The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Shinichi Demura - One of the best experts on this subject based on the ideXlab platform.
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Examination of Effective Body Sway Parameters for Healthy Elderly
American Journal of Sports Science and Medicine, 2018Co-Authors: Tamotsu Kitabayashi, Shinichi Demura, Hiroki AokiAbstract:This study aimed to examine Body Sway characteristics and to propose effective Body Sway parameters for healthy elderly. The subjects were 311 healthy elderly and 380 healthy young adults. None of the subjects had evidence or known history of gait, posture, or skeletal disorders. The center of foot pressure measurement for 1 min was performed in 1 trial Using Anima’s stabilometer G5500. The data sampling frequency was 20 Hz. Thirty parameters with high reliability were selected from 5 domains of distance, area, velocity, power spectrum, and Body Sway vector. In comparison with the results for young adults, the elderly had markedly larger values of mean path length and root mean square of x-axis, as well as for 5 velocity parameters and 4 vector velocity parameters. In addition, approximately 10% of the data for parameters related to Body Sway velocity, especially front/back Body Sway, even in the healthy elderly fell in an abnormal range of values (mean ± 3 SD). In conclusion, the following parameters may be useful to adequately and simply evaluate the Body Sway characteristics of the elderly: Sway size, Sway velocity, and from a directional viewpoint, Sway size in the right/left direction and Sway velocity in the front/back direction.
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The Effect of External Stimulus Produced by Vibration Stimulus Instrument on Body Sway
American Journal of Sports Science and Medicine, 2017Co-Authors: Hiroshi Hirai, Tamotsu Kitabayashi, Shinichi Demura, Yoshimasa MatsuuraAbstract:This study aimed to examine the effect of right-left or front-back vibration stimulus during standing on Body Sway. Subjects were 10 healthy young male adults. They had no evidence or known history of a gait, posture or skeletal disorder. After a weak vibratory stimulus (20 Hz) for 1 min, subjects stood under the strong stimulus (70 Hz) of front-back or right-left vibratory for 1 min. The subjects were measured Body Sway for 1 min before and after the above vibratory stimulus. Four Body-Sway factors (unit time Sway, front-back Sway, left-right Sway, and the high frequency band power) were used as evaluation parameters. A significant decrease was found only in a unit time Sway factor after vibratory stimulus. A significant difference between front-back and right-left vibratory stimuli was found only in a left-right Sway factor and the latter stimulus produced a large change. In conclusion, even in the vibratory stimulus with the same intensity, Body Sway decreases after front-back stimulus, but increases after right-left stimulus. In short, the effect of vibratory stimulus on posture control system may differ by the vibratory direction.
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Changes in Muscle Activity and Body Sway Over Time During One-Leg Stance
2014Co-Authors: Yu Uchida, Shinichi DemuraAbstract:It is considered that a one-leg stance (OLS) requires greater lower limb muscle strength and balance than a two-leg stance (TLS), and imposes a burden on the lower limb that progresses with time. This study aimed to compare and examine muscle activity and Body Sway between the OLS and TLS in young men, focusing on changes over time. A total of 15 subjects stood with their eyes open on a stabilometer for 1 min in either OLS or TLS after the surface electrodes were placed over gastrocnemius, soleus, and tibialis anterior. Maximum and mean % root mean square values and path lengths of X and Y axes, as well as their total path lengths, were calculated over 20-s periods (0–20 s, 20–40 s, 40–60 s) as evaluation parameters for muscle activity and Body Sway. Muscle activity and Body Sway were significantly larger in OLS than in TLS, and both total and X axis path lengths in the initial 20-s OLS period were significantly longer than those in the other 2 periods. Lower limb muscles showed little changes in activity over time for either stance but a left–right Body Sway become small during the OLS. In conclusion, lower limb muscle activity and Body Sway are decreased in the TLS compared to the OLS. Change in muscle activity over time is small in both stances; however, left–right Body Sway during the OLS becomes stable within 1 min.
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Proposal for a new Body Sway evaluation method
Perceptual and Motor Skills, 2011Co-Authors: Tamotsu Kitabayashi, Shinichi Demura, Hitoshi MuraseAbstract:This study is aimed at examining Body Sway factors for 1,107 healthy people aged 16 to 69 years and to propose a practical Body Sway evaluation method. The center of foot pressure measurement was carried out twice for 1 min. with a 1-min. rest. 30 parameters with high reliability selected from 6 domains (distance, distribution of amplitude, area, velocity, power spectrum, and Body Sway vector) were summarized objectively into 4 Body Sway factors (unit time Sway, front-back Sway, left-right Sway, and high frequency band power). Factor scores were calculated by the estimate equation and the total standard scores of parameters with high factor loadings. Considering this result, a total standard score for each factor was classified into 4 percentile categories based on percentile rank. Using this classification criteria, Body Sway scores for each individual were classified into any of the above 4 domains for each factor. It was confirmed that young adults mainly belong to percentile Categories A and B and the...
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Body Sway characteristics during a static upright posture in the elderly
Geriatrics & Gerontology International, 2008Co-Authors: Shinichi Demura, Tamotsu Kitabayashi, Hiroki AokiAbstract:Aim: This study aimed to determine the reliability and sex and age-level differences of Body-Sway parameters, based on center of pressure (COP) measurements, during a static upright posture in the elderly and to clarify their Body-Sway characteristics in comparison with those of young adults. Methods: The subjects were 50 healthy elderly and 50 healthy young adults. They had no evidence or known history of disorder. The data sampling frequency was 20 Hz. Thirty-six highly reliable parameters were selected from the following seven domains: distance; position; distribution of amplitude; area; velocity; power spectrum; and vector. In addition, four Body-Sway factors (unit time Sway, front-back Sway and a left-right Sway and the high-frequency band power) were also measured. Results: In the elderly, most Body-Sway parameters had very high reliability and did not show significant sex or age-level differences. The degree of Body Sway was greater in the elderly than in young adults, and marked differences were found, especially in Sway velocity and periodicity. The four Body-Sway factors showed almost the same tendency as the 32 Sway parameters. Conclusion: We judged that the Body Sway in the elderly showed large individual differences. Approximately 10% of the elderly subjects may be outside the standard range as compared to young adults, mainly in parameters relating to velocity and spectrum. Because the Body-Sway characteristics of the elderly are considerably different from those of young adults, we may need unique criteria to evaluate their Body Sway.
Yoshio Iwai - One of the best experts on this subject based on the ideXlab platform.
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ACPR - Identifying People Using Temporal and Spatial Changes in Local Movements Measured from Body Sway
2017 4th IAPR Asian Conference on Pattern Recognition (ACPR), 2017Co-Authors: Takuya Kamitani, Masashi Nishiyama, Hiroki Yoshimura, Yoshio IwaiAbstract:We propose a novel method of identifying people using temporal and spatial changes in local movements measured from a video sequence of Body Sway. Existing methods identify people using a gait feature mainly representing the large swinging of the limbs. The use of the gait feature introduces a problem in that the identification performance decreases when people stop walking. To extract an informative feature from people who have stopped walking, our method measures small swings of the Body, which is called Body Sway. We extract the feature from local movements of Body Sway by participially dividing the Body into regions. Experimental results for a dataset of Body Sway of 118 participants show that the local movement feature obtained using our method outperforms the gait feature obtained using an existing method.
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Identifying People Using Temporal and Spatial Changes in Local Movements Measured from Body Sway
2017 4th IAPR Asian Conference on Pattern Recognition (ACPR), 2017Co-Authors: Takuya Kamitani, Masashi Nishiyama, Hiroki Yoshimura, Yoshio IwaiAbstract:We propose a novel method of identifying people using temporal and spatial changes in local movements measured from a video sequence of Body Sway. Existing methods identify people using a gait feature mainly representing the large swinging of the limbs. The use of the gait feature introduces a problem in that the identification performance decreases when people stop walking. To extract an informative feature from people who have stopped walking, our method measures small swings of the Body, which is called Body Sway. We extract the feature from local movements of Body Sway by participially dividing the Body into regions. Experimental results for a dataset of Body Sway of 118 participants show that the local movement feature obtained using our method outperforms the gait feature obtained using an existing method.
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synthesizing realistic image based avatars by Body Sway analysis
Human-Agent Interaction, 2016Co-Authors: Masashi Nishiyama, Tsubasa Miyauchi, Hiroki Yoshimura, Yoshio IwaiAbstract:We propose a method for synthesizing Body Sway to give human-like movement to image-based avatars. This method is based on an analysis of Body Sway in real people. Existing methods mainly handle the action states of avatars without sufficiently considering the wait states that exist between them. The wait state is essential for filling the periods before and after interaction. Users require both wait and action states to naturally communicate with avatars in interactive systems. Our method measures temporal changes in the Body Sway motion of each Body part of a standing subject using a single-camera video sequence. We are able to synthesize a new video sequence with Body Sway over an arbitrary length of time by randomly transitioning between points in the sequence when the motion is close to zero. The results of a subjective assessment show that avatars with Body Sway synthesized by our method appeared more alive to users than those using baseline methods.
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HAI - Synthesizing Realistic Image-based Avatars by Body Sway Analysis
Proceedings of the Fourth International Conference on Human Agent Interaction - HAI '16, 2016Co-Authors: Masashi Nishiyama, Tsubasa Miyauchi, Hiroki Yoshimura, Yoshio IwaiAbstract:We propose a method for synthesizing Body Sway to give human-like movement to image-based avatars. This method is based on an analysis of Body Sway in real people. Existing methods mainly handle the action states of avatars without sufficiently considering the wait states that exist between them. The wait state is essential for filling the periods before and after interaction. Users require both wait and action states to naturally communicate with avatars in interactive systems. Our method measures temporal changes in the Body Sway motion of each Body part of a standing subject using a single-camera video sequence. We are able to synthesize a new video sequence with Body Sway over an arbitrary length of time by randomly transitioning between points in the sequence when the motion is close to zero. The results of a subjective assessment show that avatars with Body Sway synthesized by our method appeared more alive to users than those using baseline methods.
Thomas Brandt - One of the best experts on this subject based on the ideXlab platform.
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phobic postural vertigo Body Sway during visually induced roll vection
Experimental Brain Research, 2002Co-Authors: Veronika Querner, S Krafczyk, Marianne Dieterich, Thomas BrandtAbstract:Patients with phobic postural vertigo (PPV) often report a particularly increased unsteadiness when looking at moving visual scenes. Therefore, the differential effects of large-field visual motion stimulation in roll plane on Body Sway during upright stance were analyzed in 23 patients with PPV, who had been selected for the integrity of their vestibular and balance systems, and in 17 healthy subjects. Visual motion stimulation induced a sensation of apparent Body motion (roll vection) in all patients and normal subjects. Normal subjects showed an increased lateral Sway path with a lateral shift of the center of pressure (COP) in stimulus direction (mean 1.67 cm, SD 1.63). The patients also exhibited an increase in Sway path during visual motion stimulation; however, their Body Sway differed from that of normals in that there was no lateral displacement of COP (mean 0.19 cm, SD 0.73). The lateral displacement of COP and the increase in RMS of Body Sway during visual motion stimulation were significantly greater in normals than in the patients (p<0.05). The patients’ increased Body Sway without COP deviation does not imply an increased risk of falling. Two explanations are conceivable for this increased Body Sway without Body deviation in patients with PPV: (a) the patients rely more on proprioceptive and vestibular rather than on visual cues to regulate upright stance; or (b) they depend on visual, vestibular, and proprioceptive information, but the threshold at which they initiate a compensatory Body Sway opposite in direction to a perceived Body deviation is lower than in normal subjects. The data support the second explanation.
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Phobic postural vertigo: Body Sway during visually induced roll vection
Experimental Brain Research, 2002Co-Authors: Veronika Querner, S Krafczyk, Marianne Dieterich, Thomas BrandtAbstract:Patients with phobic postural vertigo (PPV) often report a particularly increased unsteadiness when looking at moving visual scenes. Therefore, the differential effects of large-field visual motion stimulation in roll plane on Body Sway during upright stance were analyzed in 23 patients with PPV, who had been selected for the integrity of their vestibular and balance systems, and in 17 healthy subjects. Visual motion stimulation induced a sensation of apparent Body motion (roll vection) in all patients and normal subjects. Normal subjects showed an increased lateral Sway path with a lateral shift of the center of pressure (COP) in stimulus direction (mean 1.67 cm, SD 1.63). The patients also exhibited an increase in Sway path during visual motion stimulation; however, their Body Sway differed from that of normals in that there was no lateral displacement of COP (mean 0.19 cm, SD 0.73). The lateral displacement of COP and the increase in RMS of Body Sway during visual motion stimulation were significantly greater in normals than in the patients (p
Hiroki Aoki - One of the best experts on this subject based on the ideXlab platform.
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Examination of Effective Body Sway Parameters for Healthy Elderly
American Journal of Sports Science and Medicine, 2018Co-Authors: Tamotsu Kitabayashi, Shinichi Demura, Hiroki AokiAbstract:This study aimed to examine Body Sway characteristics and to propose effective Body Sway parameters for healthy elderly. The subjects were 311 healthy elderly and 380 healthy young adults. None of the subjects had evidence or known history of gait, posture, or skeletal disorders. The center of foot pressure measurement for 1 min was performed in 1 trial Using Anima’s stabilometer G5500. The data sampling frequency was 20 Hz. Thirty parameters with high reliability were selected from 5 domains of distance, area, velocity, power spectrum, and Body Sway vector. In comparison with the results for young adults, the elderly had markedly larger values of mean path length and root mean square of x-axis, as well as for 5 velocity parameters and 4 vector velocity parameters. In addition, approximately 10% of the data for parameters related to Body Sway velocity, especially front/back Body Sway, even in the healthy elderly fell in an abnormal range of values (mean ± 3 SD). In conclusion, the following parameters may be useful to adequately and simply evaluate the Body Sway characteristics of the elderly: Sway size, Sway velocity, and from a directional viewpoint, Sway size in the right/left direction and Sway velocity in the front/back direction.
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Body Sway characteristics during a static upright posture in the elderly
Geriatrics & Gerontology International, 2008Co-Authors: Shinichi Demura, Tamotsu Kitabayashi, Hiroki AokiAbstract:Aim: This study aimed to determine the reliability and sex and age-level differences of Body-Sway parameters, based on center of pressure (COP) measurements, during a static upright posture in the elderly and to clarify their Body-Sway characteristics in comparison with those of young adults. Methods: The subjects were 50 healthy elderly and 50 healthy young adults. They had no evidence or known history of disorder. The data sampling frequency was 20 Hz. Thirty-six highly reliable parameters were selected from the following seven domains: distance; position; distribution of amplitude; area; velocity; power spectrum; and vector. In addition, four Body-Sway factors (unit time Sway, front-back Sway and a left-right Sway and the high-frequency band power) were also measured. Results: In the elderly, most Body-Sway parameters had very high reliability and did not show significant sex or age-level differences. The degree of Body Sway was greater in the elderly than in young adults, and marked differences were found, especially in Sway velocity and periodicity. The four Body-Sway factors showed almost the same tendency as the 32 Sway parameters. Conclusion: We judged that the Body Sway in the elderly showed large individual differences. Approximately 10% of the elderly subjects may be outside the standard range as compared to young adults, mainly in parameters relating to velocity and spectrum. Because the Body-Sway characteristics of the elderly are considerably different from those of young adults, we may need unique criteria to evaluate their Body Sway.
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Body‐Sway characteristics during a static upright posture in the elderly
Geriatrics & Gerontology International, 2008Co-Authors: Shinichi Demura, Tamotsu Kitabayashi, Hiroki AokiAbstract:Aim: This study aimed to determine the reliability and sex and age-level differences of Body-Sway parameters, based on center of pressure (COP) measurements, during a static upright posture in the elderly and to clarify their Body-Sway characteristics in comparison with those of young adults. Methods: The subjects were 50 healthy elderly and 50 healthy young adults. They had no evidence or known history of disorder. The data sampling frequency was 20 Hz. Thirty-six highly reliable parameters were selected from the following seven domains: distance; position; distribution of amplitude; area; velocity; power spectrum; and vector. In addition, four Body-Sway factors (unit time Sway, front-back Sway and a left-right Sway and the high-frequency band power) were also measured. Results: In the elderly, most Body-Sway parameters had very high reliability and did not show significant sex or age-level differences. The degree of Body Sway was greater in the elderly than in young adults, and marked differences were found, especially in Sway velocity and periodicity. The four Body-Sway factors showed almost the same tendency as the 32 Sway parameters. Conclusion: We judged that the Body Sway in the elderly showed large individual differences. Approximately 10% of the elderly subjects may be outside the standard range as compared to young adults, mainly in parameters relating to velocity and spectrum. Because the Body-Sway characteristics of the elderly are considerably different from those of young adults, we may need unique criteria to evaluate their Body Sway.
Santiago Calero - One of the best experts on this subject based on the ideXlab platform.
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connection between performance and Body Sway morphology in juvenile olympic shooters
Journal of Human Sport and Exercise, 2019Co-Authors: Maria S Zakynthinaki, Santiago CaleroAbstract:The objective of the study was to examine, via use of a simple specific test, the correlation between Body Sway and performance in Juvenile Olympic shooters, to compare the differences in Body morphology between different shooting modalities and to know if the anthropometric profile of a shooter influences performance. 38 national level juvenile shooters (24 pistol and 14 rifle) who competed at a pistol and air rifle Young Promises Spanish Championship participated in the study. Body Sway (measured in terms of movements of the Centre of Pressure (COP): maximum displacements, maximum and minimum average velocities, rotation angles and total areas) and anthropometric data (age, height and weight) were recorded under competition conditions during shooting simulations. Performance was measured in terms of average points per shot. The variables of stress and experience before competition were also considered. The study was observational and descriptive following a cross-sectional design. The results showed that, in the juvenile category, rifle shooters perform better than pistol shooters, but pistol shooters have less Body Sway. Performance was found to be statistically related to COP displacements, only in pistol shooters. Body weight was found to be related to Body Sway but not with performance. Body height was found to be related neither with Body Sway, nor with performance No anthropometric differences have been found to exist between the different modalities (pistol and rifle).
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Connection between performance and Body Sway/morphology in juvenile Olympic shooters
Journal of Human Sport and Exercise, 2019Co-Authors: Maria S Zakynthinaki, Santiago CaleroAbstract:The objective of the study was to examine, via use of a simple specific test, the correlation between Body Sway and performance in Juvenile Olympic shooters, to compare the differences in Body morphology between different shooting modalities and to know if the anthropometric profile of a shooter influences performance. 38 national level juvenile shooters (24 pistol and 14 rifle) who competed at a pistol and air rifle Young Promises Spanish Championship participated in the study. Body Sway (measured in terms of movements of the Centre of Pressure (COP): maximum displacements, maximum and minimum average velocities, rotation angles and total areas) and anthropometric data (age, height and weight) were recorded under competition conditions during shooting simulations. Performance was measured in terms of average points per shot. The variables of stress and experience before competition were also considered. The study was observational and descriptive following a cross-sectional design. The results showed that, in the juvenile category, rifle shooters perform better than pistol shooters, but pistol shooters have less Body Sway. Performance was found to be statistically related to COP displacements, only in pistol shooters. Body weight was found to be related to Body Sway but not with performance. Body height was found to be related neither with Body Sway, nor with performance No anthropometric differences have been found to exist between the different modalities (pistol and rifle).