Effect of wearable chair on gait, balance, and discomfort of new users during level walking with anterior loads.

INTRODUCTION: Walking with anterior loads is common in industrial scenarios, but as exoskeletons are increasingly used in work environments to alleviate musculoskeletal disorders (MSDs), this new "human-robot" system composed of the human body and exoskeleton may be associated with new risks and harm that warrant further investigation. Therefore, this study will discuss the effect of a wearable chair on the gait, balance, and discomfort of new users with different weights of anterior loads during level walking. METHOD: Twenty-two healthy subjects (sex balanced) participated in the experiment. Each exposure comprised one of two exoskeleton states (with/without) and four load conditions: No carried load, carrying an empty box (0.3 kg), 5%Body Weight (BW), and 10%BW. The order of exoskeleton states and load conditions was randomly assigned. Using an eight-camera motion capture system to record the entire movement. And the subjective discomfort and perceived balance after each exposure were recorded on an 11-point numeric rating scale, respectively. Using SPSS 26.0 software (IBM Inc., Chicago) to conduct statistical analyses. RESULTS: Level walking with a wearable chair in different load conditions significantly affected gait parameters (like cadence) and gait balance. The perceived balance decreased with the exoskeleton, consistent with objective results. For subjective discomfort, wearing the exoskeleton significantly impacted global discomfort. Also, it increased the local discomfort of the shoulders, waist, thighs, shanks, and feet/ankles. CONCLUSIONS: For new users, the risk of losing balance or falling may be increased when wearing an exoskeleton for non-target task behaviors (level walking/anterior load), and caution is recommended when the anterior load exceeds 5% BW. PRACTICAL APPLICATION: The proposed strategy for assessing human gait, balance, and discomfort in wearable chairs may be applied during the iterative design of the product. These controls will help develop training programs and implementation guidelines for this exoskeleton type.

Effect of robotic exoskeleton gait training during acute stroke on functional ambulation.

BACKGROUND: Stroke is a leading cause of disability resulting in long-term functional ambulation deficits. Conventional therapy can improve ambulation, but may not be able to provide consistent, high dose repetition of movement, resulting in variable recovery with residual gait deviations. OBJECTIVE: The objective of this preliminary prospective investigation is to evaluate the ability of a robotic exoskeleton (RE) to provide high dose gait training, and measure the resulting therapeutic effect on functional ambulation in adults with acute stroke. METHODS: Participants (n = 14) received standard of care (SOC) and RE overground gait training during their scheduled physical therapy (PT) sessions at the same inpatient rehabilitation facility. The outcome measures included distance walked during their PT training sessions (RE and SOC), and functional ambulation measures (10-meter walk test (10MWT), 6-minute walk test (6 MWT), and timed up and go (TUG)). RESULTS: The average total distance walked during RE and the average distance per RE session was significantly higher than SOC sessions. Total walking distance during PT (RE+SOC) showed a strong positive correlation to the total number of steps during RE sessions and number of RE sessions. All functional ambulation measures showed significant improvement at follow-up compared to baseline. The improvement in functional ambulation measures showed a positive correlation with the increase in number of RE gait training sessions. CONCLUSION: The RE can be utilized for inpatient rehabilitation in conjunction with SOC gait training sessions and may result in improved functional ambulation in adults with acute stroke. This preliminary research provides information on the ability of the robotic exoskeleton to provide high dose therapy and its therapeutic effect on functional ambulation in adults with acute stroke during inpatient rehabilitation.

The Effects of Upper-Body Exoskeletons on Human Metabolic Cost and Thermal Response during Work Tasks-A Systematic Review.

BACKGROUND: New wearable assistive devices (exoskeletons) have been developed for assisting people during work activity or rehabilitation. Although exoskeletons have been introduced into different occupational fields in an attempt to reduce the risk of work-related musculoskeletal disorders, the effectiveness of their use in workplaces still needs to be investigated. This systematic review focused on the effects of upper-body exoskeletons (UBEs) on human metabolic cost and thermophysiological response during upper-body work tasks. METHODS: articles published until 22 September 2020 were selected from Scopus, Web of Science, and PubMed for eligibility and the potential risk of bias was assessed. RESULTS: Nine articles resulted in being eligible for the metabolic aspects, and none for the thermal analysis. All the studies were based on comparisons between conditions with and without exoskeletons and considered a total of 94 participants (mainly males) performing tasks involving the trunk or overhead work, 7 back-support exoskeletons, and 1 upper-limb support exoskeleton. Eight studies found a significant reduction in the mean values of the metabolic or cardiorespiratory parameters considered and one found no differences. CONCLUSIONS: The reduction found represents a preliminary finding that needs to be confirmed in a wider range of conditions, especially in workplaces, where work tasks show different characteristics and durations compared to those simulated in the laboratory. Future developments should investigate the dependence of metabolic cost on specific UBE design approaches during tasks involving the trunk and the possible statistical correlation between the metabolic cost and the surface ElectroMyoGraphy (sEMG) parameters. Finally, it could be interesting to investigate the effect of exoskeletons on the human thermophysiological response.

Assessing the potential for "undesired" effects of passive back-support exoskeleton use during a simulated manual assembly task: Muscle activity, posture, balance, discomfort, and usability.

Back-support exoskeletons (BSEs) are wearable systems designed to reduce physical demands on the back, but which could have undesired effects beyond this design intention. Participants (n = 18) used two commercial BSEs to complete a brief (~15-20 s) simulated manual assembly task in varying conditions, with outcome measures that included: working posture, activity levels in "secondary" muscle groups (shoulders and thighs), perceived balance, discomfort, and usability. Using a BSE led to small and inconsistent changes in working postures (e.g., < ~14° change in lumbar flexion), muscular activity in the secondary muscle groups (<±2% of maximum voluntary isometric contractions), or perceived balance. Limitations in movement were reported for both BSEs, however, along with moderate levels of discomfort. Task-specific responses were evident for all outcome measures, though these depended on the specific BSE used and differed between genders in many cases. Future work should focus on interactions between a given user, BSE design, and task conditions.

The ReWalk ReStore™ soft robotic exosuit: a multi-site clinical trial of the safety, reliability, and feasibility of exosuit-augmented post-stroke gait rehabilitation.

BACKGROUND: Atypical walking in the months and years after stroke constrain community reintegration and reduce mobility, health, and quality of life. The ReWalk ReStore™ is a soft robotic exosuit designed to assist the propulsion and ground clearance subtasks of post-stroke walking by actively assisting paretic ankle plantarflexion and dorsiflexion. Previous proof-of-concept evaluations of the technology demonstrated improved gait mechanics and energetics and faster and farther walking in users with post-stroke hemiparesis. We sought to determine the safety, reliability, and feasibility of using the ReStore™ during post-stroke rehabilitation. METHODS: A multi-site clinical trial (NCT03499210) was conducted in preparation for an application to the United States Food and Drug Administration (FDA). The study included 44 users with post-stroke hemiparesis who completed up to 5 days of training with the ReStore™ on the treadmill and over ground. In addition to primary and secondary endpoints of safety and device reliability across all training activities, an exploratory evaluation of the effect of multiple exposures to using the device on users' maximum walking speeds with and without the device was conducted prior to and following the five training visits. RESULTS: All 44 study participants completed safety and reliability evaluations. Thirty-six study participants completed all five training days. No device-related falls or serious adverse events were reported. A low rate of device malfunctions was reported by clinician-operators. Regardless of their reliance on ancillary assistive devices, after only 5 days of walking practice with the device, study participants increased both their device-assisted (Δ: 0.10 ± 0.03 m/s) and unassisted (Δ: 0.07 ± 0.03 m/s) maximum walking speeds (P's < 0.05). CONCLUSIONS: When used under the direction of a licensed physical therapist, the ReStore™ soft exosuit is safe and reliable for use during post-stroke gait rehabilitation to provide targeted assistance of both paretic ankle plantarflexion and dorsiflexion during treadmill and overground walking. TRIAL REGISTRATION: NCT03499210. Prospectively registered on March 28, 2018.

[Benefits of robotics in gait rehabilitation in cerebral palsy: A systematic review]. / Beneficios de la robótica en la rehabilitación de la marcha en la parálisis cerebral: una revisión sistemática.

BACKGROUND AND AIM: Cerebral palsy is the most common motor disability in childhood, with an estimated incidence of two out of every 1,000 live births. The impairment mostly affects gait. The aim of rehabilitation programmes is to enhance independence in affected individuals, especially mobility. To do this, robot-assisted gait rehabilitation programmes have been developed. Therefore, this study aimed to identify the benefits of robotics in gait rehabilitation in cerebral palsy. MATERIAL AND METHODS: We performed a literature search using the MeSH terms «cerebral palsy¼, «robotics¼ and «gait¼. RESULTS: After applying the selection criteria, we obtained 10 research studies and three protocols analysing the benefits of robotics in cerebral palsy and demonstrating that their use provides major advantages.

Circumferential tissue compression at the lower limb during walking, and its effect on discomfort, pain and tissue oxygenation: Application to soft exoskeleton design.

Soft exoskeletons apply compressive forces at the limbs via connection cuffs to actuate movement or stabilise joints. To avoid excessive mechanical loading, the interface with the wearer's body needs to be carefully designed. The purpose of this study was to establish the magnitude of circumferential compression at the lower limb during walking that causes discomfort/pain. It was hypothesized that the thresholds differ from those during standing. A cohort of 21 healthy participants were tested using two sizes of pneumatic cuffs, inflated at the thigh and calf in a tonic or phasic manner. The results showed lower inflation pressures triggering discomfort/pain at the thigh, with tonic compression, and wider pneumatic cuffs. The thresholds were lower during walking than standing still. Deep tissue oxygenation increased during phasic compression and decreased during tonic compression. According to the findings, circumferential compression by soft exoskeletons is preferably applied at anatomical sites with smaller volumes of soft tissue, using narrow connection cuffs and inflation pressures below 14 kPa.

Characterizing the comfort limits of forces applied to the shoulders, thigh and shank to inform exosuit design.

Recent literature emphasizes the importance of comfort in the design of exosuits and other assistive devices that physically augment humans; however, there is little quantitative data to aid designers in determining what level of force makes users uncomfortable. To help close this knowledge gap, we characterized human comfort limits when applying forces to the shoulders, thigh and shank. Our objectives were: (i) characterize the comfort limits for multiple healthy participants, (ii) characterize comfort limits across days, and (iii) determine if comfort limits change when forces are applied at higher vs. lower rates. We performed an experiment (N = 10) to quantify maximum tolerable force pulling down on the shoulders, and axially along the thigh and shank; we termed this force the comfort limit. We applied a series of forces of increasing magnitude, using a robotic actuator, to soft sleeves around their thigh and shank, and to a harness on their shoulders. Participants were instructed to press an off-switch, immediately removing the force, when they felt uncomfortable such that they did not want to feel a higher level of force. On average, participants exhibited comfort limits of ~0.9-1.3 times body weight on each segment: 621±245 N (shoulders), 867±296 N (thigh), 702±220 N (shank), which were above force levels applied by exosuits in prior literature. However, individual participant comfort limits varied greatly (~250-1200 N). Average comfort limits increased over multiple days (p<3e-5), as users habituated, from ~550-700 N on the first day to ~650-950 N on the fourth. Specifically, comfort limits increased 20%, 35% and 22% for the shoulders, thigh and shank, respectively. Finally, participants generally tolerated higher force when it was applied more rapidly. These results provide initial benchmarks for exosuit designers and end-users, and pave the way for exploring comfort limits over larger time scales, within larger samples and in different populations.

The safety and feasibility of a new rehabilitation robotic exoskeleton for assisting individuals with lower extremity motor complete lesions following spinal cord injury (SCI): an observational study.

STUDY DESIGN: A pre-post observational study. OBJECTIVES: To evaluate the safety and feasibility of a new rehabilitation robotic device for assisting individuals with lower extremity motor complete lesions following spinal cord injury (SCI). SETTING: Three hospitals in Sichuan Province, China. METHODS: Individuals aged 15-75 years with an SCI between vertebrae six (T6) and lumbar 1 (L1) and complete motor paralysis participated in an exoskeletal-assisted walking (EAW) programme (2 weeks, 5 days/week, 30 min/day). Data were collected pre-, mid- (week 1) and post-intervention (week 2). RESULTS: Twenty-eight individuals (mean age = 41.3, 71% males) participated in the EAW programme. The distance walked during the 6-min walking test (6MWT) increased relative to that at baseline, during week 1 (13.0 ± 5.3 m) and week 2 (16.2 ± 5.3 m) when wearing the exoskeleton. The walking speed during the 10-m walking test (10MWT) increased from 0.039 ± 0.016 to 0.045 ± 0.016 m/s. The Hoffer walking ability grade, the Spinal Cord Independence Measure (SCIM), and the Walking Index for SCI II (WISCI II) changed after 2 weeks of EAW. No improvement in lower extremity motor score (LEMS) was observed. The rates of adverse events and serious adverse events were 21% and 4%, respectively. CONCLUSIONS: The EAW programme with the new robotic exoskeleton provided potential meaningful improvements in mobility for individuals with SCI and had few adverse events.

Objective and Subjective Effects of a Passive Exoskeleton on Overhead Work.

Overhead work is a frequent cause of shoulder work-related musculoskeletal disorders. Exoskeletons offering arm support have the potential to reduce shoulder strain, without requiring large scale reorganization of the workspace. Assessment of such systems however requires to take multiple factors into consideration. This paper presents a thorough in-lab assessment of PAEXO, a novel passive exoskeleton for arm support during overhead work. A list of evaluation criteria and associated performance metrics is proposed to cover both objective and subjective effects of the exoskeleton, on the user and on the task being performed. These metrics are measured during a lab study, where 12 participants perform an overhead pointing task with and without the exoskeleton, while their physical, physiological and psychological states are monitored. Results show that using PAEXO reduces shoulder physical strain as well as global physiological strain, without increasing low back strain nor degrading balance. These positive effects are achieved without degrading task performance. Importantly, participants' opinions of PAEXO are positive, in agreement with the objective measures. Thus, PAEXO seems a promising solution to help prevent shoulder injuries and diseases among overhead workers, without negatively impacting productivity.

Case Report: Description of two fractures during the use of a powered exoskeleton.

Introduction: Powered robotic exoskeletons are a promising solution to enable standing and walking in patients with spinal cord injury (SCI). Although training and walking with an exoskeleton in motor complete SCI patients is considered safe, the risks of unexpected (technical) adverse events and the risk of fractures are not fully understood. This article reports the occurrence of two different cases of bone fracture during exoskeleton usage. Furthermore, advice is given for extra safety training and instructions. Case presentation: The first case concerns a 47-year-old woman with T12 AIS A SCI. Her exoskeleton shut down unexpectedly probably causing a misalignment of the joints of her lower extremities relative to the joints of the exoskeleton, which resulted in a fracture of her left tibia. The second case involves a 39-year-old man with L1 AIS B SCI. An unexpected fracture of the right distal tibia occurred without a specific prior (traumatic) incident. Discussion: Exoskeleton training instructors, SCI patients and their buddies should be instructed how to handle emergency situations. Furthermore, they should be aware of the risk of stress fractures of the lower extremities. Proper alignment of the exoskeleton relative to the body is of utmost importance to reduce fracture risk. In the case of swelling and discoloring of the skin, radiographic examination should be performed in order to exclude any fracture.

Clinical Outcomes with the Intrepid Dynamic Exoskeletal Orthosis: A Retrospective Analysis.

INTRODUCTION: Severe lower limb injuries have a negative impact on many aspects of an individual's life. One rehabilitative option for patients who have undergone limb salvage is the Intrepid Dynamic Exoskeletal Orthosis (IDEO). The IDEO is a custom-made dynamic response device which is used to restore function for patients with a wide variety of injuries. Clinical outcomes were routinely collected on patients fit with IDEOs at the Center for the Intrepid, Brooke Army Medical Center. The purpose of this retrospective study was to analyze the clinical outcomes collection process and the patient outcomes collected as part of routine clinical care. METHODS: The Brooke Army Medical Center IRB approved this study and granted waivers of informed consent and HIPAA authorization. Electronic medical records were reviewed over an 18-month period from July 2014 to January 2016. Records were examined to obtain the date of IDEO delivery, date of outcomes form completion, responses on the forms, and to verify diagnosis or injury. Data gathered included wear time, IDEO comfort, pain with and without the IDEO, Lower Extremity Functional Scale scores with and without the IDEO, and global rating of change questions for everyday activities and high impact activities. Wilcoxon signed-ranked tests were used to compare pain and function with vs. without the IDEO. RESULTS: During the 18-month period, new IDEOs were delivered to 156 unique patients. Outcomes forms were collected as part of routine clinical care from 90 of these 156 patients (58%). An additional nine forms were collected from patients who received their IDEOs prior to July 2014. In all, 99 outcomes forms were collected. Mean follow-up time from IDEO delivery to outcomes form completion was 35 ± 31 days for the original 90 patients. The most common patient diagnoses were fracture, nerve injury, arthritis, and fusion. Responses on the forms indicated that patients were generally comfortable wearing their IDEOs (8.3 ± 1.3 on a 0-10 scale) and wore them most of the day (10.7 ± 3.4 hours per day). Improvement in pain (from 5.2 ± 2.9 to 1.7 ± 1.6 points on a 0-10 scale) and Lower Extremity Functional Scale scores (from 29.7 ± 16.6 to 59.5 ± 13.6 points) with the IDEO were both more than the minimal clinically important difference and were statistically significant (p < 0.001). CONCLUSION: This descriptive retrospective study demonstrated that it was feasible to collect clinical outcomes data which were relevant for characterizing the effects of IDEO use and enabled quantification of improvements in self-reported function and walking pain with the IDEO. Due to the retrospective nature of this study, limitations include missing data and the lack of any performance measures to complement the self-reported data. Clinical outcomes collection continues as a routine part of clinical care and there remains an ongoing aim to collect information on all patients to obtain an accurate assessment of devices and services and ultimately better serve our patients.

Robotic exoskeletons for reengaging in everyday activities: promises, pitfalls, and opportunities.

PURPOSE: Media images and marketing materials suggest a future in which individuals with spinal cord injury (SCI) can utilize robotic exoskeletons to reengage in everyday activities, yet these narratives may not align with the current technological realities. The purpose of this paper is to present and describe the current use of robotic exoskeletons in rehabilitation and home settings and discuss the benefits and limitations of the devices. MATERIALS AND METHODS: We provide an overview of the features and limitations of the four robotic exoskeleton products (EKSO Bionics, ReWalk, Rex Bionics, and Indego) that are currently being used in in the United States in rehabilitation settings. We follow by suggesting ways that these devices fall short of fulfilling the promise of reengage in everyday activities in real-world life contexts. RESULTS AND DISCUSSION: Available devices appear to be better suited for rehabilitation settings than for home use. Device weight, the need for upper extremity supports, supervision requirements, and a limited range of movements are all issues that limit functionality and restrict opportunities for using such devices in real-world contexts. Designing the next generation of exoskeletons to be more useful in everyday life will require further collaboration among engineers, clinicians, and patients. Implications for Rehabilitation Exoskeletons offer the promise of allowing individuals with neurological injury to reengage in everyday activities from a standing position. Several exoskeleton devices are currently available for use in the United States. Weight of exoskeleton devices, the need for upper extremity supports, supervision requirements of hone units, and a limited range of movements are issues that restrict opportunities for using such devices in real-world contexts. Further development of exoskeleton technologies is warranted to improve the devices for real-world use.

Initial Outcomes from a Multicenter Study Utilizing the Indego Powered Exoskeleton in Spinal Cord Injury.

Objective: To assess safety and mobility outcomes utilizing the Indego powered exoskeleton in indoor and outdoor walking conditions with individuals previously diagnosed with a spinal cord injury (SCI). Methods: We conducted a multicenter prospective observational cohort study in outpatient clinics associated with 5 rehabilitation hospitals. A convenience sample of nonambulatory individuals with SCI (N = 32) completed an 8-week training protocol consisting of walking training 3 times per week utilizing the Indego powered exoskeleton in indoor and outdoor conditions. Participants were also trained in donning/doffing the exoskeleton during each session. Safety measures such as adverse events (AEs) were monitored and reported. Time and independence with donning/doffing the exoskeleton as well as walking outcomes to include the 10-meter walk test (10MWT), 6-minute walk test (6MWT), Timed Up & Go test (TUG), and 600-meter walk test were evaluated from midpoint to final evaluations. Results: All 32 participants completed the training protocol with limited device-related AEs, which resulted in no interruption in training. The majority of participants in this trial were able to don and doff the Indego independently. Final walking speed ranged from 0.19 to 0.55 m/s. Final average indoor and outdoor walking speeds among all participants were 0.37 m/s (SD = 0.08, 0.09, respectively), after 8 weeks of training. Significant (p < .05) improvements were noted between midpoint and final gait speeds in both indoor and outdoor conditions. Average walking endurance also improved among participants after training. Conclusion: The Indego was shown to be safe for providing upright mobility to 32 individuals with SCIs who were nonambulatory. Improvements in speed and independence were noted with walking in indoor and outdoor conditions as well as with donning/doffing the exoskeleton.

Comparison of energy efficiency between Wearable Power-Assist Locomotor (WPAL) and two types of knee-ankle-foot orthoses with a medial single hip joint (MSH-KAFO).

OBJECTIVE: To compare the energy efficiency of Wearable Power-Assist Locomotor (WPAL) with conventional knee-ankle-foot orthoses (MSH-KAFO) such as Hip and Ankle Linked Orthosis (HALO) or Primewalk. STUDY DESIGN: Cross over case-series. SETTING: Chubu Rosai Hospital, Aichi, Japan, which is affiliated with the Japan Organization of Occupational Health and Safety. METHODS: Six patients were trained with MSH-KAFO (either HALO or Primewalk) and WPAL. They underwent 6-minute walk tests with each orthosis. Energy efficiency was estimated using physiological cost index (PCI) as well as heart rate (HR) and modified Borg score. Trial energy efficiency with MSH-KAFO was compared with WPAL to assess if differences in PCI became greater between MSH-KAFO and WPAL as time goes on during the 6-minute walk. Spearman correlation coefficient of time (range: 0.5-6.0 minutes) with the difference was calculated. The same statistical procedures were repeated for HR and modified Borg score. RESULTS: Greater energy efficiency, representing a lower gait demand, was observed in trials with WPAL compared with MSH-KAFO (Spearman correlation coefficients for PCI, HR and modified Borg were 0.93, 0.90 and 0.97, respectively, all P < 0.0001). CONCLUSIONS: WPAL is a practical and energy efficient type of robotics that may be used by patients with paraplegia.

Results of the first interim analysis of the RAPPER II trial in patients with spinal cord injury: ambulation and functional exercise programs in the REX powered walking aid.

BACKGROUND: The RAPPER II study investigates the feasibility, safety and acceptability of using the REX self-stabilising robotic exoskeleton in people with spinal cord injury (SCI) who are obligatory wheelchair users. Feasibility is assessed by the completion of transfer into the REX device, competency in achieving autonomous control and completion of upper body exercise in an upright position in the REX device. Safety is measured by the occurrence of serious adverse events. Device acceptability is assessed with a user questionnaire. METHODS: RAPPER II is a prospective, multi-centre, open label, non-randomised, non-comparative cohort study in people with SCI recruited from neurological rehabilitation centres in the United Kingdom, Australia and New Zealand. This is the planned interim report of the first 20 participants. Each completed a transfer into the REX, were trained to achieve machine control and completed Timed Up and Go (TUG) tests as well as upper body exercises in standing in a single first time session. The time to achieve each task as well as the amount of assistance required was recorded. After finishing the trial tasks a User Experience questionnaire, exploring device acceptability, was completed. RESULTS: All participants could transfer into the REX. The mean transfer time was 439 s. Nineteen completed the exercise regime. Eighteen could achieve autonomous control of the REX, 17 of whom needed either no assistance or the help of just one therapist. Eighteen participants completed at least one TUG test in a mean time of 313 s, 15 with the assistance of just one therapist. The questionnaire demonstrated high levels of acceptability amongst users. There were no Serious Adverse Events. CONCLUSIONS: This first interim analysis of RAPPER II shows that it is feasible and safe for people with SCI to use the REX powered assisted walking device to ambulate and exercise in. Participants with tetraplegia and paraplegia could walk and perform a functional exercise program when standing needing only modest levels of assistance in most cases. User acceptability was high. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02417532 . Registered 11 April 2015.

Lower extremity robotic exoskeleton training: Case studies for complete spinal cord injury walking.

BACKGROUND: Recent advances in exoskeleton technology has made lower extremity powered exoskeletons (LEPE) a viable treatment tool to restore upright walking mobility to persons with spinal cord injury (SCI). OBJECTIVE: Evaluate ARKE exoskeleton training within a rehabilitation centre environment. METHODS: Case studies are presented for two male participants, age 41 and 30, motor complete SCI at T6 (N01) and T12 (N02), respectively, as they progress from new LEPE users to independent walking. The ARKE 2.0 LEPE (Bionik Laboratories Inc., Toronto, Canada) was used for all training (hip and knee powered, forearm crutches, control tablet). Data were collected on session times, activity metrics from ARKE system logs, and qualitative questionnaire feedback. RESULTS AND CONCLUSION: N01 required 18, 30-minute training sessions to achieve independent walking. N01 walked independently within the 12 session target. Foot strikes were frequently before the end of the programmed swing phase, which were handled by the ARKE control system. Subjective ratings of LEPE learning, comfort, pain, fatigue, and overall experience were high for sitting-standing and moderate to high for walking. This reflected the complexity of learning to safely walk. Qualitative feedback supported the continuation of LEPE use in rehabilitation settings based on end-user desire for upright mobility.

The features of Gait Exercise Assist Robot: Precise assist control and enriched feedback.

BACKGROUND: In a patient with severe hemiplegia, the risk of the knee giving way is high during the early stage of gait exercise with an ankle-foot orthosis. However, use of a knee-ankle-foot orthosis has many problems such as large amount of assistance and compensatory motions. To resolve these problems, we have engaged in the development of the Gait Exercise Assist Robot (GEAR). OBJECTIVE: To evaluate the improvement efficiency of walk with GEAR in a stroke patient. METHODS: The subject was a 70-year-old man presented with left thalamus hemorrhage and right hemiplegia. The patient underwent exercise with the GEAR 5 days a week, for 40 minutes per day. We evaluated the Functional Independence Measure score for walk (FIM-walk score) every week. The control group consisted of 15 patients aged 20-75 years with hemiplegia after primary stroke, who had equivalent walking ability with the subject at start. As the primary outcome, we defined improvement efficiency of FIM-walk, which was gain of FIM-walk divided the number of required weeks. RESULTS: Improvement efficiency of FIM-walk of the subject was 1.5, while that of control group was 0.48±3.2 (mean±SD). CONCLUSIONS: GEAR is potentially useful for gait exercise in hemiplegic patients.

Clinical feasibility of gait training with a robotic exoskeleton (WPAL) in an individual with both incomplete cervical and complete thoracic spinal cord injury: A case study.

BACKGROUND: Patients with tetraplegia can achieve independent gait with lateral-type powered exoskeletons; it is unclear whether medial-type powered exoskeletons allow for this. OBJECTIVE: To investigate gait training with a medial-type powered exoskeleton wearable power-assist locomotor (WPAL) in an individual with incomplete cervical (C5) and complete thoracic (T12) spinal cord injury (SCI). METHODS: The 60-session program was investigated retrospectively using medical records. Upon completion, gait performance was examined using three-dimensional motion analyses and surface electromyography (EMG) of the upper limbs. RESULTS: The subject achieved independent gait with WPAL and a walker in 12 sessions. He continuously extended his right elbow; his left elbow periodically flexed/extended. His pelvic inclination was larger than the trunk inclination during single-leg stance. EMG activity was increased in the left deltoid muscles during ipsilateral foot-contact. The right anterior and medial deltoid muscle EMG activity increased just after foot-off for each leg, as did the right biceps activity. Continuous activity was observed in the left triceps throughout the gait cycle; activity was unclear in the right triceps. CONCLUSIONS: These results suggest the importance of upper limb residual motor function, and may be useful in extending the range of clinical applications for robotic gait rehabilitation in patients with SCI.

Assessment of In-Hospital Walking Velocity and Level of Assistance in a Powered Exoskeleton in Persons with Spinal Cord Injury.

BACKGROUND: Individuals with spinal cord injury (SCI) often use a wheelchair for mobility due to paralysis. Powered exoskeletal-assisted walking (EAW) provides a modality for walking overground with crutches. Little is known about the EAW velocities and level of assistance (LOA) needed for these devices. OBJECTIVE: The primary aim was to evaluate EAW velocity, number of sessions, and LOA and the relationships among them. The secondary aims were to report on safety and the qualitative analysis of gait and posture during EAW in a hospital setting. METHODS: Twelve individuals with SCI ≥ 1.5 years who were wheelchair users participated. They wore a powered exoskeleton (ReWalk; ReWalk Robotics, Inc., Marlborough, MA) with Lofstrand crutches to complete 10-meter (10 MWT) and 6-minute (6MWT) walk tests. LOA was defined as modified independence (MI), supervision (S), minimal assistance (Min), and moderate assistance (Mod). Best effort EAW velocity, LOA, and observational gait analysis were recorded. RESULTS: Seven of 12 participants ambulated ≥ 0.40 m/s. Five participants walked with MI, 3 with S, 3 with Min, and 1 with Mod. Significant inverse relationships were noted between LOA and EAW velocity for both 6 MWT (Z value = 2.63, Rho = 0.79, P = .0086) and 10 MWT (Z value = 2.62, Rho = 0.79, P = .0088). There were 13 episodes of mild skin abrasions. MI and S groups ambulated with 2-point alternating crutch pattern, whereas the Min and Mod groups favored 3-point crutch gait. CONCLUSIONS: Seven of 12 individuals studied were able to ambulate at EAW velocities ≥ 0.40 m/s, which is a velocity that may be conducive to outdoor activity-related community ambulation. The ReWalk is a safe device for in-hospital ambulation.