共查询到20条相似文献，搜索用时 15 毫秒
1.
Mehdi Kordi Nicos Haralabidis Matthew Huby Paul R. Barratt Glyn Howatson Jon Stephen Wheat 《Journal of sports sciences》2019,37(1):36-41
Gross thigh volume is a key anthropometric variable to predict sport performance and health. Currently, it is either estimated by using the frustum method, which is prone to high inter-and intra-observer error, or using medical imaging, which is expensive and time consuming. Depth camera 3D-imaging systems offer a cheap alternative to measure thigh volume but no between-session reliability or comparison to medical imaging has been made. This experiment established between-session reliability and examined agreement with magnetic resonance imaging (MRI). Forty-eight male cyclists had their thigh volume measured by the depth camera system on two occasions to establish between-session reliability. A subset of 32 participants also had lower body MRIs, through which agreement between the depth camera system and MRI was established. The results showed low between-session variability (CV = 1.7%; Absolute Typical Error = 112 cm3) when measuring thigh volume using the depth camera system. The depth camera systematically measured gross thigh volume 32.6cm3 lower than MRI. These results suggest that depth camera 3D-imaging systems are reliable tools for measuring thigh volume and show good agreement with MRI scanners, providing a cheap and time-saving alternative to medical imaging analysis. 相似文献
2.
Use of anthropometric data to infer sporting performance is increasing in popularity, particularly within elite sport programmes. Measurement typically follows standards set by the International Society for the Advancement of Kinanthropometry (ISAK). However, such techniques are time consuming, which reduces their practicality. Schranz et al. recently suggested 3D body scanners could replace current measurement techniques; however, current systems are costly. Recent interest in natural user interaction has led to a range of low-cost depth cameras capable of producing 3D body scans, from which anthropometrics can be calculated. A scanning system comprising 4 depth cameras was used to scan 4 cylinders, representative of the body segments. Girth measurements were calculated from the 3D scans and compared to gold standard measurements. Requirements of a Level 1 ISAK practitioner were met in all 4 cylinders, and ISO standards for scan-derived girth measurements were met in the 2 larger cylinders only. A fixed measurement bias was identified that could be corrected with a simple offset factor. Further work is required to determine comparable performance across a wider range of measurements performed upon living participants. Nevertheless, findings of the study suggest such a system offers many advantages over current techniques, having a range of potential applications. 相似文献
3.
Abstract The purpose of this study was to determine the validity and reliability of a new method for measuring three-dimensional (3D) putting stroke kinematics using the TOMI® device. A putting robot and a high-speed camera were used to simultaneously collect data for the validity evaluation. The TOMI® device, when used in conjunction with standard 3D coordinate data processing techniques, was found to be a valid and reliable method for measuring face angle, stroke path, putter speed, and impact spot at the moment of ball contact. The validity of the TOMI® measurement system was quantified using the 95% limits of agreement method for each aforementioned variable. The practical significance of each validity score was assessed by incorporating the maximum estimated measurement error into the stroke of the putting robot for 10 consecutive putts. All putts were executed from a distance of 4 m on a straight and flat synthetic putting surface. Since all putts were holed successfully, the measurement error for each variable was deemed to be negligible for the purposes of measuring putting stroke kinematics. The influence of key kinematic errors, at impact, on the outcome of a putt was also determined. 相似文献
4.
Thigh muscle volume is a useful determinant of functional fitness. However, anthropometric prediction of muscle content is influenced by the variability of adipose tissue accumulation. The aims of this study were to predict thigh muscle and adipose tissue volumes from anthropometry and to assess the validity of the method by examining the various components of the measurements and the assumptions involved. The 19 participants (9 men, 10 women; age 23-49 years) varied in adiposity. They all underwent magnetic resonance imaging (MRI) of the upper leg and the eight men and two women with the lowest adiposity underwent detailed anthropometry involving girths and skinfolds. Using MRI as the reference method, muscle volume was predicted from anthropometry using a circular concentric model, and the assumptions inherent in the method were tested further using the MRI data alone. Muscle volume was best predicted by anthropometry in the 10 leanest participants using a five-slice truncated cone model that overestimated the mean MRI value by 30% ( R 2 = 0.95; standard error of estimate = 288 cm 3 ; P ? 0.001). A single skinfold plus girth measurement at the mid-thigh almost matched its predictive ability, but with an increased bias. Measurements of leg circumference by means of the two techniques agreed well. The assumption of a circular cross-section was valid. In contrast, the agreement between skinfold thickness measured by caliper and superficial adipose tissue thickness by MRI was poor, contributing to the scatter of fat and lean area comparisons. An anterior skinfold thickness measurement underestimated the area of superficial adipose tissue at that level, particularly at the most proximal and distal sites. Although these limitations increase the uncertainties of muscle volume determination by anthropometry, they do not prevent its valid prediction in leaner individuals. The prediction of superficial adipose tissue was poorer. 相似文献
5.
Thigh muscle volume is a useful determinant of functional fitness. However, anthropometric prediction of muscle content is influenced by the variability of adipose tissue accumulation. The aims of this study were to predict thigh muscle and adipose tissue volumes from anthropometry and to assess the validity of the method by examining the various components of the measurements and the assumptions involved. The 19 participants (9 men, 10 women; age 23-49 years) varied in adiposity. They all underwent magnetic resonance imaging (MRI) of the upper leg and the eight men and two women with the lowest adiposity underwent detailed anthropometry involving girths and skinfolds. Using MRI as the reference method, muscle volume was predictedfrom anthropometry using a circular concentric model, and the assumptions inherent in the method were tested further using the MRI data alone. Muscle volume was best predicted by anthropometry in the 10 leanest participants using a five-slice truncated cone model that overestimated the mean MRI value by 30% (R2 = 0.95; standard error of estimate = 288 cm3; P < 0.001). A single skinfold plus girth measurement at the mid-thigh almost matched its predictive ability, but with an increased bias. Measurements of leg circumference by means of the two techniques agreed well. The assumption of a circular cross-section was valid. In contrast, the agreement between skinfold thickness measured by caliper and superficial adipose tissue thickness by MRI was poor, contributing to the scatter of fat and lean area comparisons. An anterior skinfold thickness measurement underestimated the area of superficial adipose tissue at that level, particularly at the most proximal and distal sites. Although these limitations increase the uncertainties of muscle volume determination by anthropometry, they do not prevent its valid prediction in leaner individuals. The prediction of superficial adipose tissue was poorer. 相似文献
6.
Nathan Elliott Simon Choppin Simon Goodwill Terry Senior John Hart Tom Allen 《Sports Engineering》2018,21(2):137-147
Stereo camera systems have been used to track markers attached to a racket, allowing its position to be obtained in three-dimensional (3D) space. Typically, markers are manually selected on the image plane, but this can be time-consuming. A markerless system based on one stationary camera estimating 3D racket position data is desirable for research and play. The markerless method presented in this paper relies on a set of racket silhouette views in a common reference frame captured with a calibrated camera and a silhouette of a racket captured with a camera whose relative pose is outside the common reference frame. The aim of this paper is to provide validation of these single view fitting techniques to estimate the pose of a tennis racket. This includes the development of a calibration method to provide the relative pose of a stationary camera with respect to a racket. Mean static racket position was reconstructed to within ±2 mm. Computer generated camera poses and silhouette views of a full size racket model were used to demonstrate the potential of the method to estimate 3D racket position during a simplified serve scenario. From a camera distance of 14 m, 3D racket position was estimated providing a spatial accuracy of 1.9 ± 0.14 mm, similar to recent 3D video marker tracking studies of tennis. 相似文献
7.
Brian Hanley Catherine B. Tucker Athanassios Bissas 《Journal of sports sciences》2018,36(11):1250-1255
Race walking is an event where the knee must be straightened from first contact with the ground until midstance. The aim of this study was to compare knee angle measurements between 2D videography and 3D optoelectronic systems. Passive retroreflective markers were placed on the right leg of 12 race walkers and 3D marker coordinate data captured (250 Hz), with 2D video data (100 Hz) recorded simultaneously. Knee angle data were first derived based on the markers’ coordinates, and separately by using a 3D model that also incorporated thigh and shank clusters; the video data were analysed using both automatic tracking and manual digitising, creating four conditions overall. Differences were calculated between conditions for stance (using root mean square values), and at discrete events. There were few differences between systems, although the 3D model produced larger angles at midstance than using automatic tracking and marker coordinates (by 3 – 6°, P < 0.05). These differences might have occurred because of how the 3D model locates the hip joint, and because of the addition of marker clusters. 2D videography gave similar results to the 3D model when using manual digitising, as it allowed for errors caused by skin movement to be corrected. 相似文献
8.
吕季东 《上海体育学院学报》2000,24(1):53-58
运用高速摄影及三维测力同步测试法,研究在不同的高台至起点远度的起跳腿啃深跳远练习中,运动员的踏跳动作结构变化及不同的着板技术对人体受力的影响。提出不同训练水平运动员合理的高台至起跳点远度及其在运用中的变化方法,认为起跳腿跳深跳远练习可作为男子跳远运动员的专门练习之一。 相似文献
9.
目的:研究音乐渐进放松配合音乐心率训练对运动性疲劳消除的影响,并探讨其与传统恢复方法的比较优势。方法:15～22周岁的男运动员共36名,进行为期7天的同等负荷量度的实验训练,中间休整1天,前3天每天早上测量晨脉,运动前测量RPE值、大腿围、小腿围。训练中记录RPE值,运动后即刻测量心率、大腿围、小腿围。测量结束后采用5min传统的整理运动恢复练习,之后再次测量心率、大腿围、小腿围。后3天每天运动前测量RPE值、大腿围、小腿围。训练中记录RPE值,运动后即刻测量心率、大腿围、小腿围。测量结束后采用5min的音乐渐进放松配合音乐心率训练恢复,之后再次测量心率、大腿围、小腿围和RPE值。结果:与运动后即刻相比,音乐渐进放松配合音乐心率训练干预后RPE值下降的幅度在23.77%～25.41%;大、小腿围减少的幅度分别在1.07%～1.16%和0.47%～0.64%;与传统恢复相比,音乐疗法后RPE值比传统恢复法有所下降,下降幅度为1.15%～1.76%;大、小腿围减少幅度分别在0.07%～0.18%和0.16%～0.22%。结论:音乐渐进放松配合音乐心率训练对运动疲劳的恢复有积极作用;与传统恢复法相比,音乐疗法更有利于促进心血管系统、中枢神经系统和心理状态的恢复,且经济实用、易于推广。 相似文献
10.
Jaymee R. Shell Shawn M. K. Robbins Philippe C. Dixon Philippe J. Renaud René A. Turcotte Tom Wu 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(3):313-324
The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete’s sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males’ maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics. 相似文献
11.
12.
This study applied a vision-based tracking approach to the analysis of articulated, three-dimensional (3D) whole-body human
movements. A 3D computer graphics model of the human body was constructed from ellipsoid solids and customized to two gymnasts
for size and colour. The model was used in the generation of model images from multiple camera views with simulated environments
based on measurements taken on each of three synchronized video cameras and the lighting sources present in the original recording
environment. A hierarchical procedure was used whereby the torso was tracked initially to establish whole-body position and
orientation and subsequently body segments were added successively to the model to establish body configuration. An iterative
procedure was used at each stage to optimize each new set of variables using a score based on the RGB colour difference between
the model images and video images at each stage. Tracking experiments were carried out on movement sequences using both synthetic
and video image data. Promising qualitative results were obtained with consistent model matching in all sequences, including
sequences involving whole-body rotational movements. Accurate tracking results were obtained for the synthetic image sequences.
Automatic tracking results for the video images were also compared with kinematic estimates obtained via manual digitization
and favourable comparisons were obtained. It is concluded that with further development this model-based approach using colour
matching should provide the basis of a robust and accurate tracking system applicable to data collection for biomechanics
studies. 相似文献
13.
借助高速摄像机,运用编成数据软件,对网球比赛录像相关数据进行记录、梳理,旨在研制一个网球三维运动参数采集及技战术实时自动分析系统.该系统具有扫描网球比赛中网球及运动员人体的三维运动轨迹及三维投影图,数字化同步重放、任意运动点及运动时段（或时刻）运动员动作图像,网球各项技战术统计、归整、分析,快速灵活查询运动员档案等功能,对运动员在网球比赛中技战术运用和策略制定提供直观的、科学的数据参考. 相似文献
14.
Lucas Antônio Monezi Thiago Pinguelli Magalhães Márcio Pereira Morato Luciano Allegretti Mercadante Milton Shoiti Misuta 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(5):470-481
In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players’ movement patterns during goalball matches that can be used to plan more effective training. 相似文献
15.
Alexander H. K. Montoye Joe R. Mitrzyk Monroe J. Molesky 《Measurement in physical education and exercise science》2017,21(4):201-211
The purpose of the current study was to determine the accuracy of the Fitbit Charge HR and Hexoskin smart shirt. Participants (n = 32, age: 23.5 ± 1.3 years) wore a Fitbit and Hexoskin while performing 14 activities in a laboratory and on a track (lying, sitting, standing, walking various speeds and inclines, jogging, and cycling). Steps, kcals, heart rate, breathing rate, depth, and volume were measured by the Fitbit and Hexoskin and compared to criterion measures. The Fitbit and Hexoskin had low mean absolute percent error for steps (9.7%, 9.4%). The mean absolute percent error was low for heart rate (6.6% and 2.4%), with the Fitbit underestimating heart rate at higher intensities. Both devices had high mean absolute percent error for kcals (43.7% and 27.9%, respectively), and the Hexoskin had high mean absolute percent error for breathing rate, depth, and volume (19.4%, 35.6%, and 33.6%, respectively). The Fitbit and Hexoskin have utility for measurement of some, but not all, physical activity and physiologic variables which they measure. 相似文献
16.
Abstract With the use of three-dimensional whole body scanning technology, this study compared the 'traditional' anthropometric model [one-dimensional (1D) measurements] to a 'new' model [1D, two-dimensional (2D), and three-dimensional (3D) measurements] to determine: (1) which model predicted more of the variance in self-reported best 2000-m ergometry rowing performance; and (2) what were the best anthropometric predictors of ergometry performance, for junior rowers competing at the 2007 and 2008 Australian Rowing Championships. Each rower (257 females, 16.3?±?1.4 years and 243 males, 16.6?±?1.5 years) completed a performance and demographic questionnaire, had their mass, standing and sitting height physically measured and were landmarked and scanned using the Vitus Smart? 3D whole body scanner. Absolute and proportional anthropometric measurements were extracted from the scan files. Partial least squares regression analysis, with anthropometric measurements and age as predictor variables and self-reported best 2000-m ergometer time as the response variable, was used to first compare the two models and then to determine the best performance predictors. The variance explained by each model was similar for both male [76.1% (new) vs. 73.5% (traditional)] and female [72.3% (new) vs. 68.6% (traditional)] rowers. Overall, absolute rather than proportional measurements, and 2D and 3D rather than 1D measurements, were the best predictors of rowing ergometry performance, with whole body volume and surface area, standing height, mass and leg length the strongest individual predictors. 相似文献
17.
目的:观察3个月综合锻炼对社区老年人步态的影响.方法:研究对象为自愿参加本次测试的控江社区60～80岁老年女性16名.志愿者参加每周3次、每次1.5小时、为期3个月的针对性综合锻炼干预,步态指标由VICON系统与KISTLER测力台进行数据同步采集,并使用VISUAL3D软件进行分析.结果:经过运动干预后,志愿者步态指标发生显著变化,表现为步长增加(0.54 ±0.07m VS 0.60±0.06 m,P＜0.01)、步速加快(1.10±0.18 VS1.29±0.22 m/s,P＜0.01)、双支撑时相缩短(24.10％±5.10％ VS 21.08％±3.99％,P＜0.01)、步态各周期中髋、膝、踝关节活动幅显著加大.结论:简易的综合性锻炼计划对老年人步态有显著的改善效果,建议可作为预防老年人跌倒的运动干预手段. 相似文献
18.
Henrik S⊘rensen Morten Zacho Erik B. Simonsen Poul Dyhre‐Poulsen Klaus Klausen 《Journal of sports sciences》2013,31(6):483-495
Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo‐distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon‐do practitioners were filmed using a high‐speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion‐dependent moments. The results indicated that thigh deceleration was caused by motion‐dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion‐dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration. 相似文献
19.
The purpose of the study was to determine the anthropological status of elite male and female speed skaters, who were members of the 1985–7 Canadian national teams. The data were compared to those for a control group of University students. The subjects were 8 males and 6 females between 19 and 27 years of age. Nine breadth, 14 girth, 16 length and 15 skinfold measurements were used to compute parameters of body build and the composition; corrected diameters, masses, volumes and fat‐free volumes of the upper arm, forearm, thigh and calf. The speed skaters were found to be similar in body height and mass (males: 178 ± 7.6 cm and 75.5 ± 5.5 kg, females: 165.8 ± 3.8 cm and 62.3 ± 5.8 kg) to the student controls, but they had relatively and absolutely shorter legs and longer trunks. The speed skaters had a lower amount of body fat and higher FFM than their respective student controls and significantly greater relative (P ≤ 0.01) and absolute (P ≤ 0.05) total muscle mass. Analysis of composition within segments indicated that the additional muscle mass is located entirely in the lower extremity. The volume and mass of the thigh was greater (P ≤ 0.01 for the males) than that of the respective controls while the estimated volume of fat was lower. The female speed skaters were found to have more fat on their thigh than either the male speed skaters or male controls. The corrected diameter and mass of the thigh were greater (with respect to the sex) than those reported for 400 m sprinters, marathon runners, cross‐country skiers and figure skaters. The results of the initial assessment were compared to the two consecutive tests of the men's team (conducted 8 and 12 months later) and to one repeated test of the women's team (3 months later). Changes were recorded in skinfold measurements and the muscle component of the thigh. 相似文献
20.
关于乒乓球选材标准的教练员观点调查 总被引：1，自引：0，他引：1
S.Limoochi 《体育科研》2005,26(3):105-107,110
本调查的目的是确定一些选材标准和原则,它们大都基于乒乓球教练员们对人体形态测量、身体运动素质能力、生理心理素质、心理以及体型因素的观点。针对不同运动项目选材的重要性,研究人员试图找出天才的乒乓球儿童和少年。研究对象与方法:随机对40名乒乓球教练员(其中伊朗教练员26人,另外14人来自其它国家)进行问卷量表调查,该量表由14个答题组成。研究结果:在上述所提及的选材因素中,约有34%的教练员考虑了人体形态测量作为优先指标,约有31.6%的教练员选择了心理素质能力和心理因素作为优先指标。 相似文献