Laboratory versus field testing in cricket bowling: a review of current and past practice in modelling techniques

In cricket bowling, the reconstruction of elbow angle data is of utmost importance to the bowling versus throwing argument. This paper reviews system and modelling errors inherent in three-dimensional reconstruction processes with respect to the elbow extension tolerance set by the International Cricket Council. An understanding of these factors will enable more informed decisions about the choice of in-field versus laboratory testing in the calculation of elbow extension during bowling in cricket. Although there is a paucity of objective data related to in-field and laboratory testing, biomechanists must be guided by the greater accuracy of opto-reflective than video-based systems and so testing, at least for the present, should be conducted in a laboratory setting.     

Seasonal progression and variability of repeat-effort line-drill performance in elite junior basketball players

To determine gender differences, positional differences, and patterns of change in the performance of the basketball line-drill test, 93 male (mean age 16.8 years, s = 1.1) and 95 female (mean age 16.5 years, s = 1.0) basketball players undertook 516 line-drill tests over a 5-year period. Log-transformed performance times were analysed using a mixed model that included quadratic within-participant fixed effects for time in the season and time in the programme. Changes and differences were standardized for interpretation of magnitudes. Mean performance times were 28.0 s (s = 1.3) for males and 30.4 s (s = 1.3) for females. The mean pattern of change in performance within a season differed substantially between the sexes and playing positions: male guards and female centres showed moderate to very large improvements mid-season of 1.1% and 3.5% respectively (90% confidence limits +/-2.1% and +/-3.0%), while female guards and male forwards showed large to very large decrements of -1.6% (+/-2.6%) and -2.4% (+/-2.0%). Over 3 years, males improved performance across all three playing positions by 1.4% (+/-1.3%) and females by 2.9% (+/-1.4%). Males improved performance by 0.2% (+/-0.5%) per year, whereas the performance of females deteriorated by 0.6% (+/-0.4%) per year. The differing patterns of performance change presumably reflect variations in training and competition loads, with short-term fluctuations in performance being managed to promote longer-term improvements.     

Factors contributing to preservice teachers' management of children's problem behaviors

The purpose of this study was to assess factors that contribute to preservice teachers' choice of a helping or a restrictive strategy to manage social immaturity and social defiance behaviors among children. Levels of tolerance, opinions as to the causes of behavior, perceptions of adverse effects or costs of problem behaviors, and choice of strategy were measured in response to hypothetical samples of problem behavior. Regression analyses indicated that the costs of problem behavior significantly predicted the type of strategy that would be chosen. Training preservice teachers to manage these costs was the main implication for teacher training programs.     

A knock to the system: A new sociotechnical systems approach to sport-related concussion

Broader contextual factors that influence concussion management have tended to be overlooked. To address this, the present study used a sociotechnical systems approach to identify perceived responsibilities and applied strategies for three domains of concussion management (i.e., prevention, identification and treatment). Participants were 118 members of the community rugby union system in Australia (69.2% male). Participants from throughout the rugby system (e.g., players, parents, coaches, club management) were asked open-ended questions about their perceived responsibilities and the strategies they use for concussion management. It was found that (a) proper training, technique correction and education were recurrent prevention themes; (b) the majority of key stakeholders felt that they could consistently identify concussion; however, medical aids (medics) were the only system actors who stated a responsibility to use standardised concussion assessment measures and (c) less than one third of the respondents indicated their involvement in treating concussion. This study identifies specific junctures in the system that prevents effective concussion management strategies. A sociotechnical systems approach improves the understanding of concussion prevention, and management beliefs and behaviours.     

The validity and reliability of a sample of 10 Wattbike cycle ergometers

ABSTRACT

The purpose of the study was to assess the validity and inter-bike reliability of 10 Wattbike cycle ergometers, and to assess the test–retest reliability of one Wattbike. Power outputs from 100 to 1000 W were applied using a motorised calibration rig (LODE) at cadences of 70, 90, 110 and 130 rev · min^?1, which created nineteen different intensities for comparison. Significant relationships (P < 0.01, r² = 0.99) were found between each of the Wattbikes and the LODE. Each Wattbike was found to be valid and reliable and had good inter-bike agreement. Within-bike mean differences ranged from 0.0 W to 8.1 W at 300 W and 3.3 W to 19.3 W at 600 W. When taking into account the manufacturers stated measurement error for the LODE (2%), the mean differences were less than 2%. Comparisons between Wattbikes at each of the nineteen intensities gave differences from 0.6 to 25.5 W at intensities of 152 W and 983 W, respectively. There was no significant difference (P > 0.05) between the measures of power recorded in the test–retest condition. The data suggest that the Wattbike is an accurate and reliable tool for training and performance assessments, with data between Wattbikes being able to be used interchangeably.     

Latino Portrayals in Local News Media: Underrepresentation,Negative Stereotypes,and Institutional Predictors of Coverage

Given the rise in negative rhetoric about Latinos in the U.S., it is essential to examine whether this negative tone extends to general, local news as well. An analysis of 2426 news articles drawn from 55 local newspapers in 2015 reveals several important findings. First, despite the intense spotlight on Latinos, they are still underrepresented in local news media. Relative to the other ethnic groups and whites, Latinos are more likely to be portrayed through negative stereotypes. However, the probability of this negative coverage is smaller for news media with a big proportion of Latino audiences, or for publicly-owned media outlets.