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MeLisa Creamer, Heather R. Bowles, Belinda von Hofe, Kelley Pettee Gabriel, Harold W. Kohl III and Adrian Bauman

Background:

Computer-assisted techniques may be a useful way to enhance physical activity surveillance and increase accuracy of reported behaviors.

Purpose:

Evaluate the reliability and validity of a physical activity (PA) self-report instrument administered by telephone and internet.

Methods:

The telephone-administered Active Australia Survey was adapted into 2 forms for internet self-administration: survey questions only (internet-text) and with videos demonstrating intensity (internet-video). Data were collected from 158 adults (20–69 years, 61% female) assigned to telephone (telephone-interview) (n = 56), internet-text (n = 51), or internet-video (n = 51). Participants wore an accelerometer and completed a logbook for 7 days. Test-retest reliability was assessed using intraclass correlation coefficients (ICC). Convergent validity was assessed using Spearman correlations.

Results:

Strong test-retest reliability was observed for PA variables in the internet-text (ICC = 0.69 to 0.88), internet-video (ICC = 0.66 to 0.79), and telephone-interview (ICC = 0.69 to 0.92) groups (P-values < 0.001). For total PA, correlations (ρ) between the survey and Actigraph+logbook were ρ = 0.47 for the internet-text group, ρ = 0.57 for the internet-video group, and ρ = 0.65 for the telephone-interview group. For vigorous-intensity activity, the correlations between the survey and Actigraph+logbook were 0.52 for internet-text, 0.57 for internet-video, and 0.65 for telephone-interview (P < .05).

Conclusions:

Internet-video of the survey had similar test-retest reliability and convergent validity when compared with the telephone-interview, and should continue to be developed.

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Roel De Ridder, Julien Lebleu, Tine Willems, Cedric De Blaiser, Christine Detrembleur and Philip Roosen

needed to obtain the gait parameters. This aspect is really important to facilitate technology adoption. 7 However, before using them for clinical interpretation, we need to define their reliability and validity. The latter can be done by comparing the spatiotemporal parameters of gait obtained from the

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James W. Navalta, Jeffrey Montes, Nathaniel G. Bodell, Charli D. Aguilar, Ana Lujan, Gabriela Guzman, Brandi K. Kam, Jacob W. Manning and Mark DeBeliso

Groot, 2017 ; Nelson, Kaminsky, Dickin, & Montoye, 2016 ), or during flat ground walking and/or stair climbing ( An, Jones, Kang, Welk, & Lee, 2017 ; Huang, Xu, Yu, & Shull, 2016 ). These settings represent conditions that are relatively controlled. While some devices return more valid step measures

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Ricky Watari, Blayne Hettinga, Sean Osis and Reed Ferber

The purpose of this study was to validate measures of vertical oscillation (VO) and ground contact time (GCT) derived from a commercially-available, torso-mounted accelerometer compared with single marker kinematics and kinetic ground reaction force (GRF) data. Twenty-two semi-elite runners ran on an instrumented treadmill while GRF data (1000 Hz) and three-dimensional kinematics (200 Hz) were collected for 60 s across 5 different running speeds ranging from 2.7 to 3.9 m/s. Measurement agreement was assessed by Bland-Altman plots with 95% limits of agreement and by concordance correlation coefficient (CCC). The accelerometer had excellent CCC agreement (> 0.97) with marker kinematics, but only moderate agreement, and overestimated measures between 16.27 mm to 17.56 mm compared with GRF VO measures. The GCT measures from the accelerometer had very good CCC agreement with GRF data, with less than 6 ms of mean bias at higher speeds. These results indicate a torsomounted accelerometer provides valid and accurate measures of torso-segment VO, but both a marker placed on the torso and the accelerometer yield systematic overestimations of center of mass VO. Measures of GCT from the accelerometer are valid when compared with GRF data, particularly at faster running speeds.

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Leanne Liggett, Andrew Gray, Winsome Parnell, Rob McGee and Yvette McKenzie

Background:

Objective measures, such as accelerometers, are increasingly being used to measure physical activity (PA) levels in children, and the use of validated and reliable instruments is desirable when measuring the effectiveness of programs. The purpose of this study was to determine the validity and reliability of the New Lifestyles NL-1000 accelerometer among preschoolers using a modified version of the Children’s Activity Rating Scale (CARS).

Methods:

Fourteen preschoolers wore the NL-1000 at their waist while the device measured activity levels [in seconds of moderate-to-vigorous physical activity (MVPA)]. They were also videoed for approximately 12 minutes while participating in normal activities at an early childhood center. At approximately 2-minute intervals, activity level readings derived from the NL-1000 were recorded. The video footage was analyzed using a modified CARS technique and the CARS scores compared with data obtained from the accelerometer.

Results:

Within subject reliability was measured using intraclass correlation coefficients (0.58 for CARS and 0.59 for NL-1000). Furthermore, 95% of the variation in CARS could be explained by variation in the accelerometer counts, with 2.4% of the variation being participant-specific.

Conclusion:

The NL-1000 is a sufficiently reliable and valid tool for assessing MVPA in preschoolers.

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Adam Šimůnek, Jan Dygrýn, Lukáš Jakubec, Filip Neuls, Karel Frömel and Gregory John Welk

has evaluated total energy expenditure ( 2 , 7 , 28 ), time spent in different zones of PA intensity, and step counts per day per week ( 1 , 2 , 3 , 21 ), as well as in specific isolated activities ( 3 , 9 , 14 , 28 , 32 ). In general, studies have supported the validity of the step count estimates in

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Kerri L. Vasold, Andrew C. Parks, Deanna M.L. Phelan, Matthew B. Pontifex and James M. Pivarnik

displacement plethysmography has shown high reliability and validity for evaluating body composition in many populations, and it has been used frequently as a criterion measure for field techniques in the past two decades, as other methods such as hydrodensitometry and dual-energy X-ray absorptiometry are not

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Liang Hu, Edward McAuley and Steriani Elavsky

This study was designed to address whether the Perceived Physical Ability (PPA) subscale of the Physical Self-Efficacy Scale (PSES; Ryckman, Robbins, Thornton, & Cantrell, 1982) measures self-efficacy or self-esteem. Secondary analyses of four previously reported data sets were conducted to examine the extent to which the PPA overlaps with multidimensional self-esteem measures. Once the factor structure of the PPA was confirmed, multitrait-multimethod analyses were employed to establish convergent and discriminant validity of the PPA and task-specific self-efficacy measures with self-esteem measures. The results support the position that the PPA may be more reflective of esteem than efficacy. Additionally, task-specific self-efficacy measures demonstrated stronger associations with behavioral outcomes than did the PPA. It is recommended that if the PPA is to be used for research purposes, it may have greater utility as a measure of physical self-esteem rather than self-efficacy.

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Loren Z.F. Chiu, Brian K. Schilling, Andrew C. Fry and Lawrence W. Weiss

Displacement-based measurement systems are becoming increasingly popular for assessment of force expression variables during resistance exercise. Typically a linear position transducer (LPT) is attached to the barbell to measure displacement and a double differentiation technique is used to determine acceleration. Force is calculated as the product of mass and acceleration. Despite the apparent utility of these devices, validity data are scarce. To determine whether LPT can accurately estimate vertical ground reaction forces, two men and four women with moderate to extensive resistance training experience performed concentric-only (CJS) and rebound (RJS) jump squats, two sessions of each type in random order. CJS or RJS were performed with 30%, 50%, and 70% one-repetition maximum parallel back squat 5 minutes following a warm-up and again after a 10-min rest. Displacement was measured via LPT and acceleration was calculated using the finite-difference technique. Force was estimated from the weight of the lifter-barbell system and propulsion force from the lifter-barbell system. Vertical ground reaction force was directly measured with a single-component force platform. Two-way random average-measure intraclass correlations (ICC) were used to assess the reliability of obtained measures and compare the measurements obtained via each method. High reliability (ICC > 0.70) was found for all CJS variables across the load-spectrum. RJS variables also had high ICC except for time parameters for early force production. All variables were significantly (p < 0.01) related between LPT and force platform methods with no indication of systematic bias. The LPT appears to be a valid method of assessing force under these experimental conditions.

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Richard A. Brindle, David Ebaugh and Clare E. Milner

is unclear whether the peak force during a hip abductor eccentric strength test occurs before or after the leg begins to lower. For measures to be useful in clinical decision making, they need to be both reliable and valid. Substantial intrarater reliability of a hip abductor eccentric strength test