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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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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

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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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Esra Uzelpasaci, Türkan Akbayrak, Serap Özgül, Ceren Orhan, Emine Baran, Gülbala Nakip, Sinan Beksac and Semra Topuz

easy, inexpensive, and noninvasive tools to use and allow accurate estimation of the intensity and type of physical activity. In addition, studies in which physical activity is assessed by questionnaires and diaries have shown that these methods are valid and reliable with significant correlation

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Sofie Martien, Christophe Delecluse, Jan Seghers and Filip Boen

The primary purpose of this study was to assess the validity of two motion sensors in measuring steps in institutionalized older adults during daily life activities. Sixty-eight nursing home residents (85.8 ± 5.6 years) were equipped with a hip-worn and ankle-worn piezoelectric pedometer (New Lifestyles 2000) and with an arm-mounted multisensor (SenseWear Mini). An investigator with a hand counter tallied the actual steps. The results revealed that the multisensor and hip- and ankle-worn pedometer significantly underestimated step counts (89.6 ± 17.2%, 72.9 ± 25.8%, and 20.8 ± 24.6%, respectively). Walking speed accounted for 41.6% of the variance in percent error of the ankle-worn pedometer. The threshold value for accurate step counting was set at 2.35 km/hr, providing percent error scores within ± 5%. The ankle-worn piezoelectric pedometer can be useful for accurate quantification of walking steps in the old and old-old (> 85 years) walking faster than 2.35 km/hr.

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Lydia Kwak, Maria Hagströmer and Michael Sjostrom

Background:

To be able to draw any conclusions regarding the health effects of occupational physical activity (OPA), more information is needed regarding valid measures to assess OPA. Aims were to compare OPA as assessed with the International Physical Activity Questionnaire long version (IPAQ-L) with OPA assessed with an accelerometer and to assess the contribution of OPA to total PA.

Methods:

Working adults (n = 441; mean age = 49.4 yrs; 44% males) wore an accelerometer for 7 days in free-living situations and completed the IPAQ-L. Comparisons were made between IPAQ-L-work and accelerometer data limited to working time (Moderate and Vigorous PA (accelerometer-MVPA-work) and average intensity). Subgroup analyses were performed.

Results:

Spearman correlation was r = .46 (P < .01) between IPAQ-L-work and accelerometer-MVPA-work. Correlations ranged from r = .27 to r = .55 in respectively obese and overweight subjects. The contribution of IPAQ-L-work to IPAQ-total was 24.7%.

Conclusions:

The IPAQ-L work domain is a moderately good measure of time spent on MVPA at work and can be used to assess the contribution of OPA to total PA. This study provides valuable information regarding the use of the IPAQ-L in assessing work domain specific PA, and underscores the importance of assessing OPA, as it can contribute for a substantial part to total PA.

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Jo Doyle and Gaynor Parfitt

This study attempted to assess the construct validity of the performance profile technique (Butler, 1989) within elite track and field athletics. Twelve elite (senior international honors) athletes (5 male, 7 female: mean age = 21.2, SD = 1.81) completed their profile on five occasions across winter training and the indoor season. Support for the construct validity of the profile was identified by a reduction in profile areas of perceived need (F (4, 44) = 11.77, p < .05) which was congruent with the observed increase in performance (F (4, 44) = 26.30, p < .05) as athletes progressed from winter training to the peak of the competitive indoor season. Trend analyses also identified that areas of perceived need in profile constructs, which were classified as most important to performance, showed a greater and more rapid reduction across the five occasions compared to the least important constructs. However, the results raise some concern over the usefulness of the profile for detecting subtle but important changes in performance and perceived need.

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Erika Rees-Punia, Charles E. Matthews, Ellen M. Evans, Sarah K. Keadle, Rebecca L. Anderson, Jennifer L. Gay, Michael D. Schmidt, Susan M. Gapstur and Alpa V. Patel

feasible and cost-effective option for large-scale epidemiologic studies ( Haskell, 2012 ; Masse & de Niet, 2012 ; Sallis & Saelens, 2000 ). Given these issues, it is important to conduct validity studies of PA surveys to understand how measurement error may affect results of future association studies

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Serkan Usgu, Günseli Usgu, Fatma Uygur and Yavuz Yakut

) assess athletic injuries or functional limitations and successfully identify foot- and ankle-related impairments. 12 The FAAM is a reliable and valid instrument used to measure physical function 13 in sport and high-intensity daily living activities. 14 Notably, the sport subscale of the FAAM