Comparing Measurement Error Between Two Different Methods of Measurement of Various Magnitudes

Measurement error is a common problem in several fields of research such as medicine, physiology, and exercise science. The standard deviation of repeated measurements on the same person is the measurement error. One way of presenting measurement error is called the repeatability, which is 2.77 multiplied by the within subject standard deviation. In this article, the two different repeatabilities obtained from two different protocols or “tests” are statistically compared. Briefly, the squared differences between protocols are natural log transformed to achieve normality and compared with a paired t-test. The natural log transformation guarantees that the squared differences follow a normal distribution. When more than two repeatabilities are compared from more than two protocols or “tests,” repeated-measures ANOVA comparing the log transformation of the squared differences is used. When comparing repeatabilities between protocols and between different magnitudes of measurement, repeated-measures ANOVA compares the natural log transformation of the squared differences between protocols and between different magnitudes of measurement.     

体育测量中确定测量次数的研究

体育测量中,通过增加重复测量次数可减小随机误差,达到提高测量的可靠性。但测量次数的增加,进行测量所付出的代价也会加大,特别是体育测量中还要考虑受试者的生理、心理承受能力及测量客观条件等因素。正确的确定所需测量次数,是进行体育测量首先要解决的实际问题。笔者对确定合适的体育测量次数进行分析和探讨。     

论12min跑测验在高校体育教学中的运用

针对目前大学生体质逐年下降的问题,普通高校体育应以大众健身运动为主要工作,以开展有氧代谢运动为主要方式,以增强心脑血管系统机能为主要目标。提出在普通高校体育教学中开展12min 跑测验的生理学价值、测量学价值和心理学价值,以及在实践过程中的可操作性,并根据5 年的教学实践,制定了大学生12min 跑测验的评价标准,供有关部门参考。     

对体育测量理论若干问题的探讨

主要以文献资料法 ,针对教学中容易引起误解、教材本身又忽略的重点和难点问题进行探讨 ,以图在提高教学质量的同时 ,丰富体育测量评价教材内容。     

The dynamic control ratio at the equilibrium point (DCRe): introducing relative and absolute reliability scores

Analytical methods to assess thigh muscle balance need to provide reliable data to allow meaningful interpretation. However, reproducibility of the dynamic control ratio at the equilibrium point has not been evaluated yet. Therefore, the aim of this study was to compare relative and absolute reliability indices of its angle and moment values with conventional and functional hamstring–quadriceps ratios. Furthermore, effects of familiarisation and angular velocity on reproducibility were analysed. A number of 33 male volunteers participated in 3 identical test sessions. Peak moments (PMs) were determined unilaterally during maximum concentric and eccentric knee flexion (prone) and extension (supine position) at 0.53, 1.57 and 2.62 rad · s^–1. A repeated measure, ANOVA, confirmed systematic bias. Intra-class correlation coefficients and standard errors of measurement indicated relative and absolute reliability. Correlation coefficients were averaged over respective factors and tested for significant differences. All balance scores showed comparable low-to-moderate relative (<0.8–0.9) and good absolute reliability (<10%). Relative reproducibility of dynamic control equilibrium parameters augmented with increasing angular velocity, but not with familiarisation. At 2.62 rad · s^–1, high (moment: 0.906) to moderate (angle: 0.833) relative reliability scores with accordingly high absolute indices (4.9% and 6.4%) became apparent. Thus, the dynamic control equilibrium is an equivalent method for the reliable assessment of thigh muscle balance.     

Validation of a wireless shoe insole for ground reaction force measurement

Ground reaction force measurements are a fundamental element of kinetic analyses of locomotion, yet they are traditionally constrained to laboratory settings or stationary frames. This study assessed the validity and reliability of a new wireless in-shoe system (Novel Loadsol/Pedoped) for field-based ground reaction force measurement in hopping, walking, and running. Twenty participants bilaterally hopped on a force plate and walked (5 km/hr) and ran (10 km/hr) on an instrumented treadmill on two separate days while wearing the insoles. GRFs were recorded simultaneously on each respective system. Peak GRF in hopping and peak GRF, contact time (CT), and impulse (IMP) in walking and running were compared on a per-hop and step-by-step basis. In hopping, the insoles demonstrated excellent agreement with the force plate (ICC: 0.96). In walking and running, the insoles demonstrated good-to-excellent agreement with the treadmill across all measures (ICCs: 0.88–0.96) and were reliable across sessions (ICCs within 0.00–0.03). A separate verification study with ten participants was conducted to assess a correction algorithm for further agreement improvement but demonstrated little meaningful change in systemic agreements. These results indicated that the Novel Loadsol system is a valid and reliable tool for wireless ground reaction force measurement in hopping, walking, and running.     

Precision of the optimized carbon monoxide rebreathing method to determine total haemoglobin mass and blood volume

Abstract

The aim of this study was to evaluate the influence of different apparatuses, procedures and calculations on the precision of the optimized carbon monoxide method. Total haemoglobin mass was determined twice on consecutive days in 11 subjects using both venous and capillary blood samples. To estimate loss of carbon monoxide due to exhalation, carbon monoxide concentration was measured by two portable carbon monoxide analysers (Fluke CO-220, Fluke, Norwich, UK and Pac 7000 Carbon Monoxide, Draeger Safety, Northumberland, UK) and alveolar ventilation was specified using an automated metabolic gas analysis system (Cosmed Quark b2, Cosmed, Rome, Italy). Blood volume was derived from total haemoglobin mass using haemoglobin concentration and haematocrit obtained in both the supine and the seated position. Two different formulae to calculate blood volume were also compared. Precision was good for both total haemoglobin mass and blood volume measurements performed on consecutive days (typical error < 2%). Using Fluke CO-220 analyser, an estimated alveolar ventilation and capillary blood, total haemoglobin mass (917±136 g) was similar when compared to the Pac 7000 Draeger CO-analyser (904±137 g; mean bias –13 g with 95% limits of agreement –26 to + 1 g, P=0.76), specified alveolar ventilation (911±132 g, mean bias –6 g with 95% limits of agreement –18 g to + 6 g, P =0.87) and venous blood (917±134 g, mean bias 0 g with 95% limits of agreement –38 to + 38 g, P=0.99), respectively. Blood volume determination was also not significantly affected by the supine vs. seated position (6.7±0.8 l vs. 6.6±0.8 l, P=0.56) but can deviate by ~0.6 l (P=0.01) depending on the formula applied. Thus, the good precision of the assessment of total haemoglobin mass and blood volume using the optimized carbon monoxide rebreathing method is not significantly influenced by the make of CO analyser, method of obtaining alveolar ventilation, blood sampling method and subject position, but should for longitudinal monitoring purposes use the same formula.     

The importance of accurate site location for skinfold measurement

Abstract

We assessed the importance of accurate site location for skinfold measurement in ten healthy males in a cross-sectional quantitative study. Nine measurements, in a 1-cm grid pattern, centred on each of eight ISAK-specified skinfold sites, were taken three times at each grid point by each of two ISAK Level 4 practitioners using Harpenden skinfold callipers. The presence of significant systematic discrepancy between reliability measures of different skinfold sites and grid points for each of the two testers was determined using P-values. Effect sizes were calculated to show the magnitude of effects. Skinfolds taken at the eight peripheral grid points were generally different from the skinfolds taken at a central ISAK grid point and there was an effect by direction away from the central ISAK point (anterior, posterior, superior or inferior). The subscapular skinfold had the least number of differences (three) and the abdominal had the most (eight). All other skinfold sites showed some variation with most care needed in marking the biceps and triceps skinfold sites. Adherence to identifying, marking, and measuring at the defined site is essential.     

职业足球球迷忠诚度的建模测量实证研究——以2010赛季中超北京、上海、南京三个赛区为例

对2010赛季中超北京、上海、南京三个赛区的球迷忠诚度进行了调查。运用品牌忠诚理论、数学中的复平面概念的方法对球迷忠诚度进行分类和测量,较准确地反映了职业足球球迷忠诚度的现状,并试析其下一步的政策导向。     

The Reliability and Validity of Protocols for the Assessment of Endurance Sports Performance: An Updated Review

Sports performance testing is one of the most common and important measures used in sport science. Performance testing protocols must have high reliability to ensure any changes are not due to measurement error or inter-individual differences. High validity is also important to ensure test performance reflects true performance. Time-trial protocols commonly have a coefficient of variation (CV) of <5%, however, familiarization, well-trained subjects and/or conducting the trial outdoors in the athlete’s most familiar environment can lead to CVs of < 1%. Long duration time-trials or the inclusion of sprints within a time-trial appears to not negatively influence reliability. Few studies have assessed the validity of endurance performance tests, and as such more research should evaluate different ways of simulating outdoor performances in the laboratory. The use of warm-up, simulation of convection load, and implementation of race specific hydration practices are important considerations for researchers regarding test validity.     

Validity and Reliability of Three Self-Report Instruments for Assessing Attainment of Physical Activity Guidelines in University Students

The purpose of this study was to compare the validity and reliability of three short physical activity self-report instruments to determine their potential for use with university student populations. The participants (N = 155; 44.5% male; 22.9 ± 5.13 years) wore an accelerometer for 9 consecutive days and completed a single-item measure, the a brief two item measure and the International Physical Activity Questionnaire—Short Form questionnaires on day 1 and 9. Correlations between self-reported and accelerometer derived moderate-to-vigorous physical activity levels were moderate for the International Physical Activity Questionnaire—Short Form, while poor for the single-item measure and the a brief two item measure. The agreement level was high with the International Physical Activity Questionnaire—Short Form (77.4%) and moderate for both the single-item measure (45.2 %) and a brief two item measure (44.5 %). The intraclass correlations between the two administrations were moderate to strong across all measures (0.52–0.70) in 133 participants. The International Physical Activity Questionnaire—Short Form is the most suitable of these three self-report instruments for use with this population due to higher correlations and levels of agreement with accelerometry.     

生物医学测量的现状与发展

生物医学测量技术是生物医学科研工作必备的素质之一，通过对生物医学测量的基本特点，范围与分类以及目前国内外的研究现状和发展趋势作一较全面的综述，以期对生物医学（包括运动医学）科研工作有所裨益。     

Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.     

体育院校“非技术性体育专业”招生体育加试内容与录取办法的研究

在剖析我国体育院校“非技术性体育专业”招生考试制度与录取办法的基础上,提出了在“非技术性体育专业”招生考试中增设体育加试的内容、评分标准与录取办法     

Measuring Physical Activity in Preschoolers: Reliability and Validity of the System for Observing Fitness Instruction Time for Preschoolers (SOFIT-P)

The purpose of this study is describe the initial feasibility, reliability, and validity of an instrument to measure physical activity in preschoolers using direct observation. The System for Observing Fitness Instruction Time for Preschoolers was developed and tested among 3- to 6-year-old children over fall 2008 for feasibility and reliability (Phase I, n = 67) and in fall 2009 for concurrent validity (Phase II, n = 27). Phase I showed that preschoolers spent >75% of their active time at preschool in light physical activity. The mean inter-observer agreements scores were ≥.75 for physical activity level and type. Correlation coefficients, measuring construct validity between the lesson context and physical activity types with and with the activity levels, were moderately strong. Phase II showed moderately strong correlations ranging from .50 to .54 between the System for Observing Fitness Instruction Time for Preschoolers and Actigraph accelerometers for physical activity levels. The System for Observing Fitness Instruction Time for Preschoolers shows promising initial results as a new method for measuring physical activity among preschoolers.     

常见便携式遥测气体代谢仪核心测量指标的信度和效度分析

现代社会生活方式的改变,给人类健康带来极大的威胁。通过增加日常体力活动量（约占总能量消耗量的20%）,可以有效减少和控制慢性非传染性疾病的发生和发展,减轻社会医疗负担。便携式遥测气体代谢仪可测量自由状态下的体力活动量,因而被广泛应用于智能手机、可穿戴和虚拟现实设备的开发和应用,以及竞技体育科研等健康促进领域的研究,目前对便携式遥测气体代谢仪准确的使用范围知之不深。本文对常见的几种便携式遥测气体代谢仪（包括：Cosmed K4b2、Metamax 3B/VmaxST、Oxycon Mobile、VO2000）在不同环境、不同条件下测量的信度和效度及其核心指标VO2、VCO2和VE进行分析,以期为相关的研究和应用提供参考。     

全国重点青年男排训练课质量测评情况的分析

通过对全国重点青年男排训练课质量测评指标数据的定量分析,反映了青年男排训练质量的现状,并构建了青年男排技术课质量评价标准模型。     

Reliability of metrics associated with a counter-movement jump performed on a force plate

The counter-movement jump is a consequence of maximal force, rate of force developed, and neuromuscular coordination. Thus, the counter-movement jump has been used to monitor various training adaptations. However, the smallest detectable difference of counter-movement jump metrics has yet to be established. The objective of the present study was to measure the reliability of counter-movement jump metrics, including rate of force development, flight time, time to max force, and max force. Twenty-nine male participants (mean age 25 ± 3 years) were divided into three groups. Each participant performed five counter-movement jumps on a force plate, on three consecutive days. Flight time detected trivial changes, (effect size < .2) and typical error of measurement of .25%; max force detected small changes (effect size < .5) with a typical error of measurement of .3%; rate of force development detected small to medium change (effect size .5–.8) with a typical error of measurement of .3%.