Simulating space walking: a systematic review on anti-gravity technology in neurorehabilitation.

Neurological disorders, such as Parkinson's disease (PD), multiple sclerosis (MS), cerebral palsy (CP) and stroke are well-known causes of gait and balance alterations. Innovative devices (i.e., robotics) are often used to promote motor recovery. As an alternative, anti-gravity treadmills, which were developed by NASA, allow early mobilization, walking with less effort to reduce gait energy costs and fatigue. A systematic search, according to PRISMA guidelines, was conducted for all peer-reviewed articles published from January 2010 through September 2023, using the following databases: PubMed, Scopus, PEDro and IEEE Xplore. After an accurate screening, we selected only 16 articles (e.g., 5 RCTs, 2 clinical trials, 7 pilot studies, 1 prospective study and 1 exploratory study). The evidence collected in this systematic review reported promising results in the field of anti-gravity technology for neurological patients, in terms of improvement in gait and balance outcomes. However, we are not able to provide any clinical recommendation about the dose and parameters of anti-gravity treadmill training, because of the lack of robust high-quality RCT studies and large samples. Registration number CRD42023459665.

Validation of the Kinematic Assessment Protocol Used in the Technology-Supported Neurorehabilitation System, Rehabilitation Technologies for Hand and Arm (R3THA™), in Children and Teenagers with Cerebral Palsy.

This study evaluates the R3THA™ assessment protocol (R3THA-AP™), a technology-supported testing module for personalized rehabilitation in children with cerebral palsy (CP). It focuses on the reliability and validity of the R3THA-AP in assessing hand and arm function, by comparing kinematic assessments with standard clinical assessments. Conducted during a 4-week summer camp, the study assessed the functional and impairment levels of children with CP aged 3-18. The findings suggest that R3THA is more reliable for children aged 8 and older, indicating that age significantly influences the protocol's effectiveness. The results also showed that the R3THA-AP's kinematic measurements of hand and wrist movements are positively correlated with the Box and Blocks Test Index (BBTI), reflecting hand function and dexterity. Additionally, the R3THA-AP's accuracy metrics for hand and wrist activities align with the Melbourne Assessment 2's Range of Motion (MA2-ROM) scores, suggesting a meaningful relationship between R3THA-AP data and clinical assessments of motor skills. However, no significant correlations were observed between the R3THA-AP and MA2's accuracy and dexterity measurements, indicating areas for further research. These findings validate the R3THA-AP's utility in assessing motor abilities in CP patients, supporting its integration into clinical practice.

Opportunities, Risks, Strengths and Weaknesses of Robotic Systems in Early Neurological Rehabilitation.

Given the conference's focus on innovative healthcare solutions, our investigation into robotic assistance systems highlights crucial advancements in early motor rehabilitation, aligning closely with emerging healthcare priorities. In combination with conventional therapy, the assistance systems offer new possible therapy programs. They can be used to mobilize and move patients as early as possible. The paper discusses the possibilities that arise from their use and considers the obstacles that arise. As part of a qualitative survey, nine expert interviews from different fields were conducted to guide them on robotic assisted living systems. The results obtained were summarized by coding into categories and evaluated. Our analysis of 148 coding points from nine expert interviews reveals significant insights into the strengths and weaknesses of robotic systems in neurorehabilitation. Each point was meticulously categorized to reflect its impact on both practice and patient outcomes, highlighting the practical implications of our findings. The results of the survey and the literature indicate a positive effect of robotic assistance systems in early rehabilitation. Their use requires intensive monitoring and studies on the long-term application of the systems.

Proprioception enhancement for robot assisted neural rehabilitation: a dynamic electrical stimulation based method and preliminary results from EEG analysis.

Objective.In recent years, the robot assisted (RA) rehabilitation training has been widely used to counteract defects of the manual one provided by physiotherapists. However, since the proprioception feedback provided by the robotic assistance or the manual methods is relatively weak for the paralyzed patients, their rehabilitation efficiency is still limited. In this study, a dynamic electrical stimulation (DES) based proprioception enhancement and the associated quantitative analysis methods have been proposed to overcome the limitation mentioned above.Approach.Firstly, the DES based proprioception enhancement method was proposed for the RA neural rehabilitation. In the method, the relationship between the surface electromyogram (sEMG) envelope of the specified muscle and the associated joint angles was constructed, and the electrical stimulation (ES) pulses for the certain joint angles were designed by consideration of the corresponding sEMG envelope, based on which the ES can be dynamically regulated during the rehabilitation training. Secondly, power spectral density, source estimation, and event-related desynchronization of electroencephalogram, were combinedly used to quantitatively analyze the proprioception from multiple perspectives, based on which more comprehensive and reliable analysis results can be obtained. Thirdly, four modes of rehabilitation training tasks, namely active, RA, DES-RA, and ES-only training, were designed for the comparison experiment and validation of the proposed DES based proprioception enhancement method.Main results.The results indicated that the activation of the sensorimotor cortex was significantly enhanced when the DES was added, and the cortex activation for the DES-RA training was similar to that for the active training. Meanwhile, relatively consistent results from the multiple perspectives were obtained, which validates the effectiveness and robustness of the proposed proprioception analysis method.Significance.The proposed methods have the potential to be applied in the practical rehabilitation training to improve the rehabilitation efficiency.

Enhanced Muscle Activation Using Robotic Assistance Within the Electromechanical Delay: Implications for Rehabilitation?

Robotic rehabilitation has been shown to match the effects of conventional physical therapy on motor function for patients with neurological diseases. Rehabilitation robots have the potential to reduce therapists' workload in time-intensive training programs as well as perform actions that are not replicable by human therapists. We investigated the effects of one such modality that cannot be achieved by a human therapist: assistance and resistance within the electromechanical delay between muscle activation and muscle contraction during arm extension. We found increased muscle activation when providing robotic assistance within this electromechanical delay. Assistance provided within this delay moves the participant's arm quicker than their own muscle and increases the subsequent peak voluntary muscle activation compared to normal arm extension by 68.97 ± 80.05 % (SE = 0.021; p = 0.007 ). This is surprising since all previous literature shows that muscle activation either decreases or does not change when participants receive robotic assistance. As a consequence, traditional robotic rehabilitation incrementally reduces assistance as the patient improves to maintain levels of muscle activation which is suggested to be important for neuronal repair. The present result may enable therapists to no longer have to choose between providing assistance or increasing muscle activation. Instead, therapists may be able to provide assistance while also increasing muscle activation.

Integration of music-based game approaches with wearable devices for hand neurorehabilitation: a narrative review.

BACKGROUND: Restoring hand functionality is critical for fostering independence in individuals with neurological disorders. Various therapeutic approaches have emerged to address motor function restoration, with music-based therapies demonstrating notable advantages in enhancing neuroplasticity, an integral component of neurorehabilitation. Despite the positive effects observed, there remains a gap in the literature regarding implementing music treatments in neurorehabilitation, such as Neurologic Music Therapy (NMT), especially in conjunction with emerging fields like wearable devices and game-based therapies. METHODS: A literature search was conducted in various databases, including PubMed, Scopus, IEEE Xplore, and ACM Digital Library. The search was performed using a literature search methodology based on keywords. Information collected from the studies pertained to the approach used in music therapy, the design of the video games, and the types of wearable devices utilized. RESULTS: A total of 158 articles were found, including 39 from PubMed, 34 from IEEE Xplore, 48 from Scopus, 37 from ACM Digital Library, and 35 from other sources. Duplicate entries, of which there were 41, were eliminated. In the first screening phase, 152 papers were screened for title and abstract. Subsequently, 89 articles were removed if they contained at least one exclusion criterion. Sixteen studies were considered after 63 papers had their full texts verified. CONCLUSIONS: The convergence of NMT with emerging fields, such as gamification and wearable devices designed for hand functionality, not only expands therapeutic horizons but also lays the groundwork for innovative, personalized approaches to neurorehabilitation. However, challenges persist in effectively incorporating NMT into rehabilitation programs, potentially hindering its effectiveness.

Immersive VR for upper-extremity rehabilitation in patients with neurological disorders: a scoping review.

BACKGROUND: Neurological disorders, such as stroke and chronic pain syndromes, profoundly impact independence and quality of life, especially when affecting upper extremity (UE) function. While conventional physical therapy has shown effectiveness in providing some neural recovery in affected individuals, there remains a need for improved interventions. Virtual reality (VR) has emerged as a promising technology-based approach for neurorehabilitation to make the patient's experience more enjoyable. Among VR-based rehabilitation paradigms, those based on fully immersive systems with headsets have gained significant attention due to their potential to enhance patient's engagement. METHODS: This scoping review aims to investigate the current state of research on the use of immersive VR for UE rehabilitation in individuals with neurological diseases, highlighting benefits and limitations. We identified thirteen relevant studies through comprehensive searches in Scopus, PubMed, and IEEE Xplore databases. Eligible studies incorporated immersive VR for UE rehabilitation in patients with neurological disorders and evaluated participants' neurological and motor functions before and after the intervention using clinical assessments. RESULTS: Most of the included studies reported improvements in the participants rehabilitation outcomes, suggesting that immersive VR represents a valuable tool for UE rehabilitation in individuals with neurological disorders. In addition, immersive VR-based interventions hold the potential for personalized and intensive training within a telerehabilitation framework. However, further studies with better design are needed for true comparison with traditional therapy. Also, the potential side effects associated with VR head-mounted displays, such as dizziness and nausea, warrant careful consideration in the development and implementation of VR-based rehabilitation programs. CONCLUSION: This review provides valuable insights into the application of immersive VR in UE rehabilitation, offering the foundation for future research and clinical practice. By leveraging immersive VR's potential, researchers and rehabilitation specialists can design more tailored and patient-centric rehabilitation strategies, ultimately improving the functional outcome and enhancing the quality of life of individuals with neurological diseases.

Effect on functional outcome of robotic assisted rehabilitation versus conventional rehabilitation in patients with complete spinal cord injury: a prospective comparative study.

STUDY DESIGN: Prospective Comparative Study. OBJECTIVE: This study aims to compare the functional outcomes of Robotic-assisted rehabilitation by Lokomat system Vs. Conventional rehabilitation in participants with Dorsolumbar complete spinal cord injury (SCI). SETTING: University level teaching hospital in a hilly state of northern India. METHODS: 15 participants with Dorsolumbar SCI with ASIA A neurology were allocated to robotic rehabilitation and 15 participants to conventional rehabilitation after an operative procedure. Pre-and Post-rehabilitation parameters were noted in terms of ASIA Neurology, Motor and sensory function scores, WISCI II score (Walking Index in SCI score), LEMS (Lower Extremity Motor Score), SCI M III score (Spinal Cord Independence Measure III score), AO Spine PROST (AO Patient Reported Outcome Spine Trauma), McGill QOL score (Mc Gill Quality of Life score), VAS score (Visual Analogue Scale) for pain and Modified Ashworth scale for spasticity in lower limbs. RESULTS: On comparing robotic group with conventional group there was a statistically significant improvement in Robotic-assisted rehabilitation group in terms of Motor score (p = 0.034), WISCI II score (p = 0.0001), SCIM III score (p = 0.0001), AO PROST score (p = 0.0001), Mc GILL QOL score (p = 0.0001), Max velocity (p = 0.0001) and Step length (p = 0.0001). Whereas LEMS score (p = 0.052), ASIA neurology (p = 0.264 (ASIA A); 1.000 (ASIA B); 0.053 (ASIA C)), VAS score (p = 0.099), Sensory score (p = 0.422) and Modified Ashworth scale for spasticity (p = 0.136) were not statically significant when comparing between two groups. CONCLUSION: Robot-assisted rehabilitation is superior than conventional rehabilitation in people living with SCI with AIS A neurology. Differences in the patient group, type of a lesion its and severity, duration from onset to initiation of rehabilitation, devices employed, administration of the therapies and regulation of interventions are likely the cause of variations in the findings seen in the literature for robotic assisted training. LEVEL OF EVIDENCE: III.

Exoskeleton-Assisted Rehabilitation and Neuroplasticity in Spinal Cord Injury.

Spinal cord injury (SCI) results in neurological deficits below the level of injury, causing motor dysfunction and various severe multisystem complications. Rehabilitative training plays a crucial role in the recovery of individuals with SCI, and exoskeleton serves as an emerging and promising tool for rehabilitation, especially in promoting neuroplasticity and alleviating SCI-related complications. This article reviews the classifications and research progresses of medical exoskeletons designed for SCI patients and describes their performances in practical application separately. Meanwhile, we discuss their mechanisms for enhancing neuroplasticity and functional remodeling, as well as their palliative impacts on secondary complications. The potential trends in exoskeleton design are raised according to current progress and requirements on SCI rehabilitation.

Walking naturally after spinal cord injury using a brain-spine interface.

A spinal cord injury interrupts the communication between the brain and the region of the spinal cord that produces walking, leading to paralysis1,2. Here, we restored this communication with a digital bridge between the brain and spinal cord that enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. This brain-spine interface (BSI) consists of fully implanted recording and stimulation systems that establish a direct link between cortical signals3 and the analogue modulation of epidural electrical stimulation targeting the spinal cord regions involved in the production of walking4-6. A highly reliable BSI is calibrated within a few minutes. This reliability has remained stable over one year, including during independent use at home. The participant reports that the BSI enables natural control over the movements of his legs to stand, walk, climb stairs and even traverse complex terrains. Moreover, neurorehabilitation supported by the BSI improved neurological recovery. The participant regained the ability to walk with crutches overground even when the BSI was switched off. This digital bridge establishes a framework to restore natural control of movement after paralysis.

Sensing and decoding the neural drive to paralyzed muscles during attempted movements of a person with tetraplegia using a sleeve array.

Motor neurons convey information about motor intent that can be extracted and interpreted to control assistive devices. However, most methods for measuring the firing activity of single neurons rely on implanted microelectrodes. Although intracortical brain-computer interfaces (BCIs) have been shown to be safe and effective, the requirement for surgery poses a barrier to widespread use that can be mitigated by instead using noninvasive interfaces. The objective of this study was to evaluate the feasibility of deriving motor control signals from a wearable sensor that can detect residual motor unit activity in paralyzed muscles after chronic cervical spinal cord injury (SCI). Despite generating no observable hand movement, volitional recruitment of motor units below the level of injury was observed across attempted movements of individual fingers and overt wrist and elbow movements. Subgroups of motor units were coactive during flexion or extension phases of the task. Single digit movement intentions were classified offline from the electromyogram (EMG) power [root-mean-square (RMS)] or motor unit firing rates with median classification accuracies >75% in both cases. Simulated online control of a virtual hand was performed with a binary classifier to test feasibility of real-time extraction and decoding of motor units. The online decomposition algorithm extracted motor units in 1.2 ms, and the firing rates predicted the correct digit motion 88 ± 24% of the time. This study provides the first demonstration of a wearable interface for recording and decoding firing rates of motor units below the level of injury in a person with motor complete SCI.NEW & NOTEWORTHY A wearable electrode array and machine learning methods were used to record and decode myoelectric signals and motor unit firing in paralyzed muscles of a person with motor complete tetraplegia. The myoelectric activity and motor unit firing rates were task specific, even in the absence of visible motion, enabling accurate classification of attempted single-digit movements. This wearable system has the potential to enable people with tetraplegia to control assistive devices through movement intent.

Our child's TBI: a rehabilitation engineer's personal experience, technological approach, and lessons learned.

I (JS) am currently a faculty member at The University of Texas at Austin in Mechanical Engineering. My primary research focus is rehabilitation engineering. In May 2020, a week before her fourth birthday, our daughter suffered a severe traumatic brain injury in the early days of the coronavirus pandemic. The purpose of this article is to describe the current state of pediatric neurorehabilitation from technologically-adept parents' first-person perspectives in order to inform and motivate rehabilitation engineering researchers. We describe the medical and personal challenges faced during the aftermath of the accident, the technological approaches to her recovery that my wife (LKS) and I have examined, some of which may be considered beyond standard practice, and the lessons we have absorbed during this period regarding both the state of rehabilitation research and the clinical uptake of rehabilitation technologies. We introduce a set of questions for designers to consider as they create and evaluate new technologies for pediatric rehabilitation.

High-wearable EEG-based distraction detection in motor rehabilitation.

A method for EEG-based distraction detection during motor-rehabilitation tasks is proposed. A wireless cap guarantees very high wearability with dry electrodes and a low number of channels. Experimental validation is performed on a dataset from 17 volunteers. Different feature extractions from spatial, temporal, and frequency domain and classification strategies were evaluated. The performances of five supervised classifiers in discriminating between attention on pure movement and with distractors were compared. A k-Nearest Neighbors classifier achieved an accuracy of 92.8 ± 1.6%. In this last case, the feature extraction is based on a custom 12 pass-band Filter-Bank (FB) and the Common Spatial Pattern (CSP) algorithm. In particular, the mean Recall of classification (percentage of true positive in distraction detection) is higher than 92% and allows the therapist or an automated system to know when to stimulate the patient's attention for enhancing the therapy effectiveness.

Clinical utility of the over-ground bodyweight-supporting walking system Andago in children and youths with gait impairments.

BACKGROUND: The Andago is a rehabilitation robot that allows training walking over-ground while providing bodyweight unloading (BWU). We investigated the practicability, acceptability, and appropriateness of the device in children with gait impairments undergoing neurorehabilitation. Concerning appropriateness, we investigated whether (i) stride-to-stride variability of the stride time and inter-joint coordination was higher when walking over-ground in Andago versus treadmill walking, and (ii) activation of antigravity leg muscles decreased with higher levels of BWU. METHODS: Eighteen children and adolescents with gait impairments participated in three sessions. Practicability was assessed by determining the time needed to get a patient in and out of Andago, the accuracy of the BWU system, and other aspects. Acceptability was assessed by patients responding to questions, while six therapists filled out the System Usability Scale. To determine appropriateness, the participants were equipped with surface electromyography (sEMG) electrodes, electrogoniometers and accelerometers. Various parameters were compared between walking over-ground and on a treadmill, and between walking with three different levels of BWU (median: 20%, 35% and 50% of the bodyweight) over-ground. RESULTS: Practicability: the average time needed to get in and out of Andago amounted to 60 s and 16 s, respectively. The BWU system seemed accurate, especially at higher levels. We experienced no technical difficulties and Andago prevented 12 falls. However, participants had difficulties walking through a door without bumping into it. Acceptability: after the second session, nine participants felt safer walking in Andago compared to normal walking, 15 preferred walking in Andago compared to treadmill walking, and all wanted to train again with Andago. Therapists rated the usability of the Andago as excellent. Appropriateness: stride-to-stride variability of stride duration and inter-joint coordination was higher in Andago compared to treadmill walking. sEMG activity was not largely influenced by the levels of BWU investigated in this study, except for a reduced M. Gluteus Medius activity at the highest level of BWU tested. CONCLUSIONS: The Andago is a practical and well-accepted device to train walking over-ground with BWU in children and adolescents with gait impairments safely. The system allows individual stride-to-stride variability of temporospatial gait parameters without affecting antigravity muscle activity strongly. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03787199.

What Factors Influence Clinicians' Use of Technology in Neurorehabilitation? A Multisite Qualitative Study.

OBJECTIVE: Technology is being increasingly used for physical assessment and interventions in health care settings. However, clinical adoption is relatively slow, and the factors affecting use remain underexplored. This study aimed to investigate factors influencing technology use by clinicians working in neurorehabilitation. METHODS: In this qualitative study, 9 physical therapists and 9 occupational therapists (N = 18) were recruited from urban and regional locations in Australia and in Singapore. Three 60-minute focus groups were conducted via video conferencing. Each group comprised 3 physical therapists and 3 occupational therapists working across different neurorehabilitation settings. Participants were asked to discuss which technologies they used in their workplace for physical assessment and treatment and barriers, motivators, and future desires for technology use. Transcripts were analyzed independently using an inductive approach to generate codes and themes. RESULTS: Our results comprised 3 themes and 7 categories. These were encompassed by a single overarching theme, namely "Technology use is influenced by the benefits and challenges of the technology itself, users, and organizational context." Themes showed that technology should promote effective interventions, is preferred if easy to use, and should be dependable. Furthermore, clinical reasoning is important, and users have varying levels of receptivity and confidence in technology use. Also, organizational resources are required, along with supportive cultures and processes, to facilitate technology use. CONCLUSIONS: The themes identified multiple and interlinking factors influencing clinicians' use of technology in neurorehabilitation settings. Clinicians often consider context-specific benefits and challenges when deciding whether to use technology. Although our study found that clinicians generally perceived technology as having a beneficial role in improving health outcomes, there were several challenges raised. Therefore, the characteristics of the technology itself, individual users, and organizational context should be considered. IMPACT: These findings will guide successful technology implementation and future developments.

Neuroprosthetics: an outlook on active challenges toward clinical adoption.

Neural prostheses are designed to counter the effects of neurotrauma and restore the fundamental building blocks of human experience including motor action, sensation, and meaningful communication with other individuals. Here, we present an overview of active avenues, open questions, and debated topics in neuroprosthetics, such as targeting the mechanisms of sensorimotor recovery and designing brain interfaces for scalability. We review leading opinions in this thriving field, aiming to inform translational practice toward clinical adoption.

Kinesiology Taping in Duchenne Muscular Dystrophy: Acute Effects on Performance, Gait Characteristics, and Balance.

AIM: This study was aimed to investigate the acute effects of kinesiology taping (KT) on physical performance, gait characteristics, and balance in early-stage Duchenne Muscular Dystrophy (DMD). METHOD: Forty-five children at early functional level of DMD were included. 6-minute walk test (6MWT), and timed performance tests were performed; gait characteristics, and balance were assessed before and one hour after taping. KT was applied to bilateral quadriceps and tibialis anterior muscles. The comparison of assessments was performed by using Wilcoxon Signed Ranks test. RESULTS: Significant increase in the distance of 6MWT, decrease in the duration of descending 4 steps, and 10 m walk timed performance tests, improvements in all of the gait characteristics, and balance were determined after taping (p < .05). CONCLUSIONS: KT has positive acute effects on performance and gait of children with DMD at early functional level which encourages therapists to use KT as a complementary approach in rehabilitation programs.

Effects of Virtual Reality Therapy on Gait and Balance Among Individuals With Spinal Cord Injury: A Systematic Review and Meta-analysis.

Background and Purpose. The use of virtual reality (VR) therapy among individuals with spinal cord injury (SCI) is a relatively new rehabilitation approach replicating real-life scenarios. The aim of this study was to evaluate the effectiveness of VR therapy for improving gait and balance in individuals with SCI. Methods. Databases of PubMed, Web of Science, Scopus, SportDiscuss, and CINHAL were searched from inception until September 2019. Two independent reviewers screened articles for inclusion, extracted data, and evaluated methodological quality of the trials. Results. Ten trials, including 3 randomized clinical trials (RCTs) and 7 pre-post trials, with a total of 149 participants were analyzed. Meta-analysis of RCTs demonstrated significant improvement in sitting balance (standardized mean difference [SMD] = 1.65; 95% CI 1.21-2.09; P < .01) after VR therapy with conventional rehabilitation compared with only conventional rehabilitation. Also, pre-post studies using VR therapy without a control group showed improvement in standing balance (Berg Balance Scale, MD = 4.22; 95% CI 1.78-6.66; P < .01 and Activities-specific Balance Confidence scale, MD = 8.53; 95% CI 2.52-14.53; P = .01) and a trend for improvement in gait (SMD = 0.34; 95% CI 0.02-0.66; P = .04). Conclusion. This study demonstrated the beneficial effects of VR therapy to enhance sitting and standing balance and showed a trend of gait improvement in individuals with SCI. This conclusion is based on mainly preliminary data and therefore, more RCTs are needed to confirm the effects of the use of VR in individuals with SCI.

Do Patients With Parkinson's Disease With Freezing of Gait Respond Differently Than Those Without to Treadmill Training Augmented by Virtual Reality?

Background. People with Parkinson's disease and freezing of gait (FOG+) have more falls, postural instability and cognitive impairment compared with FOG-. Objective. To conduct a secondary analysis of the V-TIME study, a randomized, controlled investigation showing a greater reduction of falls after virtual reality treadmill training (TT + VR) compared with usual treadmill walking (TT) in a mixed population of fallers. We addressed whether these treadmill interventions led to similar gains in FOG+ as in FOG-. Methods. A total of 77 FOG+ and 44 FOG- were assigned randomly to TT + VR or TT. Participants were assessed pre- and posttraining and at 6 months' follow-up. Main outcome was postural stability assessed by the Mini Balance Evaluation System Test (Mini-BEST) test. Falls were documented using diaries. Other outcomes included the New Freezing of Gait Questionnaire (NFOG-Q) and the Trail Making Test (TMT-B). Results. Mini-BEST scores and the TMT-B improved in both groups after training (P = .001), irrespective of study arm and FOG subgroup. However, gains were not retained at 6 months. Both FOG+ and FOG- had a greater reduction of falls after TT + VR compared with TT (P = .008). NFOG-Q scores did not change after both training modes in the FOG+ group. Conclusions. Treadmill walking (with or without VR) improved postural instability in both FOG+ and FOG-, while controlling for disease severity differences. As found previously, TT + VR reduced falls more than TT alone, even among those with FOG. Interestingly, FOG itself was not helped by training, suggesting that although postural instability, falls and FOG are related, they may be controlled by different mechanisms.