Experimental studies on static postural balance using the body center of gravity test system

Author(s):  
Yun Ling ◽  
Ying Xue ◽  
Jianguo Xing ◽  
Tao Jiang ◽  
Chaona Guo
2018 ◽  
Vol 124 ◽  
pp. 33-37 ◽  
Author(s):  
Natascia Bertoncelli ◽  
Laura Lucaccioni ◽  
Luca Ori ◽  
Christa Einspieler ◽  
Heinz F.R. Prechtl ◽  
...  

2002 ◽  
Vol 95 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Marc S. J. Boschker ◽  
Frank C. Bakker

The purpose of this study was to evaluate whether observing an expert climber would enable inexperienced climbers to perceive and accomplish new possibilities for action and whether this would facilitate their climbing performance. The focus was on what information is obtained during observation of a motor action. Three groups of inexperienced male participants ( N=24) observed either a video model of an expert method of climbing, a video model of a novice method of climbing, or the climbing wall on video without a model. Participants subsequently climbed the wall. This procedure of observation followed by climbing was repeated five times. Analysis showed participants perceived and subsequently utilized information from the videotapes and that this resulted in faster and more fluent climbing (as assessed by the geometric entropy of the body center of gravity). The results are discussed in terms of perceiving and accomplishing opportunities For action or affordances.


2020 ◽  
Vol 10 (11) ◽  
pp. 2754-2763
Author(s):  
Sunhye Shin ◽  
Chul Un Hong ◽  
Kyong Kim ◽  
Tae Kyu Kwon

Research regarding the cerebral cortex and muscle activity patterns of the body used for postural balance control when sudden instability stimuli occur is lacking. This study analyzed individuals' physiological signals when direction-specific instability stimuli were applied while their eyes were closed. Healthy adults in their 20s maintained their postural balance while looking at the center of gravity provided by a monitor with a three-dimensional dynamic postural balance training system. We performed electroencephalography (EEG) and measured trunk and lower extremity muscle activity of participants with their eyes closed when subjected to four direction-specific instability stimuli (anterior, posterior, left, and right). EEG results showed that gamma waves increased significantly with an unbalanced stimulus when the participant's eyes were open and closed. The increased gamma wave rate with eyes closed was low in the exercise planning area, where information is relatively integrated and exercise is planned without visual information. EMG results showed fewer gamma waves on EEG due to the low focus on postural control because participants could not observe the center of gravity, which is the basis for balance. The trunk and lower extremity muscles tended to be used more due to the larger body perturbation angle. These outcomes can be used as basic data regarding how the human brain and muscles maintain postural balance when an unexpected external instability stimulus occurs. Quantitative postural balance rehabilitation training protocols for the elderly and those with disabilities can be created based on these outcomes.


Author(s):  
Tae-Whan Kim ◽  
Jae-Won Lee ◽  
Seoung-Ki Kang ◽  
Kyu-Yeon Chae ◽  
Sang-Hyup Choi ◽  
...  

The purpose of this study is to compare and analyze the kinematic characteristics of the upper limb segments during the archery shooting of Paralympic Wheelchair Class archers (ARW2—second wheelchair class—paraplegia or comparable disability) and Paralympic Standing Class archers (ARST—standing archery class—loss of 25 points in the upper limbs or lower limbs), where archers are classified according to their disability grade among elite disabled archers. The participants of this study were selected as seven elite athletes with disabilities by the ARW2 (n = 4) and ARST (n = 3). The analysis variables were (1) the time required for each phase, (2) the angle of inclination of the body center, (3) the change of trajectory of body center, and (4) the change of the movement trajectory of the bow center by phase when performing six shots in total. The ARW2 group (drawing phase; M = 2.228 s, p < 0.05, holding phase; M = 4.414 s, p < 0.05) showed a longer time than the ARST group (drawing phase; M = 0.985 s, holding phase; M = 3.042 s), and the angle of the body did not show a significant difference between the two groups. Additionally, in the direction of the anteroposterior axis in the drawing phase, the change in the movement trajectory of the body center showed a more significant amount of change in the ARW2 group than in the ARST group, and the change in the movement trajectory of the bow center did not show a significant difference between the two groups.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takeshi Yamaguchi ◽  
Kei Shibata ◽  
Hiromi Wada ◽  
Hiroshi Kakehi ◽  
Kazuo Hokkirigawa

AbstractHerein, we investigated the effect of friction between foot sole and floor on the external forward moment about the body center of mass (COM) in normal and shuffling gaits. Five young male adults walked with normal and shuffling gaits, under low- and high-friction surface conditions. The maximum external forward moment about the COM (MEFM-COM) in a normal gait appeared approximately at initial foot contact and was unaffected by floor condition. However, MEFM-COM in a shuffling gait under high-friction conditions exceeded that under low-friction conditions (p < 0.001). Therein, MEFM-COM increased with an increasing utilized coefficient of friction at initial foot contact; this effect was weaker during a normal gait. These findings indicate that increased friction between foot sole and floor might increase tripping risk during a shuffling gait, even in the absence of discrete physical obstacles.


2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.


2021 ◽  
Author(s):  
Marta Grabowicz ◽  
Anna Daniluk ◽  
Anna Hadamus ◽  
Dariusz Białoszewski

BACKGROUND Balance training in young adults may increase coordination, cognitive function or the symmetry of strength on both sides of the body. It is an essential tool for injury or fall prevention and a precondition for becoming a professional athlete. OBJECTIVE The aim of this study was to assess the effect of Xbox 360 Kinect training on postural balance in young, healthy individuals. METHODS The study enrolled 75 individuals who were randomly assigned to three equal groups. The first group (Group VR) performed exercises on an Xbox 360 Kinect console, and the second group (Group T) performed conventional all-round exercises. The third group was a control group (Group C). Each group underwent balance assessments on the Biodex Balance posturographic platform, including the Balance Error Scoring System test, before and after the training cycle. The level of statistical significance was set at P<.05. RESULTS Group VR and Group T achieved statistically significant improvements in the sway index compared with baseline. Group T gained significant decrease in the sway index on the unstable surface (P=.002). Group VR and group T demonstrated significant decreases in the mean sway index on stable and unstable surfaces (group VR — P=.035; group T — P=.001) Group C did not achieve a statistically significant improvement in the sway index. None of the groups demonstrated a statistically significant decrease in the test error count. CONCLUSIONS Virtual reality in the form of video games played on an Xbox 360 Kinect console may be an effective method of balance training in healthy individuals.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pilar Mata Tutor ◽  
Catherine Villoria Rojas ◽  
María Benito Sánchez

Decomposition is a natural process that begins approximately four minutes after death and continues until the body is degraded to simpler biochemical components which are gradually recycled back to the environment. This process is dependent on extrinsic and intrinsic factors. Embalming is a chemical preservation technique that aims to preserve the external appearance of the body in good condition for an indeterminate period. In Spain, there is a lack of experimental studies carried out to analyse the variables that affect decomposition in embalmed bodies, therefore, in accordance with the conclusions reached by previous authors, it is hypothesised that embalmed bodies show quantifiable characteristics during the late stage decomposition which distinguish them from control, unembalmed, cadavers. An anthropological and statistical analysis was performed on 14 individuals from Cementerio Sur de Madrid exhumed after ten years according to the Mortuary Health Law of the Autonomous Region of Madrid. The preliminary results obtained showed that there is a qualitative and statistically significant relationship between the variables evaluated, being the presence or absence of soft tissue the most notable difference. The mortuary or thanatopraxy treatments performed before the burial and the microenvironmental conditions of the burial positively influence the soft tissue preservation on embalmed bodies. These results contribute to the understanding about the decomposition rate of an embalmed cadavers in cemeteries, and the related extrinsic variables.


2021 ◽  
Vol 1 (1) ◽  
pp. 72-78

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.


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