear envelopes of all subjects were graphically superimposed and averaged. This was performed for each muscle, for each movement, for each leg and for each ski tested. The EMG data were considered in combination with anthropometric values, with snow characteristics and with the velocity of skiing. This study showed systematic differences between the use of the racing, soft and compact ski. On average the soft ski showed the lowest muscle activity patterns and thus the most economical muscular efforts for all muscles investigated and within all movements.  相似文献   

4.
The purpose of this study was to examine whether differences in construction between the compact ski, the racing ski and the soft ski influence the behavioural and electromuscular responses of the user. Eight qualified male ski instructors performed two ‘shuss’ trials and three different basic turns. Six muscles (M. biceps femoris, M. gastrocnemius lateralis and medialis, M. rectus femoris, M. vastus lateralis and M. tibialis anterior) were studied, using a conventional but portable electromyographic (EMG) registration with telemetric synchronization, active electrodes and a six‐channel portable data recorder. Muscle contractions were continuously registered and visualized in raw EMG form and linear envelopes. The differences between the mean rectified EMG data of dynamic contractions while skiing and the mean rectified EMG data of the maximal voluntary contraction were used in the primary analysis of data, from which the participation levels of the muscles investigated could be calculated for each type of ski. Based on this comparison, differences between the effects on muscle activity of the three types of skis were unimportant. In a second phase, the normalized linear envelopes of all subjects were graphically superimposed and averaged. This was performed for each muscle, for each movement, for each leg and for each ski tested. The EMG data were considered in combination with anthropometric values, with snow characteristics and with the velocity of skiing. This study showed systematic differences between the use of the racing, soft and compact ski. On average the soft ski showed the lowest muscle activity patterns and thus the most economical muscular efforts for all muscles investigated and within all movements.  相似文献   

5.
岳春波 《精武》2013,(36):120-121
赛马运动历史悠久,在最早的为军事和劳动服务之外,只有在很少的娱乐项目中出现,而今的赛马不单单是为了测试马匹的优良程度,也为娱乐和商业增添了新的血液,也是属于比较频繁的大众体育娱乐之一。在处于赛马之乡的内蒙古,赛马体育文化产业已经逐渐占据重要地位,本文将简单阐述赛马运动在内蒙古的发展优势和地位。  相似文献   

6.
Alpine ski racing is a popular sport in many countries and a lot of research has gone into optimising athlete performance. Two factors influence athlete performance in a ski race: speed and the chosen path between the gates. However, to date there is no objective, quantitative method to determine instantaneous skiing performance that takes both of these factors into account. The purpose of this short communication was to define a variable quantifying instantaneous skiing performance and to study how this variable depended on the skiers' speed and on their chosen path. Instantaneous skiing performance was defined as time loss per elevation difference dt/dz, which depends on the skier's speed v(z), and the distance travelled per elevation difference ds/dz. Using kinematic data collected in an earlier study, it was evaluated how these variables can be used to assess the individual performance of six ski racers in two slalom turns. The performance analysis conducted in this study might be a useful tool not only for athletes and coaches preparing for competition, but also for sports scientists investigating skiing techniques or engineers developing and testing skiing equipment.  相似文献   

7.
A common anterior cruciate ligament (ACL) injury situation in alpine ski racing is landing back-weighted after a jump. Simulated back-weighted landing situations showed higher ACL-injury risk for increasing ski boot rear stiffness (SBRS) without considering muscles. It is well known that muscle forces affect ACL tensile forces during landing. The purpose of this study is to investigate the effect of different SBRS on the maximal ACL tensile forces during injury prone landings considering muscle forces by a two-dimensional musculoskeletal simulation model. Injury prone situations for ACL-injuries were generated by the musculoskeletal simulation model using measured kinematics of a non-injury situation and the method of Monte Carlo simulation. Subsequently, the SBRS was varied for injury prone landings. The maximal ACL tensile forces and contributing factors to the ACL forces were compared for the different SBRS. In the injury prone landings the maximal ACL tensile forces increased with increasing SBRS. It was found that the higher maximal ACL force was caused by higher forces acting on the tibia by the boot and by higher quadriceps muscle forces both due to the higher SBRS. Practical experience suggested that the reduction of SBRS is not accepted by ski racers due to performance reasons. Thus, preventive measures may concentrate on the reduction of the quadriceps muscle force during impact.  相似文献   

8.
Abstract

Alpine ski racing is a popular sport in many countries and a lot of research has gone into optimising athlete performance. Two factors influence athlete performance in a ski race: speed and the chosen path between the gates. However, to date there is no objective, quantitative method to determine instantaneous skiing performance that takes both of these factors into account. The purpose of this short communication was to define a variable quantifying instantaneous skiing performance and to study how this variable depended on the skiers' speed and on their chosen path. Instantaneous skiing performance was defined astime loss per elevation difference dt/dz, which depends on the skier's speed v(z), and the distance travelled per elevation difference ds/dz. Using kinematic data collected in an earlier study, it was evaluated how these variables can be used to assess the individual performance of six ski racers in two slalom turns. The performance analysis conducted in this study might be a useful tool not only for athletes and coaches preparing for competition, but also for sports scientists investigating skiing techniques or engineers developing and testing skiing equipment.  相似文献   

9.
A new sensor for detecting ski bending and torsional deflection during an actual ski turn on the snow has been developed. It consisted of bending and torsion sensors connected by light rigid beams. This structure was fixed to the upper surface of a ski and passed through a tunnel in the central binding plate. The bending and torsion sensors were strain cells, designed to reject strain orthogonal to the desired measurement direction. The calibration factor for each sensor was determined in a jig, then the calibration of the overall sensor assembly was checked by static bending experiments and a free vibration test. A data logger recorded the strain signals synchronously with other data such as the components of the earth’s magnetic field measured by a sensor on the ski. The data set allowed reconstruction in software of the instantaneous shape, direction and edge angle of the ski. The purpose of this paper is mainly to introduce the equipment used and methods developed. Tests of the sensor performance are described. Results from a ski run on snow are presented to show how the various types of data can be combined. A skilled ski athlete performed long turns with the ski at about 60 km/h on a groomed snow surface at Shiga Kogen in Japan. The experiment on snow showed that the deformation of the ski was predominantly bending; torsional deflection, although measurable, had only a small effect on the shape of the running edge. The ski edge adopted a symmetrical circular bent shape with an unexpectedly small radius when on the outside, but was unconstrained, lightly loaded and nearly straight when on the inside.  相似文献   

10.
Thirty-four youth competitive skiers (mean age = 13.74 years) completed measures of social evaluative concern and competitive anxiety. Consistent with past research, regression analyses showed that cognitive anxiety was related to performance-specific evaluative concerns. However, contrary to current conceptualizations of sport competition anxiety, somatic anxiety was correlated with concerns about evaluation of other non-performance aspects of ski racing. Competitive skiers were most concerned about parents' and friends' evaluations of their performance, and other competitors' and friends' evaluations of their skiing in general. These findings are discussed in relation to the theory and management of sport competition state anxiety.  相似文献   

11.
Thirty-four youth competitive skiers (mean age = 13.74 years) completed measures of social evaluative concern and competitive anxiety. Consistent with past research, regression analyses showed that cognitive anxiety was related to performance-specific evaluative concerns. However, contrary to current conceptualizations of sport competition anxiety, somatic anxiety was correlated with concerns about evaluation of other non-performance aspects of ski racing. Competitive skiers were most concerned about parents' and friends' evaluations of their performance, and other competitors' and friends' evaluations of their skiing in general. These findings are discussed in relation to the theory and management of sport competition state anxiety.  相似文献   

12.
The critical importance of the start phase in bicycle motocross (BMX) racing is increasingly acknowledged. Past experiments underlined that the internal lane of the starting gate provides a strong positional advantage. However, how lane position affects start performance and cognitive and somatic state anxiety remains unexplored. We examined the start performance and anxiety responses of youth national-level BMX riders in both experimental and ecological contexts. We used contextualization motor imagery routines to evaluate start performance and state anxiety from the internal and external lanes. Cycle ergometer measures revealed a better start performance from the external lane, but we did not record any lane effect on actual gate start times. Both somatic and cognitive anxiety scores were higher before racing from the internal compared to the external lane. Finally, state anxiety (i.e., somatic anxiety, worry and concentration disruptions) negatively predicted the start performance. Present findings provide original insights on psychological factors involved in BMX start performance, and might contribute to fruitful coping interventions and training programmes in sports overlapping the framework of “handicap races” taking the specific form of positional advantages/disadvantages at the start (e.g., ski/snowboard cross, athletics, swimming, motorsports, etc.).  相似文献   

13.
  相似文献   

14.
  相似文献   

15.
The pressure/force acting between the running surface of a ski and the snow may indirectly change glide friction. Thus, measuring the pressure/force distribution may be important for a deeper understanding of glide in skiing. The present aim was to construct a device that allowed the pressure/force underneath the ski running surface (SRS) to be recorded. Pressure sensors were attached on top of a platform. Sheets of different materials were used to improve the interaction between the SRS and the sensors. Possible functions of the device are demonstrated in three applications that emphasized comparison of force distribution underneath skis selected for similarity, force distribution under both skis and a single ski as well as backward weight distribution. The results show that the device with the pressure sensors mapped pressure/force distribution underneath the skis in the applications presented, and the system can thus be a useful tool for further optimizing e.g., ski designs.  相似文献   

16.
Time differences between medalists at Olympic or World Cup alpine ski races are often less than 0.01 s. One factor that could affect these small differences is the line taken between the numerous gates passed through while speeding down the ski slope. The determination of the ‘quickest line’ is therefore critical to winning races. In this study the quickest lines are calculated by direct optimal control theory which converts an optimal control problem into a parameter optimization problem that is solved using a nonlinear programming method. Specifically, the problem is described in terms of an objective function in which state and control variables are implicitly involved. The objective function is the time between the starting point and finishing gate, while state variables are positions of the ski-skier systems on a ski slope, rotational angles of skis, velocities, and rotational velocity at a discrete time, i.e., a node. The control variable at each node is the skier-controlled edging angle between the ski sole and snow surface. Equations of motion of the ski-skier system on a ski slope are numerically satisfied at the midpoint between neighbouring nodes, and the original problem is converted into a nonlinear programming problem with equality and inequality constraints. The problem is solved by the sequential quadratic programming method in which numerical calculations are carried out using the MATLAB Optimization Toolbox. Numerical calculations are presented to determine the quickest lines of an uphill and a downhill ski turn with a starting point, first gate, and second gate (finish line) having been successfully carried out. The quickest line through four gates could not be calculated due to numerical difficulty. Instead, the descent line was respectively calculated for an uphill and downhill turn and simply added, giving a resultant time that represents an upper bound.  相似文献   

17.
Abstract

The present study is designed to examine the influence of individual differences in perceived evaluative threat and baseline responses on changes in feeling states experienced during acute exercise in college-age women with high social physique anxiety. Thirty women with high social physique anxiety completed acute bouts of stationary cycling at either a self-selected or imposed intensity in both naturalistic fitness centre and laboratory environments. Multivariate analysis of changes in feeling states during exercise yielded a significant baseline×perceived evaluative threat×intensity interaction during exercise in the naturalistic fitness centre environment. Decomposition of this interaction revealed that, within the naturalistic environment, women with the least favourable baseline feeling states who perceived the lowest amount of evaluative threat during exercise demonstrated the greatest improvements in affect during self-selected intensity exercise. These findings suggest that, among women with high social physique anxiety, changes in feeling states reported during exercise are influenced by an interaction between baseline affective responses, the intensity of exercise, and environmentally induced perceptions of evaluative threat.  相似文献   

18.
现代赛马产业性质与特征探讨   总被引：1，自引：0，他引：1  
世界现代赛马已成为一种休闲文化活动。赛马业具有显著的福利性特征,是一种强大的集资手段,成为当代经济中的一项支柱产业,对经济、社会发展和繁荣体育事业日益显示出巨大作用。赛马的投注与股票、彩票是同类性质的经济现象,带有一定投机性,然而马迷投注的心态更注重于休闲文化与社会福利事业的参与,而不是博彩本身。政府通过政策指导和宏观管理,可以使这项经济活动的投机性缩小到最低限度,引导赛马市场健康发展。  相似文献   

19.
朱晔  朱仁杰 《体育科研》2010,31(6):74-77
通过对中国赛艇产业及赛艇产业相关器材的专利分析及国内外具备较强实力的赛艇企业拥有专利所做的比较,发现了国内外研发重点的差异,国外所掌握和目标研发的专利都是决定赛艇前进速度的关键专利,而中国公司掌握的专利则仅仅暂时还充当着一个辅助的角色。笔者以为中国的赛艇制造企业若想在国际赛艇制造企业界占有一席之地,则必须将着眼点置于那些影响赛艇速度的关键专利。  相似文献   

20.
This qualitative study investigates how skiers’ transport is addressed in environmental communications (ECs) produced by ski areas on New Zealand’s South Island. Ski areas can build social legitimacy by positioning themselves as pro-environmental. Skiers’ transport, which accounts for more CO2 emissions than the daily operations of ski areas in New Zealand, is one of the most pressing issues facing the industry. The topic of skiers’ transport was explored via an analysis of the ski areas’ ECs in addition to semi-structured, in-depth interviews with managers from the ski areas and with skiers. The research found that the impacts of skiers’ non-local transport are largely ignored by both ski area managers and skiers. Ski areas are viewed as detached from transport networks, they do not face pressures from skiers to mitigate those impacts, and they are thus able to build social legitimacy by engaging in and communicating relatively simple pro-environmental initiatives (such as recycling). These findings demonstrate a need to reconceptualise what constitutes a sustainable sport tourism organisation in order to account for the salience of transport-related impacts and to consider the extent to which ski areas are responsible for mitigating emissions stemming from tourists’ transport.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号