Approaching Process in Walking through an Aperture for Individuals with Stroke.

Muroi et al. show that individuals with stroke have improved collision avoidance behavior when passing through an aperture while entering from the paretic-side of the body. However, the underlying mechanism remains unknown. We reanalyzed Muroi et al.'s data to reveal how individuals with stroke walk through an aperture by examining changes in walking velocity and behavioral complexity (i.e., sample entropy, an index of (ir)regularity of time series, regarded lower entropy as more regular and less complex) by focusing on the approaching process. The results showed that individuals with stroke reduced their walking velocity and behavioral complexity before passing through the narrow aperture when approaching from the paretic side. We interpreted that the improved obstacle avoidance when penetrating from the paretic side may be due to careful body rotation and adjusting the walking velocity in advance.

Unilateral spatial neglect affected by right-sided stimuli in a three-dimensional virtual environment: A preliminary proof-of-concept study.

Unilateral spatial neglect (USN) is defined as the inability to attend and see on one side, which seriously interferes with daily life. Clinically, patients with left USN commonly demonstrate a striking immediate capture of attention from ipsilesional, right-sided items as soon as a visual scene unfolds (i.e., magnetic attraction [MA]). Therefore, this preliminary study utilized a three-dimensional (3D) virtual environment to evaluate the effects of eliminating stimuli in the rightward space and directing attention to the left on neglect symptoms. METHODS: Seven patients with USN participated in this study, and two types of visual stimuli were created: the numbers and objects in the 3D virtual environment. To eliminate the visual stimuli on the right side, a moving slit was introduced in the virtual environment. During the experiment, patients were required to orally identify each object and number both in moving and nonmoving slit conditions. RESULTS: A statistical comparison of scores with and without the moving slit in the 3D virtual space indicated significant changes in the object stimuli condition; however, no statistically significant difference was observed in the number stimuli condition. CONCLUSIONS: Masking the right side within the 3D virtual space increased the number of objects that can be recognized on the left side by patients with USN. The results may allow interventions in a virtual reality environment that closely resembles the patient's real-life space.Clinical Relevance-Magnetic attraction is a symptom seen in patients in clinical practice, but there is no method of rehabilitation. The proposed moving slit method is expected to be effective because it enables attention guidance in a three-dimensional space.

Training for walking through an opening improves collision avoidance behavior in subacute patients with stroke: a randomized controlled trial.

PURPOSE: Paretic side collisions frequently occur in stroke patients, especially while walking through narrow spaces. We determined whether training for walking through an opening (T-WTO) while entering from the paretic side would improve collision avoidance behavior and prevent falls after 6 months. MATERIALS AND METHODS: Thirty-eight adults with moderate-to-mild hemiparetic gait after stroke who were hospitalized in a rehabilitation setting were randomly allocated to the T-WTO (n = 20) or regular rehabilitation (R-Control; n = 18) program. Both groups received five sessions of 40 min per week, for three weeks total. T-WTO included walking through openings of various widths while rotating with the paretic side in front, and R-Control involved normal walking without body rotation. Obstacle avoidance ability, 10-m walking test, timed Up and Go test, Berg Balance Scale, Activities-specific Balance Confidence, the perceptual judgment of passability, and fall incidence were assessed. RESULTS: Collision rate and time to passage of the opening in obstacle avoidance task significantly improved in the T-WTO group compared with those in the R-Control group. Contrast, T-WTO did not lead to significant improvements in other outcomes. CONCLUSIONS: T-WTO improved efficiency and safety in managing subacute stroke patients. Such training could improve patient outcomes/safety because of the paretic body side during walking. CLINICAL TRIAL REGISTRATION NO.: R000038375 UMIN000033926.

Individuals with stroke often collide with the paretic side while walking through narrow spaces.Training for walking through a narrow opening from the paretic side improved an individual's ability to avoid obstacles in similar tasks.Moreover, such training could improve patient outcomes/safety because such interventions may temporarily increase attentional focus to the paretic side in specific tasks.

Pathophysiological and motor factors associated with collision avoidance behavior in individuals with stroke.

BACKGROUND: High collision rates and frequency of entering the opening from non-paretic sides are associated with collision in individuals with stroke. OBJECTIVE: To identify factors associated with collision avoidance behavior when individuals with stroke walked through narrow openings. METHODS: Participants with subacute or chronic stroke walked through a narrow opening and had to avoid colliding with obstacles. Multiple regression analyses were conducted with pathophysiology, motor function, and judgment ability as predictor variables; collision rate and frequency of entering the opening from non-paretic sides were outcome variables. RESULTS: Sixty-one eligible individuals with stroke aged 63±12 years were enrolled. Thirty participants collided twice or more and 37 entered the opening from the non-paretic side. Higher collision occurrence was associated with slower Timed Up and Go tests and left-right sway (odds ratios, 1.2 and 5.6; 95% confidence intervals, 1.1-1.3 and 1.3-28.2; p = .008 and.025, respectively). Entering from non-paretic sides was associated with lesions in the thalamus, left-sided hemiplegia, and Brunnstrom stage 3 or lower (odds ratios, 6.6, 8.7, and 6.7; 95% confidence intervals, 1.3-52.5, 2.5-36.5, and 1.2-57.5; and p = .038,.001, and.048, respectively). CONCLUSION: Walking ability is associated with avoiding obstacle collision, while pathophysiological characteristics and degree of paralysis are associated with a preference for which side of the body enters an opening first. Interventions to improve walking ability may improve collision avoidance. Avoidance behavior during intervention varies depending on the lesion position.

Walking through a narrow opening improves collision avoidance behavior in a patient with stroke and unilateral spatial neglect: an ABA single-case design.

We investigated the effect of a 3-week intervention-wherein a patient with unilateral spatial neglect walks through a narrow opening while entering from the contralesional side-to improve walking ability or ADL. A 66-year-old man was diagnosed with right parietal subcortical hemorrhage. We used an ABA single-case design; period B was set as the intervention. The intervention improved the continuous walking distance and balance ability and decreased the number of collisions when walking through the narrow opening; however, it exerted minimal effect on ADL. Thus, the intervention may effectively improve continuous physical or spatial attention behavior, regardless of ADL improvement.

Walking through an aperture while penetrating from the paretic side improves safety managing the paretic side for individuals with stroke who had previous falls.

BACKGROUND: Safety management of the paretic side of the body is critical for individuals with stroke. We previously reported that individuals with stroke who walk through an aperture while penetrating from the paretic side had fewer collisions with the frame of an aperture than did those penetrating from the non-paretic side. We observed spontaneous behavior of collision avoidance in our previous study; this study thus used penetration from the paretic and non-paretic sides as independent variables to confirm the usefulness of penetrating from the paretic side. OBJECTIVE: This study aimed to (1) reconfirm whether walking through a narrow space while penetrating from the paretic side leads to reduced frequency of collision only for individuals with stroke with previous falls by manipulating the direction of penetration as independent variables and to (2) determine whether the behavioral or cognitive characteristics of passing through the aperture are observed in individuals with stroke who had previous falls. METHODS: Individuals with stroke (12 with previous falls, 13 without) were required to walk through a narrow space while penetrating from the paretic and non-paretic sides. The collision rate and kinematic characteristics at the moment of crossing the aperture (body rotation angle, deviation of body's midpoint, and movement speed) were recorded as dependent variables. We also confirmed whether the participants expected collision after passing. RESULTS: Individuals with stroke with previous falls were less likely to have a collision when penetrating from the paretic side. The stroke fall group was likely to experience more collisions because of deleterious changes in body rotation angle and movement speed in narrow apertures. Moreover, individuals with stroke have many unexpected collisions, but the decline in anticipatory ability was not unique to the stroke fall group. CONCLUSIONS: Penetrating a narrow space from the paretic side improved safety management of the paretic side in patients with previous falls despite poor adjustment to narrow apertures. Penetrating a narrow space from the paretic side may make it easier to view and pay attention to the paretic side.

Investigation of optimal gait speed for motor learning of walking using the vibro-tactile biofeedback system.

In stroke patients, sensory loss often reduces the sensation of ground contact, which impairs motor learning during rehabilitation. In our previous study, we proposed a vibro-tactile biofeedback system (which we called the perception-empathy biofeedback system) for gait rehabilitation. The results of our 9-week pilot clinical test suggested that patients who had reached the autonomous phase in gait learning had difficulty noticing the external vibratory feedback provided by the biofeedback system, leading to ineffective intervention. We considered the possibility that slower walking speed might return the patient to the association phase and allow patients to improve their gait according to the sensory feedback provided. Thus, in this research, a method based on reducing walking speed to guide patients' attention was derived. A pilot clinical trial shows that there is a statistically significant increase of ankle dorsiflexion in the initial contact phase and increase of ankle plantarflexion in the push-off phase after vibro-tactile biofeedback system intervention with speed reduction, compared to intervention without speed reduction. The results suggest that, by reducing their walking speed during intervention, patients return to the association phase and recognize external vibratory feedback, which may result in better intervention effects.Clinical Relevance-This study provides knowledge about the optimal walking speed when using vibro-tactile biofeedback for motor learning in stroke patients.

Obstacle avoidance training for individuals with stroke: a systematic review and meta-analysis.

OBJECTIVES: To accumulate evidence that obstacle avoidance training alone is effective in improving the locomotor ability of individuals with stroke. DESIGN: Systematic review and meta-analysis. SETTING: MEDLINE, EMBASE, CENTRAL, ICTRP and PEDro were searched for related information until December 2018. Two independent reviewers extracted data. Outcome measurement data were subjected to meta-analyses using random-effects models. Data syntheses were conducted using RevMan V.5.3, and the certainty of evidence was determined using the Grading of Recommendations Assessment, Development, and Evaluation approach. PARTICIPANTS: Participants with various types and phases of stroke were included. INTERVENTION: The usual gait training including obstacle avoidance training (interventions of any type, intensity, duration and frequency). PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were gait speed, composite gait ability and objective balance ability. Secondary outcomes were subjective balance ability, gait endurance and fall incidence. RESULTS: Two randomised controlled trials with a total of 49 participants were used as data sources for this study. The obstacle avoidance training (training) group had lower gait speed than the control group (mean difference (MD) 0.03, 95% CI -0.11 to 0.16, p=0.51). Further, the certainty of evidence was very low. The subjective balance ability (Activities-specific Balance Confidence scale) was not significantly different between the training and control groups (MD 6.65, 95% CI -7.59 to 20.89, p=0.36), and it showed very low certainty of evidence. CONCLUSIONS: Obstacle avoidance training may have little or no effect on individuals with stroke. The failure to find the effectiveness of obstacle avoidance training alone is possibly attributable to the insufficient amount of training in the intervention and the lack of well-designed studies that measured relevant outcomes. PROSPERO REGISTRATION NUMBER: CRD42017060691.

Differing effects of an immersive virtual reality programme on unilateral spatial neglect on activities of daily living.

In clinical practice, therapists often encounter cases of unilateral spatial neglect (USN) observed in far and near space. In this case report, immersive virtual reality (VR) technology was adopted as a therapy tool in a patient with stroke with severe near and far space neglect. Neuropsychological tests in near and far space as well as the Catherine Bergego Scale (CBS), as an index of neglect in daily living, were measured preintervention and postintervention. Improvement of neuropsychological tests, particularly in far space, was clearly demonstrated postintervention. However, CBS score did not change postintervention. This may be because the patient unsuccessfully translated these visual search task skills used in far space to activities of daily living. Our findings suggest the potential use of immersive VR technology in patients with USN and highlight the VR programme's limited ability to fully recover a patient's disability in natural settings.

Validation of an immersive virtual reality system for training near and far space neglect in individuals with stroke: a pilot study.

BACKGROUND: Unilateral spatial neglect (USN) is defined as impaired ability to attend and see on one side, and when present, it interferes seriously with daily life. These symptoms can exist for near and far spaces combined or independently, and it is important to provide effective intervention for near and far space neglect. OBJECTIVE: The purpose of this pilot study was to propose an immersive virtual reality (VR) rehabilitation program using a head-mounted display that is able to train both near and far space neglect, and to validate the immediate effect of the VR program in both near and far space neglect. METHODS: Ten USN patients underwent the VR program with a pre-post design and no control. In the virtual environment, we developed visual searching and reaching tasks using an immersive VR system. Behavioral inattention test (BIT) scores obtained pre- and immediate post-VR program were compared. RESULTS: BIT scores obtained pre- and post-VR program revealed that far space neglect but not near space neglect improved promptly after the VR program. This effect for far space neglect was observed in the cancelation task, but not in the line bisection task. CONCLUSIONS: Positive effects of the immersive VR program for far space neglect are suggested by the results of the present pilot study. However, further studies with rigorous designs are needed to validate its clinical effectiveness.

Walking through Apertures in Individuals with Stroke.

OBJECTIVE: Walking through a narrow aperture requires unique postural configurations, i.e., body rotation in the yaw dimension. Stroke individuals may have difficulty performing the body rotations due to motor paralysis on one side of their body. The present study was therefore designed to investigate how successfully such individuals walk through apertures and how they perform body rotation behavior. METHOD: Stroke fallers (n = 10), stroke non-fallers (n = 13), and healthy controls (n = 23) participated. In the main task, participants walked for 4 m and passed through apertures of various widths (0.9-1.3 times the participant's shoulder width). Accidental contact with the frame of an aperture and kinematic characteristics at the moment of aperture crossing were measured. Participants also performed a perceptual judgment task to measure the accuracy of their perceived aperture passability. RESULTS AND DISCUSSION: Stroke fallers made frequent contacts on their paretic side; however, the contacts were not frequent when they penetrated apertures from their paretic side. Stroke fallers and non-fallers rotated their body with multiple steps, rather than a single step, to deal with their motor paralysis. Although the minimum passable width was greater for stroke fallers, the body rotation angle was comparable among groups. This suggests that frequent contact in stroke fallers was due to insufficient body rotation. The fact that there was no significant group difference in the perceived aperture passability suggested that contact occurred mainly due to locomotor factors rather than perceptual factors. Two possible explanations (availability of vision and/or attention) were provided as to why accidental contact on the paretic side did not occur frequently when stroke fallers penetrated the apertures from their paretic side.

Walking through an aperture with visual information obtained at a distance.

The present study addressed whether visual information about the width of an aperture, obtained at a distance, would be sufficient to guide walking through the aperture without collision. For this purpose, we asked twelve young participants to walk while holding a 66-cm horizontal bar (bar length needs to be considered in order to perceive space necessary for crossing) and pass through an aperture without vision from 3 m in front of the aperture. Participants performed the tasks under each of four visual conditions, which differed in how vision was available: observation for 1.5 s while standing (static vision), observation during two forward steps and stopping (dynamic vision), observation during two forward steps and not stopping (dynamic vision with nonstop walking), and full vision. The results showed that, for narrow apertures (the widths were 0.8 and 1.0 times the bar length), the rate of collision without vision was about 40-50 %. This was mainly due to the maladaptive planning of body rotation. For the aperture 1.0 times the bar length, the percentage of trials with no body rotation was high, suggesting that at least some participants underestimated the space necessary for crossing. The location at which maximum body rotation occurred became farther from the obstacle, which may have been related to decreased movement speed. The availability of dynamic visual sampling during two forward steps did not contribute to improving collision avoidance. These results suggest that, while fundamental locomotor patterns are maintained even without online vision, both the underestimation of space required for crossing and the lack of fine-tuning of behavior prior to crossing increased collision rates.