The Experts below are selected from a list of 12822 Experts worldwide ranked by ideXlab platform
Glen E. Foster - One of the best experts on this subject based on the ideXlab platform.
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Effect of carrying a weighted Backpack on lung mechanics during treadmill walking in healthy men
European Journal of Applied Physiology, 2012Co-Authors: Paolo B. Dominelli, A. William Sheel, Glen E. FosterAbstract:Weighted Backpacks are used extensively in recreational and occupational settings, yet their effects on lung mechanics during acute exercise is poorly understood. The purpose of this study was to determine the effects of different Backpack weights on lung mechanics and breathing patterns during treadmill walking. Subjects ( n = 7, age = 28 ± 6 years), completed two 2.5-min exercise stages for each Backpack condition [no Backpack (NP), an un-weighted Backpack (NW) or a Backpack weighing 15, 25 or 35 kg]. A maximal expiratory flow volume curve was generated for each Backpack condition and an oesophageal balloon catheter was used to estimate pleural pressure. The 15, 25 and 35 kg Backpacks caused a 3, 5 and 8% ( P
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effect of carrying a weighted Backpack on lung mechanics during treadmill walking in healthy men
European Journal of Applied Physiology, 2012Co-Authors: Paolo B. Dominelli, William A Sheel, Glen E. FosterAbstract:Weighted Backpacks are used extensively in recreational and occupational settings, yet their effects on lung mechanics during acute exercise is poorly understood. The purpose of this study was to determine the effects of different Backpack weights on lung mechanics and breathing patterns during treadmill walking. Subjects (n = 7, age = 28 ± 6 years), completed two 2.5-min exercise stages for each Backpack condition [no Backpack (NP), an un-weighted Backpack (NW) or a Backpack weighing 15, 25 or 35 kg]. A maximal expiratory flow volume curve was generated for each Backpack condition and an oesophageal balloon catheter was used to estimate pleural pressure. The 15, 25 and 35 kg Backpacks caused a 3, 5 and 8% (P < 0.05) reduction in forced vital capacity compared with the NP condition, respectively. For the same exercise stage, the power of breathing (POB) requirement was higher in the 35 kg Backpack compared to NP (32 ± 4.3 vs. 88 ± 9.0 J min−1, P < 0.05; respectively). Independent of changes in minute ventilation, end-expiratory lung volume decreased as Backpack weight increased. As Backpack weight increased, there was a concomitant decline in calculated maximal ventilation, a rise in minute ventilation, and a resultant greater utilization of maximal available ventilation. In conclusion, wearing a weighted Backpack during an acute bout of exercise altered operational lung volumes; however, adaptive changes in breathing mechanics may have minimized changes in the required POB such that at an iso-ventilation, wearing a Backpack weighing up to 35 kg does not increase the POB requirement.
Chaz Firestone - One of the best experts on this subject based on the ideXlab platform.
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how paternalistic is spatial perception why wearing a heavy Backpack doesn t and couldn t make hills look steeper
Perspectives on Psychological Science, 2013Co-Authors: Chaz FirestoneAbstract:A chief goal of perception is to help us navigate our environment. According to a rich and ambitious theory of spatial perception, the visual system achieves this goal not by aiming to accurately depict the external world, but instead by actively distorting the environment’s perceived spatial layout to bias action selection toward favorable outcomes. Scores of experimental results have supported this view—including, famously, a report that wearing a heavy Backpack makes hills look steeper. This perspective portrays the visual system as unapologetically paternalistic: Backpacks make hills harder to climb, so vision steepens them to discourage ascent. The “paternalistic” theory of spatial perception has, understandably, attracted controversy; if true, it would radically revise our understanding of how and why we see. Here, this view is subjected to a kind and degree of scrutiny it has yet to face. After characterizing and motivating the case for paternalistic vision, I expose several unexplored defects in i...
Paolo B. Dominelli - One of the best experts on this subject based on the ideXlab platform.
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Effect of carrying a weighted Backpack on lung mechanics during treadmill walking in healthy men
European Journal of Applied Physiology, 2012Co-Authors: Paolo B. Dominelli, A. William Sheel, Glen E. FosterAbstract:Weighted Backpacks are used extensively in recreational and occupational settings, yet their effects on lung mechanics during acute exercise is poorly understood. The purpose of this study was to determine the effects of different Backpack weights on lung mechanics and breathing patterns during treadmill walking. Subjects ( n = 7, age = 28 ± 6 years), completed two 2.5-min exercise stages for each Backpack condition [no Backpack (NP), an un-weighted Backpack (NW) or a Backpack weighing 15, 25 or 35 kg]. A maximal expiratory flow volume curve was generated for each Backpack condition and an oesophageal balloon catheter was used to estimate pleural pressure. The 15, 25 and 35 kg Backpacks caused a 3, 5 and 8% ( P
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effect of carrying a weighted Backpack on lung mechanics during treadmill walking in healthy men
European Journal of Applied Physiology, 2012Co-Authors: Paolo B. Dominelli, William A Sheel, Glen E. FosterAbstract:Weighted Backpacks are used extensively in recreational and occupational settings, yet their effects on lung mechanics during acute exercise is poorly understood. The purpose of this study was to determine the effects of different Backpack weights on lung mechanics and breathing patterns during treadmill walking. Subjects (n = 7, age = 28 ± 6 years), completed two 2.5-min exercise stages for each Backpack condition [no Backpack (NP), an un-weighted Backpack (NW) or a Backpack weighing 15, 25 or 35 kg]. A maximal expiratory flow volume curve was generated for each Backpack condition and an oesophageal balloon catheter was used to estimate pleural pressure. The 15, 25 and 35 kg Backpacks caused a 3, 5 and 8% (P < 0.05) reduction in forced vital capacity compared with the NP condition, respectively. For the same exercise stage, the power of breathing (POB) requirement was higher in the 35 kg Backpack compared to NP (32 ± 4.3 vs. 88 ± 9.0 J min−1, P < 0.05; respectively). Independent of changes in minute ventilation, end-expiratory lung volume decreased as Backpack weight increased. As Backpack weight increased, there was a concomitant decline in calculated maximal ventilation, a rise in minute ventilation, and a resultant greater utilization of maximal available ventilation. In conclusion, wearing a weighted Backpack during an acute bout of exercise altered operational lung volumes; however, adaptive changes in breathing mechanics may have minimized changes in the required POB such that at an iso-ventilation, wearing a Backpack weighing up to 35 kg does not increase the POB requirement.
Karen Grimmer - One of the best experts on this subject based on the ideXlab platform.
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adolescent standing postural response to Backpack loads a randomised controlled experimental study
BMC Musculoskeletal Disorders, 2002Co-Authors: Karen Grimmer, Brenton Dansie, Steve Milanese, Ubon Pirunsan, Patricia TrottAbstract:Background Backpack loads produce changes in standing posture when compared with unloaded posture. Although 'poor' unloaded standing posture has been related to spinal pain, there is little evidence of whether, and how much, exposure to posterior load produces injurious effects on spinal tissue. The objective of this study was to describe the effect on adolescent sagittal plane standing posture of different loads and positions of a common design of school Backpack. The underlying study aim was to test the appropriateness of two adult 'rules-of-thumb'-that for postural efficiency, Backpacks should be worn high on the spine, and loads should be limited to 10% of body weight.
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the associations between adolescent head on neck posture Backpack weight and anthropometric features
Spine, 1999Co-Authors: Karen Grimmer, Marie T Williams, Tiffany K GillAbstract:Study Design. A Cross-sectional, observational study, examining the effects of Backpack weight on adolescent posture. Objectives. To investigate the response of the craniovertebral angle to Backpack load. Summary of Background Data. There is a widely held belief that repeated carrying of heavy loads, such as school Backpacks, places additional stress on rapidly growing adolescent spinal structures, making them prone to postural change. Methods. Ten volunteer state high schools in metropolitan Adelaide, South Australia, provided 985 students, aged 12 to 18 years and from five different high school years, for this study. Students’ posture was measured with and without their school Backpack. All data analyses were undertaken per school year level to account for specific load-carrying requirements and spinal development associated with the age group. Results. A significant change in craniovertebral angle was found at every year level, when comparing standing posture with no Backpack with posture when carrying a Backpack. The change was greatest for the youngest students. Incremental change in craniovertebral angle was not strongly associated with Backpack loads. The association became stronger for the oldest girls when controlled for body mass index and for weight. Conclusion. The results support a differential postural response per gender and per level of spinal development but also suggest that the craniovertebral angle may not be the most sensitive measure of head-on-neck postural change for adolescents.
Alycia M. Hund - One of the best experts on this subject based on the ideXlab platform.
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Perceptually walking in another’s shoes: goals and memories constrain spatial perception
Psychological Research, 2017Co-Authors: D.w. Vinson, J. Scott Jordan, Alycia M. HundAbstract:Perceptual variables such as perceived distance contain information about future actions. Often our goals involve the integration of another’s goals, such as lifting heavy objects together. The purpose of this study was to investigate how another’s actions might influence one’s own goal-oriented perceptions (i.e., verbal distance estimates). Using a within-subject paradigm, we replicated a well-known finding that carrying a weighted Backpack results in larger distance estimates relative to not carrying a Backpack. In a crucial second condition, this effect was reversed: distance estimates were significantly greater when not carrying a weighted Backpack than when carrying a Backpack. In this condition, participants provided distance estimates while wearing a weighted Backpack during the first phase and then gave estimates while not wearing a Backpack, but following an experimenter wearing a weighted Backpack in the second phase. Three additional conditions systematically documented how the observation of another’s actions influenced distance estimates.
