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1.
A. Millward 《Journal of sports sciences》2013,31(2):93-103
A model of the motion of a single‐scull rowing hull has been developed and verified against rowing performance data. The model was then used to explore the effect of changes in the cyclic rowing force on the boat speed. The calculations have shown that the shape of the rowing force curve and the proportion of recovery time in the total stroke can have an important effect on the boat speed. It has also been shown that a study of the fluid mechanics of the oar blade would be advantageous in determining whether a reduction in the power wasted can be obtained by changing the ratio of rowing force to normal force. 相似文献
2.
Factors that affect boat speed are important determinants of rowing performance and should form the basis of feedback to rowers and their coaches. Biomechanical analysis of rowing has led to variables that are causally linked to boat speed. With modern technology, these variables can be measured and feedback can be presented instantaneously on-water, or be presented simultaneously with video after the event. This paper demonstrates the links between the criterion of success in rowing, the time for completing 2000 m and the forces acting on the boat, and describes an instrumentation system for providing feedback of these variables to rowers and coaches. These feedback techniques have been used with rowers from national to Olympic competition standard. Aspects of technique have been linked to the determinants of boat speed and several examples are presented here. The motor learning literature supports the effectiveness of kinetic information feedback for the improvement of motor skill and provides a relevant conceptual framework for the improvement of rowing performance. However, although rowers and their coaches value this feedback, further research must be undertaken to establish a sound basis for comparing the effectiveness of such feedback compared with traditional styles, such as verbal feedback of performance. 相似文献
3.
Factors that affect boat speed are important determinants of rowing performance and should form the basis of feedback to rowers and their coaches. Biomechanical analysis of rowing has led to variables that are causally linked to boat speed. With modern technology, these variables can be measured and feedback can be presented instantaneously on-water, or be presented simultaneously with video after the event. This paper demonstrates the links between the criterion of success in rowing, the time for completing 2000 m and the forces acting on the boat, and describes an instrumentation system for providing feedback of these variables to rowers and coaches. These feedback techniques have been used with rowers from national to Olympic competition standard. Aspects of technique have been linked to the determinants of boat speed and several examples are presented here. The motor learning literature supports the effectiveness of kinetic information feedback for the improvement of motor skill and provides a relevant conceptual framework for the improvement of rowing performance. However, although rowers and their coaches value this feedback, further research must be undertaken to establish a sound basis for comparing the effectiveness of such feedback compared with traditional styles, such as verbal feedback of performance. 相似文献
4.
Yang Liu Binghong Gao Jiru Li Zuchang Ma Yining Sun 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(2):168-179
AbstractThe aim of this study was to investigate whether changes on foot-stretcher height were associated with characteristics of better rowing performance. Ten male rowers performed a 200 m rowing trial at their racing rate at each of three foot-stretcher heights. A single scull was equipped with an accelerometer to collect boat acceleration, an impeller with embedded magnets to collect boat speed, specially designed gate sensors to collect gate force and angle, and a compact string potentiometer to collect leg drive length. All sensor signals were sampled at 50 Hz. A one-way repeated measures ANOVA showed that raising foot-stretcher position had a significant reduction on total gate angle and leg drive length. However, a raised foot-stretcher position had a deeper negative peak of boat acceleration at the catch, a lower boat fluctuation, a faster leg drive speed, a larger gate force for the port and starboard side separately. This could be attributed to the optimisation of the magnitude and direction of the foot force with a raised foot-stretcher position. Although there was a significant negative influence of a raised foot-stretcher position on two kinematic variables, biomechanical evidence suggested that a raised foot-stretcher position could contribute to the improvement of rowing performance. 相似文献
5.
Holger Hill 《Journal of sports sciences》2015,33(15):1637-1638
In a case study, Schaffert and Mattes reported the application of acoustic feedback (sonification) to optimise the time course of boat acceleration. The authors attributed an increased boat speed in the feedback condition to an optimised boat acceleration (mainly during the recovery phase). However, in rowing it is biomechanically impossible to increase the boat speed significantly by reducing the fluctuations in boat acceleration during the rowing cycle. To assess such a, potentially small, optimising effect experimentally, the confounding variables must be controlled very accurately (that is especially the propulsive forces must be kept constant between experimental conditions or the differences in propulsive forces between conditions must be much smaller than the effects on boat speed resulting from an optimised movement pattern). However, this was not controlled adequately by the authors. Instead, the presented boat acceleration data show that the increased boat speed under acoustic feedback was due to increased propulsive forces. 相似文献
6.
7.
The aim of the present study was to find a more optimal blade design for rowing performance than the Big Blade, which has been shown to be less than optimal for propulsion. As well as the Big Blade, a flat Big Blade, a flat rectangular blade, and a rectangular blade with the same curvature and projected area as the Big Blade were tested in a water flume to determine their fluid dynamic characteristics at the full range of angles at which the oar blade might present itself to the water. Similarities were observed between the flat Big Blade and rectangular blades. However, the curved rectangular blade generated significantly more lift in the angle range 0-90 degrees than the curved Big Blade, although it was similar between 90 and 180 degrees. This difference was attributed to the shape of the upper and lower edges of the blade and their influence on the fluid flow around the blade. Although the influence of oar blade design on boat speed was not investigated here, the significant increases in fluid force coefficients for the curved rectangular blade suggest that this new oar blade design could elicit a practically significant improvement in rowing performance. 相似文献
8.
Assessment and feedback devices have been regularly used in technique training in high-performance sports. Biomechanical analysis is mainly visually based and so can exclude athletes with visual impairments. The aim of this study was to examine the effects of auditory feedback on mean boat speed during on-water training of visually impaired athletes. The German National Para-Rowing team (six athletes, mean ± s, age 34.8 ± 10.6 years, body mass 76.5 ± 13.5 kg, stature 179.3 ± 8.6 cm) participated in the study. Kinematics included boat acceleration and distance travelled, collected with Sofirow at two intensities of training. The boat acceleration-time traces were converted online into acoustic feedback and presented via speakers during rowing (sections with and without alternately). Repeated-measures within-participant factorial ANOVA showed greater boat speed with acoustic feedback than baseline (0.08 ± 0.01 m·s?1). The time structure of rowing cycles was improved (extended time of positive acceleration). Questioning of athletes showed acoustic feedback to be a supportive training aid as it provided important functional information about the boat motion independent of vision. It gave access for visually impaired athletes to biomechanical analysis via auditory information. The concept for adaptive athletes has been successfully integrated into the preparation for the Para-Rowing World Championships and Paralympics. 相似文献
9.
Our aim was to present a mathematical model of rowing and sculling that allowed for a comparison of oar blade designs. The relative movement between the oar blades and water during the drive phase of the stroke was modelled, and the lift and drag forces generated by this complex interaction were determined. The model was driven by the oar shaft angular velocity about the oarlock in the horizontal plane, and was shown to be valid against measured on-water mean steady-state shell velocity for both a heavyweight men's eight and a lightweight men's single scull. Measured lift and drag force coefficients previously presented by the authors were used as inputs to the model, whichs allowed for the influence of oar blade design on rowing performance to be determined. The commonly used Big Blade, which is curved, and it's flat equivalent were compared, and blade curvature was shown to generate a 1.14% improvement in mean boat velocity, or a 17.1-m lead over 1500 m. With races being won and lost by much smaller margins than this, blade curvature would appear to play a significant role in propulsion. 相似文献
10.
The aim of this study was to assess the effect of manipulating stroke rate on the distribution of mechanical power in rowing. Two causes of inefficient mechanical energy expenditure were identified in rowing. The ratio between power not lost at the blades and generated mechanical power (P(rower)) and the ratio between power not lost to velocity fluctuations and P(rower) were used to quantify efficiency (e(propelling) and e(velocity) respectively). Subsequently, the fraction of P(rower) that contributes to the average velocity (chi(boat)) was calculated (e(net)). For nine participants, stroke rate was manipulated between 20 and 36 strokes per minute to examine the effect on the power flow. The data were analysed using a repeated-measures analysis of variance. Results indicated that at higher stroke rates, P(rower), chi(boat), e(propelling), and e(net) increase, whereas e(velocity) decreases (P < 0.0001). The decrease in e(velocity) can be explained by a larger impulse exchange between rower and boat. The increase in e(propelling) can be explained because the work at the blades decreases, which in turn can be explained by a change in blade kinematics. The increase in e(net) results because the increase in e(propelling) is higher than the decrease in e(velocity). Our results show that the power equation is an adequate conceptual model with which to analyse rowing performance. 相似文献
11.
Abstract The aim of the present study was to find a more optimal blade design for rowing performance than the Big Blade, which has been shown to be less than optimal for propulsion. As well as the Big Blade, a flat Big Blade, a flat rectangular blade, and a rectangular blade with the same curvature and projected area as the Big Blade were tested in a water flume to determine their fluid dynamic characteristics at the full range of angles at which the oar blade might present itself to the water. Similarities were observed between the flat Big Blade and rectangular blades. However, the curved rectangular blade generated significantly more lift in the angle range 0 – 90° than the curved Big Blade, although it was similar between 90 and 180°. This difference was attributed to the shape of the upper and lower edges of the blade and their influence on the fluid flow around the blade. Although the influence of oar blade design on boat speed was not investigated here, the significant increases in fluid force coefficients for the curved rectangular blade suggest that this new oar blade design could elicit a practically significant improvement in rowing performance. 相似文献
12.
赛艇技术的生物力学研究 总被引：1，自引：0，他引：1
使用赛艇多参数遥测分析系统和IPL型高速摄影机同步测试方法,对我国国家赛艇集训队16名高水平运动员(男10,女6)的双桨技术进行了测试研究,分析结果如下:①在三种划桨类型中,“平缓力型”的动力学效率最高。“平缓力型”意味着拉桨力平稳增长达到峰值,然后对称下降直至拉桨结束。②艇速曲线有“单峰型”和“双峰型”两种类型。“单峰型”的特点是艇速变化平稳、能量消耗较少;“双峰型”能量消耗多。出现“双峰型”的主要原因是没有“边拉边按”和运动员身体在滑轨上加速不稳。③建立了浆力有效冲量与艇平均速度、艇速波动程度关系式。④发现一些选手左右手划桨力差别较大,桨叶入水角偏小和“拉提”时拉的不够等问题。 相似文献
13.
Abstract Our aim was to present a mathematical model of rowing and sculling that allowed for a comparison of oar blade designs. The relative movement between the oar blades and water during the drive phase of the stroke was modelled, and the lift and drag forces generated by this complex interaction were determined. The model was driven by the oar shaft angular velocity about the oarlock in the horizontal plane, and was shown to be valid against measured on-water mean steady-state shell velocity for both a heavyweight men's eight and a lightweight men's single scull. Measured lift and drag force coefficients previously presented by the authors were used as inputs to the model, whichs allowed for the influence of oar blade design on rowing performance to be determined. The commonly used Big Blade, which is curved, and it's flat equivalent were compared, and blade curvature was shown to generate a 1.14% improvement in mean boat velocity, or a 17.1-m lead over 1500 m. With races being won and lost by much smaller margins than this, blade curvature would appear to play a significant role in propulsion. 相似文献
14.
A mathematical model relating power output of rower to stroke rate on an ergometer (the Concept II Indoor Rower TM, Model
C) is studied. The model is used to analyse the ergometer performance of a particular rower. It is determined that he can
be more efficient (i.e. decrease power output while maintaining fixed velocity) by decreasing stroke rate, but at the expense
of increasing force during the drive. It is also shown that he can be more efficient by increasing the drag factor (using
higher vent setting) without increasing force. Dependence of power output on rowing style (the shape of the force curve) is
also examined. It is shown that variation of force during the drive has little effect on efficiency, but efficiency is reduced
by asymmetry of the force curve that favours the legs. 相似文献
15.
专项功率评价与赛艇水陆训练强度统一的研究 总被引：2，自引：0，他引：2
分析了国际上和中国赛艇队对功率评价与赛艇水陆训练强度控制问题的有关研究，对于如何把赛艇陆上测试的功与功率与水上的运动强度统一起来，如何运用功和功率在水陆训练整体评价运动员体能的方法进行了分析；对如何建立起赛艇水陆训练强度测评统一、完整的国家标准和体系进行了探讨。通过水上测试与陆上测功仪的功率数据的合理对应，能准确发现各种技能的细节问题，结合生化指标测试，就可能迅速建立起赛艇水陆训练强度测评统一、完整、先进的国家标准和体系，对2008年奥运会中国体能项目的全面突破和“119工程”的完成有实质的意义。 相似文献
16.
浅析赛艇运动员的专项力量训练 总被引：7，自引：0，他引：7
赛艇运动员的专项力量即为:赛艇运动员在完成划浆技术动作过程中,神经肌肉克服内外阻力的活动能力,由此可知,专项力量训练对赛艇运动的重要性.它是影响赛艇运动成绩的基本因素.所以,专项力量的训练,受到国内外教练的普遍重视.虽然他们的训练方法各有不同,但其训练原理是一致的.即发展肌肉克服外界对船的阻力而产生的能力. 相似文献
17.
Lotte L. Lintmeijer Mathijs J. Hofmijster Guido A. Schulte Fischedick Patrick J. Zijlstra A. J. “Knoek” Van Soest 《Journal of sports sciences》2018,36(18):2138-2146
In rowing, mechanical power output is a key parameter for biophysical analyses and performance monitoring and should therefore be measured accurately. It is common practice to estimate on-water power output as the time average of the dot product of the moment of the handle force relative to the oar pin and the oar angular velocity. In a theoretical analysis we have recently shown that this measure differs from the true power output by an amount that equals the mean of the rower’s mass multiplied by the rower’s center of mass acceleration and the velocity of the boat. In this study we investigated the difference between a rower’s power output calculated using the common proxy and the true power output under different rowing conditions. Nine rowers participated in an on-water experiment consisting of 7 trials in a single scull. Stroke rate, technique and forces applied to the oar were varied. On average, rowers’ power output was underestimated with 12.3% when determined using the common proxy. Variations between rowers and rowing conditions were small (SD = 1.1%) and mostly due to differences in stroke rate. To analyze and monitor rowing performance accurately, a correction of the determination of rowers’ on-water power output is therefore required. 相似文献
18.
目的:讨论一种在赛艇训练中增加训练阻力同时又不影响运动员技术动作的设备,即赛艇阻力器,在不同攻角、不同速度状态下,阻力、压力的变化,阻力与速度之间的关系以及增阻效果分析。方法:运用CFD软件FLUENT 6.2版本进行数值模拟。结果:速度不同,攻角相同状态下的阻力系数是相等的,阻力随速度和攻角的增大而增大,速度变化对阻力板阻力及压力的影响要大于角度的变化所产生的影响,阻力大小与速度的平方成正比,而阻力系数是常数。以155kg和175kg赛艇,阻力板攻角90°,赛艇划行速度5m/s为例,当无风状态时,安装阻力板的155kg赛艇增加的阻力(20.58N)比增加20kg重量(175kg)的阻力值(7.25N)大13.33N,增加的阻力值接近2倍。当顺风风速为3m/s时,阻力板增加的阻力为3.26N,比增加20kg重量的阻力值小3.99N,当逆风风速为3m/s时,阻力板增加的阻力为51.94N,比增加20kg重量增加的阻力值大44.69N,增加的阻力值近6倍多。结论:FLUENT软件对赛艇阻力板阻力计算是准确的,模拟的结果可以应用于具体的实际问题中。90°攻角状态下使用阻力板增加的阻力要优于由于赛艇艇重增加所达到的增阻效果。当处于顺风训练时,风速使阻力板增加的阻力值减小,减弱增阻效果,而逆风训练时,风速使阻力板产生的阻力值增大,加大了增阻效果。因此,采用阻力板训练,可以不改变赛艇的吃水和重心,保证运动员技术的完整性和连贯性,并且增加训练的强度,提高了训练的科学化水平。 相似文献
19.
赛艇运动中拉桨阶段的桨力曲线反映了运动员的发力特征，是专项竞技能力诊断的重要途径。根据国家队的测试实例，对不同艇种、不同桨位的桨力曲线特征进行归纳分析总结，对赛艇项目进行系列测试（桨频：35桨/min），结合专项认为专项技术较好的多人艇运动员大多采用A型；双人单桨项目中．领桨手倾向于采用A型桨力-时间曲线，一号位桨手倾向于采用B型桨力-时间曲线。不同桨频下的桨力-时间曲线特征可作为训练效果的评估依据，低桨频训练必须保持合理的拉桨速度和拉桨力量。 相似文献
20.
Fiona Wilson Conor Gissane John Gormley Ciaran Simms 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):132-142
Lumbar spine injury in rowers is common and ergometer rowing has been cited as a risk factor for this injury. The purpose of this study is to compare lumbar kinematics between ergometer and single scull rowing and to examine the effect of fatigue on kinematics. The sagittal lumbar spine motion of 19 elite male rowers (lumbar spine injury free in the previous six months) was measured with an electrogoniometer during a ‘step test’ on an ergometer and in a single sculling boat. Maximum range of lumbar flexion was recorded in standing for reference. Power output and heart rate were recorded during the ergometer tests. Heart rate was used as a surrogate for power output in the sculling test. Maximum lumbar flexion increased during the step test and was significantly greater on the ergometer (4.4° ± 0.9°change), compared with the boat (+1.3° ± 1.1°change), (3.1°difference, p = 0.035). Compared to the voluntary range of motion, there is an increase of 11.3% (ergometer) and 4.1% (boat). Lumbar spine flexion increases significantly during the course of an ergometer trial while changes in a sculling boat were minimal. Such differences may contribute to the recent findings linking ergometer use to lower-back injury. 相似文献