scholarly journals Complexity-Based Measures of Postural Sway during Walking at Different Speeds and Durations Using Multiscale Entropy

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1128 ◽  
Author(s):  
Liau ◽  
Wu ◽  
Lung ◽  
Zhang ◽  
Wang ◽  
...  
Keyword(s):  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Physical Activities ◽  
Multiscale Entropy ◽  
Complexity Index ◽  
Significant Difference ◽  
Daily Physical Activities ◽  
Walking Speeds ◽  
Pressure Measurement System

: Participation in various physical activities requires successful postural control in response to the changes in position of our body. It is important to assess postural control for early detection of falls and foot injuries. Walking at various speeds and for various durations is essential in daily physical activities. The purpose of this study was to evaluate the changes in complexity of the center of pressure (COP) during walking at different speeds and for different durations. In this study, a total of 12 participants were recruited for walking at two speeds (slow at 3 km/h and moderate at 6 km/h) for two durations (10 and 20 minutes). An insole-type plantar pressure measurement system was used to measure and calculate COP as participants walked on a treadmill. Multiscale entropy (MSE) was used to quantify the complexity of COP. Our results showed that the complexity of COP significantly decreased (p < 0.05) after 20 min of walking (complexity index, CI = −3.51) compared to 10 min of walking (CI = −3.20) while walking at 3 km/h, but not at 6 km/h. Our results also showed that the complexity index of COP indicated a significant difference (p < 0.05) between walking at speeds of 3 km/h (CI = −3.2) and 6 km/h (CI = −3.6) at the walking duration of 10 minutes, but not at 20 minutes. This study demonstrated an interaction between walking speeds and walking durations on the complexity of COP.

scholarly journals Physiological complexity and system adaptability: evidence from postural control dynamics of older adults

2010 ◽  
Vol 109 (6) ◽  
pp. 1786-1791 ◽  
Author(s):  
Brad Manor ◽  
Madalena D. Costa ◽  
Kun Hu ◽  
Elizabeth Newton ◽  
Olga Starobinets ◽  
...  
Keyword(s):  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Quiet Standing ◽  
Multiscale Entropy ◽  
Postural Control System ◽  
Dual Tasking ◽  
Complexity Index ◽  
Pressure Dynamics ◽  
Boston Study

The degree of multiscale complexity in human behavioral regulation, such as that required for postural control, appears to decrease with advanced aging or disease. To help delineate causes and functional consequences of complexity loss, we examined the effects of visual and somatosensory impairment on the complexity of postural sway during quiet standing and its relationship to postural adaptation to cognitive dual tasking. Participants of the MOBILIZE Boston Study were classified into mutually exclusive groups: controls [intact vision and foot somatosensation, n = 299, 76 ± 5 (SD) yr old], visual impairment only (<20/40 vision, n = 81, 77 ± 4 yr old), somatosensory impairment only (inability to perceive 5.07 monofilament on plantar halluxes, n = 48, 80 ± 5 yr old), and combined impairments ( n = 25, 80 ± 4 yr old). Postural sway (i.e., center-of-pressure) dynamics were assessed during quiet standing and cognitive dual tasking, and a complexity index was quantified using multiscale entropy analysis. Postural sway speed and area, which did not correlate with complexity, were also computed. During quiet standing, the complexity index (mean ± SD) was highest in controls (9.5 ± 1.2) and successively lower in the visual (9.1 ± 1.1), somatosensory (8.6 ± 1.6), and combined (7.8 ± 1.3) impairment groups ( P = 0.001). Dual tasking resulted in increased sway speed and area but reduced complexity ( P < 0.01). Lower complexity during quiet standing correlated with greater absolute ( R = −0.34, P = 0.002) and percent ( R = −0.45, P < 0.001) increases in postural sway speed from quiet standing to dual-tasking conditions. Sensory impairments contributed to decreased postural sway complexity, which reflected reduced adaptive capacity of the postural control system. Relatively low baseline complexity may, therefore, indicate control systems that are more vulnerable to cognitive and other stressors.

scholarly journals Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

2021 ◽  
Vol 17 (6) ◽  
pp. 418-427
Author(s):  
Yücel Makaracı ◽  
Recep Soslu ◽  
Ömer Özer ◽  
Abdullah Uysal
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Force Plate ◽  
Basketball Players ◽  
Male Athletes ◽  
Significant Difference ◽  
Single Leg Stance ◽  
Volleyball Players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n= 11) and volleyball (n= 12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

scholarly journals Effect of Walking Speeds on Complexity of Plantar Pressure Patterns

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ben-Yi Liau ◽  
Fu-Lien Wu ◽  
Yameng Li ◽  
Chi-Wen Lung ◽  
Ayman A. Mohamed ◽  
...  
Keyword(s):  
Plantar Pressure ◽  
Repeated Measures ◽  
Multiscale Entropy ◽  
Fast Walking ◽  
Slow Walking ◽  
Significant Difference ◽  
Nonlinear Features ◽  
Plantar Pressure Measurement ◽  
Walking Speeds ◽  
Pressure Measurement System

Various walking speeds may induce different responses on the plantar pressure patterns. Current methods used to analyze plantar pressure patterns are linear and ignore nonlinear features. The purpose of this study was to analyze the complexity of plantar pressure images after walking at various speeds using nonlinear bidimensional multiscale entropy (MSE2D). Twelve participants (age: 27.1 ± 5.8 years; height: 170.3 ± 10.0 cm; and weight: 63.5 ± 13.5 kg) were recruited for walking at three speeds (slow at 1.8 mph, moderate at 3.6 mph, and fast at 5.4 mph) for 20 minutes. A plantar pressure measurement system was used to measure plantar pressure patterns. Complexity index (CI), a summation of MSE2D from all time scales, was used to quantify the changes of complexity of plantar pressure images. The analysis of variance with repeated measures and Fisher’s least significant difference correction were used to examine the results of this study. The results showed that CI of plantar pressure images of 1.8 mph (1.780) was significantly lower compared with 3.6 (1.790) and 5.4 mph (1.792). The results also showed that CI significantly increased from the 1st min (1.780) to the 10th min (1.791) and 20th min (1.791) with slow walking (1.8 mph). Our results indicate that slow walking at 1.8 mph may not be good for postural control compared with moderate walking (3.6 mph) and fast walking (5.4 mph). This study demonstrates that bidimensional multiscale entropy is able to quantify complexity changes of plantar pressure images after different walking speeds.

Recovery Trajectory of Postural Control Impairments Following a Concussion: A Case Study

2020 ◽  
Vol 29 (3) ◽  
pp. 346-351
Author(s):  
Adam C. King
Keyword(s):  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Recovery Phase ◽  
Multiscale Entropy ◽  
Single Subject ◽  
Healthy Controls ◽  
Post Injury ◽  
Recovery Trajectory

Context: Altered postural control represents one of the most common motor consequences following a concussion and there is a paucity of data monitoring the recovery trajectory that identifies the persistent changes of postural control. Objective: To determine whether the recovery trajectory of postural control was consistent across different measures of postural stability and whether increased postural challenge (ie, sloped surface) revealed subtle postural impairments. Design: A single-subject case study. Setting: Research laboratory. Patients or Other Participants: One concussed individual with a cohort of healthy controls (n = 10) used for comparison. Main Outcome Measures: Center of pressure variability (linear—SD and nonlinear—multiscale entropy) was used to index postural sway preinjury and at periodic intervals following the concussion. Results: The concussed individuals displayed reduced amounts of sway during the initial recovery phase that failed to returned to preinjury levels but reached the level of healthy controls at 1-month postinjury. The multiscale entropy analysis revealed increased center of pressure irregularity throughout recovery that persisted up to 1-month post injury. Conclusions: The findings identified subtle, persistent postural control impairments revealed through the nonlinear analysis of center of pressure and supports the notion that the consequences of a concussion (ie, impaired postural control) need to be considered beyond the resolution of behavioral symptoms.

“Going Backward”: Effects of age and fatigue on posterior-directed falls in Parkinson disease

2021 ◽  
pp. 1-9
Author(s):  
Evan V. Papa ◽  
Rita M. Patterson ◽  
Nicoleta Bugnariu
Keyword(s):  
Postural Control ◽  
Parkinson Disease ◽  
Repeated Measures ◽  
Center Of Pressure ◽  
Angular Displacement ◽  
Reaction Times ◽  
Older Individuals ◽  
Peak Knee ◽  
Significant Difference ◽  
Fatiguing Exercise

BACKGROUND: Nearly half of persons with Parkinson disease (PD) report fatigue as a factor in their fall history. However, it is unknown whether these self-reported falls are caused by a sensation of fatigue or performance fatigue. OBJECTIVE: We sought to investigate the influences of performance fatigue and age on postural control in persons with PD. METHODS: Individuals with PD (n = 14) underwent postural control assessments before (T0) and immediately after (T1) fatiguing exercise. Biomechanical data were gathered on participants completing a treadmill-induced, posterior-directed fall. Performance fatigue was produced using lower extremity resistance exercise on an isokinetic ergometer. Repeated measures ANCOVAs were used with age as a covariate to determine the effects of performance fatigue on biomechanical variables. RESULTS: After adjustment for age, there was a statistically significant difference in peak center of pressure (COP) latency during the support phase of recovery. Pairwise comparisons demonstrated a decrease in peak ankle displacement from T0 to T1. Age was also found to be significantly related to reaction time and peak knee displacement while participants were fatigued. CONCLUSIONS: The decreased peak COP latency, along with decreased ankle angular displacement, suggest that persons with PD adopt a stiffening strategy in response to backward directed falls. Postural stiffening is not uncommon in persons with PD and could be a risk factor for falls. Older individuals with PD demonstrate slower mobility scores and decreased reaction times in the setting of fatigue, suggesting a combined effect of the aging and fatigue processes.

scholarly journals Is Postural Control Different in Boys and Girls? Comparison Between Sex

2020 ◽  
Vol 27 (4) ◽  
pp. 385-391
Author(s):  
Jessica Caroliny de Jesus Neves ◽  
Aryane Karoline Vital Souza ◽  
Dirce Shizuko Fujisawa
Keyword(s):  
Physical Activity ◽  
Postural Control ◽  
Test Performance ◽  
Center Of Pressure ◽  
Cross Sectional Study ◽  
Lateral Velocity ◽  
Cross Sectional ◽  
Stage Of Development ◽  
Significant Difference ◽  
Pressure Area

ABSTRACT The purpose of this study was to compare the postural control between eight-year-old boys and girls, considering the nutritional classification and level of physical activity. This was a cross-sectional study, with a sample of 346 participants, classified by the WHO AnthroPlus software, evaluated on the force platform and the Questionnaire Physical Activity for Children. The results demonstrated that girls showed lower values in relation to the opposite sex (p<0.001), in the center of pressure area (COP) (girls: 11.88 vs boys: 15.86cm2), Antero-posterior Amplitude (girl: 5.40 vs boy: 6.05cm), Medial-lateral Amplitude (girl: 3.97 vs boy: 4.40cm), Antero-posterior velocity (girl: 3.98 vs boy: 4.94cm/s), Medial-lateral velocity (girl: 3.98 vs boy: 4.59cm/s), Antero-posterior frequency (girl: 0.70 vs boy: 0.84Hz). Physical activity was associated with male sex (p=0.001; X2=11.195; odds ratio=0.372). In relation to the center of pressure of sedentary children, girls showed better postural control (p<0.001), but when we analyzed the center of pressure of both sexes who were active there was no statistically significant difference (p=0.112). The Z score of both sexes presented no difference in the center of pressure area (p=0.809 and p=0.785 respectively). Girls showed better postural control, while boys are more active; when both sexes performed physical activity COP area was similar. Therefore, special care should be taken when assessing postural control in boys and girls due to their differences in test performance and stage of development. As for interventions, exercise should be considered for better performance of the COP.

scholarly journals Characteristics of Standing Postural Control in Women under Additional Load

2020 ◽  
Vol 17 (2) ◽  
pp. 490
Author(s):  
Bożena Wojciechowska-Maszkowska ◽  
Dorota Borzucka
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Stability Control ◽  
Standing Posture ◽  
Additional Load ◽  
Eyes Open ◽  
Heavy Loads ◽  
Load Conditions

The aim of this study was to evaluate the effect of additional load on postural-stability control in young women. To evaluate postural control in the 34 women in this study (mean age, 20.8 years), we measured postural sway (center of pressure, COP) in a neutral stance (with eyes open) in three trials of 30 s each. Three load conditions were used in the study: 0, 14, and 30 kg. In analysis, we used three COP parameters, variability (linear), mean sway velocity (linear), and entropy (nonlinear). Results suggested that a considerable load on a young woman’s body (approximately 48% of body weight) had significant influence on stability. Specifically, heavy loads triggered random movements, increased the dynamics of postural-stability control, and required more attention to control standing posture. The results of our study indicate that inferior postural control mainly results from insufficient experience in lifting such a load.

scholarly journals The Effects of Active Self-Correction on Postural Control in Girls with Adolescent Idiopathic Scoliosis: The Role of an Additional Mental Task

2020 ◽  
Vol 17 (5) ◽  
pp. 1640 ◽  
Author(s):  
Elżbieta Piątek ◽  
Michał Kuczyński ◽  
Bożena Ostrowska
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Postural Control ◽  
Repeated Measures ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Force Plate ◽  
Stroop Test ◽  
Quiet Standing ◽  
Mental Task

Due to balance deficits that accompany adolescent idiopathic scoliosis (AIS), the potential interaction between activities of daily living and active self-correction movements (ASC) on postural control deserves particular attention. Our purpose was to assess the effects of ASC movements with or without a secondary mental task on postural control in twenty-five girls with AIS. It is a quasi-experimental within-subject design with repeated measures ANOVA. They were measured in four 20-s quiet standing trials on a force plate: no task, ASC, Stroop test, and both. Based on the center-of-pressure (COP) recordings, the COP parameters were computed. The ASC alone had no effect on any of the postural sway measures. Stroop test alone decreased COP speed and increased COP entropy. Performing the ASC movements and Stroop test together increased the COP speed and decreased COP entropy as compared to the baseline data. In conclusion, our results indicate that AIS did not interfere with postural control. The effects of the Stroop test accounted for good capacity of subjects with AIS to take advantage of distracting attentional resources from the posture. However, performing both tasks together exhibited some deficits in postural control, which may suggest the need for therapeutic consultation while engaging in more demanding activities.

scholarly journals Comparison of postural balance between professional tae kwon do athletes and young adults

2014 ◽  
Vol 21 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Lucas Maciel Rabello ◽  
Christiane de Souza Guerino Macedo ◽  
André Wilson Gil ◽  
Marcio Rogério de Oliveira ◽  
Vinícius Arantes Coelho ◽  
...  
Keyword(s):  
Postural Balance ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Force Platform ◽  
Adult Group ◽  
Tae Kwon Do ◽  
Rehabilitation Programs ◽  
Significant Difference ◽  
Single Leg Stance ◽  
Postural Assessment

This study aimed to compare the postural balance of professional tae kwon do athletes with a non-tae kwon do adult group. Nineteen participants (nine tae kwon do practitioners and ten non-tae kwon do practitioners) were tested. To measure the postural sway, a force platform was used and the equipment recorded the main parameters: area of center of pressure; mean frequency, and velocity of center of pressure for both anteroposterior and mediolateral directions were measured for all participants. Before starting the assessment, the subjects received instructions and performed familiarization with the equipment and protocol. Participants were instructed to carry out three balance tests on a single-leg stance position with eyes opened. Values obtained in the postural assessment of professional athletes with the force platform were lower for all parameters compared to non-practitioners, except the frequency of center of pressure in the mediolateral direction. However, a significant difference (p=0.021) between the groups was found only in the center of pressure velocity parameter in the anteroposterior direction. These results have any implications on sport rehabilitation programs for balance assessments in athletes.

Influences of Arm Proprioception and Degrees of Freedom on Postural Control With Light Touch Feedback

2008 ◽  
Vol 99 (2) ◽  
pp. 595-604 ◽  
Author(s):  
Ely Rabin ◽  
Paul DiZio ◽  
Joel Ventura ◽  
James R. Lackner
Keyword(s):  
Postural Control ◽  
Degrees Of Freedom ◽  
Biceps Brachii ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Tactile Feedback ◽  
Contact Forces ◽  
Light Touch ◽  
Postural Stabilization ◽  
And Control

Lightly touching a stable surface with one fingertip strongly stabilizes standing posture. The three main features of this phenomenon are fingertip contact forces maintained at levels too low to provide mechanical support, attenuation of postural sway relative to conditions without fingertip touch, and center of pressure (CP) lags changes in fingertip shear forces by ∼250 ms. In the experiments presented here, we tested whether accurate arm proprioception and also whether the precision fingertip contact afforded by the arm's many degrees of freedom are necessary for postural stabilization by finger contact. In our first experiment, we perturbed arm proprioception and control with biceps brachii vibration (120-Hz, 2-mm amplitude). This degraded postural control, resulting in greater postural sway amplitudes. In a second study, we immobilized the touching arm with a splint. This prevented precision fingertip contact but had no effect on postural sway amplitude. In both experiments, the correlation and latency of fingertip contact forces to postural sway were unaffected. We conclude that postural control is executed based on information about arm orientation as well as tactile feedback from light touch, although precision fingertip contact is not essential. The consistent correlation and timing of CP movement and fingertip forces across conditions in which postural sway amplitude and fingertip contact are differentially disrupted suggests posture and the fingertip are controlled in parallel with feedback from the fingertip in this task.

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