Impact of Virtual Reality–Generated Construction Environments at Different Heights on Postural Stability and Fall Risk

Background Falls due to postural instability are common in construction environments especially from a height. The purpose of the study was to investigate the impact of virtual reality (VR)-generated environments at different virtual heights on postural stability. Methods Nineteen adults were analyzed for postural stability, tested in real (No VR) environment and in three VR environments, randomly assigned, at virtual heights of 0 ft. (VR0), 40 ft. (VR40), and 120 ft. (VR120). Postural stability was quantified using center of pressure postural sway variables and analyzed using a repeated measures analysis of variance (ANOVA). Participants also completed a simulation sickness questionnaire (SSQ) before and after VR exposure and a presence questionnaire (PQ) after VR exposure. Findings Significant postural instability ( p < .05) was identified between VR and No VR, in which increased postural instability was evident in all VR conditions compared with No VR. Scores from SSQ were within a pre–post score difference of five and the PQ score was (104.21 ± 14.03). Conclusion/Application to Practice Findings suggest that VR environments, regardless of virtual height, induced increased postural instability, which can be attributed to visual sensory conflicts to the postural control system created by VR exposure. Participants’ subjective responses on SSQ and PQ confirmed the feasibility of using VR to represent realistic immersions in virtual heights. However, objectively, VR could potentially lead to postural instability, stressing caution. VR can be a potential tool for providing virtual high-altitude environment exposure for fall prevention training, however, more research is needed on postural adaptation with acute and chronic exposure to VR.

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Virtual-Reality-Induced Visual Perturbations Impact Postural Control System Behavior

Behavioral Sciences ◽

10.3390/bs9110113 ◽

2019 ◽

Vol 9 (11) ◽

pp. 113 ◽

Cited By ~ 4

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Christopher M. Hill ◽

Alana J. Turner ◽

Shuchisnigdha Deb ◽

...

Keyword(s):

Virtual Reality ◽

Control System ◽

Postural Control ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Control System ◽

Postural Responses ◽

The Impact

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.

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Postural Stability in Obese Preoperative Bariatric Patients Using Static and Dynamic Evaluation

Obesity Facts ◽

10.1159/000509163 ◽

2020 ◽

Vol 13 (5) ◽

pp. 499-513

Author(s):

Gabriel M. Pagnotti ◽

Amna Haider ◽

Ariel Yang ◽

Kathryn E. Cottell ◽

Catherine M. Tuppo ◽

...

Keyword(s):

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Instability ◽

Patient Specific ◽

Morbidly Obese ◽

Tissue Quality ◽

Eyes Closed ◽

Obese Subjects ◽

The Impact

Introduction: Globally, 300 million adults have clinical obesity. Heightened adiposity and inadequate musculature secondary to obesity alter bipedal stance and gait, diminish musculoskeletal tissue quality, and compromise neuromuscular feedback; these physiological changes alter stability and increase injury risk from falls. Studies in the field focus on obese patients across a broad range of body mass indices (BMI >30 kg/m2) but without isolating the most morbidly obese subset (BMI ≥40 kg/m2). We investigated the impact of obesity in perturbing postural stability in morbidly obese subjects elected for bariatric intervention, harboring a higher-spectrum BMI. Subjects and Methods: Traditional force plate measurements and stabilograms are gold standards employed when measuring center of pressure (COP) and postural sway. To quantify the extent of postural instability in subjects with obesity before bariatric surgery, we assessed 17 obese subjects with an average BMI of 40 kg/m2 in contrast to 13 nonobese subjects with an average BMI of 30 kg/m2. COP and postural sway were measured from static and dynamic tasks. Involuntary movements were measured when patients performed static stances, with eyes either opened or closed. Two additional voluntary movements were measured when subjects performed dynamic, upper torso tasks with eyes opened. Results: Mean body weight was 85% (p < 0.001) greater in obese than nonobese subjects. Following static balance assessments, we observed greater sway displacement in the anteroposterior (AP) direction in obese subjects with eyes open (87%, p < 0.002) and eyes closed (76%, p = 0.04) versus nonobese subjects. Obese subjects also exhibited a higher COP velocity in static tests when subjects’ eyes were open (47%, p = 0.04). Dynamic tests demonstrated no differences between groups in sway displacement in either direction; however, COP velocity in the mediolateral (ML) direction was reduced (31%, p < 0.02) in obese subjects while voluntarily swaying in the AP direction, but increased in the same cohort when swaying in the ML direction (40%, p < 0.04). Discussion and Conclusion: Importantly, these data highlight obesity’s contribution towards increased postural instability. Obese subjects exhibited greater COP displacement at higher AP velocities versus nonobese subjects, suggesting that clinically obese individuals show greater instability than nonobese subjects. Identifying factors contributory to instability could encourage patient-specific physical therapies and presurgical measures to mitigate instability and monitor postsurgical balance improvements.

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Effect of Cardiovascular Fatigue on Postural Stability

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.18.5.38 ◽

2013 ◽

Vol 18 (5) ◽

pp. 38-40 ◽

Cited By ~ 1

Author(s):

Hamid Bateni ◽

Gina Leno ◽

Rebeca Manjarres ◽

Bailey Ouellette ◽

Mark Wolber

Keyword(s):

Outcome Measures ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Standing Position ◽

Treadmill Running ◽

Upper Body ◽

Mean Square Distance ◽

Squat Jumps

Context:Previous research has demonstrated that localized leg muscle fatigue induced by lower extremity exercises (e.g., squat jumps, sprints, and treadmill running) has an adverse effect on postural stability.Objective:To assess the effect of cardiovascular fatigue induced by upper extremity exercise on postural stability.Design:Repeated measures.Participants:Fourteen healthy young adults between the ages of 22 and 30 years (7 male and 7 female).Intervention:Participants performed an exercise protocol on an upper-body ergometer to induce cardiovascular fatigue.Main Outcome Measures:Postural sway, represented by center of pressure excursion, during bilateral standing in two different foot positions.Results:In a tandem standing position, mediolateral mean distance, root mean square distance, resultant power, and centroidal frequency increased signifcantly after inducement of cardiovascular fatigue.Conclusion:Cardiovascular fatigue adversely affects postural stability.

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Functional Task Constraints Foster Enhanced Postural Control in Children With Cerebral Palsy

Physical Therapy ◽

10.2522/ptj.20140425 ◽

2016 ◽

Vol 96 (3) ◽

pp. 348-354 ◽

Cited By ~ 8

Author(s):

Jennifer M. Schmit ◽

Michael Riley ◽

Sarah Cummins-Sebree ◽

Laura Schmitt ◽

Kevin Shockley

Keyword(s):

Cerebral Palsy ◽

Postural Control ◽

Postural Stability ◽

Postural Sway ◽

Postural Instability ◽

Apparent Difference ◽

Typical Development ◽

Postural Control System ◽

Study Objective ◽

Functional Play

BackgroundPostural instability is a classical characteristic of cerebral palsy (CP), but it has not been examined during functional play activity. Recent work has demonstrated that when motor tasks are made functionally more relevant, performance improves, even in children with movement pathology. It is possible that in a disease state, the underlying control mechanisms that are associated with healthy physiology must be elicited.ObjectiveThe study objective was to explore the utility of the functional play task methodology as a more rich and interpretable approach to the quantification of postural instability in children with CP.DesignPostural stability measures obtained from a cross-sectional cohort of children with CP (n=30) were compared with stability measures taken from children with typical development (n=30) during a single measurement period.MethodsPostural stability data were obtained with a portable force platform system. Postural sway was quantified during a precision manual functional play task. A baseline condition (no task) also was included. Postural sway variability and postural sway regularity were analyzed with analyses of variance.ResultsThere was an apparent difference in postural control (greater irregularity, greater sway variability) during quiet stance between children with CP and peers with typical development; this difference was mitigated during the performance of the precision functional play task.LimitationsA small and nonprobability sample of convenience may limit the findings of this study.ConclusionsThe findings illustrate flexibility and adaptability in the postural control system despite the pathological features associated with CP.

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Is Weight-Bearing Asymmetry Associated with Postural Instability after Stroke? A Systematic Review

Stroke Research and Treatment ◽

10.1155/2013/692137 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 19

Author(s):

Jip F. Kamphuis ◽

Digna de Kam ◽

Alexander C. H. Geurts ◽

Vivian Weerdesteyn

Keyword(s):

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Weight Bearing ◽

Postural Instability ◽

Quality Of Reporting ◽

Eligibility Criteria ◽

And Performance ◽

Balance Rehabilitation

Introduction. Improvement of postural stability is an important goal during poststroke rehabilitation. Since weight-bearing asymmetry (WBA) towards the nonparetic leg is common, training of weight-bearing symmetry has been a major focus in post-stroke balance rehabilitation. It is assumed that restoration of a more symmetrical weight distribution is associated with improved postural stability.Objective. To determine to what extent WBA is associated with postural instability in people after stroke.Methods. Electronic databases were searched (Cochrane, MEDLINE, EMBASE, and CINAHL) until March 2012.Main Eligibility Criteria. (1) Participants were people after stroke. (2) The association between WBA and postural stability was reported. Quality of reporting was assessed with the STROBE checklist and a related tool for reporting of confounding.Results. Nine observational studies met all criteria. Greater spontaneous WBA was associated with higher center of pressure (COP) velocity and with poorer synchronization of COP trajectories between the legs (two and one studies, resp.). Evidence for associations between WBA and performance on clinical balance tests or falls was weak.Conclusion. Greater WBA after stroke was associated with increased postural sway, but the current literature does not provide evidence for a causal relationship. Further studies should investigate whether reducing WBA would improve postural stability.

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Impact of Prolonged Exposure to a Slippery Surface on Postural Stability

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052214 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2214

Author(s):

Sachini N. K. Kodithuwakku Arachchige ◽

Harish Chander ◽

Alana J. Turner ◽

Adam C. Knight

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Prolonged Exposure ◽

Postural Sway ◽

Stable Condition ◽

Extrinsic Factors ◽

Intrinsic Factors ◽

Causative Factors ◽

Slippery Surface ◽

The Impact

Falls are extremely common in occupational settings. Intrinsic factors such as overexertion and extrinsic factors such as the supporting surface are causative factors of falls. The impact of prolonged exposure to a slippery surface on postural stability has not been previously studied. The purpose of the study was to analyze the effect of extended exposure to a dry and a slippery surface on postural stability. Eighteen males (age: 21.17 ± 3.38 years; height: 1.77 ± 0.08 m; mass: 89.81 ± 14.23 kg) were recruited and subjected to one-hour walking on a dry surface and a slippery surface on two different days. Participants’ balance was assessed using a force platform in stable and unstable conditions at 0, 30, and 60 min. Postural sway variables were analyzed using a 2 (surface) × 3 (time) repeated-measures ANOVA. Significant time main effects were observed in the stable condition with greater balance decrements at 30 and 60 min. Greater balance decrements were observed on the slippery surface compared to the dry surface in the unstable condition. The balance decrements can be attributed to overexertion due to the physiological workload of prolonged walking and to the potential gait modifications due to walking on the slippery surface.

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Differences in the Effect of Sleep Deprivation on the Postural Stability among Men and Women

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18073796 ◽

2021 ◽

Vol 18 (7) ◽

pp. 3796

Author(s):

Marta Ołpińska-Lischka ◽

Karolina Kujawa ◽

Janusz Maciaszek

Keyword(s):

Physical Activity ◽

Sleep Deprivation ◽

Postural Stability ◽

Center Of Pressure ◽

The Body ◽

Postural Control System ◽

Physically Active ◽

Before And After ◽

Eyes Open ◽

The Impact

Objective: Sleepiness caused by sleep deprivation may increase the risk of injuries and damages during physical activity. Individual data so far indicate a generally better static postural stability of women regardless of sleeping conditions. The main aim of this study was to assess the impact of sleep deprivation on postural stability according to gender after 24 h of sleep deprivation. Methods: Participants included 83 students (36 men and 47 women). Postural stability was measured with eyes open and closed eyes before and after sleep deprivation. Data from posturographic platform were used to assess postural stability objectively. Results: The type of test determined the size of observed changes in postural stability. The data suggest that women are better able to cope with the effects of sleep deprivation than men. Conclusion: Postural control system is very important in sport and in physically active people. The results show that men are more sensitive to sleep deprivation than women because they had higher COP (center of pressure) values in tests. Less postural stability of the body due to sleep deprivation indicates a higher risk of injury during physical activity.

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Stroboscopic Vision as a Dynamic Sensory Reweighting Alternative to the Sensory Organization Test

Journal of Sport Rehabilitation ◽

10.1123/jsr.2019-0466 ◽

2021 ◽

Vol 30 (1) ◽

pp. 166-172

Author(s):

Kyung-Min Kim ◽

Joo-Sung Kim ◽

Jeonghoon Oh ◽

Dustin R. Grooms

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Center Of Pressure ◽

Postural Instability ◽

Clinical Test ◽

Sensory Organization Test ◽

Sensory Organization ◽

Unstable Surface ◽

Significant Difference ◽

The Difference

Context: The sensory organization test (SOT) is a standard for quantifying sensory dependence via sway-referenced conditions (sway-referenced support and sway-referenced vision [SRV]). However, the SOT is limited to expensive equipment. Thus, a practical version of the SOT is more commonly employed—the clinical test for sensory integration in balance; however, it fails to induce postural instability to the level of SRV. Objective: Determine if Stroboscopic vision (SV), characterized by intermittent visual blocking, may provide an alternative to the SRV for assessing postural stability. Design: Descriptive laboratory study. Setting: Research laboratory. Participants: Eighteen participants (9 males, 9 females; age = 22.1 [2.1] y, height = 169.8 [8.5] cm, weight = 66.5 [10.6] kg). Intervention: Participants completed the SOT conditions, and then repeated SOT conditions 2 and 5 with SV created by specialized eyewear. Main Outcome Measures: A repeated-measures analysis of variance was completed on the time-to-boundary metrics of center-of-pressure excursion in the anteroposterior and mediolateral directions in order to determine the difference between the full-vision, SV, and SRV conditions. Results: Postural stability with either SRV or SV was significantly worse than with full vision (P < .05), with no significant difference between SV and SRV (P > .05). Limits of agreement analysis revealed similar effects of SV and SRV except for unstable surface mediolateral time-to-boundary. Conclusions: In general, SV was found to induce a degree of postural instability similar to that induced by SRV, indicating that SV could be a portable and relatively inexpensive alternative for the assessment of sensory dependence and reweighting.

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The Influence of Proprioceptive Training with the Use of Virtual Reality on Postural Stability of Workers Working at Height

Sensors ◽

10.3390/s20133731 ◽

2020 ◽

Vol 20 (13) ◽

pp. 3731

Author(s):

Magdalena Cyma-Wejchenig ◽

Jacek Tarnas ◽

Katarzyna Marciniak ◽

Rafał Stemplewski

Keyword(s):

Virtual Reality ◽

Dual Task ◽

Postural Stability ◽

Center Of Pressure ◽

Force Plate ◽

Control Group ◽

Eyes Closed ◽

Proprioceptive Training ◽

Eyes Open ◽

The Impact

The aim of the study was to assess the impact of proprioceptive training with the use of virtual reality (VR) on the level of postural stability of high–altitude workers. Twenty-one men working at height were randomly assigned to the experimental group (EG) with training (n = 10) and control group (CG) without training (n = 11). Path length of the displacement of the center of pressure (COP) signal and its components in the anteroposterior and medial–lateral directions were measured with use of an AccuGaitTM force plate before and after intervention (6 weeks, 2 sessions × 30 min a week). Tests were performed at two different platform heights, with or without eyes open and with or without a dual task. Two–way ANOVA revealed statistically significant interaction effects for low–high threat, eyes open-eyes closed, and single task-dual task. Post-training values of average COP length were significantly lower in the EG than before training for all analyzed parameters. Based on these results, it can be concluded that the use of proprioceptive training with use of VR can support, or even replace, traditional methods of balance training.

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Role of Occupational Footwear and Prolonged Walking on Lower Extremity Muscle Activation during Maximal Exertions and Postural Stability Tasks

Biomechanics ◽

10.3390/biomechanics1020017 ◽

2021 ◽

Vol 1 (2) ◽

pp. 202-213

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Alana J. Turner ◽

Reuben F. Burch V ◽

Adam C. Knight ◽

...

Keyword(s):

Lower Extremity ◽

Muscle Activity ◽

Repeated Measures ◽

Postural Stability ◽

Muscle Activation ◽

Medial Gastrocnemius ◽

Lower Extremity Muscle ◽

Prolonged Duration ◽

The Mean ◽

The Impact

Background: Occupational footwear and a prolonged duration of walking have been previously reported to play a role in maintaining postural stability. The purpose of this paper was to analyze the impact of three types of occupational footwear: the steel-toed work boot (ST), the tactical work boot (TB), and the low-top work shoe (LT) on previously unreported lower extremity muscle activity during postural stability tasks. Methods: Electromyography (EMG) muscle activity was measured from four lower extremity muscles (vastus medialis (VM), medial hamstrings (MH), tibialis anterior (TA), and medial gastrocnemius (MG) during maximal voluntary isometric contractions (MVIC) and during a sensory organization test (SOT) every 30 min over a 4 h simulated workload while wearing ST, TB, and LT footwear. The mean MVIC and the mean and percentage MVIC during each SOT condition from each muscle was analyzed individually using a repeated measures ANOVA at an alpha level of 0.05. Results: Significant differences (p < 0.05) were found for maximal exertions, but this was limited to only the time main effect. No significant differences existed for EMG measures during the SOT. Conclusion: The findings suggest that occupational footwear type does not influence lower extremity muscle activity during both MVIC and SOT. Significantly lower muscle activity during maximal exertions over the course of the 4 h workload was evident, which can be attributed to localized muscular fatigue, but this was not sufficient to impact muscle activity during postural stability tasks.

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