Patterns of Center of Pressure Migration during Prolonged Unconstrained Standing

Motor Control ◽  
1999 ◽  
Vol 3 (1) ◽  
pp. 12-27 ◽  
Author(s):  
Marcos Duarte ◽  
Valdimir M. Zatsiorsky
Keyword(s):  
Healthy Subjects ◽  
Center Of Pressure ◽  
Large Displacement ◽  
Time Intervals ◽  
Migration Patterns ◽  
Software Code ◽  
Continuous Displacement ◽  
Parameter Values ◽  
Anterior Posterior ◽  
Average Position

Prolonged (>30 min) unconstrained standing (PUS) was studied in 10 young healthy subjects. The usual methods of stabilographic analysis assume a random center of pressure (COP) migration. This study was based on the opposite idea and showed that during PUS, specific and consistent patterns of the COP migration can be recognized by a computer algorithm. Three COP migration patterns were found: (a) shifting, a fast displacement of the average position of COP from one region to another; (b) fidgeting, a fast and large displacement and returning of COP to approximately the same position; and (c) drifting, a slow continuous displacement of the average position of COP. A software code was written and default parameter values were chosen for recognizing COP migration patterns. For 30-min PUS the following patterns were identified: Shifting was generally observed every 316 ± 292 sec in the anterior-posterior (a-p) direction with an average shift amplitude of 17 ± 15 mm, and every 199 ± 148 sec in the medial-lateral (m-1) direction with an average shift amplitude of 22 ± 38 mm. Corresponding time intervals for fidgeting were 59 ± 15 sec in the a-p direction and 49±16 sec in the m-1 direction. The average drift-to-drift interval was 319 ± 173 sec in the a-p direction and 529 ± 333 sec in the m-1 direction.

A Comparison of Two Thera-Band Training Rehabilitation Protocols on Postural Control

2007 ◽  
Vol 16 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Alecia Puls ◽  
Phillip Gribble
Keyword(s):  
Postural Control ◽  
Healthy Subjects ◽  
Mixed Model ◽  
Outcome Measure ◽  
Center Of Pressure ◽  
Main Outcome Measure ◽  
Rehabilitation Protocols ◽  
Ankle Rehabilitation ◽  
Eyes Open ◽  
Anterior Posterior

Context:Thera-Band™ (TB) exercises are commonly utilized in ankle rehabilitation, but previous studies have shown inconsistent results.Objective:To compare two TB protocols among healthy subjects in improving postural control.Design:Mixed model design.Setting:Research laboratory.Participants:Thirty healthy subjects divided into a control (CON), three times/week (TB3) or five times/week (TB5) group.Intervention:Training groups completed TB quick-kick protocols for six weeks either three (TB3) or five times (TB5) per week.Main Outcome Measure:Center of pressure velocity in the anterior/posterior (COPVX) and medial/lateral (COPVY) directions.Results:There were no differences related to Group or Side. COPVX in the eyes open (EO) condition increased pre-post. COPVY decreased pre-post.Conclusion:The lack of differences between Groups and Side indicates these specific TB training protocols did not impact static postural control differently among healthy subjects.

scholarly journals Baropodometric technology used to analyze types of weight-bearing during hemiparetic upright position

2012 ◽  
Vol 25 (3) ◽  
pp. 583-594 ◽  
Author(s):  
Lidiane Teles de Menezes ◽  
Paulo Henrique Ferreira de Araujo Barbosa ◽  
Abraão Souza Costa ◽  
Anderson Castro Mundim ◽  
Gabrielly Craveiro Ramos ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Center Of Pressure ◽  
Weight Bearing ◽  
Upright Position ◽  
The Other ◽  
Control Group ◽  
Gender And Age ◽  
Coordination System ◽  
Support Area ◽  
Arch Index

INTRODUCTION: Although baropodometric analysis has been published since the 1990s, only now it is found a considerable number of studies showing different uses in the rehabilitation. OBJECTIVE: To amplify the use of this technology, this research aimed to analyze baropodometric records during upright position of subjects with hemiparesis, describing a way to define weight-bearing profiles in this population. METHOD: 20 healthy subjects were matched by gender and age with 12 subjects with chronic spastic hemiparesis. This control group was formed to establish the limits of symmetry during weight-bearing distribution in the hemiparesis group. Next, hemiparesis group was submitted to procedures to measure baropodometric records used to provide variables related to the weight-bearing distribution, the arch index and the displacements in the center of pressure (CoP). Data were used to compare differences among kinds of weight-bearing distribution (symmetric, asymmetric toward non-paretic or paretic foot) and coordination system for CoP displacements. RESULTS: Hemiparesis group was compounded by eight symmetrics, eight asymmetrics toward non-paretic foot and four asymmetric toward paretic foot. Significant differences in the weight-bearing distributions between non-predominantly and predominantly used foot did not promote differences in the other baropodometric records (peak and mean of pressure, and support area). Mainly in the asymmetry toward non-paretic foot it was observed significant modifications of the baropodometric records. CONCLUSION: Baropodometric technology can be used to analyze weight-bearing distribution during upright position of subjects with hemiparesis, detecting different kinds of weight-bearing profiles useful to therapeutic programs and researches involving subjects with this disability.

scholarly journals Assessment of Static Plantar Pressure, Stabilometry, Vitamin D and Bone Mineral Density in Female Adolescents with Moderate Idiopathic Scoliosis

2020 ◽  
Vol 17 (6) ◽  
pp. 2167
Author(s):  
Liliana Cațan ◽  
Simona Cerbu ◽  
Elena Amaricai ◽  
Oana Suciu ◽  
Delia Ioana Horhat ◽  
...  
Keyword(s):  
Vitamin D ◽  
Idiopathic Scoliosis ◽  
Bone Mineral ◽  
Vitamin D3 ◽  
Plantar Pressure ◽  
Healthy Subjects ◽  
Center Of Pressure ◽  
Female Adolescents ◽  
Z Score ◽  
Mineral Density

(1) Background: Adolescent idiopathic scoliosis (AIS) can be associated with vitamin D deficiency and osteopenia. Plantar pressure and stabilometry offer important information about posture. The objectives of our study were to compare static plantar pressure and stabilometric parameters, serum 25-OH-vitamin D3 and calcium levels, and bone mineral densitometry expressed as z-score in patients with moderate AIS and healthy subjects. (2) Methods: 32 female adolescents (idiopathic S shaped moderate scoliosis, main lumbar curve) and 32 gender and age-matched controls performed: static plantar pressure, stabilometry, serum 25-OH-vitamin D3 and calcium levels, and dual X-ray absorptiometry scans of the spine. (3) Results: In scoliosis patients, significant differences were recorded between right and left foot for total foot, first and fifth metatarsal, and heel loadings. Stabilometry showed a poorer postural control when compared to healthy subjects (p < 0.001). Patients had significantly lower vitamin D, calcium levels, and z-scores. Lumbar Cobb angle was significantly correlated with the z-score (r = −0.39, p = 0.02), with right foot fifth metatarsal load (r = −0.35, p = 0.04), center of pressure CoPx (r = −0.42, p = 0.01), CoP displacement (r = 0.35, p = 0.04) and 90% confidence ellipse area (r = −0.38, p = 0.03). (4) Conclusions: In our study including female adolescents with idiopathic S shaped moderate scoliosis, plantar pressure and stabilometric parameters were influenced by the main scoliotic curve.

Comparing Standing Balance at Real and Virtual Elevated Environments

2002 ◽  
Vol 46 (26) ◽  
pp. 2169-2173
Author(s):  
Peter Simeonov ◽  
Hongwei Hsiao ◽  
Brian Dotson ◽  
Douglas Amnions
Keyword(s):  
Postural Balance ◽  
Occupational Safety ◽  
Center Of Pressure ◽  
Ground Level ◽  
Occupational Safety And Health ◽  
Visual Simulation ◽  
Mean Velocity ◽  
Deformable Surfaces ◽  
Safety And Health ◽  
Anterior Posterior

The study evaluated the efficacy of a surround-screen virtual reality (SSVR) system in simulating heights for studying human postural balance at elevation. Twenty four subjects performed standing tasks at 9-m elevation and ground level, on firm and deformable surfaces, in a real environment (RE) and a comparable virtual environment (VE). The RE was the interior of the high-bay laboratory at the National Institute for Occupational Safety and Health (NIOSH) in Morgantown, West Virginia; the VE simulated this environment in the SSVR system. Medial-lateral and anterior-posterior body sways and mean velocity of the human center-of-pressure displacement were collected using a force platform. The results indicated that the sway parameters were similar in VE and RE at elevation on both firm and deformable surfaces. At ground level, the sway parameters were significantly increased in the VE compared to the RE on a deformable surface, but not on a firm surface. It appears that visual simulation of elevated environments within a SSVR is adequate for studying the risk factors leading to losing balance and fall incidents.

scholarly journals The center of pressure and ankle muscle co-contraction in response to anterior-posterior perturbations

PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0207667 ◽  
Author(s):  
Dongwon Kim ◽  
Jong-Moon Hwang
Keyword(s):  
Center Of Pressure ◽  
Ankle Muscle ◽  
Anterior Posterior

scholarly journals Effect of Eye-Object Distance on Body Sway during Galvanic Vestibular Stimulation

2018 ◽  
Vol 8 (11) ◽  
pp. 191 ◽  
Author(s):  
Osamu Aoki ◽  
Yoshitaka Otani ◽  
Shinichiro Morishita
Keyword(s):  
Healthy Subjects ◽  
Center Of Pressure ◽  
Force Plate ◽  
Distance Effect ◽  
Vestibular Stimulation ◽  
Galvanic Vestibular Stimulation ◽  
Body Sway ◽  
Mean Square ◽  
Visual Condition ◽  
Object Distance

Gazing at objects at a near distance (small eye-object distance) can reduce body sway. However, whether body sway is regulated by movement in the mediolateral or anteroposterior direction remains unclear. Galvanic vestibular stimulation (GVS) can induce body tilting in the mediolateral or anteroposterior direction. This study examined the directionality of the eye-object distance effect, using body-tilting GVS manipulations. Ten healthy subjects (aged 21.1 ± 0.3 years) stood on a force plate covered with a piece of foamed rubber and either closed their eyes or gazed at a marker located 0.5 m, 1.0 m, or 1.5 m in front of them. The GVS polarities were set to evoke rightward, forward, and backward body tilts. To compare the effects of eye-object distance in the mediolateral and anteroposterior directions, the root mean square (RMS) of the center of pressure (COP) without GVS was subtracted from the COP RMS during GVS. For swaying in the mediolateral direction, significant visual condition-related differences were found during rightward and forward GVS (p < 0.05). Thus, reductions in mediolateral body sway are more evident for smaller eye-object distances during rightward GVS. It would be appropriate to use body-tilting GVS to detect the directionality of the eye-object distance effect.

scholarly journals Probability distributions of COVID-19 tweet posted trends use a nonhomogeneous Poisson process

2020 ◽  
Vol 1 (4) ◽  
pp. 229-238
Author(s):  
Devi Munandar ◽  
Sudradjat Supian ◽  
Subiyanto Subiyanto
Keyword(s):  
Social Media ◽  
Poisson Process ◽  
Exponential Distribution ◽  
Probability Distributions ◽  
Nonhomogeneous Poisson Process ◽  
Time Interval ◽  
Initial State ◽  
Time Intervals ◽  
Time Parameters ◽  
Parameter Values

The influence of social media in disseminating information, especially during the COVID-19 pandemic, can be observed with time interval, so that the probability of number of tweets discussed by netizens on social media can be observed. The nonhomogeneous Poisson process (NHPP) is a Poisson process dependent on time parameters and the exponential distribution having unequal parameter values and, independently of each other. The probability of no occurrence an event in the initial state is one and the probability of an event in initial state is zero. Using of non-homogeneous Poisson in this paper aims to predict and count the number of tweet posts with the keyword coronavirus, COVID-19 with set time intervals every day. Posting of tweets from one time each day to the next do not affect each other and the number of tweets is not the same. The dataset used in this study is crawling of COVID-19 tweets three times a day with duration of 20 minutes each crawled for 13 days or 39 time intervals. The result of this study obtained predictions and calculated for the probability of the number of tweets for the tendency of netizens to post on the situation of the COVID-19 pandemic.

scholarly journals Influence of Foot Progression Angle on Center of Pressure During Stair Ascending in Subjects With Chronic Ankle Instability

2021 ◽  
Vol 15 ◽  
pp. 350-354
Author(s):  
Jung-Hyun Ban ◽  
Tae-Ho Kim
Keyword(s):  
Center Of Pressure ◽  
Ankle Instability ◽  
Chronic Ankle Instability ◽  
Foot Progression Angle ◽  
Significant Difference ◽  
The Stability ◽  
Neutral Posture ◽  
Criteria For Selection ◽  
Anterior Posterior ◽  
Selection Of

The purpose of this study was to identify changes in the center of pressure during stair ascending in subjects with chronic ankle instability while different angles of foot are applied. The subjects of this study were 20 male and female adults with chronic ankle instability were selected from among the employees of D Hospital in Daegu Metropolitan City. The criteria for selection of subjects with chronic ankle instability were those who felt wobbling in the ankle joint and scored not higher than 24 points in a test using the Cumberland Ankle Instability Tool (CAIT). The subjects carried out stair ascending in neutral, toe-in and toe-out postures, respectively, and changes in the center of pressure (COP) were compared and analyzed. The results of this study, no statistically significant difference appeared in the comparison between the toe-in posture and neutral posture or between the neutral posture and the toe-out posture but medial/lateral movements of the center of pressure showed significant differences between the toe-in and toe-out postures. In addition, the total travel range and the moving range of the center of pressure, the average velocity, and the anterior/posterior movements of the center of pressure showed no statistically significant difference among all three postures. As a result, it could be seen that when adults with chronic ankle instability climb the stairs, the toe-in posture reduce the medial/lateral movements of the center of pressure thereby increasing the stability of the ankle and effectively preventing re-injuries.

scholarly journals Differences in Balance Function Between Cancer Survivors and Healthy Subjects: A Pilot Study

2018 ◽  
Vol 17 (4) ◽  
pp. 1144-1149 ◽  
Author(s):  
Shinichiro Morishita ◽  
Yuta Mitobe ◽  
Atsuhiro Tsubaki ◽  
Osamu Aoki ◽  
Jack B. Fu ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cancer Survivors ◽  
Healthy Subjects ◽  
Center Of Pressure ◽  
Healthy Adults ◽  
Body Sway ◽  
Balance Function ◽  
Adult Cancer Survivors ◽  
Eyes Open ◽  
The Mean

Older adults who have survived cancer experience significantly more falls compared with healthy adults. Adult cancer survivors may also have a lower balance function than healthy adults. We examined muscle strength and balance function among 19 cancer survivors and 14 healthy subjects. The mean age of the cancer survivors was 51.5 ± 11.2 years; 6 men and 13 women. Cancer diagnoses included breast cancer, retroperitoneal sarcoma, acute leukemia, lung cancer, colorectal cancer, thyroid cancer, Ewing’s sarcoma, and tongue cancer. The mean age of healthy subjects was 47.4 ± 14 years; 3 men, 11 women. Muscle strength was assessed using hand grip and knee extensor strength tests. Balance function was evaluated using the Timed Up and Go (TUG) test, and body sway was tested using a force platform. No significant differences were found with respect to right and left grip strength or right and left knee extension strength between the 2 groups. A significantly higher TUG time was observed in cancer survivors than in healthy subjects ( P < .05). With eyes open, the area of the center of pressure was significantly larger in cancer survivors than in healthy subjects ( P < .05). Similarly, the length per area was significantly lower both with eyes open and closed for cancer survivors than for healthy subjects ( P < .05). TUG was significantly correlated with muscle strength in both groups ( P < .05). However, no body sway parameters were related to muscle strength in either group. Cancer survivors had lower balance function that might not have been related to muscle strength. Cancer survivors should be evaluated for balance function as there is a potential for impairment. The findings of this study will be relevant for planning the prevention of falls for cancer survivors.

Sign in / Sign up

Export Citation Format

Share Document