commonly purchased options ( 10 , 11 ). The features of Fitbit activity devices, including their validity and reliability, have been investigated in a number of empirical studies with adults ( 11 , 18 ). Findings generally suggest that, with adults, Fitbit devices demonstrate an overall tendency to
Xiyao Sun, Stephanie A. Adams, Chuchu Li, Josephine N. Booth, Judy Robertson, and Samantha Fawkner
Pedro L. Valenzuela, Almudena Montalvo-Perez, Lidia B. Alejo, Mario Castellanos, Jaime Gil-Cabrera, Eduardo Talavera, Alejandro Lucia, and David Barranco-Gil
might, thus, be unable to provide valid estimates of actual PO, particularly at certain cadences or PO levels. In this regard, some studies have assessed the validity of pedal-based devices (eg, Garmin Vector, PowerTap P1, Favero Assioma) using their bilateral version, 3 – 6 but to the best of our
Paul D. Loprinzi, Bradley J. Cardinal, Carlos J. Crespo, Gary R. Brodowicz, Ross E. Andersen, and Ellen Smit
The exclusion of participants with invalid accelerometry data (IAD) may lead to biased results and/or lack of generalizability in large population studies. The purpose of this study was to investigate whether demographic, behavioral, and biological differences occur between those with IAD and valid accelerometry data (VAD) among adults using a representative sample of the civilian noninstitutionalized U.S. population.
Ambulatory participants from NHANES (2003−2004) who were 20−85 years of age were included in the current study and wore an ActiGraph 7164 accelerometer for 7 days. A “valid person” was defined as those with 4 or more days of at least 10+ hrs of monitoring per day. Among adults (20−85 yrs), 3088 participants provided VAD and 987 provided IAD. Demographic, behavioral, and biological information were obtained from the household interview or from data obtained in a mobile examination center.
Differences were observed in age, BMI, ethnicity, education, smoking status, marital status, use of street drugs, current health status, HDL-cholesterol, C-reactive protein, self-reported vigorous physical activity, and plasma glucose levels between those with VAD and IAD.
Investigators should take into consideration the potential cut-off bias in interpreting results based on data that excludes IAD participants.
Dylan Kobsar, Chad Olson, Raman Paranjape, and John M. Barden
A single triaxial accelerometer has the ability to collect a large amount of continuous gait data to quantitatively assess the control of gait. Unfortunately, there is limited information on the validity of gait variability and fractal dynamics obtained from this device. The purpose of this study was to test the concurrent validity of the variability and fractal dynamic measures of gait provided by a triaxial accelerometer during a continuous 10 minute walk in older adults. Forty-one healthy older adults were fitted with a single triaxial accelerometer at the waist, as well as a criterion footswitch device before completing a ten minute overground walk. The concurrent validity of six outcome measures was examined using intraclass correlation coefficients (ICC) and 95% limits of agreement. All six dependent variables measured by the accelerometer displayed excellent agreement with the footswitch device. Mean parameters displayed the highest validity, followed by measures of variability and fractal dynamics in stride times and measures of variability and fractal dynamics in step times. These findings suggest that an accelerometer is a valid and unique device that has the potential to provide clinicians with valid quantitative data for assessing their clients’ gait.
Jacqueline M. Miotto, Wojtek J. Chodzko-Zajko, Jennifer L. Reich, and Melissa M. Supler
A limiting factor in evaluating the functional status of older people is the lack of appropriate measurement tools for assessing functional mobility, muscle strength, aerobic endurance, agility, and flexibility. In this study, the reliability and validity of the seven-item Fullerton Functional Fitness Test (FFT) battery, designed for use with community-dwelling older adults, was examined. The test items were as follows: floor sit-and-reach, back scratch, 8-ft up-and-go, arm curl, 30-s chair stand. 2-min step, and 9-min walk. Seventy-nine participants (42 physically active, 37 sedentary) completed the FFT battery three times within a 2-week period. The test-retest reliability intraclass correlation coefficients were high. Construct validity analysis revealed that five of the seven FFT items discriminated between the physically active and sedentary groups. In conclusion, most of the evidence from the stability reliability and discriminant validity analyses supports the view that the Fullerton FFT battery is a reliable and valid test of functional fitness.
Abderrehmane Rahmani, Georges Dalleau, Fabrice Viale, Christophe A. Hautier, and Jean-René Lacour
This study determined the validity and reliability of the kinematic device developed by Bosco et al. (1995) by comparing its peak force, peak velocity, and peak power measurements to data obtained simultaneously with a force platform placed under the subject’s feet. Fifteen international downhill skiers performed maximal half-squats on a guided barbell with masses of 60–180 kg. The coefficient of correlation (r) between the two peak forces (r = 0.85–0.95, p < .001), the two peak velocities (r = 0.74–0.91, p < .001), and the two peak powers (r = 0.85–0.95, p < .001) indicated that the kinematic device measurements were valid. The trial-to-trial reliability of half-squat exercises measured by the kinematic device gave an intraclass coefficient of correlation (CR) of: 0.70-0.90 for peak force, 0.62-0.90 for peak velocity, and 0.57-0.91 for peak power. There were no statistical differences between the two trials. The standard error of the means (SEM%) was less than 5% for peak force, less than 4% for peak velocity, and less than 7% for power. The high CR and low SEM% indicate that the kinematic device is reliable. The movement recorded by the kinematic device accurately described the action measured by the force platform.
Saurabh Sharma and M. Ejaz Hussain
can be established by its measurement properties, such as validity and reliability. A vast majority of people in India and abroad (544 million) speak and understand Hindi well, as it is a national language. 10 The SPADI original and its translations (Greek, Spanish, Thai, Tamil, etc.) have undergone
Moeini Babak, Barati Majid, Heidarimoghadam Rashid, Tapak Leili, and Parsamajd Shahryar
version of the tool were examined in Phase 2. Psychometric Properties This phase consisted of examining the tool’s content validity, face validity, and construct validity. In addition, the tool’s internal consistency and stability were examined. Content Validity Content validity was carried out
Golnoush Mehrabani, Douglas P. Gross, Saeideh Aminian, and Patricia J. Manns
number of steps, a surrogate for physical activity levels ( Balto, Kinnett-Hopkins, & Motl, 2016 ). A valid consumer-grade activity tracker in a free-living condition has the potential to provide valuable information as it is easy to use and may be beneficial for documenting individuals’ status in
Veronika van der Wardt, Jennie E. Hancox, Clare Burgon, Rupinder Bajwa, Sarah Goldberg, and Rowan H. Harwood
issues with the activity monitors, most participants considered them as acceptable. However, the relationship between levels of PA as measured using the monitor and other assessment methods was not evaluated, limiting the validity of the devices for this population. Accurately measuring PA or exercise