Virtual Reality-Based Interventions to Improve Balance in Patients with Traumatic Brain Injury: A Scoping Review.

INTRODUCTION: Virtual reality (VR)-based interventions to improve balance and mobility are gaining increasing traction across patient populations. VR-based interventions are believed to be more enjoyable and engaging for patients with traumatic brain injury. This scoping review aims to summarize existing studies from the literature that used VR to improve balance and mobility and determine the gap in VR-based balance literature specific to individuals with traumatic brain injury. METHODS: Two authors independently searched the literature using the search terms "Virtual Reality Traumatic Brain Injury Lower Limb", "Virtual Reality Traumatic Brain Injury Balance", and "Virtual Reality Traumatic Brain Injury Gait". RESULTS: A total of seventeen studies, specifically, three randomized controlled trials, one one-arm experimental study, two retrospective studies, two case studies, one feasibility/usability study, one cohort study, and seven diagnostic (validation) studies, met the inclusion criteria for this review. The methodological quality of the studies evaluated using the PEDro scale was fair. DISCUSSION: Future studies should focus on large-scale clinical trials using validated technology to determine its effectiveness and dose-response characteristics. Additionally, standard assessment tools need to be selected and utilized across interventional studies aimed at improving balance and mobility to help compare results between studies.

Usability and ease of use of long-term remote monitoring of physical activity for individuals with acquired brain injury in community: a qualitative analysis.

Introduction: Objective and continuous monitoring of physical activity over the long-term in the community is perhaps the most important step in the paradigm shift toward evidence-based practice and personalized therapy for successful community integration. With the advancement in technology, physical activity monitors have become the go-to tools for objective and continuous monitoring of everyday physical activity in the community. While these devices are widely used in many patient populations, their use in individuals with acquired brain injury is slowly gaining traction. The first step before using activity monitors in this population is to understand the patient perspective on usability and ease of use of physical activity monitors at different wear locations. However, there are no studies that have looked at the feasibility and patient perspectives on long-term utilization of activity monitors in individuals with acquired brain injury. Methods: This pilot study aims to fill this gap and understand patient-reported aspects of the feasibility of using physical activity monitors for long-term use in community-dwelling individuals with acquired brain injury. Results: This pilot study found that patients with acquired brain injury faced challenges specific to their functional limitations and that the activity monitors worn on the waist or wrist may be better suited in this population. Discussion: The unique wear location-specific challenges faced by individuals with ABI need to be taken into account when selecting wearable activity monitors for long term use in this population.

Implementing Remote Patient Monitoring of Physical Activity in Clinical Practice.

PURPOSE: Remote patient monitoring (RPM) is a tool for patients to share data collected outside of office visits. RPM uses technology and the digital transmission of data to inform clinician decision-making in patient care. Using RPM to track routine physical activity is feasible to operationalize, given contemporary consumer-grade devices that can sync to the electronic health record. Objective monitoring through RPM can be more reliable than patient self-reporting for physical activity. DESIGN AND METHODS: This article reports on four pilot studies that highlight the utility and practicality of RPM for physical activity monitoring in outpatient clinical care. Settings include endocrinology, cardiology, neurology, and pulmonology settings. RESULTS: The four pilot use cases discussed demonstrate how RPM is utilized to monitor physical activity, a shift that has broad implications for prediction, prevention, diagnosis, and management of chronic disease and rehabilitation progress. CLINICAL RELEVANCE: If RPM for physical activity is to be expanded, it will be important to consider that certain populations may face challenges when accessing digital health services. CONCLUSION: RPM technology provides an opportunity for clinicians to obtain objective feedback for monitoring progress of patients in rehabilitation settings. Nurses working in rehabilitation settings may need to provide additional patient education and support to improve uptake.

A Novel Core Strengthening Intervention for Improving Trunk Function, Balance and Mobility after Stroke.

This paper a novel core-strengthening intervention (CSI) delivered using the AllCore360°, a device that targets trunk muscles through a systematic, high-intensity rotating-plank exercise. Three individuals (age: 61.7 ± 3.2 years; range: 58-64 years) with post-stroke hemiplegia participated in 12-sessions of the CSI. The participants completed up to 142 rotating planks at inclination angles (IAs) that ranged from 40° to 65°, over 12 sessions. The interventional effects on the functional outcomes of trunk performance, balance and mobility were assessed using the Trunk Impairment Scale (TIS), the Berg Balance Scale (BBS), the Timed-Up and Go (TUG) test, the 10-m walk test (10MWT), and the 6-min walk test (6MWT). Postural outcomes were assessed using the center of pressure (CoP) data recorded during quiet standing on a balance platform, and neuromuscular outcomes were assessed using electromyography (EMG) during AllCore360° rotations. All participants completed the CSI (minimum of 120 rotations), demonstrating the feasibility of the CSI in chronic stroke. The CoP data suggested improved lateral control of posture during standing across participants (averaging an over 30% reduction in lateral sway), while the EMG data revealed the ability of the CSI to systematically modulate trunk muscle responses. In summary, the current investigation presents the feasibility of a novel delivery method for core strengthening to maximize rehabilitation outcomes in the chronic phase of stroke.

Wearable devices for tracking physical activity in the community after an acquired brain injury: A systematic review.

OBJECTIVE: The application of wearable devices in individuals with acquired brain injury (ABI) resulting from stroke or traumatic brain injury (TBI) for monitoring physical activity (PA) has been relatively recent. The current systematic review aims to provide insights into the adaption of these devices, the outcome metrics, and their transition from the laboratory to the community for PA monitoring of individuals with ABI. LITERATURE SURVEY: The PubMed and Google Scholar databases were systematically reviewed using appropriate search terms. A total of 20 articles were reviewed from the last 15 years. METHODOLOGY: Articles were classified into three categories: PA measurement studies, PA classification studies, and validation studies. The quality of studies was assessed using a quality appraisal checklist. SYNTHESIS: It was found that the transition of wearable devices from in-lab to community-based studies in individuals with stroke has started but is not widespread. The transition of wearable devices in the community has not yet started for individuals with TBI. Accelerometer-based devices were more frequently chosen than pedometers and inertial measurement units. No consensus on a preferred wearable device (make or model) or wear location could be identified, although step count was the most common outcome metric. The accuracy and validity of most outcome metrics used in the community were not reported for many studies. CONCLUSIONS: To facilitate future studies using wearable devices for PA measurement in the community, we recommend that researchers provide details on the accuracy and validity of the outcome metrics specific to the study environment. Once the accuracy and validity are established for a specific population, wearable devices and their derived outcomes can provide objective information on mobility impairment as well as the effect of rehabilitation in the community.

Predicting physical activity intensity using raw accelerometer signals in manual wheelchair users with spinal cord injury.

STUDY DESIGN: Cross-sectional validation study. OBJECTIVES: The performance of previously published physical activity (PA) intensity cutoff thresholds based on proprietary ActiGraph counts for manual wheelchair users (MWUs) with spinal cord injury (SCI) was initially evaluated using an out-of-sample dataset of 60 individuals with SCI. Two types of PA intensity classification models based on raw accelerometer signals were developed and evaluated. SETTING: Research institutions in Pittsburgh PA, Birmingham AL, and Bronx NY. METHODS: Data were collected from 60 MWUs with SCI who followed a structured activity protocol while wearing an ActiGraph activity monitor on their dominant wrist and portable metabolic cart which measured criterion PA intensity. Data was used to assess published models as well as develop and assess custom models using recall, specificity, precision, as well as normalized Mathew's correlation coefficient (nMCC). RESULTS: All the models performed well for predicting sedentary vs non-sedentary activity, yielding an nMCC of 0.87-0.90. However, all models demonstrated inadequate performance for predicting moderate to vigorous PA (MVPA) with an nMCC of 0.76-0.82. CONCLUSIONS: The mean absolute deviation (MAD) cutoff threshold yielded the best performance for predicting sedentary vs non-sedentary PA and may be used for tracking daily sedentary activity. None of the models displayed strong performance for MVPA vs non-MVPA. Future studies should investigate combining physiological measures with accelerometry to yield better prediction accuracies for MVPA.

Objective evaluation of the risk of falls in individuals with traumatic brain injury: feasibility and preliminary validation.

Falls are a significant health concern for individuals with traumatic brain injury (TBI). For developing effective preemptive strategies to reduce falls, it is essential to get an accurate and objective assessment of fall-risk. The current investigation evaluates the feasibility of a robotic, posturography-based fall-risk assessment to objectively quantify the risk of falls in individuals with TBI. Five individuals with chronic TBI (age: 56.2 ± 4.7 years, time since injury: 13.09±11.95 years) performed the fall-risk assessment on hunova- a commercial robotic platform for assessing and training balance. The unique assessment considers multifaceted fall-driving components, including static and dynamic balance, sit-to-stand, limits of stability, responses to perturbations, gait speed, and history of previous falls and provides a composite score for risk of falls, called silver index (SI), a number between 0 (no risk) and 100 (high risk) based on a machine learning-based predictive model. The SI score for individuals with TBI was 66±32.1 (min: 32, max: 100) - categorized as medium-to-high risk of falls. The construct validity of SI outcome was performed by evaluating its relationship with clinical outcomes of functional balance and mobility (Berg Balance Scale (BBS), Timed-Up and Go (TUG), and gait speed) as well as posturography outcomes (Center of Pressure (CoP) area and velocity). The bivariate Pearson correlation coefficient, although not statistically significant, suggested the presence of linear relationships (0.52 > r > 0.84) between SI and functional and posturography outcomes, supporting the construct validity of SI. A large sample is needed to further prove the validity of the SI outcome before it is used for meaningful interpretations of the risk of falls in individuals with TBI.Clinical Relevance- Clinical assessments of risk of falls are traditionally based on questionnaires that may lack objectivity, consistency, and accuracy. The current work tests the feasibility of using a robotic platform-based assessment to objectively quantify the risk of falls in individuals with TBI.

A Novel Core-Strengthening Program for Improving Trunk Function, Balance and Mobility after Stroke: a Case Study.

The objective of the current investigation was to evaluate the feasibility of a core-strengthening program delivered to a chronic stroke participant using a novel robotic device, AllCore360°, which targets trunk muscles through a systematic, consistent, high-intensity exercise. A 58-year old male with hemiplegia post stroke (time since injury: 18 years) was enrolled and performed 12-sessions of the core-strengthening program on AllCore360°. The participant completed a total of 142 360°-rotating-planks (called as 'spins') at four inclination angles, over 12 sessions. Assessments at baseline and follow up included posturography during quiet standing, electromyography (EMG) during AllCore360° spins, and assessments for trunk function (Trunk Impairment Scale (TIS)), balance (Berg Balance Scale (BBS) and mobility (Timed-Up and Go (TUG), 10-meter Walk test (10MWT), 6-minute Walk Test (6MWT)). Clinically meaningful improvements were observed in the TIS (73%), the BBS (45.2%), and the TUG test (22.7%). Medial-lateral Center of Pressure (MLCoP) data showed reduced RMS and range by 32.3% and 29.2%, respectively. EMG data from left and right rectus abdominis (RAB) muscles showed increased levels of activations for both inclination angles, 65° (LRAB: 74%, RRAB: 48.4%) and 55° (LRAB: 22.3%, RRAB: 28.7%). The participant rated the core-strengthening program 71 (scale: 0-126) on Physical ACtivity Enjoyment Scale at the follow up, showing a high level of satisfaction and engagement toward the training program. The preliminary results suggest that the novel robotic design and enhanced engagement of neuromuscular mechanisms features of AllCore360° core-strengthening program could facilitate improvements in trunk function, balance and mobility post stroke. A study with a large sample and an appropriate control group needs to be performed in the future.Clinical Relevance- The majority of clinical programs include core-stability exercises for improving trunk function. The current investigation presents a novel robotic-device based core-strengthening program that can provide systematic, consistent, and repetitive practice for optimal functional gains.

Balance Control Strategies during Perturbed Standing after a Traumatic Brain Injury: Kinematic Analysis.

The objective of the current investigation was to examine the presence, absence or alteration of fundamental postural control strategies in individuals post traumatic brain injury (TBI) in response to base of support perturbations in the anterior-posterior (AP) direction. Four age-matched healthy controls (age: 46.50 ± 5.45 years) and four individuals diagnosed with TBI (age: 48.50 ± 9.47 years, time since injury: 6.02 ± 4.47 years) performed standing on instrumented balance platform with integrated force plates while 3D motion capture data was collected at 60 Hz. The platform was programmed to move in the AP direction, during a sequence of 5 perturbations delivered in a sinusoidal pattern at a frequency of 1 Hz, with decreasing amplitudes of 10, 8, 6, 4, and 2 mm respectively. The sagittal plane peak-to-peak range and root mean square (RMS) of the hip, knee, and ankle joint angles during the 5 seconds of perturbation were computed from optical motion capture data. The TBI group had a higher mean range (5.17 ± 1.91°) about the ankle compared to the HC group (4.17 ± 0.81°) for the 10mm perturbation, but their mean range was smaller than the HCs for the other 4 conditions. About the hip, the TBI group's mean range was larger than the HC's for all conditions. For both groups, the mean range decreased with perturbation amplitude for all conditions. The TBI group showed larger changes in mean range and RMS values as the amplitude of the perturbation changed, while the HC group showed smaller intertrial changes. The results suggest that the TBI group was substantially more reliant on the hip strategy to maintain balance during the perturbations and this reliance was well linked with perturbation amplitude.Clinical Relevance- Existing information regarding changes in postural control strategies in individuals post TBI is limited. The current work demonstrates lower limb kinematic differences between HC and TBI and some preliminary evidence on increased hip movement in the TBI group.

Accuracy comparison of machine learning algorithms at various wear-locations for activity identification post stroke: A pilot analysis.

Objective and accurate activity identification of physical activities in everyday life is an important aspect in assessing the impact of various post-stroke rehabilitation therapies and interventions. Since post-stroke hemiparesis affects gait and balance in individuals with stroke, activity identification algorithms that consider stroke-specific movement irregularities are needed. While wearable physical activity monitors provide the means to detect activities in the free-living, algorithms using their data are specific to the wear location of the device. This pilot study builds, validates, and compares three machine learning algorithms (linear support vector machine, Random Forest, and RUSBoosted trees) at three popular wear locations (wrist, waist, and ankle) to identify and accurately distinguish mobility-related activities (sitting, standing and walking) in individuals with chronic stroke. A total of 102 minutes of data from two lab visits of three-stroke participants was used to build the classifiers. A 5-fold cross-validation technique was used to validate and compare the accuracy of classifiers. RUSBoosted trees using data from waist and ankle activity monitors, with an accuracy of 99.1%, outperformed other classifiers in detecting three activities of interest.Clinical Relevance- One of the major aims of post-stroke rehabilitation is improving mobility, which may be facilitated by understanding the structure and pattern of everyday mobility through real-world, objective outcomes. Accurate activity identification, as shown in this pilot investigation, is an essential first step before developing objective outcomes for monitoring mobility and balance in everyday life of these individuals.

Enhancing sensory acuity and balance function using near-sensory biofeedback-based perturbation intervention for individuals with traumatic brain injury.

BACGROUND: Interventions addressing balance dysfunction after traumatic brain injury (TBI) only target compensatory aspects and do not investigate perceptual mechanisms such as sensory acuity. OBJECTIVE: To evaluate the efficacy of a novel intervention that integrates sensory acuity with a perturbation-based approach for improving the perception and functional balance after TBI. METHODS: A two-group design was implemented to evaluate the effect of a novel, perturbation-based balance intervention. The intervention group (n = 5) performed the intervention with the sinusoidal (0.33, 0.5, and 1 Hz) perturbations to the base of support with amplitudes derived using our novel outcome of sensory acuity - perturbation perception threshold (PPT). The efficacy is evaluated using changes in PPT and functional outcomes (Berg Balance Scale (BBS), Timed-up and Go (TUG), 5-meter walk test (5MWT), and 10-meter walk test (10MWT)). RESULTS: There was a significant post-intervention change in PPT for 0.33 Hz (p = 0.021). Additionally, clinically and statistically significant improvements in TUG (p = 0.03), 5MWT (p = 0.05), and 10MWT (p = 0.04) were observed. CONCLUSIONS: This study provides preliminary efficacy of a novel, near-sensory balance intervention for individuals with TBI. The use of PPT is suggested for a comprehensive understanding and treatment of balance dysfunction. The promising results support the investigation in a larger cohort.

Augmented-reality guided treadmill training as a modality to improve functional mobility post-stroke: A proof-of-concept case series.

Objective: To provide a proof-of-concept for a novel stroke-gait-specific augmented reality (AR)-guided treadmill intervention by evaluating its effect on temporospatial and functional outcomes of mobility.Methods: Two females with hemiplegia post stroke were recruited for participation in a 4-week intervention, and a single healthy control was recruited for baseline comparisons. The stroke-intervention (SI) participant (aged 54-years), completed 12 sessions of AR-guided treadmill intervention. The stroke-control (SC) participant (aged 59-years) completed 12 sessions of conventional treadmill intervention. Temporospatial and functional mobility were assessed pre-intervention, post-intervention, and at 1-month follow-up. Physical ACtivity Enjoyment Scale (PACES) was administered post-intervention.Results: The SI participant showed clinically meaningful improvements in functional outcomes post-intervention and at 1-month follow-up (Berg balance score (BBS): +6 and +10 points; Dynamic Gait Index (DGI): +2 at post-intervention only; walking speed: +0.19 and +0.24 m/s; 6-minute walk test (6MWT): +51.9 and +38.9) respectively. The SC showed clinically meaningful improvements in BBS (+3 and +3) and walking speed (+0.06 at post-intervention). The PACES scores showed that the SI participant had a significantly higher (23 points) enjoyment level during the intervention compared to the SC participant. The SI participant was more asymmetric compared to the SC participant at pre and post-intervention visits.Conclusions: The SI participant showed greater improvement in functional assessments compared to the SC participant post intervention. The AR-guided approach may have added benefits compared to traditional treadmill training, while providing better customization, patient enjoyment, and engagement. Further investigation with a larger sample is warranted.

Evaluating Sensory Acuity as a Marker of Balance Dysfunction After a Traumatic Brain Injury: A Psychophysical Approach.

There is limited research on sensory acuity i.e., ability to perceive external perturbations via body-sway during standing in individuals with a traumatic brain injury (TBI). It is unclear whether sensory acuity diminishes after a TBI and if it is a contributing factor to balance dysfunction. The objective of this investigation is to first objectively quantify the sensory acuity in terms of perturbation perception threshold (PPT) and determine if it is related to functional outcomes of static and dynamic balance. Ten individuals with chronic TBI and 11 age-matched healthy controls (HC) performed PPT assessments at 0.33, 0.5, and 1 Hz horizontal perturbations to the base of support in the anterior-posterior direction, and a battery of functional assessments of static and dynamic balance and mobility [Berg balance scale (BBS), timed-up and go (TUG) and 5-m (5MWT) and 10-m walk test (10MWT)]. A psychophysical approach based on Single Interval Adjustment Matrix Protocol (SIAM), i.e., a yes-no task, was used to quantify the multi-sensory thresholds of perceived external perturbations to calculate PPT. A mixed-design analysis of variance (ANOVA) and post-hoc analyses were performed using independent and paired t-tests to evaluate within and between-group differences. Pearson correlation was computed to determine the relationship between the PPT and functional measures. The PPT values were significantly higher for the TBI group (0.33 Hz: 2.97 ± 1.0, 0.5 Hz: 2.39 ± 0.7, 1 Hz: 1.22 ± 0.4) compared to the HC group (0.33 Hz: 1.03 ± 0.6, 0.5 Hz: 0.89 ± 0.4, 1 Hz: 0.42 ± 0.2) for all three perturbation frequencies (p < 0.006 post Bonferroni correction). For the TBI group, the PPT for 1 Hz perturbations showed significant correlation with the functional measures of balance (BBS: r = -0.66, p = 0.037; TUG: r = 0.78, p = 0.008; 5MWT: r = 0.67, p = 0.034, 10MWT: r = 0.76, p = 0.012). These findings demonstrate that individuals with TBI have diminished sensory acuity during standing which may be linked to impaired balance function after TBI.

Correction: Comparative validity of energy expenditure prediction algorithms using wearable devices for people with spinal cord injury.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Estimation of Physical Activity Intensity in Spinal Cord Injury Using a Wrist-Worn ActiGraph Monitor.

OBJECTIVES: To derive accelerometer count thresholds for classifying time spent in sedentary, light intensity, and moderate-to-vigorous physical activity (MVPA) in manual wheelchair users (MWUs) with spinal cord injury (SCI). DESIGN: Participants completed 18 activities of daily living and exercises for 10 minutes each with a 3-minute break between activities while wearing a COSMED K4b2 portable metabolic cart and an ActiGraph activity monitor on the dominant wrist. A linear regression was computed between the wrist acceleration vector magnitude and SCI metabolic equivalent of task (MET) for 80% of the participants to obtain thresholds for classifying different activity intensities, and the obtained thresholds were tested for accuracy on the remaining 20% of participants. This cross-validation process was iterated for 1000 times to evaluate the stability of the thresholds on data corresponding to different proportions of sedentary, light intensity, and MVPA. MET values of 1.5 or lower were classified as sedentary behavior, MET values between 1.5 and 3 were classified as light intensity, and MET values of 3 or higher were classified as MVPA. The final thresholds were then validated on an out-of-sample independent dataset. PARTICIPANTS: MWUs (N=17) with SCI in the out-of-sample validation data set. INTERVENTIONS: Not applicable. SETTING: Research lab, community MAIN OUTCOME MEASURES: Accelerometer thresholds to classify sedentary, light intensity, and MVPA were obtained and their accuracy tested using cross-validation and an out-of-sample dataset. RESULTS: The threshold between sedentary and light intensity was 2057 counts-per-minute, and the threshold between light intensity and MVPA was 11,551 counts per minute. Based on the out-of-sample validation, the obtained thresholds had an overall accuracy of 85.6%, with a sensitivity and specificity of 95.3% and 97.4% for sedentary behavior, 87.8% and 84.5% for light intensity, 68.5% and 96.3% for MVPA, respectively. CONCLUSION: Accelerometer-based thresholds can be used to accurately identify sedentary behavior. However, thresholds may not provide accurate estimations of MVPA throughout the day when participants engage in more resistance-based activities.

Comparative validity of energy expenditure prediction algorithms using wearable devices for people with spinal cord injury.

STUDY DESIGN: Cross-sectional validation study. OBJECTIVES: To conduct a literature search for existing energy expenditure (EE) predictive algorithms using ActiGraph activity monitors for manual wheelchairs users (MWUs) with spinal cord injury (SCI), and evaluate their validity using an out-of-sample dataset. SETTING: Research institution in Pittsburgh, USA. METHODS: A literature search resulted in five articles containing five sets of predictive equations using an ActiGraph activity monitor for MWUs with SCI. Out-of-sample data were collected from 29 MWUs with chronic SCI who were asked to follow an activity protocol while wearing an ActiGraph GT9X Link on the dominant wrist. They also wore a portable metabolic cart which provided the criterion measure for EE. The out-of-sample dataset was used to evaluate the validity of the five sets of EE predictive equations. RESULTS: None of the five sets of predictive equations demonstrated equivalence within 20% of the criterion measure based on an equivalence test. The mean absolute error for the five sets of predictive equations ranged from 0.87 to 6.41 kilocalories per minute (kcal min-1) when compared with the criterion measure, and the intraclass correlation estimates ranged from 0.06 to 0.59. The range between the Bland-Altman upper and lower limits of agreement was from 4.70 kcal min-1 to 25.09 kcal min-1. CONCLUSIONS: The existing EE predictive equations based on ActiGraph monitors for MWUs with SCI showed varied performance when compared with the criterion measure. Their accuracies may not be sufficient to support future clinical and research use. More work is needed to develop more accurate EE predictive equations for this population.