加速度传感器测量不同速度运动时能量消耗的研究

目的验证RT3三轴加速度传感器和Actigraph单轴加速度传感器测量不同速度步行或跑步时能量消耗的精确度。方法受试对象为南京体育学院大学生20名,男女各10名。受试者同时佩戴RT3加速度传感器和Acti-graph加速度传感器在跑台上分别以3.2 km/h、4.8 km/h、6.4 km/h、8.1 km/h、9.7 km/h的速度完成800 m步行或跑步。以间接测热法测量不同速度步行或跑步时的实际能量消耗。结果 5种速度步行或跑步时,当速度为3.2km/h、4.8 km/h、6.4 km/h时,RT3三轴加速度传感器能够相对准确测量能量消耗,而当速度为8.1 km/h、9.7 km/h时,该传感器测量能耗值与实际能耗值比较,差异具有显著性,因而不能准确测量这两种速度时的能量消耗;当速度为3.2 km/h、4.8 km/h、6.4 km/h时,Actigraph加速度传感器测量能耗值与实际能耗值比较,差异具有显著性,因而不能准确测量这三种速度时的能量消耗。结论无论在何种运动速度下,RT3测量能耗值均高于实际能耗值,其较适合于测量步行等中低速度体力活动的能量消耗;Actigraph测量能耗值均低于实际能耗值,其较适合于测量跑步等较快速度体力活动的能量消耗。     

4 种运动传感器测量身体活动能耗的有效性研究

Actigraph(GT3X)加速度计、LivePod iMate能耗仪、AM-120与HJ-302计步器均应用了三维运动传感技术,可用于日常身体活动与运动能耗的监测.以我国的年轻成人为受试对象,年龄为(24±5)岁,包括14名男性与6名女性.受试者佩戴4个运动装置的同时,在运动跑台上分别完成4、5.6、6.4、7.2、8 km/h不同强度的走跑运动各5 min.以间接测热法的能耗值作为效标,采用Pearson相关、单因素方差以及配对T检验等分析方法,对4种运动传感器进行效度研究.结果发现:Actigraph加速度计的能耗值以低估为主,但在不同运动强度上有较低的系统误差水平;LivePod iMate能耗仪与HJ-302计步器也以低估为主,但前者随运动强度增大低估水平增加,后者则相反;AM-120计步器在6.4 km/h速度以下低估,7.2 km/h时开始变为高估.结论认为,GT3X加速度计具有较高的效度水平,而其他3种运动传感器系统误差较大,应用时可依据需要进行选择.     

基于三轴加速度传感器的大学生体力活动能量消耗模型研究

针对中国大学生人群,选择7项日常体力活动方式,通过三轴加速度传感器监控,构建不同类型运动项目的能量消耗预测模型。研究结果表明：（1）通过佩戴传感器,可以有效对运动过程进行记录,每种运动形式特征明显。（2）不同类型的运动之间具有显著性差异,同一种运动方式不同速度之间没有差异,说明传感器可以有效区分运动类型。（3）将加速度值进行分析,构建基于垂直加速度Vcz和综合加速度值VM的能量消耗模型,分别为：W/min=-9.173+0.004×ACz+1.09×Sex+0.241×BMI+0.060×HR,W/min=-12.57+0.008×VM+0.921×SEX+0.242×BMI+0.053×HR （M=1,F=0）。（4）通过回带验证,两个能量消耗方程均有很好的拟合度,预测结果与实际值很接近。     

运动传感器(SWA)在测量青少年日常体力活动水平中的应用

目的:应用运动传感器SWA测量青少年日常体力活动的能量消耗,了解青少年日常体力活动状况,探讨SWA在体力活动测量中的应用价值.方法:随机抽取上海市30名中学生作为调查对象,男女各半.受试者佩带SWA,固定于优势侧上臂肱三头肌处,每天早晨起床后戴上,一直到晚上睡觉前摘下,连续佩戴7 d,记录体力活动的能量消耗和活动时间.结果:男生1周总能量消耗和平均每天进行的中等强度、大强度体力活动能量消耗和时间高于女生(P<0.01);在平均每天的能量消耗构成比中,男生从事大强度的体力活动能耗为10%,中等强度的能耗为14%,女生从事大强度的体力活动能耗为4%,中等强度的能耗为12%.个体间体力活动能耗为10.44%-46.03%.结论:目前青少年的体力活动水平参差不齐,存在着明显的性别差异,并且随着年龄的增长,体力活动水平下降.SWA具有较好的客观性、可靠性和实用性.     

运动健身能量消耗简易测量方法的效度研究

目的:使用SWA传感器测量跑台走跑和实地自行车运动时的能量消耗,并与间接测热法测量结果相比较,对SWA测量运动健身时能量消耗的有效性进行研究,为传感器的准确应用提供参考。方法:15名成年男性在平板运动跑台完成4.8km/h、6.4km/h、8.0km/h 3个速度的走、跑运动,并在室内完成10km/h、13km/h、15km/h的场地自行车运动,使用SWA(两个软件版本V6.1、V7.0)和间接测热法预测运动时的能量消耗,对预测数据进行配对t检验、回归分析、相关性分析、ICC系数以及Bland-Altman一致性检验。结果:1)SWA 6.1高估了跑台走跑(高估1%)和实地自行车运动(高估9%)的能量消耗,但相关性和一致性较好(r=0.91,ICC=0.91)。2)SWA 7.0高估了跑台走跑(高估325%)和实地自行车运动(高估357%)的能量消耗,其与IC预测能量消耗的差值随着强度的增加而增大,但两者之间的相关性较好(r=0.91),一致性在可接受的范围之内(ICC=0.44),且SWA 7.0预测走跑能量消耗时与IC的一致性大于预测自行车运动能量消耗与IC的一致性。结论:SWA传感器预测的运动健身能量消耗值远远大于间接测热法预测的能量消耗,且预测的能量消耗差值随着运动速度的增加而不断增加,与该传感器旧版本高估低强度运动能量消耗和低估高强度能量消耗有所不同,但预估的能量消耗与间接测热法之间有较高的相关性和一致性。     

Actigraph及其信效度研究

体力活动不足是影响人类健康的重要因素,客观、准确的体力活动监测方法和仪器对于开展体力活动研究、运动干预和人们的日常健康管理具有重要意义。Actigraph是目前国外应用最多的加速度传感器能量消耗监测仪器之一,首先介绍了Actigraph的基本技术、参数,然后对相关Actigraph的文献从"信度"、"效度"、"能量消耗推算方程"、"仪器对比研究"等方面进行回顾,以期为相关研究提供有益参考。     

环卫工人日常体力活动现状监测分析

体力活动是提高人体健康水平的基本手段之一,对体力活动评估一直是运动健康领域的研究热点.目的:以职业分类角度,探讨环卫工人一日体力活动及能量消耗特征.方法:采用型号为LivePod imate R3的三维人体运动能量消耗监测仪,对男、女环卫工人各20名进行连续7天的体力活动监测.结果:环卫工人体力活动每日动作数工作日男性每天平均为27 066.0次,女性每天为22 789.4次.在工作日的工作时间体力活动动作数则是女性高于男性.在能量消耗方面,工作日男性、女性每天平均分别为635.8kcal、546.7Kcal,二者不存在显著性差异.结论:环卫工人工作日体力活动动作数较高,并且男性每日动作数高于女性.但在工作时间内则是女性动作数高于男性.工作日每日能量消耗男、女差异的不显著,提示环卫工作是一项性别差异不明显的工作.环卫工人每日较高的动作数并没有伴随较高的能量消耗,提示该类人群需进行适当强度的健身锻炼提高身体机能.     

体力活动测量方法研究进展

体力活动水平与健康之间存在着剂量反应,如何准确测量体力活动水平是研究人员关心的问题。本文综述了体力活动研究的几种主要方法:行为观察法,双标水法,间接热量测量法,心率法,运动传感器法,问卷法。双标水法被认为是人体能量消耗测量的金标准,间接热量测量法也经常被用来校正其他测量方法,但这两种方法很难在大规模人群中应用。运动传感器和问卷法是在大规模人群中应用比较多的两种方法。     

基于加速度传感器的学龄前儿童体力活动簇集特征研究

目的以客观测量的体力活动水平为基础,分析不同持续时间活动的频率及其占总活动时间的比例,从而掌握学龄前儿童体力活动簇集特征。方法根据知情、自愿原则,在上海市杨浦和宝山2个区共招募306名学龄前儿童为受试者,通过连续7 d佩戴加速度传感器ActiGraph GT3X+测量其日常体力活动水平,在此基础上将每次体力活动按强度和持续时间进行分类,并统计不同持续时间的活动平均每天出现的频率及其占总累积活动的比例。结果共有146名受试者[男85名,女61名;平均月龄为(57.7±5.0)月]7 d测量数据均有效,被纳入最终统计分析。发现采样间隔为1 s时,学龄前儿童平均每次体力活动持续时间≤4 s,且70%以上的中等强度和大强度体力活动持续时间为2~3 s。结论学龄前儿童体力活动以持续时间较短的零星活动为主。为准确测量学龄前儿童体力活动,特别是中到大强度体力活动水平,宜采用较短的加速度传感器采样间隔(如3 s或更短时间)。     

三维加速度counts估算不同步速能量消耗应用初探

以间接热测定法为标准,探索counts与能量消耗之间的关系,建立基于三维加速度counts能耗推算方程,寻求不同强度身体运动的counts切点。实验选取115名受试者,佩戴Cortex-3B便携式气体代谢分析仪与ActiGraph GT3X三轴加速度计,分别采用4.8km/h、5.6km/h、6.4km/h、7.2km/h、8.0km/h、8.8km/h步速。结果认为:不同步速下合矢量counts性别间差异不显著;不同步速下体重组别合矢量counts差异无统计学意义;身高、去脂体重与VO2、MET相关性较低,而性别、BMI都在0.2左右水平上显著相关;将BMI与性别引入推算方程,有效提高了counts预测能耗的准确性。     

Caution using data from triaxial accelerometers housed in player tracking units during running

Usage of accelerometers within player tracking devices in sport to quantify load, vertical ground reaction force (vGRF) or energy expenditure is contrary to placement guidelines. This study aimed to determine whether trunk-mounted accelerometers were a valid and reliable method to estimate thoracic segment or centre of gravity (COG) acceleration or vGRF, and the whether the elasticised harness contributes to the overestimation of acceleration. Ten male amateur rugby players performed five linear running tasks per lower limb at three speeds, twice, each with a different player tracking unit. Three-dimensional data were recorded and triaxial accelerometers were attached lateral to the device on the harness and skin and both shanks. Accelerometers demonstrated poor reliability (ICC:0.0–0.67), high variability (CV%:14–33%) and change in mean (41–160%), and were not valid to estimate vertical acceleration of the COG and thoracic segment nor vGRF. Caution is advised when utilising trunk-mounted triaxial accelerometer data as it is not a valid or reliable means to estimate peak vertical acceleration for its thoracic location nor whole-body COG acceleration or vGRF during running. To improve player tracking instrument validity and reliability, a new attachment method and/or harness material(s), that reduce or eliminate extraneous acceleration during running, are urgently required.     

GT3X+ accelerometer placement affects the reliability of step-counts measured during running and pedal-revolution counts measured during bicycling

Accelerometers provide a measure of step-count. Reliability and validity of step-count and pedal-revolution count measurements by the GT3X+ accelerometer, placed at different anatomical locations, is absent in the literature. The purpose of this study was to investigate the reliability and validity of step and pedal-revolution counts produced by the GT3X+ placed at different anatomical locations during running and bicycling.

Twenty-two healthy adults (14 men and 8 women) completed running and bicycling activity bouts (5 minutes each) while wearing 6 accelerometers: 2 each at the waist, thigh and shank. Accelerometer and video data were collected during activity.

Excellent reliability and validity were found for measurements taken from accelerometers mounted at the waist and shank during running (Reliability: intraclass correlation (ICC) ≥ 0.99; standard error of measurement (SEM) ≤1.0 steps; Validity: Pearson ≥ 0.99) and at the thigh and shank during bicycling (Reliability: ICC ≥ 0.99; SEM ≤1.0 revolutions; Validity: Pearson ≥ 0.99). Excellent reliability was found between measurements taken at the waist and shank during running (ICC ≥ 0.98; SEM ≤1.6 steps) and between measurements taken at the thigh and shank during bicycling (ICC ≥ 0.99; SEM ≤1.0 revolutions). These data suggest that the GT3X+ can be used for measuring step-count during running and pedal-revolution count during bicycling. Only shank placement is recommended for both activities.     

Reliability and validity of the Zebris FDM-THQ instrumented treadmill during running trials

Little is known about the reliability, validity and smallest detectable differences of selected kinetic and temporal variables recorded by the Zebris FDM-THQ instrumented treadmill especially during running. Twenty male participants (age = 31.9 years (±5.6), height = 1.81 m (±0.08), mass = 80.2 kg (±9.5), body mass index = 24.53 kg/m² (±2.53)) walked (5 km/h) and ran (10 and 15 km/h) on an instrumented treadmill, wearing running shoes fitted with Pedar-X insoles. A test-double retest protocol was conducted over two consecutive days. Maximal vertical force (F_max), contact time (CT) and flight time (FT) data from 10 consecutive steps were collected. Within- and between-day reliability, smallest detectable differences (SDD) and validity (95% limits of agreement (LOA)) were calculated. ICC values for the Zebris for Fmax were acceptable (ICC ≥ 0.7) while CT and FT reliability indices were predominantly good (ICC ≥ 0.8) to excellent (ICC ≥ 0.9). The Zebris significantly underestimated Fmax when compared with the Pedar-X. The 95% LOA increased with speed. SDD ranged between 96 N and 169 N for Fmax, 0.017s and 0.055s for CT and 0.021s and 0.026s for FT. In conclusion, Zebris reliability was acceptable to excellent for the variables examined, but inferior in comparison with Pedar-X. With increased running speeds, a bias effect (underestimation) existed for the Zebris compared with Pedar-X.     

Validity and reliability of a low-cost digital dynamometer for measuring isometric strength of lower limb

Lower limb isometric strength is a key parameter to monitor the training process or recognise muscle weakness and injury risk. However, valid and reliable methods to evaluate it often require high-cost tools. The aim of this study was to analyse the concurrent validity and reliability of a low-cost digital dynamometer for measuring isometric strength in lower limb. Eleven physically active and healthy participants performed maximal isometric strength for: flexion and extension of ankle, flexion and extension of knee, flexion, extension, adduction, abduction, internal and external rotation of hip. Data obtained by the digital dynamometer were compared with the isokinetic dynamometer to examine its concurrent validity. Data obtained by the digital dynamometer from 2 different evaluators and 2 different sessions were compared to examine its inter-rater and intra-rater reliability. Intra-class correlation (ICC) for validity was excellent in every movement (ICC > 0.9). Intra and inter-tester reliability was excellent for all the movements assessed (ICC > 0.75). The low-cost digital dynamometer demonstrated strong concurrent validity and excellent intra and inter-tester reliability for assessing isometric strength in the main lower limb movements.     

The reliability of force-velocity-power profiling during over-ground sprinting in children and adolescents

ABSTRACT

Anaerobic performance in youth has received little attention partly due to the lack of a “gold-standard” measurement. However, force-velocity-power (F-v-P) profiling recently showed high reliability and validity in trained adults. Therefore, the aim was to determine the reliability of F-v-P profiling in children and adolescents. Seventy-five children (60 boys, 15 girls; age: 14.1 ± 2.6 years) completed three 30 m sprints. Velocity was measured at 46.875 Hz using a radar device. The F-v-P profile was fitted to a velocity-time curve allowing instantaneous power variables to be calculated. Reliability was assessed using the intra-class correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM) and smallest worthwhile change (SWC). High reliability was evident for absolute peak (P_peak) and mean power (P_mean), P_peak and P_mean expressed relative to body mass, peak and mean velocity, 30 m sprint time, peak horizontal force (F₀), relative F₀, mechanical efficiency index and fatigue rate (ICC: 0.75–0.88; CV: 1.9–9.4%) with time to peak power demonstrating moderate reliability (ICC: 0.50; CV: 9.5%). The F-v-P model demonstrated at least moderate reliability for all variables. This therefore provides a potential alternative for paediatric researchers assessing sprint performance and the underlying kinetics.     

A Comparison of Accelerometers for Predicting Energy Expenditure and Vertical Ground Reaction Force in School-Age Children

In this pilot study of 16 children, we evaluated the reliability and validity of three accelerometers (Mini-Motionlogger [MML], Computer Science Applications, Inc. Actigraph [CSA], and BioTrainer) as indicators of energy expenditure and vertical ground reaction force. The children wore 2 of each type of monitor while they walked, ran, and performed 2 jumping tasks on a force plate and walked, jogged, and ran on a treadmill. Intrainstrument reliability of the monitors ranged from .64 to .98 across the treadmill tasks and from .69 to .98 across the force plate tasks, with the MML and CSA appearing more consistent than the BioTrainer. Analyses of variance were conducted to compare activity counts with criterion measures (oxygen utilization and force plate scores). All of the monitors generally differentiated among the treadmill tasks, mirroring the change in oxygen utilization. The CSA monitors corresponded more closely to the changes in force plate scores than the BioTrainer or the MML. Simple regression analyses indicated that count scores from all of the monitors were associated with oxygen utilization, with the MML and CSA exhibiting stronger relations (R values = .81 and .83, respectively) than the BioTrainer (R= .60). Similar analyses between the activity monitors and the force plate scores were also significant but the relations were not as strong as for oxygen utilization (R values = .46, .51, and .52, respectively). Based on backward elimination regression analyses, caloric expenditure on the treadmill tasks was predicted significantly with each of the MML (37 and 38% of variance) and CSA (39 and 42% of variance) units when body mass was included in the model. For the BioTrainer counts to provide the best prediction of caloric expenditure, both body mass and height were retained in the model, resulting in 20 and 25% explained variance. Future research to evaluate the utility of accelerometers should employ tasks that prevent the confounding of force and caloric expenditure.     

The validation of a swimming turn wall-contact-time measurement system: a touchpad application reliability study

The effectiveness of the swimming turn is highly influential to overall performance in competitive swimming. The push-off or wall contact, within the turn phase, is directly involved in determining the speed the swimmer leaves the wall. Therefore, it is paramount to develop reliable methods to measure the wall-contact-time during the turn phase for training and research purposes. The aim of this study was to determine the concurrent validity and reliability of the Pool Pad App to measure wall-contact-time during the freestyle and backstroke tumble turn. The wall-contact-times of nine elite and sub-elite participants were recorded during their regular training sessions. Concurrent validity statistics included the standardised typical error estimate, linear analysis and effect sizes while the intraclass correlating coefficient (ICC) was used for the reliability statistics. The standardised typical error estimate resulted in a moderate Cohen’s d effect size with an R² value of 0.80 and the ICC between the Pool Pad and 2D video footage was 0.89. Despite these measurement differences, the results from this concurrent validity and reliability analyses demonstrated that the Pool Pad is suitable for measuring wall-contact-time during the freestyle and backstroke tumble turn within a training environment.     

Validity and reliability of a low-cost dynamometer to assess maximal isometric strength of upper limb

Muscle imbalance and deficit are key parameters for guiding rehabilitation and sports sessions and avoiding injuries. However, the high cost and non-portable nature of most instruments employed for muscle strength assessment frequently hamper an affordable evaluation in field conditions. This study evaluated the validity and reliability of a low-cost digital dynamometer to assess the maximal isometric strength of upper limb muscles. Fourteen physically active volunteers performed the main movements of the upper limb at maximal isometric strength: flexion-extension, internal-external rotation and abduction-adduction of the shoulder; and flexion-extension of both elbow and wrist. Validity was examined by comparing the strength values from the low-cost digital dynamometer and those measured by an isokinetic dynamometer, assumed as the gold standard. The correlation between both devices was perfect (r > 0.913), while Bland-Altman plots showed absolute agreement between both devices, the maximum range of the values of bias was ?0.99–1.00 N in wrist extension. Inter-tester and intra-tester reliability were excellent for all movements (ICC ≥ 0.855). The low-cost digital dynamometer showed strong validity and excellent reliability in assessing maximal isometric strength during the main movements of the upper limb. Professionals may use it for an affordable isometric muscle strength assessment in field situations.     

Kinematic and kinetic variability associated with the cable put and seated rotation assessments

ABSTRACT

When new protocols are developed, there is a requirement to investigate test–retest reliability of measures for valid use and interpretation of data in research and practice. Therefore, the aim of this investigation was to determine the inter-day reliability of the cable put and seated rotation assessment protocols. On three occasions, nine resistance-trained men performed cable puts and cable rotations at different loads between 6 and 42 kg on a commercially available cable cross over machine. Load stack movement was recorded using a PT5A linear position transducer from which all kinematic and kinetic variables were calculated. Reliability was excellent for peak velocity and displacement based on intraclass correlation coefficient (ICC) and coefficient of variation (CV) across the majority of loads and movements (cable put: ICC = 0.92 to 0.99, CV = 3.1% to 8.6%; cable seated rotation: ICC = 0.76 to 0.99, CV = ?1.7% to 16.1%). However, kinetic variables demonstrated inadequate reliability across the majority of days, loads and movements (ICC = 0.70, CV >10%). It was concluded that peak velocity is a reliable kinematic measure to assess muscular capability from cable put and seated rotation protocols; however, kinetic measures are too variable to provide reliable outputs across testing occasions.     

Reliability and Validity of the Flemish Physical Activity Computerized Questionnaire in Adults

The purpose of this study was to investigate the test-retest reliability and concurrent validity of the Flemish Physical Activity Computerized Questionnaire (FPACQ) in employed/unemployed and retired people. The FPACQ was developed to assess detailed information on several dimensions of physical activity and sedentary behavior over a usual week. A triaxial accelerometer, the RT3 Triaxial Research Tracker (RT3), in combination with a written 7-day activity record, was used as the objective criterion measure. In employed/unemployed people, 2-week test-retest reliability for several activity variables calculated from the FPACQ was good to excellent with intraclass correlations (ICCs) ranging from .67 to .99. In retired people ICCs were lower but, except for time spent eating, still fair to excellent, ranging from .57 to .96. Except for time spent in leisure time activities for men and the average energy expenditure related to sports participation in women, correlations between the RT3 and the FPACQ generally supported the relative validity of the FPACQ for employed/unemployed people (r ranging from .37 to .88). Values for retired people were somewhat lower (r ranging from .15 to .85), but most variables still reached at least moderate correlations. Concerning absolute validity, the FPACQ generally overestimated physical activity and underestimated sedentary behavior compared to the RT3. From this study, it can be concluded that the FPACQ is a reliable and reasonably valid questionnaire for assessing different dimensions of physical activity and sedentary behavior.