Clinical Publications

ReWalk is the most studied exoskeleton technology with multiple publications providing data on its use and benefits.

Heart rate and oxygen demand of powered exoskeleton-assisted walking in persons with paraplegia

Publication:
Journal of Rehabilitation Research & Development (JRRD), Volume 52, Number 2, 2015, Pages 147–158

Institution:
Department of Veterans Affairs (VA) Rehabilitation Research and Development National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Spinal Cord Injury Patient Care Center, and Rehabilitation Medicine, James J. Peters VA Medical Center, Bronx, NY; Departments of Medicine and Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY

Authors:
Pierre Asselin, MS; Steven Knezevic, MS; Stephen Kornfeld, DO; Christopher Cirnigliaro, MS; Irina Agranova-Breyter, PT; William A. Bauman, MD; Ann M. Spungen, EdD

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Historically, persons with paralysis have limited options for overground ambulation. Recently, powered exoskeletons, which are systems that translate the user’s body movements to activate motors that move the lower limbs through a predetermined gait pattern, have become available. As part of an ongoing clinical study (NCT01454570), eight nonambulatory persons with paraplegia were trained to ambulate with a powered exoskeleton. Measurements of oxygen uptake (VO2) and heart rate (HR) were recorded for 6 min each during each maneuver while sitting, standing, and walking. The average value of VO2 during walking (11.2 +/– 1.7 mL/kg/min) was significantly higher than for sitting and standing (3.5 +/– 0.4 and 4.3 +/– 0.9 mL/kg/min, respectively; p < 0.001). The HR response during walking was significantly greater than that of either sitting or standing (118 +/– 21 vs 70 +/– 10 and 81 +/– 12 beats per minute, respectively; p < 0.001). Persons with paraplegia were able to ambulate efficiently using the powered exoskeleton for overground ambulation, providing the potential for functional gain and improved fitness.

The Effect of Using a Powered Exoskeleton Technology Training Program on Joint Range of Motion on Spinal Cord Injured Individuals: A Pilot Study

Publication:
The International Journal of Physical Therapy and Rehabilitation 2014, 1: 102

Institution:
Department of Sport Health and Exercise Science, University of Hull, Hull, East Yorkshire, United Kingdom Cyclone Technologies, Orchard House, Sunk Island Road, Ottringham, Hull, East Yorkshire, United Kingdom

Authors:
Hollie Samantha Forbes White, Stephen Hayes and Matthew White

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BACKGROUND: Paralysis and loss of normal upright function is the most commonly acknowledged ongoing impairment related to spinal cord injury, although numerous co-morbidities exist. The risk and progress of some these conditions may be mitigated by upright function. Over-ground powered exoskeletons have the potential to provide many physical health benefits associated with upright mobility; however research into the specific effects of powered exoskeleton use on the joints does not yet exist. The ReWalkTM enables people with lower limb disabilities to carry out routine ambulatory functions such as walking, standing, sitting, and ascending/descending stairs. Changes in patients’ joint range of motion as a consequence of one week of intensive powered exoskeleton training as part of a physiotherapy program were investigated.

METHODS: Sixteen participants aged 21-69 years with spinal cord injury between C3 and T12 (ASIA Impairment Scale A-D) visited the therapy center. Passive range of motion of ankle dorsi-flexion, hip extension and shoulder internal rotation and extension was measured using goniometry. Participants then undertook the training program which included use of parallel bars, crutches, different surfaces, and stairs/sitting/standing/walking. The program is supplemented by the use of functional electrical stimulation, far-infrared heat therapy and physiotherapy for exercise preparation. After five days range of motion was re-measured. Paired t-tests were run on bilaterally averaged pre and post ranges of motion, accepted significance value was p≤0.05.

RESULTS: Mean dorsi-flexion increased from 1.7° (plantigrade = 0) to 6.9° (t(11)-6.3;p<0.001). Mean hip extension increased from 8.2° to 14.1° (t(13)-3.5;p=0.017). There were no significant changes to shoulder extension (pre-64.7, post-66.7°, n=9) or shoulder internal rotation (pre-74.3, post- 78.9°, n=11).

CONCLUSION: Although this was a pilot study and lacked a control condition, the addition of ReWalk™ technology was novel as part of a physiotherapy program. Participation in the training program appeared to result in significant increases in ankle dorsi-flexion and hip extension which may be beneficial for all types of ongoing upright weight-bearing therapy in this population.

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

Publication:
Topics in Spinal Cord Injury Rehabilitation: Spring 2015, Vol. 21, No. 2, pp. 100-109.

Institution:
VA Rehabilitation Research and Development National Center of Excellence for the Medical Consequences of Spinal Cord Injury James J. Peters VA Medical Center, New York, USA

Authors:
Ajax Yang, Pierre Asselin, Steven Knezevic, Stephen Kornfeld, and Ann Spungen

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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 (10MWT) 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 6MWT (Z value = 2.63, Rho = 0.79, P = .0086) and 10MWT (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.

CONCLUSION: 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.

Exoskeletal-Assisted Walking for Persons with Motor-Complete Paraplegia

Publication:
Force Sustainment: Rehabilitation, Regeneration and Prosthetics for Re-Integration to Duty. (pp. 6-1 – 6-14). Meeting Proceedings STO-MP-HFM-228, Paper 6. Neuilly-sur-Seine, France: Apr 2013

Institution:
VA Rehabilitation Research and Development National Center of Excellence for the Medical Consequences of Spinal Cord Injury James J. Peters VA Medical Center, New York, USA

Authors:
Spungen, Ann M.; Asselin Pierre K.; Fineberg, Drew B.; Kornfeld, Stephen D.; Harel, Noam Y.

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Persons with motor-complete spinal cord injury (SCI) suffer permanent paralysis and loss of mobility. This immobilization limits their ability to access the world as they knew it. Exoskeletal technology has been used in the US and Europe by persons with SCI to perform upright activities of daily living. A single-group, pre/post intervention pilot study was performed to determine the number of sessions and level of assistance needed to execute standing, walking, and stair climbing skills in a powered exoskeleton (ReWalk™). Seven persons with motor-complete paraplegia were studied over an average of 45±20 sessions. Sessions consisted of 1 to 2 hours of standing and overground ambulation for 3 sessions per week. All 7 participants learned to perform sit-to-stand, stand-to-sit, and to walk 50 to 166 m in 6 minutes with none (n=4) to varying levels (n=3) of assistance. Four of 7 participants learned to ascend and descend ≥5 stairs with assistance, and these 4 also achieved some outdoor-specific walking skills. No relationship with achievement of exoskeletal-assisted mobility skills was found with duration or level of SCI; however, the participant with the highest cord lesion (thoracic level 1) did require the most assistance. These preliminary results suggest that exoskeletal-assisted walking and other mobility skills can be performed independently by persons with motor-complete SCI. Future advances in exoskeletal technology and ongoing training may improve overall mobility and independence in the home, work, military, and/or community environments.

Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia

Publication:
The Journal of Spinal Cord Medicine – July 2013, Voume 36, Number 4, p 313-321(9)

Institution:
VA Rehabilitation Research and Development National Center of Excellence for the Medical Consequences of Spinal Cord Injury James J. Peters VA Medical Center, New York, USA

Authors:
Fineberg, Drew B.; Asselin, Pierre; Harel, Noam Y.; Agranova-Breyter, Irina; Kornfeld, Stephen D.; Baumann, William A.; Spungen, Ann M.

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OBJECTIVE: To use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in persons with spinal cord injury (SCI) during powered exoskeleton-assisted walking.

RESEARCH DESIGN: A cross-sectional study was performed to analyze vGRF during powered exoskeleton-assisted walking (ReWalk™: Argo Medical Technologies, Inc, Marlborough, MA, USA) compared with vGRF of able-bodied gait.

SETTING: Veterans Affairs Medical Center.
PARTICIPANTS: Six persons with thoracic motor-complete SCI (T1-T11 AIS A/B) and three age-, height-, weight- and gender-matched able-bodied volunteers participated.

INTERVENTIONS: SCI participants were trained to ambulate over ground using a ReWalk™. vGRF was recorded using the F-Scan™ system (TekScan, Boston, MA, USA).

OUTCOME MEASURES: Peak stance average (PSA) was computed from vGRF and normalized across all participants by percent body weight. Peak vGRF was determined for heel strike, mid-stance, and toe-off. Relative linear impulse and harmonic analysis provided quantitative support for analysis of powered exoskeletal gait.

RESULTS: Participants with motor-complete SCI, ambulating independently with a ReWalk™, demonstrated mechanical loading magnitudes and patterns similar to able-bodied gait. Harmonic analysis of PSA profile by Fourier transform contrasted frequency of stance phase gait components between able-bodied and powered exoskeleton-assisted walking.

CONCLUSION: Powered exoskeleton-assisted walking in persons with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. This suggests the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities. vGRF profile can be used to examine both magnitude of loading and gait mechanics of powered exoskeleton-assisted walking among participants of different weight, gait speed, and level of assist.

New Bipedal Locomotion Option for Individuals with Thoracic Level Motor Complete Spinal Cord Injury

Publication:
The Journal of the Spinal Research Foundation – Spring 2013, Volume 8, Number 1, p 26-28(3)

Institution:
MossRehab, Elkins Park, Pennsylvania, USA

Authors:
Esquenazi, Alberto M.D.

The ReWalk Powered Exoskeleton to Restore Ambulatory Function to Individuals with Thoracic-Level Motor-Complete Spinal Cord Injury

Publication:
American Journal of Physical Medicine & Rehabilitation – November 2012, Volume 91, Issue 11, p 911–921(11)

Institution:
MossRehab, Elkins Park, Pennsylvania, USA

Authors:
Esquenazi, Alberto MD; Talaty, Mukul PhD; Packel, Andrew PT, NCS; Saulino, Michael MD, PhD

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OBJECTIVE: The aim of this study was to assess the safety and performance of ReWalk in enabling people with paraplegia due to spinal cord injury to carry out routine ambulatory functions.

DESIGN: This was an open, noncomparative, nonrandomized study of the safety and performance of the ReWalk powered exoskeleton. All 12 subjects have completed the active intervention; three remain in long-term follow-up.

RESULTS: After training, all subjects were able to independently transfer and walk, without human assistance while using the ReWalk, for at least 50 to 100 m continuously, for a period of at least 5 to 10 mins continuously and with velocities ranging from 0.03 to 0.45 m/sec (mean, 0.25 m/sec). Excluding two subjects with considerably reduced walking abilities, average distances and velocities improved significantly. Some subjects reported improvements in pain, bowel and bladder function, and spasticity during the trial. All subjects had strong positive comments regarding the emotional/psychosocial benefits of the use of ReWalk.

CONCLUSIONS: ReWalk holds considerable potential as a safe ambulatory powered orthosis for motor-complete thoracic-level spinal cord injury patients. Most subjects achieved a level of walking proficiency close to that needed for limited community ambulation. A high degree of performance variability was observed across individuals. Some of this variability was explained by level of injury, but other factors have not been completely identified. Further development and application of this rehabilitation tool to other diagnoses are expected in the future.

Safety and tolerance of the ReWalk™ exoskeleton suit for ambulation by people with complete spinal cord injury: A pilot study

Publication:
The Journal of Spinal Cord Medicine – March 2012, Volume 35, Number 2, p 96-101(6)

Institution:
Department of Neurological Rehabilitation, The Chaim Sheba Medical Center, Tel Hashomer, Israel Department of Rehabilitation, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel Sackler School of Medicine, Tel Aviv University, Israel Gait & Motion Analysis Laboratory, MossRehab, Philadelphia, PA, USA

Authors:
Zeilig, Gabi; Weingarden, Harold; Zwecker, Manuel; Dudkiewicz, Israel; Bloch, Ayala; Esquenazi, Alberto

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OBJECTIVES: The objective of the study was to evaluate the safety and tolerance of use of the ReWalk™ exoskeleton ambulation system in people with spinal cord injury. Measures of functional ambulation were also assessed and correlated to neurological spinal cord level, age, and duration since injury.

STUDY DESIGN: Case series observational study.

SETTING: A national spinal cord injury centre.

METHODS: Six volunteer participants were recruited from the follow-up outpatient clinic. Safety was assessed with regard to falls, status of the skin, status of the spine and joints, blood pressure, pulse, and electrocardiography (ECG). Pain and fatigue were graded by the participants using a visual analogue scale pre- and post-training. Participants completed a 10-statement questionnaire regarding safety, comfort, and secondary medical effects. After being able to walk 100 m, timed up and go, distance walked in 6 minutes and 10-m timed walk were measured.

RESULTS: There were no adverse safety events. Use of the system was generally well tolerated, with no increase in pain and a moderate level of fatigue after use. Individuals with lower level of spinal cord injury performed walking more efficiently.

CONCLUSION: Volunteer participants were able to ambulate with the ReWalk™ for a distance of 100 m, with no adverse effects during the course of an average of 13-14 training sessions. The participants were generally positive regarding the use of the system.

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