The feasibility of using virtual reality to induce mobility-related anxiety during turning

Walking (and talking) the plank: dual-task performance costs in a virtual balance-threatening environment

We evaluated the effects of engaging in extemporaneous speech in healthy young adults while they walked in a virtual environment meant to elicit low or high levels of mobility-related anxiety. We expected that mobility-related anxiety imposed by a simulated balance threat (i.e., virtual elevation) would impair walking behavior and lead to greater dual-task costs. Altogether, 15 adults (age = 25.6 ± 4.7 yrs, 7 women) walked at their self-selected speed within a VR environment that simulated a low (ground) and high elevation (15 m) setting while speaking extemporaneously (dual-task) or not speaking (single-task). Likert-scale ratings of cognitive and somatic anxiety, confidence, and mental effort were evaluated and gait speed, step length, and step width, as well as the variability of each, was calculated for every trial. Silent speech pauses (> 150 ms) were determined from audio recordings to infer the cognitive costs of extemporaneous speech planning at low and high virtual elevation. Results indicated that the presence of a balance threat and the inclusion of a concurrent speech task both perturbed gait kinematics, but the virtual height illusion led to increased anxiety and mental effort and a decrease in confidence. The extemporaneous speech pauses were longer on average when walking, but no effects of virtual elevation were reported. Trends toward interaction effects arose in self-reported responses, with participants reporting more comfort walking at virtual heights if they engaged in extemporaneous speech. Walking at virtual elevation and while talking may have independent and significant effects on gait; both effects were robust and did not support an interaction when combined (i.e., walking and talking at virtual heights). The nature of extemporaneous speech may have distracted participants from the detrimental effects of walking in anxiety-inducing settings.

The effects of trait and state anxiety on gait in healthy young adults

Stable, personality-based (trait), and fluctuating, situational (state) anxiety have both been shown to consume attentional resources and reduce functional cognitive capacity, which may play a role in gait control. However, the role of attention in the relationship between trait and state anxiety has not yet been investigated formally. This study used a virtual reality-threat environment to evaluate whether changes in attention mediate the effects of state and trait anxiety on gait. Thirty adults aged 19-28 completed five walking trials in four conditions: (i) low threat-walking across a virtual plank (0.5 m wide) on flat ground; (ii) low threat + dual task (auditory digit monitoring); (iii) high threat-walking across a virtual plank elevated above a deep pit; and (iv) high threat + dual task. Trait anxiety levels were determined by the State-Trait Anxiety Inventory, while state anxiety was captured using self-assessment manikins. Higher trait anxiety predicted slower gait velocity and longer time in double support in the high-threat condition compared to low-threat condition (i vs iii), but not when dual tasking, compared to single-task walking, in the absence of threat (ii vs i). Additionally, higher trait anxiety predicted increased step length variability in the high compared to low-threat dual-task condition. Overall, trait anxiety predicts a slower, more cautious gait pattern during threatening conditions while dual tasking during the threat.

Quantifying Turning Tasks With Wearable Sensors: A Reliability Assessment

OBJECTIVE

The aim of this study was to establish the test-retest reliability of metrics obtained from wearable inertial sensors that reflect turning performance during tasks designed to imitate various turns in daily activity.

METHODS

Seventy-one adults who were healthy completed 3 turning tasks: a 1-minute walk along a 6-m walkway, a modified Illinois Agility Test (mIAT), and a complex turning course (CTC). Peak axial turning and rotational velocity (yaw angular velocity) were extracted from wearable inertial sensors on the head, trunk, and lumbar spine. Intraclass correlation coefficients (ICCs) were established to assess the test-retest reliability of average peak turning speed for each task. Lap time was collected for reliability analysis as well.

RESULTS

Turning speed across all tasks demonstrated good to excellent reliability, with the highest reliability noted for the CTC (45-degree turns: ICC = 0.73-0.81; 90-degree turns: ICC = 0.71-0.83; and 135-degree turns: ICC = 0.72-0.80). The reliability of turning speed during 180-degree turns from the 1-minute walk was consistent across all body segments (ICC = 0.74-0.76). mIAT reliability ranged from fair to excellent (end turns: ICC = 0.52-0.72; mid turns: ICC = 0.50-0.56; and slalom turns: ICC = 0.66-0.84). The CTC average lap time demonstrated good test-retest reliability (ICC = 0.69), and the mIAT average lap time test-retest reliability was excellent (ICC = 0.91).

CONCLUSION

Turning speed measured by inertial sensors is a reliable outcome across a variety of ecologically valid turning tasks that can be easily tested in a clinical environment.

IMPACT

Turning performance is a reliable and important measure that should be included in clinical assessments and clinical trials.

Use of Virtual Reality-Based Games to Improve Balance and Gait of Children and Adolescents with Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis

BACKGROUND

Children and adolescents with sensorineural hearing loss (SNHL) often experience motor skill disturbances, particularly in balance and gait, due to potential vestibular dysfunctions resulting from inner ear damage. Consequently, several studies have proposed the use of virtual reality-based games as a technological resource for therapeutic purposes, aiming to improve the balance and gait of this population.

OBJECTIVE

The objective of this systematic review is to evaluate the quality of evidence derived from randomized or quasi-randomized controlled trials that employed virtual reality-based games to enhance the balance and/or gait of children and adolescents with SNHL.

METHODS

A comprehensive search was conducted across nine databases, encompassing articles published in any language until 1 July 2023. The following inclusion criteria were applied: randomized or quasi-randomized controlled trials involving volunteers from both groups with a clinical diagnosis of bilateral SNHL, aged 6-19 years, devoid of physical, cognitive, or neurological deficits other than vestibular dysfunction, and utilizing virtual reality-based games as an intervention to improve balance and/or gait outcomes.

RESULTS

Initially, a total of 5984 articles were identified through the searches. Following the removal of duplicates and screening of titles and abstracts, eight studies remained for full reading, out of which three trials met the eligibility criteria for this systematic review. The included trials exhibited a very low quality of evidence concerning the balance outcome, and none of the trials evaluated gait. The meta-analysis did not reveal significant differences in balance improvement between the use of traditional balance exercises and virtual reality-based games for adolescents with SNHL (effect size: -0.48; [CI: -1.54 to 0.57]; p = 0.37; I² = 0%).

CONCLUSION

Virtual reality-based games show promise as a potential technology to be included among the therapeutic options for rehabilitating the balance of children and adolescents with SNHL. However, given the methodological limitations of the trials and the overall low quality of evidence currently available on this topic, caution should be exercised when interpreting the results of the trials analyzed in this systematic review.

The Walls Are Closing In: Postural Responses to a Virtual Reality Claustrophobic Simulation

Background: Changes in the visual environment and thereby, the spatial orientation, can induce postural instability leading to falls. Virtual reality (VR) has been used to expose individuals to virtual environments (VE) that increase postural threats. Claustrophobia is an anxiety disorder categorized under situational phobias and can induce such postural threats in a VE. Purpose: The purpose of the study was to investigate if VR-generated claustrophobic simulation has any impact on postural threats that might lead to postural instability. Methods: Thirty healthy men and women (age: 20.7 ± 1.2 years; height: 166.5 ± 7.3 cm; mass: 71.7 ± 16.2 kg) were tested for postural stability while standing on a force platform, upon exposure to five different testing trials, including a normal stance (NoVR), in stationary VE (VR), and three consecutive, randomly initiated, unexpected claustrophobia trials (VR CP1, VR CP2, VR CP3). The claustrophobia trials involved all four walls closing in towards the center of the room. Center of pressure (COP)-derived postural sway variables were analyzed with a one-way repeated measures analysis of variance at an alpha level of 0.05. Results: Significant main effect differences existed in all but one dependent COP-derived postural sway variables, at p < 0.05. Post-hoc pairwise comparisons with a Bonferroni correction revealed that, predominantly, postural sway excursions were significantly lower in claustrophobia trials compared to NoVR and VR, but only accomplished with significantly increased sway velocity. Conclusion: The VR CP trials induced lower postural sway magnitude, but with increased velocity, suggesting a bracing and co-contraction strategy when exposed to virtual claustrophobic postural threats. Additionally, postural sway decreased with subsequent claustrophobia trials, suggesting potential motor learning effects. Findings from the study offer insights to postural control behavior under virtual claustrophobic simulations and can aid in VR exposure therapy for claustrophobia.

Identifying Individuals Who Currently Report Feelings of Anxiety Using Walking Gait and Quiet Balance: An Exploratory Study Using Machine Learning

Literature suggests that anxiety affects gait and balance among young adults. However, previous studies using machine learning (ML) have only used gait to identify individuals who report feeling anxious. Therefore, the purpose of this study was to identify individuals who report feeling anxious at that time using a combination of gait and quiet balance ML. Using a cross-sectional design, participants (n = 88) completed the Profile of Mood Survey-Short Form (POMS-SF) to measure current feelings of anxiety and were then asked to complete a modified Clinical Test for Sensory Interaction in Balance (mCTSIB) and a two-minute walk around a 6 m track while wearing nine APDM mobility sensors. Results from our study finds that Random Forest classifiers had the highest median accuracy rate (75%) and the five top features for identifying anxious individuals were all gait parameters (turn angles, variance in neck, lumbar rotation, lumbar movement in the sagittal plane, and arm movement). Post-hoc analyses suggest that individuals who reported feeling anxious also walked using gait patterns most similar to older individuals who are fearful of falling. Additionally, we find that individuals who are anxious also had less postural stability when they had visual input; however, these individuals had less movement during postural sway when visual input was removed.

Between-site equivalence of turning speed assessments using inertial measurement units

BACKGROUND

Turning is a component of gait that requires planning for movement of multiple body segments and the sophisticated integration of sensory information from the vestibular, visual, and somatosensory systems. These aspects of turning have led to growing interest to quantify turning in clinical populations to characterize deficits or identify disease progression. However, turning may be affected by environmental differences, and the degree to which turning assessments are comparable across research or clinical sites has not yet been evaluated.

RESEARCH QUESTION

The aim of this study was to determine the extent to which peak turning speeds are equivalent between two sites for a variety of mobility tasks.

METHODS

Data were collected at two different sites using separate healthy young adult participants (n = 47 participants total), but recruited using identical inclusion and exclusion criteria. Participants at each site completed three turning tasks: a one-minute walk (1 MW) along a six-meter walkway, a modified Illinois Agility Test (mIAT), and a custom clinical turning course (CCTC). Peak yaw turning speeds were extracted from wearable inertial sensors on the head, trunk, and pelvis. Between-site differences and two one-sided tests (TOST) were used to determine equivalence between sites, based on a minimum effect size reported between individuals with mild traumatic brain injury and healthy control subjects.

RESULTS

No outcomes were different between sites, and equivalence was determined for 6/21 of the outcomes. These findings suggest that some turning tasks and outcome measures may be better suited for multi-site studies. The equivalence results are also dependent on the minimum effect size of interest; nearly all outcomes were equivalent across sites when larger minimum effect sizes of interest were used.

SIGNIFICANCE

Together, these results suggest some tasks and outcome measures may be better suited for multi-site studies and literature-based comparisons.

Fear of falling and falls in people with multiple sclerosis: A literature review

INTRODUCTION

Fear of falling (FOF) is a widespread problem affecting about 60% of people with multiple sclerosis (pwMS). Inflammatory lesions in the brain that are caused by the disease result in gait deficits and increase the risk of fall. Falls induce fear of falling and trigger a vicious circle, which in turn increases the likelihood of falling. Objective of this review was to provide an overview of existing research on the effects of FOF and therapy options in multiple sclerosis.

METHODS

A systematic search at Web of Science and PubMed was conducted. The search included the terms (fear of falling) OR (concern about falling) OR (fall anxiety) AND (multiple sclerosis).

RESULTS

In included studies, FOF was measured by different instruments. The Falls Efficacy Scale-International (FES-I) was the most frequently used instrument for pwMS. Patients with a higher FOF score fell more frequently, had lower walking speed, shorter stride length, larger ellipse sway area and a more severe disability. At present, therapeutic offers exist mainly in the field of physiotherapy. For reducing FOF, assisted vibration (d_z = 0.68), VR (d_z =0.87) and bicycle training (d_z = 1.23) were the most effective methods.

CONCLUSION

It is advisable to develop therapies that incorporate both physical and psychological aspects in neurorehabilitation, like in a cognitive behavioral therapy. Moreover, FOF monitoring should be integrated into the clinical routine.

The direction of postural threat alters balance control when standing at virtual elevation

Anxiogenic settings lead to reduced postural sway while standing, but anxiety-related balance may be influenced by the location of postural threat in the environment. We predicted that the direction of threat would elicit a parallel controlled manifold relative to the standing surface, and an orthogonal uncontrolled manifold during standing. Altogether, 14 healthy participants (8 women, mean age = 27.5 years, SD = 8.2) wore a virtual reality (VR) headset and stood on a matched real-world walkway (2 m × 40 cm × 2 cm) for 30 s at ground level and simulated heights (elevated 15 m) in two positions: (1) parallel to walkway, lateral threat; and (2) perpendicular to walkway, anteroposterior threat. Inertial sensors measured postural sway acceleration (e.g., 95% ellipse, root mean square (RMS) of acceleration), and a wrist-worn monitor measured heart rate coefficient of variation (HR CV). Fully factorial linear-mixed effect regressions (LMER) determined the effects of height and position. HR CV moderately increased from low to high height (p = 0.050, g = 0.397). The Height × Position interaction approached significance for sway area (95% ellipse; β = - 0.018, p = 0.062) and was significant for RMS (β = - 0.022, p = 0.007). Post-hoc analyses revealed that sagittal plane sway accelerations and RMS increased from low to high elevation in parallel standing, but were limited when facing the threat during perpendicular standing. Postural response to threat varies depending on the direction of threat, suggesting that the control strategies used during standing are sensitive to the direction of threat.