Gait training after spinal cord injury: safety, feasibility and gait function following 8 weeks of training with the exoskeletons from Ekso Bionics

Barriers and facilitators to exoskeleton use in persons with spinal cord injury: a systematic review

PURPOSE

Exoskeleton can assist individuals with spinal cord injuries (SCI) with simple movements and transform their lives by enhancing strength and mobility. Nonetheless, the current utilization outside of rehabilitation contexts is limited. To promote the widespread adoption of exoskeletons, it is crucial to consider the acceptance of these devices for both rehabilitation and functional purposes. This systematic review aims to identify the barriers or facilitators of the use of lower limbs exoskeletons, thereby providing strategies to improve interventions and increase the adoption of these devices.

METHODS

A comprehensive search was conducted in EMBASE, Web of Science, Scopus, Cochrane, and PubMed. Studies reporting barriers and facilitators of exoskeleton use were included. The studies' quality was assessed using the Mixed Methods Appraisal Tool and undertook a thematic content analysis for papers examining the barriers and facilitators.

RESULTS

Fifteen articles met the inclusion criteria. These revealed various factors that impact the utilization of exoskeletons. Factors like age, engagement in an active lifestyle, and motivation were identified as facilitators, while fear of falling and unfulfilled expectations were recognized as barriers. Physical aspects such as fatigue, neuropathic discomfort, and specific health conditions were found to be barriers.

CONCLUSION

This systematic review provides a comprehensive overview of the barriers and facilitators to the use of exoskeleton technology. There are therefore still challenges to be faced, efforts must be made to improve its design, functionality, and accessibility. By addressing these barriers, exoskeletons can significantly improve the quality of life of people with SCI.

Spinal Cord Injury Associated Disease of the Skeleton, an Unresolved Problem with Need for Multimodal Interventions

Spinal cord injury is associated with skeletal unloading, sedentary behavior, decreases in skeletal muscle mass, and exercise intolerance, which results in rapid and severe bone loss. To date, monotherapy with physical interventions such as weight-bearing in standing frames, computer-controlled electrically stimulated cycling and ambulation exercise, and low-intensity vibration are unsuccessful in maintaining bone density after SCI. Strategies to maintain bone density with commonly used osteoporosis medications also fail to provide a significant clinical benefit, potentially due to a unique pathology of bone deterioration in SCI. In this review, the available data is discussed on evaluating and monitoring bone loss, fracture, and physical and pharmacological therapeutic approaches to SCI-associated disease of the skeleton. The treatment of SCI-associated disease of the skeleton, the implications for clinical management, and areas of need are considered for future investigation.

Enhancing balance and mobility in incomplete spinal cord injury with an overground gait trainer

STUDY DESIGN

Prospective intervention study.

OBJECTIVES

The study aimed to assess the effect of Andago on balance, overground walking speed, independence levels, fear of falling, and quality of life in patients with acute motor incomplete Spinal Cord Injury.

SETTING

The study was conducted in Ankara/Türkiye.

METHODS

Five participants, classified as AIS D, underwent an eight-week treatment regimen, including three days a week of Andago-assisted walking and balance exercises, supplemented by two days a week of 40-minute sessions of conventional in-bed exercises.

RESULTS

Berg Balance Scale scores increased significantly by 129% (p = 0.043). Overground walking speed calculated from 10MWT improved by 33% (p = 0.042). WISCI II levels improved significantly compared to baseline scores (p = 0.041). In the mobility subscale of SCIM III, the total SCIM III scores increased significantly (p = 0.042, p = 0.043, respectively). However, there was no significant improvement in WHOQOL-BREF scores (p = 0.080).

CONCLUSIONS

The use of Andago facilitated functional progress in patients with acute incomplete SCI, emphasizing the importance of challenging balance and walking activities in triggering motor learning.

Emerging Medical Technologies and Their Use in Bionic Repair and Human Augmentation

As both the proportion of older people and the length of life increases globally, a rise in age-related degenerative diseases, disability, and prolonged dependency is projected. However, more sophisticated biomedical materials, as well as an improved understanding of human disease, is forecast to revolutionize the diagnosis and treatment of conditions ranging from osteoarthritis to Alzheimer's disease as well as impact disease prevention. Another, albeit quieter, revolution is also taking place within society: human augmentation. In this context, humans seek to improve themselves, metamorphosing through self-discipline or more recently, through use of emerging medical technologies, with the goal of transcending aging and mortality. In this review, and in the pursuit of improved medical care following aging, disease, disability, or injury, we first highlight cutting-edge and emerging materials-based neuroprosthetic technologies designed to restore limb or organ function. We highlight the potential for these technologies to be utilized to augment human performance beyond the range of natural performance. We discuss and explore the growing social movement of human augmentation and the idea that it is possible and desirable to use emerging technologies to push the boundaries of what it means to be a healthy human into the realm of superhuman performance and intelligence. This potential future capability is contrasted with limitations in the right-to-repair legislation, which may create challenges for patients. Now is the time for continued discussion of the ethical strategies for research, implementation, and long-term device sustainability or repair.

Exoskeleton-based exercises for overground gait and balance rehabilitation in spinal cord injury: a systematic review of dose and dosage parameters

BACKGROUND

Exoskeletons are increasingly applied during overground gait and balance rehabilitation following neurological impairment, although optimal parameters for specific indications are yet to be established.

OBJECTIVE

This systematic review aimed to identify dose and dosage of exoskeleton-based therapy protocols for overground locomotor training in spinal cord injury/disease.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items Systematic Reviews and Meta-Analyses guidelines. A literature search was performed using the CINAHL Complete, Embase, Emcare Nursing, Medline ALL, and Web of Science databases. Studies in adults with subacute and/or chronic spinal cord injury/disease were included if they reported (1) dose (e.g., single session duration and total number of sessions) and dosage (e.g., frequency of sessions/week and total duration of intervention) parameters, and (2) at least one gait and/or balance outcome measure.

RESULTS

Of 2,108 studies identified, after removing duplicates and filtering for inclusion, 19 were selected and dose, dosage and efficacy were abstracted. Data revealed a great heterogeneity in dose, dosage, and indications, with overall recommendation of 60-min sessions delivered 3 times a week, for 9 weeks in 27 sessions. Specific protocols were also identified for functional restoration (60-min, 3 times a week, for 8 weeks/24 sessions) and cardiorespiratory rehabilitation (60-min, 3 times a week, for 12 weeks/36 sessions).

CONCLUSION

This review provides evidence-based best practice recommendations for overground exoskeleton training among individuals with spinal cord injury/disease based on individual therapeutic goals - functional restoration or cardiorespiratory rehabilitation. There is a need for structured exoskeleton clinical translation studies based on standardized methods and common therapeutic outcomes.

Improvement of quality of life after 2-month exoskeleton training in patients with chronic spinal cord injury

OBJECTIVE

To examine changes in quality of life (QoL) after an eight-week period of robotic exoskeleton training in a homogeneous group of patients with chronic complete spinal cord injury (SCI).

DESIGN

Prospective single-group pre-post study.

SETTING

Rehabilitation center.

PARTICIPANTS

Patients with a chronic (>6 months) motor complete SCI (T1-L1).

INTERVENTION

Twenty-four training sessions with the ReWalk exoskeleton over an eight-week period.

MAIN OUTCOME MEASURE

QoL, assessed with the sum score of the Short Form-36 with Walk Wheel modification (SF-36ww). Secondary outcome measures were the eight SF-36ww subdomains, satisfaction with bladder and bowel management, lower extremity joint passive range of motion (pROM), and lower extremity spasticity.

RESULTS

Twenty-one participants completed the training. QoL significantly improved after the training period (average SF-36 sum score 621 ± 90) compared to baseline (571 ± 133) (t(20)=-2.5, P=.02). Improvements were seen on the SF-36ww subdomains for pain (P=.003), social functioning (P=.03), mental health (P=.02), and general health perception (P=.01). Satisfaction with bladder management (range 1-5) improved from median 3 at baseline to 4 after exoskeleton training (P=0.01). No changes in satisfaction with bowel management (P=.11), pROM (hip-extension (P=.49), knee-extension (P=.36), ankle dorsiflexion (P=.69)), or spasticity (P=.94) were found.

CONCLUSION

Even in patients with chronic motor complete SCI and a relatively high level of QoL at baseline, a short-term exoskeleton training improved their QoL, pain and satisfaction with bladder management; findings that warrant further controlled studies in this specific SCI population.

Global research trends and hotspots of artificial intelligence research in spinal cord neural injury and restoration-a bibliometrics and visualization analysis

Background

Artificial intelligence (AI) technology has made breakthroughs in spinal cord neural injury and restoration in recent years. It has a positive impact on clinical treatment. This study explores AI research's progress and hotspots in spinal cord neural injury and restoration. It also analyzes research shortcomings related to this area and proposes potential solutions.

Methods

We used CiteSpace 6.1.R6 and VOSviewer 1.6.19 to research WOS articles on AI research in spinal cord neural injury and restoration.

Results

A total of 1,502 articles were screened, in which the United States dominated; Kadone, Hideki (13 articles, University of Tsukuba, JAPAN) was the author with the highest number of publications; ARCH PHYS MED REHAB (IF = 4.3) was the most cited journal, and topics included molecular biology, immunology, neurology, sports, among other related areas.

Conclusion

We pinpointed three research hotspots for AI research in spinal cord neural injury and restoration: (1) intelligent robots and limb exoskeletons to assist rehabilitation training; (2) brain-computer interfaces; and (3) neuromodulation and noninvasive electrical stimulation. In addition, many new hotspots were discussed: (1) starting with image segmentation models based on convolutional neural networks; (2) the use of AI to fabricate polymeric biomaterials to provide the microenvironment required for neural stem cell-derived neural network tissues; (3) AI survival prediction tools, and transcription factor regulatory networks in the field of genetics were discussed. Although AI research in spinal cord neural injury and restoration has many benefits, the technology has several limitations (data and ethical issues). The data-gathering problem should be addressed in future research, which requires a significant sample of quality clinical data to build valid AI models. At the same time, research on genomics and other mechanisms in this field is fragile. In the future, machine learning techniques, such as AI survival prediction tools and transcription factor regulatory networks, can be utilized for studies related to the up-regulation of regeneration-related genes and the production of structural proteins for axonal growth.

Industrial practitioner's perception on the application of exoskeleton system in automotive assembly industries: A Malaysian case study

The automotive industry is a key manufacturing industry for the Malaysian economy, where manual jobs and task are still common. Hence, Work-related Musculoskeletal Disorders (WMSD) is a common type of injury among workers. Exoskeleton system has gained global traction as a possible solution to reduce the risk of MSD among workers. Nonetheless, the application of exoskeleton in the automotive industry in Malaysia remains unknown. As such, this study attempts to provide insight into the industry's perception on the potential of exoskeleton application within the context of Malaysian automotive assembly sector. Therefore, a total of 52 management level respondents from various manufacturers participated in this study. It is found that, although the technology seems to be relatively new and disruptive, the respondents have a positive perception towards it with an acceptance rate of 86.5%. Cost of implementation exoskeleton technologies seems to be primary concern from the respondents, other concern such as maintenance cost and ease of application into existing application is also highlighted.

Clinical Delivery of Overground Exoskeleton Gait Training in Persons With Spinal Cord Injury Across the Continuum of Care: A Retrospective Analysis

Background

After spinal cord injury (SCI), inpatient rehabilitation begins and continues through outpatient therapy. Overground exoskeleton gait training (OEGT) has been shown to be feasible in both settings, yet its use as an intervention across the continuum has not yet been reported.

Objectives

This study describes OEGT for patients with SCI across the continuum and its effects on clinical outcomes.

Methods

Medical records of patients with SCI who completed at least one OEGT session during inpatient and outpatient rehabilitation from 2018 to 2021 were retrospectively reviewed. Demographic data, Walking Index for Spinal Cord Injury-II (WISCI-II) scores, and OEGT session details (frequency, "walk" time, "up" time, and step count) were extracted.

Results

Eighteen patients [male (83%), White (61%), aged 37.4 ± 15 years, with tetraplegia (50%), American Spinal Injury Association Impairment Scale A (28%), B (22%), C (39%), D (11%)] completed OEGT sessions (motor complete, 18.2 ± 10.3; motor incomplete, 16.7 ± 7.7) over approximately 18 weeks (motor complete, 15.1 ± 6.4; motor incomplete, 19.0 ± 8.2). Patients demonstrated improved OEGT session tolerance on device metrics including "walk" time (motor complete, 7:51 ± 4:42 to 24:50 ± 9:35 minutes; motor incomplete, 12:16 ± 6:01 to 20:01 ± 08:05 minutes), "up" time (motor complete, 16:03 ± 7:41 to 29:49 ± 12:44 minutes; motor incomplete, 16:38 ± 4:51 to 23:06 ± 08:50 minutes), and step count (motor complete, 340 ± 295.9 to 840.2 ± 379.4; motor incomplete, 372.3 ± 225.2 to 713.2 ± 272). Across therapy settings, patients with motor complete SCI experienced improvement in WISCI-II scores from 0 ± 0 at inpatient admission to 3 ± 4.6 by outpatient discharge, whereas the motor incomplete group demonstrated a change of 0.2 ± 0.4 to 9.0 ± 6.4.

Conclusion

Patients completed OEGT across the therapy continuum. Patients with motor incomplete SCI experienced clinically meaningful improvements in walking function.

Perspectives of wheelchair users with chronic spinal cord injury following a walking program using a wearable robotic exoskeleton

PURPOSE

To examine the perspectives of wheelchair users with spinal cord injury (WUSCI) regarding their participation in a 16-week walking program using a wearable robotic exoskeleton (WRE); and explore concerns and expectations regarding potential use of this device and intervention in the context of a home or community-based adapted physical activity program.

METHOD

Semi-structured interviews were conducted using a narrative research, 3 weeks post-intervention. Thematic analysis resulted in 6 themes and 21 subthemes.

RESULTS

Seven men and 4 women aged between 32 and 72 years were interviewed; 8 of them had a complete SCI. After the walking program, WUSCI reported positive psychological aspects (having fun and motivation) and experiencing improvements in physical aspects (strength, endurance, balance and flexibility, blood circulation and intestinal transit). The structural aspects of the WRE device were acceptable in a lab with research personnel (appearance, size, weight, and comfort). Participants had concerns about safety on uneven surfaces, and possibility of falling. They expressed the desire to use the WRE for more life habits than just walking.

CONCLUSION

This is the first study in which WUSCI report that the WRE should be implemented in initial rehabilitation. Lack of availability for community use after rehabilitation remains a concern.

Effects of a lower limb walking exoskeleton on quality of life and activities of daily living in patients with complete spinal cord injury: A randomized controlled trial

BACKGROUND

In recent years, lower limb walking exoskeletons have been widely used in the study of spinal cord injury (SCI).

OBJECTIVE

To explore the effect of a lower limb walking exoskeleton on quality of life and functional independence in patients with motor complete SCI.

METHODS

This was a multi-center, single blind, randomized controlled trial. A total of 16 SCI patients were randomly assigned to either the exoskeleton-assisted walking (EAW) group (n= 8) or the conventional group (n= 8). Both groups received conventional rehabilitation training, including aerobic exercise and strength training. The EAW group additionally conducted the exoskeleton-assisted walking training using an AIDER powered robotic exoskeleton for 40-50 minutes, 5 times/week for 8 weeks. World Health Organization quality of life-BREF (WHOQOL-BREF) and the Spinal Cord Independence Measure III (SCIM-III) were used for assessment before and after training.

RESULTS

There was an increasing tendency of scores in the psychological health, physical health, and social relationships domain of WHOQOL-BREF in the EAW group after the intervention compared with the pre-intervention period, but there was no significant difference (P> 0.05). SCIM-III scores increased in both groups compared to pre-training, with only the conventional group showing a significant difference after 8 weeks of training (P< 0.05).

CONCLUSION

A lower limb walking exoskeleton may have potential benefits for quality of life and activities of daily living in patients with motor complete SCI.

Potential Effects of an Exoskeleton-Assisted Overground Walking Program for Individuals With Spinal Cord Injury Who Uses a Wheelchair on Imaging and Serum Markers of Bone Strength: Pre-Post Study

BACKGROUND

As many as 60% of individuals use a wheelchair long term after a spinal cord injury (SCI). This mode of locomotion leads to chronic decline in lower-extremity weight-bearing activities and contributes to the development of severe sublesional osteoporosis and high rates of fragility fracture. Overground exoskeleton-assisted walking programs provide a novel opportunity to increase lower-extremity weight bearing, with the potential to improve bone health.

OBJECTIVE

The aim of the study is to measure the potential effects of an exoskeleton-assisted walking program on lower-extremity bone strength and bone remodeling biomarkers in individuals with chronic (≥18 months) SCI who use a wheelchair.

METHODS

In total, 10 participants completed a 16-week exoskeleton-assisted walking program (34 individualized 1-hour sessions, progressing from 1 to 3 per week). Bone mineral density and bone strength markers (dual-energy x-ray absorptiometry: total body, left arm, leg, total hip, and femoral neck and peripheral quantitative computed tomography: 25% of left femur and 66% of left tibia) as well as bone remodeling biomarkers (formation=osteocalcin and resorption=C-telopeptide) were measured before and after intervention and compared using nonparametric tests. Changes were considered significant and meaningful if the following criteria were met: P<0.1, effect size ≥0.5, and relative variation >5%.

RESULTS

Significant and meaningful increases were observed at the femur (femoral neck bone mineral content, bone strength index, and stress-strain index) and tibia (cortical cross-sectional area and polar moment of inertia) after the intervention (all P<.10). We also noted a decrease in estimated femoral cortical thickness. However, no changes in bone remodeling biomarkers were found.

CONCLUSIONS

These initial results suggest promising improvements in bone strength markers after a 16-week exoskeleton-assisted walking program in individuals with chronic SCI. Additional research with larger sample sizes, longer interventions (possibly of greater loading intensity), and combined modalities (eg, pharmacotherapy or functional electrical stimulation) are warranted to strengthen current evidence.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03989752; https://clinicaltrials.gov/ct2/show/NCT03989752.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/19251.

Exoskeletons: Contribution to Occupational Health and Safety

This review aims to characterize the current landscape of exoskeletons designed to promote medical care and occupational safety in industrial settings. Extensive exploration of scientific databases spanning industries, health, and medicine informs the classification of exoskeletons according to their distinctive attributes and specific footholds on the human physique. Within the scope of this review, a comprehensive analysis is presented, contextualizing the integration of exoskeletons based on different work activities. The reviewers extracted the most relevant articles published between 2008 and 2023 from IEEE, Proquest, PubMed, Science Direct, Scopus, Web of Science, and other databases. In this review, the PRISMA-ScR checklist was used, and a Cohen's kappa coefficient of 0.642 was applied, implying moderate agreement among the reviewers; 75 primary studies were extracted from a total of 344. The future of exoskeletons in contributing to occupational health and safety will depend on continued collaboration between researchers, designers, healthcare professionals, and industries. With the continued development of technologies and an increasing understanding of how these devices interact with the human body, exoskeletons will likely remain valuable for improving working conditions and safety in various work environments.

The neuromuscular control for lower limb exoskeleton- a 50-year perspective

Historically, impaired lower limb function has resulted in heavy health burden and large economic loss in society. Although experts from various fields have put large amounts of effort into overcoming this challenge, there is still not a single standard treatment that can completely restore the lost limb function. During the past half century, with the advancing understanding of human biomechanics and engineering technologies, exoskeletons have achieved certain degrees of success in assisting and rehabilitating patients with loss of limb function, and therefore has been spotlighted in both the medical and engineering fields. In this article, we review the development milestones of lower limb exoskeletons as well as the neuromuscular interactions between the device and wearer throughout the past 50 years. Fifty years ago, the lower-limb exoskeletons just started to be devised. We review several prototypes and present their designs in terms of structure, sensor and control systems. Subsequently, we introduce the development milestones of modern lower limb exoskeletons and discuss the pros and cons of these differentiated devices. In addition, we summarize current important neuromuscular control systems and sensors; and discuss current evidence demonstrating how the exoskeletons may affect neuromuscular control of wearers. In conclusion, based on our review, we point out the possible future direction of combining multiple current technologies to build lower limb exoskeletons that can serve multiple aims.

The Pathophysiology, Identification and Management of Fracture Risk, Sublesional Osteoporosis and Fracture among Adults with Spinal Cord Injury

BACKGROUND

The prevention of lower extremity fractures and fracture-related morbidity and mortality is a critical component of health services for adults living with chronic spinal cord injury (SCI).

METHODS

Established best practices and guideline recommendations are articulated in recent international consensus documents from the International Society of Clinical Densitometry, the Paralyzed Veterans of America Consortium for Spinal Cord Medicine and the Orthopedic Trauma Association.

RESULTS

This review is a synthesis of the aforementioned consensus documents, which highlight the pathophysiology of lower extremity bone mineral density (BMD) decline after acute SCI. The role and actions treating clinicians should take to screen, diagnose and initiate the appropriate treatment of established low bone mass/osteoporosis of the hip, distal femur or proximal tibia regions associated with moderate or high fracture risk or diagnose and manage a lower extremity fracture among adults with chronic SCI are articulated. Guidance regarding the prescription of dietary calcium, vitamin D supplements, rehabilitation interventions (passive standing, functional electrical stimulation (FES) or neuromuscular electrical stimulation (NMES)) to modify bone mass and/or anti-resorptive drug therapy (Alendronate, Denosumab, or Zoledronic Acid) is provided. In the event of lower extremity fracture, the need for timely orthopedic consultation for fracture diagnosis and interprofessional care following definitive fracture management to prevent health complications (venous thromboembolism, pressure injury, and autonomic dysreflexia) and rehabilitation interventions to return the individual to his/her pre-fracture functional abilities is emphasized.

CONCLUSIONS

Interprofessional care teams should use recent consensus publications to drive sustained practice change to mitigate fracture incidence and fracture-related morbidity and mortality among adults with chronic SCI.

Relevance of hazards in exoskeleton applications: a survey-based enquiry

Exoskeletons are becoming the reference technology for assistance and augmentation of human motor functions in a wide range of application domains. Unfortunately, the exponential growth of this sector has not been accompanied by a rigorous risk assessment (RA) process, which is necessary to identify the major aspects concerning the safety and impact of this new technology on humans. This situation may seriously hamper the market uptake of new products. This paper presents the results of a survey that was circulated to understand how hazards are considered by exoskeleton users, from research and industry perspectives. Our analysis aimed to identify the perceived occurrence and the impact of a sample of generic hazards, as well as to collect suggestions and general opinions from the respondents that can serve as a reference for more targeted RA. Our results identified a list of relevant hazards for exoskeletons. Among them, misalignments and unintended device motion were perceived as key aspects for exoskeletons' safety. This survey aims to represent a first attempt in recording overall feedback from the community and contribute to future RAs and the identification of better mitigation strategies in the field.

Multicentric investigation on the safety, feasibility and usability of the ABLE lower-limb robotic exoskeleton for individuals with spinal cord injury: a framework towards the standardisation of clinical evaluations

BACKGROUND

Robotic lower-limb exoskeletons have the potential to provide additional clinical benefits for persons with spinal cord injury (SCI). However, high variability between protocols does not allow the comparison of study results on safety and feasibility between different exoskeletons. We therefore incorporated key aspects from previous studies into our study protocol and accordingly conducted a multicentre study investigating the safety, feasibility and usability of the ABLE Exoskeleton in clinical settings.

METHODS

In this prospective pretest-posttest quasi-experimental study across two SCI centres in Germany and Spain, in- and outpatients with SCI were recruited into a 12-session training and assessment protocol, utilising the ABLE Exoskeleton. A follow-up visit after 4 weeks was included to assess after-training outcomes. Safety outcomes (device-related adverse events (AEs), number of drop-outs), feasibility and usability measures (level of assistance, donning/doffing-time) were recorded at every session together with changes in gait parameters and function. Patient-reported outcome measures including the rate of perceived exertion (RPE) and the psychosocial impact of the device were performed. Satisfaction with the device was evaluated in both participants and therapists.

RESULTS

All 24 participants (45 ± 12 years), with mainly subacute SCI (< 1 year after injury) from C5 to L3, (ASIA Impairment Scale A to D) completed the follow-up. In 242 training sessions, 8 device-related AEs (pain and skin lesions) were reported. Total time for don and doff was 6:50 ± 2:50 min. Improvements in level of assistance and gait parameters (time, steps, distance and speed, p < 0.05) were observed in all participants. Walking function and RPE improved in participants able to complete walking tests with (n = 9) and without (n = 6) the device at study start (p < 0.05). A positive psychosocial impact of the exoskeleton was reported and the satisfaction with the device was good, with best ratings in safety (participants), weight (therapists), durability and dimensions (both).

CONCLUSIONS

Our study results prove the feasibility of safe gait training with the ABLE Exoskeleton in hospital settings for persons with SCI, with improved clinical outcomes after training. Our study protocol allowed for consistent comparison of the results with other exoskeleton trials and can serve as a future framework towards the standardisation of early clinical evaluations. Trial Registration https://trialsearch.who.int/ , DRKS00023503, retrospectively registered on November 18, 2020.

Needs and wishes for the future lower limb exoskeleton: an interview study among people with spinal cord injury with community-based exoskeleton experience

PURPOSE

Exoskeleton use by people with complete spinal cord injury (SCI) in daily life is challenging. To optimize daily exoskeleton use, a better understanding of the purpose of use and the accompanying improvements are needed. The perspective of experienced exoskeleton users could guide design improvements.

METHODS

Face-to-face semi-structured interviews were held with 13 people with SCI with exoskeleton experience. Interviews were audio-taped, transcribed, and analysed thematically.

RESULTS

Participants expressed three future purposes of exoskeleton use: for daily activities (e.g., stair climbing), exercise (e.g., staying healthy), and social interaction (e.g., standing at parties). Exoskeleton use during daily activities was the ultimate goal. Therefore, the future exoskeleton should be: easy to use, small and lightweight, tailor made, safe, comfortable, less distinctive, durable, and affordable. Improving the ease of use was relevant for all purposes, for all participants. The other suggestions for improvement varied depending on the purpose of use and the participant.

CONCLUSION

Increasingly more advanced improvements are needed to transition from an exercise purpose to social interaction, and ultimately use during daily activities. In the current study, detailed suggestions for improvements have been made. Only when multiple of these suggestions are adjusted, can the exoskeleton be used to its full potential.IMPLICATIONS FOR REHABILITATIONThe use of an exoskeleton by people with a complete spinal cord injury in daily life is still in its infancy.To optimize daily exoskeleton use, a better understanding of the purpose of use and exoskeleton improvements is needed.More advanced improvements to future exoskeletons are needed to make a transition from use as an exercise device to use during social interaction and daily activities.Improving the ease of use of future exoskeletons is considered a priority by experienced users, followed by making the exoskeleton small, lightweight, and tailor made.

Exoskeleton-based training improves walking independence in incomplete spinal cord injury patients: results from a randomized controlled trial

BACKGROUND

In recent years, ambulatory lower limb exoskeletons are being gradually introduced into the clinical practice to complement walking rehabilitation programs. However, the clinical evidence of the outcomes attained with these devices is still limited and nonconclusive. Furthermore, the user-to-robot adaptation mechanisms responsible for functional improvement are still not adequately unveiled. This study aimed to (1) assess the safety and feasibility of using the HANK exoskeleton for walking rehabilitation, and (2) investigate the effects on walking function after a training program with it.

METHODS

A randomized controlled trial was conducted including a cohort of 23 patients with less than 1 year since injury, neurological level of injury (C2-L4) and severity (American Spinal Cord Injury Association Impairment Scale [AIS] C or D). The intervention was comprised of 15 one-hour gait training sessions with lower limb exoskeleton HANK. Safety was assessed through monitoring of adverse events, and pain and fatigue through a Visual Analogue Scale. LEMS, WISCI-II, and SCIM-III scales were assessed, along with the 10MWT, 6MWT, and the TUG walking tests (see text for acronyms).

RESULTS

No major adverse events were reported. Participants in the intervention group (IG) reported 1.8 cm (SD 1.0) for pain and 3.8 (SD 1.7) for fatigue using the VAS. Statistically significant differences were observed for the WISCI-II for both the "group" factor (F = 16.75, p < 0.001) and "group-time" interactions (F = 8.87; p < 0.01). A post-hoc analysis revealed a statistically significant increase of 3.54 points (SD 2.65, p < 0.0001) after intervention for the IG but not in the CG (0.7 points, SD 1.49, p = 0.285). No statistical differences were observed between groups for the remaining variables.

CONCLUSIONS

The use of HANK exoskeleton in clinical settings is safe and well-tolerated by the patients. Patients receiving treatment with the exoskeleton improved their walking independence as measured by the WISCI-II after the treatment.

Human Factors Assessment of a Novel Pediatric Lower-Limb Exoskeleton

While several lower-limb exoskeletons have been designed for adult patients, there remains a lack of pediatric-oriented devices. This paper presented a human factor assessment of an adjustable pediatric lower-limb exoskeleton for childhood gait assistance. The hip and knee exoskeleton uses an adjustable frame for compatibility with children 6–11 years old. This assessment evaluates the device’s comfort and ease of use through timed donning, doffing, and reconfiguration tasks. The able-bodied study participants donned the device in 6 min and 8 s, doffed it in 2 min and 29 s, and reconfigured it in 8 min and 23 s. The results of the timed trials suggest that the exoskeleton can be easily donned, doffed, and reconfigured to match the anthropometrics of pediatric users. A 6-min unpowered walking experiment was conducted while the child participant wore the exoskeletal device. Inspection of both the device and participant yielded no evidence of damage to either the device or wearer. Participant feedback on the device was positive with a system usability scale rating of 80/100. While minor improvements can be made to the adjustability indicators and padding placement, the results indicate the exoskeleton is suitable for further experimental evaluation through assistive control assessments.

Gait robot-assisted rehabilitation in persons with spinal cord injury: A scoping review

BACKGROUND

Many robots are available for gait rehabilitation (BWSTRT and ORET) and their application in persons with SCI allowed an improvement of walking function.

OBJECTIVE

The aim of the study is to compare the effects of different robotic exoskeletons gait training in persons with different SCI level and severity.

METHODS

Sixty-two studies were included in this systematic review; the study quality was assessed according to GRADE and PEDro's scale.

RESULTS

Quality assessment of included studies (n = 62) demonstrated a prevalence of evidence level 2; the quality of the studies was higher for BWSTRT (excellent and good) than for ORET (fair and good). Almost all persons recruited for BWSTRT had an incomplete SCI; both complete and incomplete SCI were recruited for ORET. The SCI lesion level in the persons recruited for BWSTRT are from cervical to sacral; mainly from thoracic to sacral for ORET; a high representation of AIS D lesion resulted both for BWSTRT (30%) and for ORET (45%). The walking performance, tested with 10MWT, 6MWT, TUG and WISCI, improved after exoskeleton training in persons with incomplete SCI lesions, when at least 20 sessions were applied. Persons with complete SCI lesions improved the dexterity in walking with exoskeleton, but did not recover independent walking function; symptoms such as spasticity, pain and cardiovascular endurance improved.

CONCLUSION

Different exoskeletons are available for walking rehabilitation in persons with SCI. The choice about the kind of robotic gait training should be addressed on the basis of the lesion severity and the possible comorbidities.

Organic Neuroelectronics: From Neural Interfaces to Neuroprosthetics

Requirements and recent advances in research on organic neuroelectronics are outlined herein. Neuroelectronics such as neural interfaces and neuroprosthetics provide a promising approach to diagnose and treat neurological diseases. However, the current neural interfaces are rigid and not biocompatible, so they induce an immune response and deterioration of neural signal transmission. Organic materials are promising candidates for neural interfaces, due to their mechanical softness, excellent electrochemical properties, and biocompatibility. Also, organic nervetronics, which mimics functional properties of the biological nerve system, is being developed to overcome the limitations of the complex and energy-consuming conventional neuroprosthetics that limit long-term implantation and daily-life usage. Examples of organic materials for neural interfaces and neural signal recordings are reviewed, recent advances of organic nervetronics that use organic artificial synapses are highlighted, and then further requirements for neuroprosthetics are discussed. Finally, the future challenges that must be overcome to achieve ideal organic neuroelectronics for next-generation neuroprosthetics are discussed.

A framework for clinical utilization of robotic exoskeletons in rehabilitation

Exoskeletons are externally worn motorized devices that assist with sit-to-stand and walking in individuals with motor and functional impairments. The Food & Drug Administration (FDA) has approved several of these technologies for clinical use however, there is limited evidence to guide optimal utilization in every day clinical practice. With the diversity of technologies & equipment available, it presents a challenge for clinicians to decide which device to use, when to initiate, how to implement these technologies with different patient presentations, and when to wean off the devices. Thus, we present a clinical utilization framework specific to exoskeletons with four aims.

These aims are to assist with clinical decision making of when exoskeleton use is clinically indicated, identification of which device is most appropriate based on patient deficits and device characteristics, providing guidance on dosage parameters within a plan of care and guidance for reflection following utilization. This framework streamlines how clinicians can approach implementation through the synthesis of published evidence with appropriate clinical assessment & device selection to reflection for success and understanding of these innovative & complex technologies.

Muscle adaptations in acute SCI following overground exoskeleton + FES training: A pilot study

Objective

To evaluate the combined effects of robotic exoskeleton and functional electrical stimulation (FES) training on muscle composition during over-ground gait training in persons with acute spinal cord injury (SCI).

Design

Randomized crossover pilot study.

Setting

Inpatient-rehabilitation Hospital.

Participants

Six individuals with acute SCI.

Intervention

Participants were randomized to either receive training with the Ekso® Bionics exoskeleton combined with FES in addition to standard-of-care or standard-of-care alone.

Outcome measures

The main outcome measures for the study were quantified using magnetic resonance imaging (MRI), specifically, lower extremity muscle volume and intramuscular adipose tissue (IMAT). Static balance and fall risk were assessed using the Berg Balance Scale.

Results

Significant improvements were observed in muscle volume in the exoskeleton intervention group when compared to only standard-of-care (p < 0.001). There was no significant difference between the groups in IMAT even though the intervention group saw a reduction in IMAT that trended towards statistical significance (p = 0.07). Static balance improved in both groups, with greater improvements seen in the intervention group.

Conclusions

Early intervention with robotic exoskeleton may contribute to improved muscle function measured using MRI in individuals with acute SCI.

Technology-assisted balance assessment and rehabilitation in individuals with spinal cord injury: A systematic review

BACKGROUND: Balance is a crucial function of basic Activities of Daily Living (ADL) and is often considered the priority in Spinal Cord Injury (SCI) patients’ rehabilitation. Technological devices have been developed to support balance assessment and training, ensuring an earlier, intensive, and goal-oriented motor therapy. OBJECTIVE: The aim of this systematic review is to explore the technology-assisted strategies to assess and rehabilitate balance function in persons with SCI. METHODS: A systematic review was conducted in the databases PubMed, Scopus, IEEE Xplore, Cochrane Library, and Embase. Full reports on Randomized Clinical Trials (RCTs) of parallel-group or cross-over design and non-RCTs were included according to the following criteria: i) publication year from 1990 to 2021; ii) balance considered as a primary or secondary outcome; iii) population of individuals with SCI with age over 18 years old, regardless of traumatic or non-traumatic lesions, Time Since Injury, lesion level, Asia Impairment Scale score and gender. The methodological quality was determined for each included study according to the recognized Downs and Black (D&B) tool. RESULTS: Nineteen articles met the inclusion criteria and were included in the analysis. Four articles focused on balance assessment while 15 targeted rehabilitation interventions to improve balance by using Treadmill-Based Devices (TBD), OverGround Devices (OGD) and Tilt Table Devices (TTD). Statistically significant effects on balance can be found in TBD subcategory, in the hip-knee guidance subcategory of OGD and in the study of TTD category. CONCLUSION: Although different studies reported positive effects, improvements due to technology-assisted rehabilitation were not greater than those obtained by means of other rehabilitation therapies. The heterogeneity, low methodological quality, and the small number of the studies included do not allow general conclusions about the usefulness of technology-assisted balance assessment and training in individuals with SCI, even if significant improvements have been reported in some studies.

Effects of robotic-assisted gait training on motor function and walking ability in children with thoracolumbar incomplete spinal cord injury

BACKGROUND: Spinal cord injury (SCI) results in neurological dysfunction of the spinal cord below the injury. OBJECTIVE: To explore the immediate and long-term effects of robotic-assisted gait training (RAGT) on the recovery of motor function and walking ability in children with thoracolumbar incomplete SCI. METHODS: Twenty-one children with thoracolumbar incomplete SCI were randomly divided into the experimental (n = 11) and control groups (n = 10). The control group received 60 min of conventional physical therapy, and the experimental group received 30 min of RAGT based on 30 minutes of conventional physical therapy. Changes in walking speed and distance, physiological cost index (PCI), lower extremity motor score (LEMS), SCI walking index and centre-of-pressure (COP) envelope area score were observed in both groups of children before and after eight weeks of training. The primary outcome measures were the 10-metre walk test (10MWT) and six-minute walk distance (6MWD) at preferred and maximal speeds. In addition, several other measures were assessed, such as postural control and balance, lower limb strength and energy expenditure. RESULTS: Compared with control group, the self-selected walk speed (SWS), maximum walking speed (MWS), 6MWD, PCI, LEMS, COP, and Walking Index for Spinal Cord injury II (WISCI II) of experimental group were improved after treatment. The 6MWD, PCI, COP, and WISCI II after eight weeks of treatment were improved in experimental group. All indicators were not identical at three different time points when compared between two groups. Pairwise comparisons in experimental group suggested that the SWS, MWS, 6MWD, PCI, LEMS, COP, and WISCI II after treatment were higher than those before treatment. The 6MWD, LEMS, COP, and WISCI II after treatment were higher than at the one-month follow-up appointment. The SWS, PCI, LEMS, COP, and WISCI II at the eight-week follow-up appointment were improved. CONCLUSION: Robotic-assisted gait training may significantly improve the immediate motor function and walking ability of children with thoracolumbar incomplete SCI.

Enhancing Voluntary Motion with Modular, Backdrivable, Powered Hip and Knee Orthoses

Mobility disabilities are prominent in society with wide-ranging deficits, motivating modular, partial-assist, lower-limb exoskeletons for this heterogeneous population. This paper introduces the Modular Backdrivable Lower-limb Unloading Exoskeleton (M-BLUE), which implements high torque, low mechanical impedance actuators on commercial orthoses with sheet metal modifications to produce a variety of hip- and/or knee-assisting configurations. Benchtop system identification verifies the desirable backdrive properties of the actuator, and allows for torque prediction within ±0.4 Nm. An able-bodied human subject experiment demonstrates that three unilateral configurations of M-BLUE (hip only, knee only, and hip-knee) with a simple gravity compensation controller can reduce muscle EMG readings in a lifting and lowering task relative to the bare condition. Reductions in mean muscular effort and peak muscle activation were seen across the primary squat musculature (excluding biceps femoris), demonstrating the potential to reduce fatigue leading to poor lifting posture. These promising results motivate applications of M-BLUE to additional populations, and the expansion of M-BLUE to bilateral and ankle configurations.

Passive double pendulum in the wake of a cylinder forced to rotate emulates a cyclic human walking gait

The goal of this work is to present a method based on fluid-structure interactions to enforce a desired trajectory on a passive double pendulum. In our experiments, the passive double pendulum represents human thigh and shank segments, and the interaction between the fluid and the structure comes from a hydrofoil attached to the double pendulum and interacting with the vortices that are shed from a cylinder placed upstream. When a cylinder is placed in flow, vortices are shed in the wake of the cylinder. When the cylinder is forced to rotate periodically, the frequency of the vortices that are shed in its wake can be controlled by controlling the frequency of cylinder's rotation. These vortices exert periodic forces on any structure placed in the wake of this cylinder. In our system, we place a double pendulum fitted with a hydrofoil at its distal end in the wake of a rotating cylinder. The vortices exert periodic forces on this hydrofoil which then forces the double pendulum to oscillate. We control the cylinder to rotate periodically, and measure the displacement of the double pendulum. By comparing the joint positions of the double pendulum with those of human hip, knee and ankle joint positions during walking, we show how the system is able to generate a human walking gait cycle on the double pendulum only using the interactions between the vortices and the hydrofoil.

The Cardiorespiratory Demands of Treadmill Walking with and without the Use of Ekso GT™ within Able-Bodied Participants: A Feasibility Study

Individuals with neurological impairments tend to lead a predominantly sedentary lifestyle due to impaired gait function and mobility. This may be detrimental to health by negatively impacting cardiorespiratory fitness and muscular strength, and increasing the risk of developing secondary health problems. Powered exoskeletons are assistive devices that may aid neurologically impaired individuals in achieving the World Health Organisation's (WHO) physical activity (PA) guidelines for health. Increased PA should elicit a sufficient cardiorespiratory stimulus to provide health benefits to exoskeleton users. This study examined the cardiorespiratory demands of treadmill walking with and without the Ekso GT™ among able-bodied participants. The Ekso GT™ is a powered exoskeleton that enables individuals with neurological impairments to walk by supporting full body mass with motors attached at the hip and knee joints to generate steps. This feasibility study consisted of one group of healthy able-bodied individuals (n = 8). Participants completed two 12 min treadmill walking assessments, one with and one without the Ekso GT™ at the same fixed speed. Throughout each walking bout, various cardiorespiratory parameters, namely, volume of oxygen per kilogram (kg) of body mass (V˙O2·kg-1), volume of carbon dioxide per kg of body mass (V˙CO2·kg-1), respiratory exchange ratio (RER), ventilation (V˙E), heart rate (HR), and rate of perceived exertion (RPE), were recorded. Treadmill walking with Ekso GT™ elevated all recorded measurements to a significantly greater level (p ≤ 0.05) (except RER at 1 km·h-1; p = 0.230) than treadmill walking without the Ekso GT™ did at the same fixed speed. An increased cardiorespiratory response was recorded during treadmill walking with the exoskeleton. Exoskeleton walking may, therefore, be an effective method to increase PA levels and provide sufficient stimulus in accordance with the PA guidelines to promote cardiorespiratory fitness and subsequently enhance overall health.

Industrial exoskeletons for overhead work: Circumferential pressures on the upper arm caused by the physical human-machine-interface

This study investigated the pressures occurring within the arm human-machine-interfaces (HMI) of four different exoskeletons that support static and dynamic work at or above head level, and the effects of the HMI on neurovascular supply of the upper extremity using an orthopedic provocation maneuver with raised arms with and without the exoskeletons. Decreased time in the provocation maneuver with exoskeletons indicated a negative effect of the HMIs on the vascular and neural supply of the arm. Average pressure in the static situation was 3.2 ± 0.7 kPa and 4.4 ± 0.4 kPa with regular peak values of 6.5 ± 0.5 kPa in the dynamic task. These pressures were significantly higher than the pressure values that guarantee adequate tissue oxygenation. It remains unknown whether the way exoskeletons apply pressure affects vascular and neural supply to the arms, or whether the regular unloading during dynamic activity has a neutralizing effect.

Comparison of Efficacy of Lokomat and Wearable Exoskeleton-Assisted Gait Training in People With Spinal Cord Injury: A Systematic Review and Network Meta-Analysis

Objective

Lokomat and wearable exoskeleton-assisted walking (EAW) have not been directly compared previously. To conduct a network meta-analysis of randomized and non-randomized controlled trials to assess locomotor abilities achieved with two different types of robotic-assisted gait training (RAGT) program in persons with spinal cord injury (SCI).

Methods

Three electronic databases, namely, PubMed, Embase, and the Cochrane Library, were systematically searched for randomized and non-randomized controlled trials published before August 2021, which assessed locomotor abilities after RAGT.

Results

Of 319 studies identified for this review, 12 studies were eligible and included in our analysis. Studies from 2013 to 2021 were covered and contained 353 valid data points (N-353) on patients with SCI receiving wearable EWA and Lokomat training. In the case of wearable EAW, the 10-m walk test (10-MWT) distance and speed scores significantly increased [distance: 0.85 (95% CI = 0.35, 1.34); speed: −1.76 (95% CI = −2.79, −0.73)]. The 6-min walk test (6-MWT) distance [−1.39 (95% CI = −2.01, −0.77)] and the timed up and go (TUG) test significantly increased [(1.19 (95% CI = 0.74, 1.64)], but no significant difference was observed in the walking index for spinal cord injury (WISCI-II) [−0.33 (95% CI = −0.79, 0.13)]. Among the patients using Lokomat, the 10-MWT-distance score significantly increased [−0.08 (95% CI = −0.14, −0.03)] and a significant increase in the WISCI-II was found [1.77 (95% CI = 0.23, 3.31)]. The result of network meta-analysis showed that the probability of wearable EAW to rank first and that of Lokomat to rank second was 89 and 47%, respectively, in the 10-MWT speed score, while that of Lokomat to rank first and wearable EAW to rank second was 73 and 63% in the WISCI-II scores.

Conclusion

Lokomat and wearable EAW had effects on the performance of locomotion abilities, namely, distance, speed, and function. Wearable EAW might lead to better outcomes in walking speed compared with that in the case of Lokomat.

Body Representation in Patients with Severe Spinal Cord Injury: A Pilot Study on the Promising Role of Powered Exoskeleton for Gait Training

Patients with spinal cord injury (SCI) complain of changes in body representation, potentially leading to negative physical and psychological consequences. The purpose of our study is to evaluate the effects of robotic training with the Ekso-GT on body representation (BR) and on the quality of life in patients with SCI. The trial was designed as a pilot, assessor-blinded study. Forty-two inpatients with a diagnosis of SCI, classified as either American Spinal Cord Injury Association Impairment Scale (AIS), were enrolled in this study and randomized into either a control (CG: n = 21) or an experimental (EG: n = 21) group. Patients in the EG received rehabilitation training with the Ekso-GT device, whereas the CG patients were trained with conventional physical therapy (CPT), which consisted of physical and occupational therapy and psychological support. We considered as a primary outcome the modified Body Uneasiness Test (MBUT), focusing on three specific subscales on the patient’s perception of BR, i.e., the Global Severity Index (MBUT-GSI), which is an indicator of body suffering; the Positive Symptom Distress Index (MBUT-PSDI) that expresses an individual’s psychological distress; and the Lower Limb MBUT (MBUT-LL), which indicates the subject’s perception of their thighs/legs. The Short-Form-12 Health Status Questionnaire (SF12) and the Beck’s Depression Inventory (BDI) were used as secondary outcomes to evaluate the effect of the training on the quality of life and the psychological status. Non-parametric statistical analysis showed that the effect of the two treatments was significantly different on MBUT (BR), SF-12 (quality of life), and, partially, BDI (mood). Particularly, patients belonging to the EG achieved a major improvement in nearly all test scores compared to those in the CG. Our data suggest that the Ekso-GT training could be helpful in achieving positive changes in BR in patients with chronic SCI, especially in reducing psychological distress (PSDI) and thigh/leg perception (MBUT-LL) with an overall improvement in quality of life (SF-12).

Overground robotic training effects on walking and secondary health conditions in individuals with spinal cord injury: systematic review

Overground powered lower limb exoskeletons (EXOs) have proven to be valid devices in gait rehabilitation in individuals with spinal cord injury (SCI). Although several articles have reported the effects of EXOs in these individuals, the few reviews available focused on specific domains, mainly walking. The aim of this systematic review is to provide a general overview of the effects of commercial EXOs (i.e. not EXOs used in military and industry applications) for medical purposes in individuals with SCI. This systematic review was conducted following the PRISMA guidelines and it referred to MED-LINE, EMBASE, SCOPUS, Web of Science and Cochrane library databases. The studies included were Randomized Clinical Trials (RCTs) and non-RCT based on EXOs intervention on individuals with SCI. Out of 1296 studies screened, 41 met inclusion criteria. Among all the EXO studies, the Ekso device was the most discussed, followed by ReWalk, Indego, HAL and Rex devices. Since 14 different domains were considered, the outcome measures were heterogeneous. The most investigated domain was walking, followed by cardiorespiratory/metabolic responses, spasticity, balance, quality of life, human–robot interaction, robot data, bowel functionality, strength, daily living activity, neurophysiology, sensory function, bladder functionality and body composition/bone density domains. There were no reports of negative effects due to EXOs trainings and most of the significant positive effects were noted in the walking domain for Ekso, ReWalk, HAL and Indego devices. Ekso studies reported significant effects due to training in almost all domains, while this was not the case with the Rex device. Not a single study carried out on sensory functions or bladder functionality reached significance for any EXO. It is not possible to draw general conclusions about the effects of EXOs usage due to the lack of high-quality studies as addressed by the Downs and Black tool, the heterogeneity of the outcome measures, of the protocols and of the SCI epidemiological/neurological features. However, the strengths and weaknesses of EXOs are starting to be defined, even considering the different types of adverse events that EXO training brought about. EXO training showed to bring significant improvements over time, but whether its effectiveness is greater or less than conventional therapy or other treatments is still mostly unknown. High-quality RCTs are necessary to better define the pros and cons of the EXOs available today. Studies of this kind could help clinicians to better choose the appropriate training for individuals with SCI.

Knowledge Gaps in Biophysical Changes After Powered Robotic Exoskeleton Walking by Individuals With Spinal Cord Injury—A Scoping Review

In addition to helping individuals with spinal cord injury (SCI) regain the ability to ambulate, the rapidly evolving capabilities of robotic exoskeletons provide an array of secondary biophysical benefits which can reduce the complications resulting from prolonged immobilization. The proposed benefits of increased life-long over-ground walking capacity include improved upper body muscular fitness, improved circulatory response, improved bowel movement regularity, and reduced pain and spasticity. Beyond the positive changes related to physical and biological function, exoskeletons have been suggested to improve SCI individuals' quality of life (QOL) by allowing increased participation in day-to-day activities. Most of the currently available studies that have reported on the impact of exoskeletons on the QOL and prevention of secondary health complications on individuals with SCI, are of small scale and are heterogeneous in nature. Moreover, few meta-analyses and reviews have attempted to consolidate the dispersed data to reach more definitive conclusions of the effects of exoskeleton use. This scoping review seeks to provide an overview on the known effects of overground exoskeleton use, on the prevention of secondary health complications, changes to the QOL, and their effect on the independence of SCI individuals in the community settings. Moreover, the intent of the review is to identify gaps in the literature currently available, and to make recommendations on focus study areas and methods for future investigations.

Exoskeletons for Mobility after Spinal Cord Injury: A Personalized Embodied Approach

Endowed with inherent flexibility, wearable robotic technologies are powerful devices that are known to extend bodily functionality to assist people with spinal cord injuries (SCIs). However, rather than considering the specific psychological and other physiological needs of their users, these devices are specifically designed to compensate for motor impairment. This could partially explain why they still cannot be adopted as an everyday solution, as only a small number of patients use lower-limb exoskeletons. It remains uncertain how these devices can be appropriately embedded in mental representations of the body. From this perspective, we aimed to highlight the homeostatic role of autonomic and interoceptive signals and their possible integration in a personalized experience of exoskeleton overground walking. To ensure personalized user-centered robotic technologies, optimal robotic devices should be designed and adjusted according to the patient's condition. We discuss how embodied approaches could emerge as a means of overcoming the hesitancy toward wearable robots.

Walking improvement in chronic incomplete spinal cord injury with exoskeleton robotic training (WISE): a randomized controlled trial

STUDY DESIGN

Clinical trial.

OBJECTIVE

To demonstrate that a 12-week exoskeleton-based robotic gait training regimen can lead to a clinically meaningful improvement in independent gait speed, in community-dwelling participants with chronic incomplete spinal cord injury (iSCI).

SETTING

Outpatient rehabilitation or research institute.

METHODS

Multi-site (United States), randomized, controlled trial, comparing exoskeleton gait training (12 weeks, 36 sessions) with standard gait training or no gait training (2:2:1 randomization) in chronic iSCI (>1 year post injury, AIS-C, and D), with residual stepping ability. The primary outcome measure was change in robot-independent gait speed (10-meter walk test, 10MWT) post 12-week intervention. Secondary outcomes included: Timed-Up-and-Go (TUG), 6-min walk test (6MWT), Walking Index for Spinal Cord Injury (WISCI-II) (assistance and devices), and treating therapist NASA-Task Load Index.

RESULTS

Twenty-five participants completed the assessments and training as assigned (9 Ekso, 10 Active Control, 6 Passive Control). Mean change in gait speed at the primary endpoint was not statistically significant. The proportion of participants with improvement in clinical ambulation category from home to community speed post-intervention was greatest in the Ekso group (>1/2 Ekso, 1/3 Active Control, 0 Passive Control, p < 0.05). Improvements in secondary outcome measures were not significant.

CONCLUSIONS

Twelve weeks of exoskeleton robotic training in chronic SCI participants with independent stepping ability at baseline can improve clinical ambulatory status. Improvements in raw gait speed were not statistically significant at the group level, which may guide future trials for participant inclusion criteria. While generally safe and tolerable, larger gains in ambulation might be associated with higher risk for non-serious adverse events.

Neurorehabilitation using a voluntary driven exoskeletal robot improves trunk function in patients with chronic spinal cord injury: a single-arm study

Body weight-supported treadmill training with the voluntary driven exoskeleton (VDE-BWSTT) has been shown to improve the gait function of patients with chronic spinal cord injury. However, little is known whether VDE-BWSTT can effectively improve the trunk function of patients with chronic spinal cord injury. In this open-label, single-arm study, nine patients with chronic spinal cord injury at the cervical or thoracic level (six males and three females, aged 37.8 ± 15.6 years, and time since injury 51.1 ± 31.8 months) who underwent outpatient VDE-BWSTT training program at Keio University Hospital, Japan from September 2017 to March 2019 were included. All patients underwent twenty 60-minute gait training sessions using VDE. Trunk muscular strength, i.e., the maximum force against which patient could maintain a sitting posture without any support, was evaluated in four directions: anterior, posterior, and lateral (right and left) after 10 and 20 training sessions. After intervention, lateral muscular strength significantly improved. In addition, a significant positive correlation was detected between the change in lateral trunk muscular strength after 20 training sessions relative to baseline and gait speed. The change in trunk muscular strength after 20 training sessions relative to baseline was greatly correlated with patient age. This suggests that older adult patients with chronic spinal cord injury achieved a greater improvement in trunk muscle strength following VDE-BWSTT. All these findings suggest that VDE-BWSTT can improve the trunk function of patients with chronic spinal cord injury and the effect might be greater in older adult patients. The study was approved by the Keio University of Medicine Ethics Committee (IRB No. 20150355-3) on September 26, 2017.

Stage 2: Who Are the Best Candidates for Robotic Gait Training Rehabilitation in Hemiparetic Stroke?

We aimed to compare the effects of robotic-assisted gait training (RAGT) in patients with FAC < 2 (low initial functional ambulation category [LFAC]) and FAC ≥ 2 (high initial functional ambulation category [HFAC]) on sensorimotor and spasticity, balance and trunk stability, the number of steps and walking distance in subacute hemiparetic stroke. Fifty-seven patients with subacute hemiparetic stroke (mean age, 63.86 ± 12.72 years; 23 women) were assigned to two groups. All patients received a 30-min Walkbot-assisted gait training session, 3 times/week, for 6 weeks. Clinical outcomes included scores obtained on the Fugl-Meyer Assessment (FMA) scale, Modified Ashworth Scale (MAS), Berg Balance Scale (BBS), trunk impairment scale (TIS), and the number of walking steps and walking distance. Analysis of covariance and analysis of variance were conducted at p < 0.05. Significant main effects of time in both groups on number of walking steps and distance (p < 0.05) were observed, but not in MAS (p> 0.05). Significant changes in FMA, BBS, and TIS scores between groups (p < 0.05) were observed. Significant main effects of time on BBS and TIS were demonstrated (p < 0.05). Our study shows that RAGT can maximize improvement in the functional score of FMA, BBS, TIS, steps, and distance during neurorehabilitation of subacute stroke patients regardless of their FAC level.

Exploring Stroke Rehabilitation in Malaysia: Are Robots Better than Humans for Stroke Recuperation?

Ranked as the second leading cause of death and the primary factor to adult disability worldwide, stroke has become a global epidemic problem and burden. As a developing country, Malaysia still faces challenges in providing ideal rehabilitation services to individuals with physical disabilities including stroke survivors. Conventional post-stroke care is often delivered in a team-based approach and involves several disciplines, such as physical therapy, occupational therapy, speech and language therapy, depending on the nature and severity of the deficits. Robots are potential tools for stroke rehabilitation as they can enhance existing conventional therapy by delivering a precise and consistent therapy of highly repetitive movements. In addition, robot-assisted physiotherapy could facilitate the effectiveness of unsupervised rehabilitation and thus, may reduce the cost and duration of therapist-assisted rehabilitation. Research on robot-assisted physiotherapy for stroke in Malaysia is slowly coming into the limelight in the past two decades. This review explores the effectiveness of robot-assisted physiotherapy particularly in improving motor functions of stroke survivors in Malaysia.

Performance Evaluation of Lower Limb Exoskeletons: A Systematic Review

Benchmarks have long been used to verify and compare the readiness level of different technologies in many application domains. In the field of wearable robots, the lack of a recognized benchmarking methodology is one important impediment that may hamper the efficient translation of research prototypes into actual products. At the same time, an exponentially growing number of research studies are addressing the problem of quantifying the performance of robotic exoskeletons, resulting in a rich and highly heterogeneous picture of methods, variables and protocols. This review aims to organize this information, and identify the most promising performance indicators that can be converted into practical benchmarks. We focus our analysis on lower limb functions, including a wide spectrum of motor skills and performance indicators. We found that, in general, the evaluation of lower limb exoskeletons is still largely focused on straight walking, with poor coverage of most of the basic motor skills that make up the activities of daily life. Our analysis also reveals a clear bias towards generic kinematics and kinetic indicators, in spite of the metrics of human-robot interaction. Based on these results, we identify and discuss a number of promising research directions that may help the community to attain a comprehensive benchmarking methodology for robot-assisted locomotion more efficiently.

A Muscle-First, Electromechanical Hybrid Gait Restoration System in People With Spinal Cord Injury

The development of a hybrid system for people with spinal cord injuries is described. The system includes implanted neural stimulation to activate the user's otherwise paralyzed muscles, an exoskeleton with electromechanical actuators at the hips and knees, and a sensory and control system that integrates both components. We are using a muscle-first approach: The person's muscles are the primary motivator for his/her joints and the motors provide power assistance. This design philosophy led to the development of high efficiency, low friction joint actuators, and feed-forward, burst-torque control. The system was tested with two participants with spinal cord injury (SCI) and unique implanted stimulation systems. Torque burst addition was found to increase gait speed. The system was found to satisfy the main design requirements as laid out at the outset.

The Effects of Powered Exoskeleton Gait Training on Cardiovascular Function and Gait Performance: A Systematic Review

Patients with neurological impairments often experience physical deconditioning, resulting in reduced fitness and health. Powered exoskeleton training may be a successful method to combat physical deconditioning and its comorbidities, providing patients with a valuable and novel experience. This systematic review aimed to conduct a search of relevant literature, to examine the effects of powered exoskeleton training on cardiovascular function and gait performance. Two electronic database searches were performed (2 April 2020 to 12 February 2021) and manual reference list searches of relevant manuscripts were completed. Studies meeting the inclusion criteria were systematically reviewed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. n = 63 relevant titles were highlighed; two further titles were identified through manual reference list searches. Following analysis n = 23 studies were included. Data extraction details included; sample size, age, gender, injury, the exoskeleton used, intervention duration, weekly sessions, total sessions, session duration and outcome measures. Results indicated that exoskeleton gait training elevated energy expenditure greater than wheelchair propulsion and improved gait function. Patients exercised at a moderate-intensity. Powered exoskeletons may increase energy expenditure to a similar level as non-exoskeleton walking, which may improve cardiovascular function more effectively than wheelchair propulsion alone.

A Real-Time Stability Control Method Through sEMG Interface for Lower Extremity Rehabilitation Exoskeletons

Herein, we propose a real-time stable control gait switching method for the exoskeleton rehabilitation robot. Exoskeleton rehabilitation robots have been extensively developed during the past decade and are able to offer valuable motor ability to paraplegics. However, achieving stable states of the human-exoskeleton system while conserving wearer strength remains challenging. The constant switching of gaits during walking may affect the center of gravity, resulting in imbalance of human–exoskeleton system. In this study, it was determined that forming an equilateral triangle with two crutch-supporting points and a supporting leg has a positive impact on walking stability and ergonomic interaction. First, the gaits planning and stability analysis based on human kinematics model and zero moment point method for the lower limb exoskeleton are demonstrated. Second, a neural interface based on surface electromyography (sEMG), which realizes the intention recognition and muscle fatigue estimation, is constructed. Third, the stability of human–exoskeleton system and ergonomic effects are tested through different gaits with planned and unplanned gait switching strategy on the SIAT lower limb rehabilitation exoskeleton. The intention recognition based on long short-term memory (LSTM) model can achieve an accuracy of nearly 99%. The experimental results verified the feasibility and efficiency of the proposed gait switching method for enhancing stability and ergonomic effects of lower limb rehabilitation exoskeleton.

Robotic Locomotor Training Leads to Cardiovascular Changes in Individuals With Incomplete Spinal Cord Injury Over a 24-Week Rehabilitation Period: A Randomized Controlled Pilot Study

OBJECTIVE

To describe the effect of robotic locomotor training (RLT) and activity-based training (ABT) on cardiovascular indices during various physiological positions in individuals with spinal cord injury.

DESIGN

Randomized controlled pilot study.

SETTING

Private practice: Therapy & Beyond Centre - Walking with Brandon Foundation, Sports Science Institute of South Africa, Cape Town, South Africa.

PARTICIPANTS

Participants with chronic traumatic motor incomplete tetraplegia (N=16) who resided in the Western Cape, South Africa.

INTERVENTION

Robotic locomotor training (Ekso GT) and activity-based training over a 24-week intervention.

MAIN OUTCOME MEASURES

Brachial and ankle blood pressure, heart rate, heart rate variability, and cardiovascular efficiency during 4 physiological positions.

RESULTS

No differences between groups or over time were evident in resting systolic and diastolic blood pressure, ankle systolic pressure, ankle brachial pressure index, and heart rate variability. Standing heart rate at 24 weeks was significantly higher in the ABT group (95.58±12.61 beats/min) compared with the RLT group (75.14±14.96 beats/min) (P=.05). In the RLT group, no significant changes in heart rate variability (standard deviation R-R interval and root mean square of successive differences) was found between the standing and 6-minute walk test physiological positions throughout the intervention. Cardiovascular efficiency in the RLT group during the 6-minute walk test improved from 11.1±2.6 at baseline to 7.5±2.8 beats per meter walked at 6 weeks and was maintained from 6 to 24 weeks.

CONCLUSIONS

Large effect sizes and significant differences between groups found in this pilot study support the clinical effectiveness of RLT and ABT for changing cardiovascular indices as early as 6 weeks and up to 24 weeks of rehabilitation. RLT may be more effective than ABT in improving cardiac responses to orthostatic stress. Based on heart rate variability metrics, the stimulus of standing has comparable effects to RLT on the parasympathetic nervous system. Cardiovascular efficiency of exoskeleton walking improved, particularly over the first 6 weeks. Both the RLT and ABT interventions were limited in their effect on brachial and ankle blood pressure. A randomized controlled trial with a larger sample size is warranted to further examine these findings.

Exoskeletal-assisted walking may improve seated balance in persons with chronic spinal cord injury: a pilot study

STUDY DESIGN

Pre-post intervention.

OBJECTIVE

To explore the potential effect of exoskeletal-assisted walking (EAW) on seated balance for persons with chronic motor complete spinal cord injury (SCI).

SETTING

A SCI research center.

METHODS

Eight participants who were over 18 years of age with chronic SCI and used a wheelchair for mobility were enrolled. Seven able-bodied participants were used for normal seated balance comparative values. Participants with chronic SCI received supervised EAW training using a powered exoskeleton (ReWalk^TM) for a median 30 sessions (range from 7 to 90 sessions). Before and after EAW training, seated balance testing outcomes were collected using computerized dynamic posturography, providing measurements of endpoint excursion (EPE), maximal excursion (MXE), and directional control (DCL). Modified functional reach test (MFRT) and the sub-scales of physical functioning and role limitations due to physical health from the Short Form (36) Health Survey (SF-36) were used to identify changes in functional activities.

RESULTS

After EAW training, seated balance significantly improved in total-direction EPE and MXE (P < 0.01 and P < 0.017 respectively). The results of MFRT and sub-scales of physical functioning and role limitations due to physical health improved after EAW training but were not statistically significant.

CONCLUSIONS

EAW training may have the potential to improve seated balance for persons with chronic motor complete SCI. Due to the limitations of the study, such as small sample size and lack of a control group, further studies are needed to clarify the effect of improving seated balance through EAW training.

Effects of robotic-assisted gait training on the central vascular health of individuals with spinal cord injury: A pilot study

Objective: To investigate the effect of a short-term, robotic-assisted (exoskeleton) gait training (RGT) program on central and peripheral hemodynamic measures in patients with spinal cord injury (SCI).Design: Parallel group, non-randomized trial with before (baseline) and after (follow-up) assessments.Setting: Single-center, community-based neuro-physiotherapy practice.Participants: Twelve individuals with SCI (ASI A to C).Interventions: Participants completed either a 5-day RGT program plus physiotherapy (n = 6), or a usual care physiotherapy only program (control group; n = 6). The RGT program consisted of daily 60-min physiotherapy and 90-min of RGT. Outcome measures were measured before and after the rehabilitation program.Main outcome measure(s): The primary outcome measure was arterial wave reflection (Augmentation index [AIx]), with central and peripheral blood pressures also reported. Data are presented as mean (SD) and effect sizes (partial eta squared; η2p).Results: There was a significant reduction in AIx (30 ± 18-21 ± 15%; η2p=0.75) and mean arterial pressure (89 ± 11-82 ± 10 mmHg; η2p=0.47) following completion of the RGT program (both P < 0.05). There were no changes in these measures for the control group. Although not significantly different, medium to large effects were observed in favor of RGT for all other central and peripheral measures (η2p=0.06-0.21), except for heart rate and pulse pressure (η2p<0.04).Conclusions: RGT using an exoskeleton is a promising therapy for improving cardiovascular health in patients with SCI. Specifically, this study indicates decreased arterial wave reflection and supports the need for larger randomized controlled trials.Trial Registration: Clinical trials Registry (https://clinicaltrials.gov/; NCT03611803).

Effects of Exercise-Based Interventions on Urogenital Outcomes in Persons with Spinal Cord Injury: A Systematic Review and Meta-Analysis

In this systematic review, objectives were to investigate dropout rates, adverse events, and effects of exercise-based therapies on urogenital function and quality of life (QoL) in persons with spinal cord injury (SCI). Database searches were conducted on MEDLINE, EMBASE, and CINAHL for studies examining any form of exercise intervention on urogenital function and/or QoL in adults with SCI. Quality of publications was evaluated using the Joanna Briggs Institute critical evaluation tools. When possible, Hedges' g was calculated for overall effect sizes. Subgroup analyses were conducted on sex and injury severity. Ten studies (228 participants) were included in this review. Three studies examined pelvic floor muscle training, and seven studies examined locomotor training. Overall quality of evidence was low because of small sample sizes and non-randomized designs in most studies. Dropout rates ranged from 12% to 25%, and adverse events were reported only in some studies investigating locomotor training. For lower urinary tract (LUT) outcomes, urodynamic findings were mixed despite moderately positive changes in maximum bladder capacity (g = 0.50) and bladder compliance (g = 0.37). Fairly consistent, but small, improvements were observed in LUT symptoms, primarily bladder awareness and incontinence. LUT QoL improved in most cases. Fewer data were available for sexual outcomes, and only minor improvements were reported. Subgroup analyses, based on sex and severity of injury, were inconclusive. There is some indication for the potential benefit of exercise on urogenital outcomes in persons with SCI, but there is insufficient evidence given the number of studies and heterogeneity of outcome measures.