scholarly journals Postural Stability during Static Upright Stance in Archers

2015 ◽  
pp. 29-35 ◽  
Author(s):  
Katerina Stambolieva ◽  
◽  
Mihail Otzetov ◽  
Dorina Petrova ◽  
Rosen Ikonomov ◽  
...  

2017 ◽  
Vol 11 (1) ◽  
pp. 49-58
Author(s):  
Carmen D'Anna ◽  
Maurizio Schmid ◽  
Andrea Scorza ◽  
Salvatore A. Sciuto ◽  
Luisa Lopez ◽  
...  

Background: The development of postural control across the primary school time horizon is a complex process, which entails biomechanics modifications, the maturation of cognitive ability and sensorimotor organization, and the emergence of anticipatory behaviour. Postural stability in upright stance has been thus object of a multiplicity of studies to better characterize postural control in this age span, with a variety of methodological approaches. The analysis of the Time-to-Boundary function (TtB), which specifies the spatiotemporal proximity of the Centre of Pressure (CoP) to the stability boundaries in the regulation of posture in upright stance, is among the techniques used to better characterize postural stability in adults, but, as of now, it has not yet been introduced in developmental studies. The aim of this study was thus to apply this technique to evaluate the development of postural control in a sample population of primary school children. Methods: In this cross-sectional study, upright stance trials under eyes open and eyes closed were administered to 107 healthy children, divided into three age groups (41 for Seven Years' Group, Y7; 38 for Nine Years' Group, Y9; 28 for Eleven Years' Group, Y11). CoP data were recorded to calculate the Time-to-Boundary function (TtB), from which four spatio-temporal parameters were extracted: the mean value and the standard deviation of TtB minima (Mmin, Stdmin), and the mean value and the standard deviation of the temporal distance between two successive minima (Mdist, Stddist). Results: With eyes closed, Mmin and Stdmin significantly decreased and Mdist and Stddist increased for the Y7 group, at Y9 Mmin significantly decreased and Stddist increased, while no effect of vision resulted for Y11. Regarding age groups, Mmin was significantly higher for Y9 than Y7, and Stdmin for Y9 was higher than both Y7 and Y11; Mdist and Stddist resulted higher for Y11 than for Y9. Conclusion: From the combined results from the spatio-temporal TtB parameters, it is suggested that, at 9 years, children look more efficient in terms of exploring their limits of stability than at 7, and at 11 the observed TtB behaviour hints at the possibility that, at that age, they have almost completed the maturation of postural control in upright stance, also in terms of integration of the spatio-temporal information.



Obesity Facts ◽  
2011 ◽  
Vol 4 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Nora S. Cruz-Gómez ◽  
Georgina Plascencia ◽  
Laura A. Villanueva-Padrón ◽  
Kathrine Jáuregui-Renaud


2020 ◽  
Vol 11 ◽  
Author(s):  
Luis Morenilla ◽  
Gonzalo Márquez ◽  
José Andrés Sánchez ◽  
Olalla Bello ◽  
Virginia López-Alonso ◽  
...  


Author(s):  
Charles M. Schneider ◽  
Ajay K. Verma ◽  
Tamanna T. K. Munia ◽  
Mark Romanick ◽  
Kouhyar Tavakolian ◽  
...  

Maintaining upright stance is a complex process, it requires appropriate functioning of a postural control system which consists of inputs from somatosensory, vestibular, musculoskeletal, and proprioceptive systems as well as from several brain regions [1–4]. A concussion is defined as a brain injury caused due to unexpected acceleration/deceleration of the head causing temporary alteration of brain function and it is a prevalent source of injury to football athletes [1]. With the altered function of the brain, the ability to maintain postural equilibrium becomes challenging due to the inability of individuals to respond promptly to stressors, thus, making maintenance of postural equilibrium rather difficult for individuals with a concussion. Effects of concussion on postural ability are shown to last up to three days post injury [5]. Postural stability test, therefore, can be performed to make a valid return to play (RTP) decision, pre-mature RTP is shown to have been catastrophic due to its potential to permanently impair previously affected region/functioning [1,5]. Postural sway data (center of pressure, COP) is traditionally analyzed to study the postural control. Therefore, COP can provide critical information regarding individual’s ability to maintain upright stance post injury. A more sensitive concussion assessment tool based on electroencephalogram (EEG) is used to accurately track effects of concussion [6]. However, sophisticated electrode placement requirement inhibits its immediate applicability. In current preliminary research, we attempt to differentiate athletes with a history of concussion (experimental) from healthy (control) using postural data. In order to do so, a concept of empirical mode decomposition (EMD) was adopted. EMD has shown evidence in the literature to infer vital information pertaining to the complex underlying physiological phenomenon [4, 7–8]. In the current research, the resultant COP (COPr) was decomposed into its finite set of band-limited signals termed as intrinsic mode functions (IMFs) [8], a set of linear and nonlinear features were extracted from COPr and its IMfs. Lastly, a test of significance was conducted to infer the potential of postural data for differentiating concussed from healthy athletes.



Author(s):  
Jang-Ho Park ◽  
Sunwook Kim ◽  
Maury A. Nussbaum ◽  
Divya Srinivasan

While occupational back support exoskeletons (BSEs) are being considered as a potential intervention to reduce physical demands in tasks such as repetitive lifting (e.g., Frost, Abdoli-E, & Stevenson, 2009; Koopman, Kingma, Faber, de Looze, & van Dieën, 2019), BSE use in practice may introduce some unexpected or unintended safety challenges (Baltrusch, van Dieën, van Bennekom, & Houdijk, 2018; de Looze, Bosch, Krause, Stadler, & O’Sullivan, 2016). One potential adverse effect is a decrease in postural balance and stability due to the extra weight and the rigid structure of a BSE. However, there is limited empirical evidence on how the use of a BSE affects postural balance and stability. In this study, we investigated the effects of using different BSEs on postural balance and stability during quiet upright stance. A total of 20, gender-balanced, healthy participants were included [males = 25.2 (3.8) years, 176.4 (7.4) cm, and 76.6 (8.8) kg; females = 27.5 (2.7) years, 166.5 (5.4) cm, and 61.2 (8.6) kg]. Each completed multiple trials of quiet upright stance at different levels of difficulty (i.e., bipedal and unipedal stance; each with eyes open and closed), while wearing two different BSEs (SuitX™ AC version, Laevo™ V2) and in a control (no-exoskeleton) condition. Respective masses of the SuitX™ and Laevo™ were 4.5 and 2.8 kg, and both devices were designed to provide external torque parallel to that created by the torso extensor muscles via three body contact points (i.e., thighs, pelvis, and chest). Center-of-pressure (COP) time series were measured using a force-plate during each trial, and traditional COP-based postural sway parameters were used as outcome measures: median frequency (MF), mean velocity (MV), root-mean-square distance (RMSD), and sway area. MF, MV, and RMSD values were obtained in both the anteroposterior (AP) and mediolateral (ML) directions. As MV, RMSD, and SwayAREA were significantly correlated with participant height, these measures were normalized using respective linear regression models to prevent undesired bias. Results from repeated measures analyses of variance indicated that wearing BSEs may adversely affect postural stability during bipedal stance. Compared to the control condition, wearing the Laevo™ increased MFAP by 50% ( p=0.015) with eyes open, and wearing the SuitX™ increased MVAP by 7% ( p=0.029) with eyes closed. However, specific to the unipedal standing with eyes closed, wearing the Laevo™ appeared to positively affect postural stability among males, whereas wearing the SuitX™ appeared to negatively affect postural stability among females. Specifically, males had a 24% decrease in RMSDAP ( p=0.003) and a 31% decrease in SwayAREA ( p=0.012) when wearing Laevo™, while females had a 15% increase in RMSDAP ( p=0.038) when wearing the SuitX™. In conclusion, we found evidence that wearing a BSE can affect postural balance and stability during quiet upright stance. More importantly, such effects appeared dependent on task conditions (i.e., bipedal and unipedal, and with eyes open/closed), and to be BSE-design and gender-dependent. Our findings may suggest complex interactive dynamics between a user and a BSE, potentially due to a change in total center of mass (i.e., body + BSE), restricted motion, and external supportive torques of the BSE. Furthermore, males and females may be differentially affected by such interactive dynamics, depending on the BSE, particularly in more challenging tasks. Future studies need to investigate the specificity of BSE effects on postural control while considering different demographic and individual factors, and also the effects of wearing BSEs on postural stability in dynamic conditions (e.g., walking, negotiating an obstacle, or recovering from an external perturbation).



2008 ◽  
Vol 41 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Sunwook Kim ◽  
Maury A. Nussbaum ◽  
Michael L. Madigan






2007 ◽  
Author(s):  
Angela DiDomenico ◽  
Krystyna Gielo-Perczak ◽  
Raymond W. McGorry ◽  
Chien-Chi Chang
Keyword(s):  


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