The impact of physiological load on anticipation skills in badminton: From testing to training

Research remains unclear on the impact of physiological load on perceptual-cognitive skills in sport. Moreover, no study has examined the training of perceptual-cognitive skills under physiological load. The current study comprised two phases. Firstly, we examined the impact of badminton-specific physiological load on anticipatory skills in expert badminton players (n = 13), including key underlying mechanisms, such as gaze behaviour. Under high physiological load, participants displayed less efficient visual search behaviour and showed a reduction in response accuracy. Secondly, we examined the effects of combining perceptual-cognitive simulation training with the high physiological load. Ten of the expert badminton players were assigned to a combined training group, where the simulation training and the physiological load intervention occurred simultaneously or an independent training group, whereby the two components were completed independently. The combined training group showed a positive change in the efficiency of their visual search behaviours compared to the independent training group, but no significant performance improvements were found. Overall, findings demonstrate that high physiological load is detrimental to experts’ anticipatory skills. However, combining perceptual-cognitive simulation training with high physiological load can potentially negate these debilitating effects.     

Validating the Sedentary Sphere method in children: Does wrist or accelerometer brand matter?

This study aimed to validate the Sedentary Sphere posture classification method from wrist-worn accelerometers in children. Twenty-seven 9–10-year-old children wore ActiGraph GT9X (AG) and GENEActiv (GA) accelerometers on both wrists, and activPAL on the thigh while completing prescribed activities: five sedentary activities, standing with a phone, walking (criterion for all 7: observation) and 10-min free-living play (criterion: activPAL). In an independent sample, 21 children wore AG and GA accelerometers on the non-dominant wrist and activPAL for two days of free-living. Per cent accuracy, pairwise 95% equivalence tests (±10% equivalence zone) and intra-class correlation coefficients (ICC) analyses were completed. Accuracy was similar, for prescribed activities irrespective of brand (non-dominant wrist: 77–78%; dominant wrist: 79%). Posture estimates were equivalent between wrists within brand (±6%, ICC > 0.81, lower 95% CI ≥ 0.75), between brands worn on the same wrist (±5%, ICC ≥ 0.84, lower 95% CI ≥ 0.80) and between brands worn on opposing wrists (±6%, ICC ≥ 0.78, lower 95% CI ≥ 0.72). Agreement with activPAL during free-living was 77%, but sedentary time was underestimated by 7% (GA) and 10% (AG). The Sedentary Sphere can be used to classify posture from wrist-worn AG and GA accelerometers for group-level estimates in children, but future work is needed to improve the algorithm for better individual-level results.     

Reviewing the Variability-Overuse Injury Hypothesis: Does Movement Variability Relate to Landing Injuries?

Purpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.     

Coordination of perspective by sixth graders and teacher trainees

Sixth grade students were compared by sex for their performance on two perspective coordination tasks. Responses were compared with understanding of the principle that still water remains invariantly horizontal. Forty-eight randomly selected sixth grade students (24 girls and 24 boys) and 12 college women were individually shown a standardized three-dimensional scene. While seated in a single position, subjects completed two tasks: (1) selecting from a set of 12 pictures (displayed together) the one which could be seen from each of eight positions marked on the displayed scene and (2) choosing the positions from which could be seen eight of the 12 pictures (shown one at a time). Four of the 12 pictures were mirror images which were impossible views. Males outperformed females on both of the coordination-of-perspective tasks. For both males and females, choosing the place was more difficult than choosing the picture. Strong relationships were found between understanding of horizontality and performance on the perspective tasks. Selection of mirror images (impossible views) indicated more understanding of perspective than other, less systematic errors. Finally, female teacher trainees performed only marginally better than sixth grade students, suggesting possible remediation needs.     

Culture jamming and Brandalism for the environment: The logic of appropriation

This article explores creative activism for environmentalism through an examination of culture jamming. Specifically, it looks to the action of the Brandalism project during COP21. This was the replacement of bus stop advertising with original artworks. This form of creative activism is unique in that it addresses the advertising industry as a key battlefield over cultural meaning and environmental sustainability. Through its use of the logic of appropriation inherent in culture jamming, this case challenges critiques about the incorporation of culture jamming within consumer culture. This work theorizes the case through the new politics of consumption, political consumerism, and culture jamming. It argues for the logic of appropriation, before it introduces the case study and explores the visual narratives of environmentalism: corporate greed, inadequate politicians, consumer saturation, Earth in mourning, and public commitment to the environment. Finally, it evaluates the contribution of Brandalism as a form of creative activism for environmentalism.     

Economics of cultural tourism: issues and perspectives

The special issue aims at exploring, with an economic perspective, the interconnections between cultural participation, in all its expressions, and tourism organization and patterns with the purpose of understanding economic effects, emerging trends and policy implications. The expanding notion of the cultural consumption of tourists makes the definition of cultural tourism increasingly elusive. Empirical investigations of the relationships between cultural participation and cultural heritage and tourism offer interesting hints in many directions. This introduction briefly overviews the premise of this special issue, the literature and the several perspectives taken by the included articles. Aside from their cultural topics—general, intangible or temporary—these essays all tackle some important economic dimensions of tourism. We encourage cultural economists to invest more in these fascinating areas as more than just intellectual tourists.     

“Stop sending your kids across our border:” Discursively constructing the unaccompanied youth migrant

The recent migration of 65,000 children across the southwestern border, coupled with allegations of abuse by the U.S. Border Patrol, enables the investigation of an overlooked immigrant category: the unaccompanied youth migrant. Analyzing audience responses to news reports of the abuse, we find that established disparaging immigrant tropes apply, describing the children as an economic burden, disease carriers, and offspring of irresponsible families. We uncover two new themes: Youth migrants are channels whereby criminals may infiltrate the U.S., and manipulate legal authorities to remain in the U.S. Finally, we demonstrate how global compassion is strategically deployed to qualify harsh retaliatory measures.     

The effect of acceleration signal processing for head impact numeric simulations

Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s²), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters.     

Validity and Reliability of Three Self-Report Instruments for Assessing Attainment of Physical Activity Guidelines in University Students

The purpose of this study was to compare the validity and reliability of three short physical activity self-report instruments to determine their potential for use with university student populations. The participants (N = 155; 44.5% male; 22.9 ± 5.13 years) wore an accelerometer for 9 consecutive days and completed a single-item measure, the a brief two item measure and the International Physical Activity Questionnaire—Short Form questionnaires on day 1 and 9. Correlations between self-reported and accelerometer derived moderate-to-vigorous physical activity levels were moderate for the International Physical Activity Questionnaire—Short Form, while poor for the single-item measure and the a brief two item measure. The agreement level was high with the International Physical Activity Questionnaire—Short Form (77.4%) and moderate for both the single-item measure (45.2 %) and a brief two item measure (44.5 %). The intraclass correlations between the two administrations were moderate to strong across all measures (0.52–0.70) in 133 participants. The International Physical Activity Questionnaire—Short Form is the most suitable of these three self-report instruments for use with this population due to higher correlations and levels of agreement with accelerometry.