A Study on Visual Perturbations Effect on Balance in a VR Environment

Author(s):  
Markus Santoso ◽  
David Phillips

Users sometimes lost their balance or even fell down when they played virtual reality (VR) games or projects. This may be attributed to degree of content, high-rate of latency, coordination of various sensory inputs, and others. The authors investigated the effect of sudden visual perturbations on human balance in VR environment. This research used the latest VR head mounted display to present visual perturbations to disturb balance. To quantify balance, measured by double-support and single-support stance, the authors measured the subject's center of pressure (COP) using a force plate. The results indicated that visual perturbations presented in virtual reality disrupted balance control in the single support condition but not in the double support condition. Results from this study can be applied to clinical research on balance and VR environment design.

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Hossein Talebi ◽  
Mohammad Taghi Karimi ◽  
Seyed Hamid Reza Abtahi ◽  
Niloofar Fereshtenejad

Aims. Vestibular system is indicated as one of the most important sensors responsible for static and dynamic postural control. In this study, we evaluated static balance in patients with unilateral vestibular impairments.Materials and Methods. We compared static balance control using Kistler force plate platform between 10 patients with unilateral vestibular impairments and 20 normal counterparts in the same sex ratio and age limits (50±7). We evaluated excursion and velocity of center of pressure (COP) and path length in anteroposterior (AP) and mediolateral (ML) planes with eyes open and with eyes closed.Results. There was no significant difference between COP excursions in ML and AP planes between both groups with eyes open and eyes closed (pvalue > 0.05). In contrast, the difference between velocity and path length of COP in the mentioned planes was significant between both groups with eyes open and eyes closed (pvalue < 0.05).Conclusions. The present study showed the static instability and balance of patients with vestibular impairments indicated by the abnormal characteristics of body balance.


Author(s):  
Dorota Borzucka ◽  
Krzysztof Kręcisz ◽  
Zbigniew Rektor ◽  
Michał Kuczyński

Abstract Background The aim of this study was to compare the postural control of the Poland national women’s volleyball team players with a control group of non-training young women. It was hypothesized that volleyball players use a specific balance control strategy due to the high motor requirements of their team sport. Methods Static postural sway variables were measured in 31 athletes and 31 non-training women. Participants were standing on a force plate with eyes open, and their center of pressure signals were recorded for the 20s with the sampling rate of 20 Hz in the medial-lateral (ML) and anterior-posterior (AP) planes. Results In both AP and ML planes, athletes had lower range and higher fractal dimension of the COP. They had also higher peak frequency than control group in the ML plane only. The remaining COP indices including variability, mean velocity and mean frequency did not display any intergroup differences. Conclusion It can be assumed that due to the high motor requirements of their sport discipline Polish female volleyball players have developed a unique posture control. On the court they have to distribute their sensory resources optimally between balance control and actions resulting from the specifics of the volleyball game. There are no clearly defined criteria for optimal postural strategies for elite athletes, but they rather vary depending on a given sport. The results of our research confirm this claim. Trial registration The tests were previously approved by the Bioethical Commission of the Chamber of Physicians in Opole. (Resolution No. 151/13.12.2007). This study adheres to the CONSORT guidelines.


2020 ◽  
Vol 55 (5) ◽  
pp. 488-493 ◽  
Author(s):  
Robert C. Lynall ◽  
Kody R. Campbell ◽  
Timothy C. Mauntel ◽  
J. Troy Blackburn ◽  
Jason P. Mihalik

Context Researchers have suggested that balance deficiencies may linger during functional activities after concussion recovery. Objective To determine whether participants with a history of concussion demonstrated dynamic balance deficits as compared with control participants during single-legged hops and single-legged squats. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants A total of 15 previously concussed participants (6 men, 9 women; age = 19.7 ± 0.9 years, height = 169.2 ± 9.4 cm, mass = 66.0 ± 12.8 kg, median time since concussion = 126 days [range = 28–432 days]) were matched with 15 control participants (6 men, 9 women; age = 19.7 ± 1.6 years, height = 172.3 ± 10.8 cm, mass = 71.0 ± 10.4 kg). Intervention(s) During single-legged hops, participants jumped off a 30-cm box placed at 50% of their height behind a force plate, landed on a single limb, and attempted to achieve a stable position as quickly as possible. Participants performed single-legged squats while standing on a force plate. Main Outcome Measure(s) Time to stabilization (TTS; time for the normalized ground reaction force to stabilize after landing) was calculated during the single-legged hop, and center-of-pressure path and speed were calculated during single-legged squats. Groups were compared using analysis of covariance, controlling for average days since concussion. Results The concussion group demonstrated a longer TTS than the control group during the single-legged hop on the nondominant leg (mean difference = 0.35 seconds [95% confidence interval = 0.04, 0.64]; F2,27 = 5.69, P = .02). No TTS differences were observed for the dominant leg (F2,27 = 0.64, P = .43). No group differences were present for the single-legged squat on either leg (P ≥ .11). Conclusions Dynamic balance-control deficits after concussion may contribute to an increased musculoskeletal injury risk. Given our findings, we suggest that neuromuscular deficits currently not assessed after concussion may linger. Time to stabilization is a clinically applicable measure that has been used to distinguish patients with various pathologic conditions, such as chronic ankle instability and anterior cruciate ligament reconstruction, from healthy control participants. Whereas the single-legged squat may not sufficiently challenge balance control, future study of the more dynamic single-legged hop is needed to determine its potential diagnostic and prognostic value after concussion.


2020 ◽  
Author(s):  
Matthew William Wittstein ◽  
Anthony Crider ◽  
Samantha Mastrocola ◽  
Mariana Guerena Gonzalez

BACKGROUND The Equitest system (Neurocom) is a computerized dynamic posturography device used by health care providers and clinical researchers to safely test an individual’s postural control. While the Equitest system has evaluative and rehabilitative value, it may be limited owing to its cost, lack of portability, and reliance on only sagittal plane movements. Virtual reality (VR) provides an opportunity to reduce these limitations by providing more mobile and cost-effective tools while also observing a wider array of postural characteristics. OBJECTIVE This study aimed to test the plausibility of using VR as a feasible alternative to the Equitest system for conducting a sensory organization test. METHODS A convenience sample of 20 college-aged healthy individuals participated in the study. Participants completed the sensory organization test using the Equitest system as well as using a VR environment while standing atop a force plate (Bertec Inc). The Equitest system measures the equilibrium index. During VR trials, the estimated equilibrium index, 95% ellipse area, path length, and anterior-posterior detrended fluctuation analysis scaling exponent alpha were calculated from center of pressure data. Pearson correlation coefficients were used to assess the relationship between the equilibrium index and center of pressure–derived balance measures. Intraclass correlations for absolute agreement and consistency were calculated to compare the equilibrium index and estimated equilibrium index. RESULTS Intraclass correlations demonstrated moderate consistency and absolute agreement (0.5 &lt; intraclass correlation coefficient &lt; 0.75) between the equilibrium index and estimated equilibrium index from the Equitest and VR sensory organization test (SOT), respectively, in four of six tested conditions. Additionally, weak to moderate correlations between force plate measurements and the equilibrium index were noted in several of the conditions. CONCLUSIONS This research demonstrated the plausibility of using VR as an alternative method to conduct the SOT. Ongoing development and testing of virtual environments are necessary before employing the technology as a replacement to current clinical tests.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0258000
Author(s):  
Shaquitta Dent ◽  
Kelley Burger ◽  
Skyler Stevens ◽  
Benjamin D. Smith ◽  
Jefferson W. Streepey

Movement of the visual environment presented through virtual reality (VR) has been shown to invoke postural adjustments measured by increased body sway. The effect of auditory information on body sway seems to be dependent on context with sounds such as white noise, tones, and music being used to amplify or suppress sway. This study aims to show that music manipulated to match VR motion further increases body sway. Twenty-eight subjects stood on a force plate and experienced combinations of 3 visual conditions (VR translation in the AP direction at 0.1 Hz, no translation, and eyes closed) and 4 music conditions (Mozart’s Jupiter Symphony modified to scale volume at 0.1 Hz and 0.25 Hz, unmodified music, and no music) Body sway was assessed by measuring center of pressure (COP) velocities and RMS. Cross-coherence between the body sway and the 0.1 Hz and 0.25 Hz stimuli was also determined. VR translations at 0.1 Hz matched with 0.1Hz shifts in music volume did not lead to more body sway than observed in the no music and unmodified music conditions. Researchers and clinicians may consider manipulating sound to enhance VR induced body sway, but findings from this study would not suggest using volume to do so.


Author(s):  
Cadence M Baker ◽  
Gordon E Barkwell

Introduction: The purpose of the present study was to compare the balance performance of control subjects and varsity figure skaters after spinning on a turntable for 6 seconds. It was hypothesized figure skaters would demonstrate better balance control after spinning. Methods: 9 female figure skaters and 9 female control subjects stood as still as possible for 15 seconds on a Kistler force plate during both a control condition and after spinning for 6 seconds on a turntable. Balance performance was quantified by the percentage of total time the center of pressure (CoP) was within a 5mm radius of the center of their base of support (BoS). Results: In the control condition, figure skaters and control participants did not have significantly different balance ability. In the post-spin condition, figure skaters were significantly better at maintaining their CoP within a smaller area. Conclusions: These results are valuable from a training and coaching perspective because they suggest that balance performance after spinning can be improved with training.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jozef Púčik ◽  
Marián Šaling ◽  
Tomáš Lukáč ◽  
Oldřich Ondráček ◽  
Martin Kucharík

Ability of humans to maintain balance in an upright stance and during movement activities is one of the most natural skills affecting everyday life. This ability progressively deteriorates with increasing age, and balance impairment, often aggravated by age-related diseases, can result in falls that adversely impact the quality of life. Falls represent serious problems of health concern associated with aging. Many investigators, involved in different science disciplines such as medicine, engineering, psychology, and sport, have been attracted by a research of the human upright stance. In a clinical practice, stabilometry based on the force plate is the most widely available procedure used to evaluate the balance. In this paper, we have proposed a low-cost extension of the conventional stabilometry by the multimedia technology that allows identifying potentially disturbing effects of visual sensory information. Due to the proposed extension, a stabilometric assessment in terms of line integral of center of pressure (COP) during moving scene stimuli shows higher discrimination power between young healthy and elderly subjects with supposed stronger visual reliance.


2015 ◽  
Vol 4 ◽  
pp. RPO.S20363 ◽  
Author(s):  
Avril Mansfield ◽  
Elizabeth L. Inness

Assessment of balance control is essential to guide physical rehabilitation poststroke. However, current observational assessment tools available to physiotherapists provide limited information about underlying dyscontrol. This paper describes a force plate-based assessment of quiet standing balance control that we have implemented for individuals attending inpatient stroke rehabilitation. The assessment uses two force plates to measure location of ground reaction forces to maintain stability in quiet standing in five conditions (eyes open, eyes closed, standing symmetrically, and maximal loading on the less-affected and more-affected limbs). Measures of interest are variability of the centers of pressure under each foot and both feet combined, weight-bearing asymmetry, and correlation of center of pressure fluctuations between limbs. We present representative values for the above-mentioned measures and case examples to illustrate how the assessment can reveal patient-specific balance control problems and direct treatment. We identify limitations to our current assessment and recommendations for future research.


2018 ◽  
Vol 30 (01) ◽  
pp. 1850014
Author(s):  
Chu-Fen Chang ◽  
Hui-Ji Fan ◽  
Hung-Bin Chen ◽  
Houu-Wooi Lim ◽  
Hsiao-Yuan Lee ◽  
...  

The aim of this study was to investigate the immediate effect of wearing the functional insoles with different slopes of forefoot wedges on postural stability in young adults during quiet stance. In this study, the functional insole was composed of a forefoot wedge and a medial arch support. Twelve healthy young adults (six males and six females) participated. Each subject wore sneakers with and without functional insole and stood as still as possible on a force plate with feet together, arms by side and head facing ahead for 60[Formula: see text]s, while eyes open and eyes closed, respectively. The functional insole was applied in the random sequence of no insole, wearing insole with a medial arch and a four-degree forefoot wedge, as well as wearing insole with a medial arch and an eight-degree forefoot wedge. The sway areas as well as the maximal excursions of the center of pressure (COP) in anterior–posterior (AP) and medial–lateral (ML) directions were used to evaluate the static postural stability. During stance with feet together and eyes closed, the sway area and maximal excursion of the COP in the AP direction were significantly decreased when wearing an eight-degree forefoot wedge functional insole. Since the reduced displacements of the COP indicated better postural control, it was suggested that the functional insole with an eight-degree forefoot wedge and a medial arch support might be beneficial to improve the postural stability in patients with impaired balance control, especially for whom having high risk of forward falls.


2008 ◽  
Vol 17 (1) ◽  
pp. 38-49 ◽  
Author(s):  
Jason P. Mihalik ◽  
Luv Kohli ◽  
Mary C. Whitton

Context:Virtual reality environments may allow researchers to investigate functional balance performance without risks associated with testing in the real world.Objective:To investigate the effects of the mass of a head-mounted display (HMD) on balance performance.Design:Counterbalanced pretest-posttest.Setting:Virtual reality laboratory.Participants:20 healthy college students.Intervention(s):Balance Error Scoring System (BESS) with a tracker-only headband and again with tracker plus HMD was performed.Main Outcome Measures:BESS error scores, elliptical sway area, and center of pressure travel distance were recorded.Results:No effect of the HMD mass on balance performance was observed. A significant stance by surface interaction was present but was negated when the HMD conditions were included in the model.Conclusions:The mass of a HMD has not been proven to adversely affect balance performance. These data suggest the HMD mass is not a contraindication to the use of immersive virtual environments in future concussion research involving balance.


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