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Rachel Arnold and David Fletcher

The purpose of this study was to synthesize the research that has identified the organizational stressors encountered by sport performers and develop a taxonomic classification of these environmental demands. This study used a meta-interpretation, which is an interpretive form of synthesis that is suited to topic areas employing primarily qualitative methods. Thirty-four studies (with a combined sample of 1809 participants) were analyzed using concurrent thematic and context analysis. The organizational stressors that emerged from the analysis numbered 1287, of which 640 were distinct stressors. The demands were abstracted into 31 subcategories, which were subsequently organized to form four categories: leadership and personnel, cultural and team, logistical and environmental, and performance and personal issues. This meta-interpretation with taxonomy provides the most accurate, comprehensive, and parsimonious classification of organizational stressors to date. The findings are valid, generalizable, and applicable to a large number of sport performers of various ages, genders, nationalities, sports, and standards.

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Jill A. Bennett, Kerri Winters-Stone, Lillian M. Nail and Jennifer Scherer

This review describes the definitions of sedentary used to screen community-dwelling adults in physical-activity-intervention trials published from 2000 to 2005. Results of 42 trials showed that definitions of sedentary varied from <20 to <150 min/week of physical activity, and few reported the type (work, household, or leisure) or intensity of activity that was used to screen participants. The range of “sedentary” samples makes it difficult to compare trial results or generalize findings. Published reports of exercise trials would be more useful to practitioners and researchers if they included an explicit description of the cut point used to define sedentary adults in the sample, in terms of maximum minutes or days per week of activity and the wording of the screening measure in terms of type and intensity of activity.

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Yucui Diao, Cuixiang Dong, Lisa M. Barnett, Isaac Estevan, Jing Li and Liu Ji

The purpose of this study was to determine the validity and reliability of the Pictorial Scale for Perceived Movement Skill Competence (PMSC) in Chinese children. A total of 241 children (girls, n = 119) aged 4 to 9 years old (6.9 ± 1.53) participated. One week later two random subsamples were selected. One (n = 52) was to determine face validity and the other (n = 56) was to determine test-retest reliability. Internal consistency analyses through Cronbach’s alpha and construct validity by confirmatory factor analysis were conducted. Results showed (a) face validity was better for object control skills; (b) internal consistency was adequate for each subscale and all 13 skills (alpha range from .73–.87); (c) Intra-Class Correlations were good for locomotor (.62), object control (.73), and all 13 skills (.78); and (d) the modified two-factor model had a good fit (CFI = .96, TLI = .94, RMSEA = .04, SRMR = .05). The Chinese version of the PMSC is appropriate to use; however, considering the participants were only from Shanghai, results may not be generalizable to all Chinese children.

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Luke E. Kelly and James H. Rimmer

The subjects were 170 moderately and severely mentally retarded men who were divided into two groups. The first group was used to formulate a new prediction equation and the second group was used to cross-validate and ascertain the stability of the derived equation. The prediction equation, employing waist and forearm circumferences, height and weight as predictors, and estimated percent body fat calculated by the generalized regression equation of Jackson and Pollock (1978) as the criterion measure, was formulated using a stepwise multiple regression analysis. A multiple R value of .86 was obtained for the derived equation with a standard error of estimate value of 3.35. The equation was cross-validated on the second sample to ascertain its stability. An r of .81 and a standard error of estimate of 4.41 was obtained between the subjects’ estimated percent body fat, using the new equation, and the criterion measure. This simplified equation provides practitioners with an accurate, reliable, and inexpensive method of estimating percent body fat for adult mentally retarded males.

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Karen L. Perell, Robert J. Gregor and A.M. Erika Scremin

Biomechanical analysis of the generalized muscle moment and power patterns involved in cycling provides information regarding coordination within each limb. The purpose of this study was to compare individual joint kinetics, bilaterally, in subjects who had experienced cerebrovascular accidents (CVAs). Two-dimensional cinematography and force pedal data in a linked-segment model were used to study 8 ambulatory subjects while they rode a recumbent bicycle. The involved lower limb was defined as the lower limb with the greatest deficits, whereas the contralateral lower limb was defined as the lower limb opposite the involved lower limb and ipsilateral to the lesion site. The contralateral lower limbs of subjects with CVAs demonstrated patterns similar to those reported for nondisabled cyclists on an upright bicycle except for a bimodal hip power generation pattern that was possibly due to compensation for a lack of involved lower limb power generation. There were two critical findings of this study: Single-joint power generation patterns during the power phase indicated that either the hip or the knee, but not both joints, generated power in the involved lower limb, and asymmetrical differences between lower limbs appeared significant at the ankle alone.

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Daniel Maykranz, Sten Grimmer and Andre Seyfarth

The work-loop method is frequently used to determine the mechanical work performed by a system, for instance, when analyzing muscles or describing the work balance at the joint level. While for these examples usually only one-dimensional movements are investigated, for two- or three-dimensional movements, such as leg function during walking and running, the work-loop has to be adapted. In this paper, we present an analytical derivation that extends the work-loop method to two-dimensional sagittal plane movements. Three effects contribute to the mechanical work of the leg: (1) forces directed along the leg axis, (2) forces acting perpendicular to the leg axis, and (3) a shift of the center of pressure (COP) during stance. These three contributors to the mechanical work performed can be interpreted as three general tasks of the leg. To demonstrate the new work-loop method, we analyzed experimental data on hopping, running and walking. The results indicate that the proposed new generalized work-loop concept is suitable for describing the overall mechanical work performed on the COM during stance with energy consistent net work balances. Depending on the type of gait, specific contributions of each work term were found that characterize leg function during locomotion.

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Joanne Kraenzle Schneider and Kenneth H. Pitetti

The purpose of this study was to compare measured V˙O2, at specific stages with the American College of Sports Medicine-predicted V˙O2, at the same stage during treadmill walking in older women. Twenty-five women (age range = 56.6 to 78.1 years; mean ± SD = 66.6 ± 5.8 years) walked on a treadmill at a speed of 2.0 mph and 0% grade for the first stage and at increased grades for each subsequent stage. The results showed considerable lack of agreement between the measured and predicted V˙O2, values. Predicted V˙O2, was lower than measured V˙O2, at 0% grade and higher than measured V˙O2, al 10.2% grade (p < .05 for both). However, predicted V˙O2, was not significantly different from measured V˙O2, at grades of 3.4% and 6.7%. These results are generalizable only to older women who can walk 2.0 mph on a treadmill and do not use handrail support. Future research is needed to develop more accurate equations for predicting V˙O2, for older women.

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Galya Bigman, Vandita Rajesh, Laura M. Koehly, Larkin L. Strong, Abiodun O. Oluyomi, Sara S. Strom and Anna V. Wilkinson

Background:

Existing racial/ethnic disparities in physical activity during childhood increase Hispanics’ risk of developing chronic diseases, which serves to increase health disparities. This study examined associations of family cohesion and conflict with self-reported moderate-tovigorous physical activity (MVPA), controlling for psychosocial covariates such as subjective social status, anxiety, and sensation-seeking.

Methods:

1000 Mexican origin adolescents reported their MVPA levels approximately 2 years apart. Psychosocial covariates, family cohesion and conflict were measured at the first assessment. Generalized Linear Models were used to prospectively examine the relationship between family cohesion and conflict and subsequent MVPA based on 711 participants who had low levels of baseline MVPA.

Results:

35% of boys and 24% of girls reported adequate MVPA levels at follow-up; girls were less likely to report adequate MVPA (RR = 0.76; 95% CI: 0.61–0.93) than boys. Overall, family cohesion was associated with MVPA (P = .01), but family cohesion was not (P = .41). Gender-based analyses revealed that adequate MVPA was associated with family cohesion (RR = 1.40; 95% CI: 1.03–1.88), sensation seeking (RR = 1.05; 95% CI: 1.00–1.10), and age (RR = 0.85; 95% CI: 0.74–0.98) among girls and with subjective social status (RR = 1.20; 95% CI: 1.08–1.33) among boys.

Conclusions:

The family social environment and gender differences should be addressed in health promotion programs targeting MVPA.

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Richard W. Best and Mary A. Steinhardt

The purpose of this study was to determine whether children from three schools could accurately count and report their exercise heart rate (HR) during physical education class. Data collection included exercise HR reported by the children and recorded using UNIQ heartwatches. All children were asked to report their exercise HR for 5 and 10 seconds during the aerobic fitness portion of the class. Each child’s reported values were then compared to the heartwatch values. To determine the accuracy of reporting and generalizability of results, a 3 × 3 × 2 (grade by school by method) ANOVA was performed. Results revealed a significant grade-by-school interaction. Children at School A were accurate in counting exercise HR at all grade levels. For schools B and C, children in Grade 5 were accurate in counting, children in Grade 4 were only marginally accurate, and children in Grade 3 were not accurate in counting exercise HR. For each school, the 5-sec count was statistically accurate whereas the 10-sec count was inaccurate. Implications for physical education curricula are discussed.

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L. R. Brawley, R. C. Powers and K. A. Phillips

This experiment examined if a general expectancy for male superiority biased subjective evaluation of motor performance. Alternatively, sex bias could be specific to tasks involving muscular work. If the former, rather than the latter explanation is viable, a bias favoring males would be generalized to a task not obviously sex typed: motor accuracy. Observers, 22 of each sex, watched the softball pitching accuracy of performers of both sexes. Performer accuracy was trained and tested to ensure equality. Observers estimated preperformance accuracy, then observed three throws, estimating postperformance after each. Unlike the muscular endurance experiments, neither preperformance nor postperformance analysis revealed a sex bias. Thus a task-specific expectancy rather than general expectancy for male superiority was suggested to explain evaluation sex bias of previous muscular endurance experiments. Surprisingly, mean error magnitude of postperformance estimates was significantly greater for performers observed second than those viewed first, although actual performer accuracy was not different. This finding appears analogous to psychophysical judgment results in which successive stimulus judgments were conditions sufficient to cause estimation error. Suggestions are made for future research.