Medical Policy
Subject: Powered Robotic Lower Body Exoskeleton Devices
Document #: OR-PR.00006Publish Date: 07/06/2022
Status: ReviewedLast Review Date: 05/12/2022
Description/Scope

This document addresses the use of powered, robotic lower body exoskeleton devices that may be utilized in the rehabilitation of or for daily use by individuals with neurological disorders that affect an individual’s ability to ambulate without assistance.

Note: For information regarding other prosthesis, please see the following:

Position Statement

Investigational and Not Medically Necessary:

The use of a powered, robotic lower body exoskeleton device is considered investigational and not medically necessary under all circumstances, including but not limited to the following:

Rationale

In a pilot study, Zeilig and colleagues (2012) evaluated the safety and tolerance of the ReWalk (ReWalk Robotics, Inc., Marlborough, MA) exoskeleton ambulation suit in a small case series of 6 subjects with complete motor spinal cord injury (SCI) between T5 and T12. Subjects averaged 33.2 years of age, weighed less than 100 kilograms (kg), and were 155 to 200 centimeters (cm) in height. All subjects underwent several 50-minute long training sessions to achieve ambulation with a powered robotic lower body exoskeleton device to walk a 100 meter (m) long path. Following this acclimation, a battery of tests, including timed up and go (TUG), 6-minute walk test (6MWT), and the 10 meter walk test (10MWT) were performed. No falls, skin or joint injuries, cardiovascular events or changes on spine radiographs were reported. Several technical issues related to the device were reported; all were resolved. Use of the system was generally well-tolerated, with no increase in pain and a moderate level of fatigue after use. A total of 3 participants with lower lesions (T9-T12) walked longer distances than the other 3 with higher lesions (T5-T7) (mean 66.3 m vs. mean 22.7 m; p<0.01). In the 10MWT, participants with lower levels of injury walked faster than those with higher levels of injury (mean 47 seconds vs. mean 85.7 seconds; p<0.05). Level of injury did not influence the results in the TUG test or the number of training sessions needed before subjects were ready for testing (p=0.15 and p=0.42, respectively). In this small sample, age and time from injury did not influence any of the test measures. Individuals with lower level of SCI performed walking more efficiently. The authors concluded that 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 to 14 training sessions. The participants were generally positive regarding the use of the system. The authors stated that the potential benefits of the ReWalk are many, including improved functional mobility, cardiovascular and respiratory status, bone metabolism, and bowel and bladder function, as well as reduction of spasticity and neuropathic pain, but such claims remain unsubstantiated by clinical trial data. The researchers noted that this study did not include individuals with quadriplegia, children, or older adults.

A small, noncomparative study of 12 paraplegic subjects with thoracic level (T3-T12) SCI evaluated the safety and ability of ReWalk to enable individuals with paraplegia due to SCI to carry out routine ambulatory functions (Esquenazi, 2012). Following approximately 8 weeks of acclimation training involving 24 60- to 90-minute sessions, all subjects were successful in independently transferring and walking in the ReWalk for at least 50 to 100 m continuously, for a period of at least 5 to 10 minutes with velocities ranging from 0.03 to 0.45 m/sec (mean of 0.25 m/sec). Excluding 2 subjects with considerably reduced walking abilities, average distances and velocities improved significantly. 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. Some subjects reported improvements in pain, bowel and bladder function, and spasticity during the trial. No falls, bone fractures, or episodes of autonomic dysreflexia occurred. Of the 12 subjects, 5 had a definite or possible study-related mild to moderate adverse event, including skin abrasions, lightheadedness, and edema of the lower limbs. The authors concluded that the ReWalk system holds considerable potential as a safe, ambulatory powered orthosis for individuals with motor-complete thoracic-level SCI.

In 2013, Esquenazi and colleagues published a small, randomized comparative trial involving 16 subjects with traumatic brain injury (TBI). This study compared the use of the ReWalk device in treadmill assisted rehabilitation training (n=8) vs. manually assisted treadmill rehabilitation training (n=8). Following training, the average self-selected walking velocity (SSV) increased by 49.8% for the ReWalk group (p=0.01) and by 31% for the manual group (p=0.06). The average maximal velocity increased by 14.9% for the ReWalk group (p=0.06) and by 30.8% for the manual group (p=0.01). Step-length asymmetry ratio improved during SSV by 33.1% for the ReWalk group (p=0.01) and by 9.1% for the manual group (p=0.73). The distance walked increased by 11.7% for the ReWalk group (p=0.21) and by 19.3% for the manual group (p=0.03). While each group demonstrated benefits from their assigned training method, no differences between groups were reported. The value of the ReWalk system in rehabilitation training following TBI is unclear given these results.

Spungen (2013) reported the results of a pilot study from the Bronx Veterans Affairs Hospital of a trial of the ReWalk system in 7 subjects with paraplegia due to SCI with permanent paralysis and loss of mobility. The study was not published in a peer-reviewed medical journal, but was made available on a Veterans Affairs website. This pre/post intervention pilot case series was performed to determine the number of sessions and level of assistance needed to execute standing, walking, and stair climbing skills with the ReWalk device. Subjects were studied over an average of 45 ± 20 sessions consisting 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 ambulation to 50 to 166 m in 6 minutes with no (n=4) to varying (n=3) levels of assistance. Ascending and descending ≥ 5 stairs with assistance was achieved by 4 subjects. These same 4 subjects also achieved some outdoor-specific walking skills. The authors reported that there was no relationship with achievement of exoskeletal-assisted mobility skills and the duration or level of SCI.

A small comparative study of 6 subjects with motor-complete SCI and 3 able-bodied volunteers using the ReWalk devices was reported by Fineberg and others in 2013. All subjects underwent 1-2 hours of combined sitting and walking sessions 3 times per week for 5 to 6 months. The objective of the study was to use vertical ground reaction force (vGRF) to show the magnitude and pattern of mechanical loading in subjects during walking using the F-Scanin-shoe pressure mapping system (Tekscan, Inc., South Boston, MA). The investigators measured the pressure imparted to both the left and right feet in all SCI subjects while walking in the ReWalk device and in control subjects during unassisted walking. A total of 3 of the SCI subjects participated in the measurement trials using assistive devices such as walkers and the remaining 3 were unassisted. For measurements of peak stance average (PSA) the assisted SCI group had significantly lower vGRF vs. control subjects (p<0.05). No significant difference in PSA was noted between the no-assist SCI group and controls. Significant differences between the assist and no assist SCI groups was also noted, with the no-assist group subjects creating greater VGRF than the assisted subjects (p=0.010 for midstance and p=0.045 for toe off). The authors concluded that powered exoskeleton-assisted walking in individuals with motor-complete SCI generated vGRF similar in magnitude and pattern to that of able-bodied walking. They suggested these results demonstrated the potential for powered exoskeleton-assisted walking to provide a mechanism for mechanical loading to the lower extremities in individuals with SCI.

Asselin and others (2015) reported the results of a small case series study of 8 non-ambulatory subjects with paraplegia who were trained to ambulate with the ReWalk device. The authors reported that the average value of oxygen uptake (VO2) during walking with the device was significantly higher in all subjects vs. when sitting and standing (p<0.001). Also, the heart rate response during walking with the device was significantly greater vs. when subjects were either sitting or standing (p<0.001). These findings are not unexpected, and align with what is commonly known about human physiology. The authors concluded that individuals with paraplegia are able to ambulate efficiently using the powered exoskeleton for overground ambulation, providing potential for functional gain and improved fitness. This study provided no data regarding the safety of the device.

Yang and colleagues (2015) described a cohort study involving 12 SCI subjects evaluated for assisted walking speed while using the ReWalk device and assistive Lofstrand crutches. All subjects underwent 10MWT and 6MWT, with the shortest time for the 10MWT and the furthest distance for the 6MWT counted as the best effort. Over a median of 55 training sessions, 7 of 12 subjects were able to ambulate at greater than or equal to 0.4 m/s. The authors reported an inverse relationship was noted for level of assistance and walking velocity for both the 6MWT (p<0.009) and the 10MWT (p=0.009). No serious adverse events were reported. There were 13 episodes of mild skin abrasions reported, and all resolved with padding and equipment adjustments.

A case series study involving 16 subjects with SCI was conducted to evaluate mobility outcomes for individuals with SCI following 5 training sessions (Hartigan, 2015). All subjects underwent 5 90-minute training sessions with the Indego® exoskeleton device (Parker Hannifin Corporation, Macedonia, OH) followed by the 10MWT and the 6MWT with the Indego devices in addition to an assistive device. Additional outdoor tasks were also evaluated during the training sessions, including walking on sidewalks, up and down Americans with Disabilities Act (ADA) compliant ramps, and over grass. A total of 3 subjects had motor complete quadriplegia (C5-C7 level injury), 5 had upper paraplegia (T1-T8 level injury), and 8 had lower paraplegia (T9-L1 level injury). One-half of the subjects were able to ambulate on both indoor and outdoor surfaces, elevators and ramps, and most used an assistive device and minimal or moderate assistance. The average distance covered during a 6MWT was 64 m for subjects with quadriplegia, 76 m for those with upper paraplegia, and 121 m for those with lower paraplegia. A total of 7 of the subjects were able to don and doff the system independently.

Stampacchia and colleagues (2016) published the findings of a cohort study investigating the impact of the Ekso GT exoskeleton system (Ekso Bionics, Inc., Richmond, CA) on pain and spasticity. Study investigators enrolled 21 subjects with partial or complete SCI due to traumatic or non-traumatic lesions. All subjects underwent a single 40-minute session of sitting to standing to walking with the Ekso device in addition to an assistive walking device (rollator). Prior to and after the session, subjects completed a subjective rating scale (1 to 10) measuring both pain and spasticity. Spasticity was further measured with the Modified Ashworth scale (MAS) and the Penn Spasm Frequency Scale (PSFS). Walking behavior was deemed to be homogenous throughout the sample based upon walking time and number of steps taken. Following the walking session, perceived spasticity was improved significantly using a subjective rating scale (p<0.001), as well as on the MAS and PSFS scales (p<0.001 for both). Overall, perceived pain was not significantly changed, but when looking at the subset of subjects with pain prior to the session, significant pain reductions were reported (p<0.002). No correlation was noted between the reduction in pain and the reduction in spasticity.

A second smaller cohort study published in 2016 evaluated the quality of life impact of the institutional version of the ReWalk device on 7 subjects with SCI (Platz, 2016). All subjects underwent a 4- to 5-week intensive inpatient device-training session which included 60 minutes of exoskeleton training 5 days per week in addition to individualized therapeutic exercise regimens as indicated. Training sessions included sit-to-stand, stand-to-sit, 2-arm standing balance, 1-arm standing balance, 10 m walking straight ahead, 10 m walking in a curve, climbing a set of 12 stairs, and 500 m outdoor walk. Evaluations included milestones for these activities and satisfaction with training and device use. With the exception of the last two activities mentioned above, all subjects met the expected milestones. Sit-to-stand and stand-to-sit were achieved by all subjects within two training sessions. Indoor walking was achieved by all subjects within 2 weeks. The majority of subjects were able to achieve these activities, as well as 1- and 2-arm standing balance activities without physical assistance or occasional help. Only 4 subjects achieved climbing the 12 steps. No data was provided for the 500 m walk evaluation. The authors reported a “fair” degree of satisfaction with the training. Pre/post measures of the physical domain of the SF-36v2 indicated significant improvements, but no other domain demonstrated significant changes. No significant adverse events were reported, including falls and cardiovascular events. Skin lesions were reported in 4 subjects, but were resolved with adjustment of the device and discontinuation of the training was not necessary. Mild pain or swelling were reported in 4 subjects. No changes in motor or sensory signs, spasticity or activities of daily living competence were reported.

A third small cohort study was published in 2016 by Benson and colleagues. This trial involved 10 subjects with C7-T12 SCI trained to use the ReWalk device in twice weekly session for a total of 20 sessions. Only 5 subjects completed the full trial; 2 decided not to continue with the training, 2 experienced recurrent skin breakdown requiring discontinuation, and a fifth experienced a fractured talus. The mean number of weeks required to complete the 20 sessions for the 5 remaining subjects was 19 weeks. The average number of sessions before a subject was deemed ready for stairs training was 6. Improvements in spasticity were noted in the 2 subjects with mild spasticity prior to training (Ashworth scale -0.70). Over the course of training, all 5 subjects experienced improvements in gait speed, walking distance, speed to standing up, rotating, and sitting. Stair ascent and descent was achieved by 4 subjects. No significant benefits were noted in the 10MWTor the TUG test, however, some improvements were noted in the 6MWT. Measures on the Appraisals of Disability: Primary and Secondary Scale (ADAPASS) showed mixed results, with improvements seen in the primary scales, but not in any of the six subscales. Results on the Assistive Technology Device Predisposition Assessment (ATD-PA) did not demonstrate significant improvements in functional abilities or personal characteristics.

A meta-analysis of the clinical effectiveness and safety of powered exoskeleton devices was published by Miller and colleagues in 2016. The investigators included 11 studies involving 111 subjects using the ReWalk (8 studies), Ekso (3 studies), and Indego (2 studies) devices. An additional study involved an unspecified device. Considerable heterogeneity was present across studies with regard to methods and duration of training, in addition to outcomes such as ambulatory performance, metabolic demand, and perceived health benefits. No serious adverse events were reported. The incidence of falls during training was 4.4% (n=3), and all falls were reported in the same study (Kozlowski, 2015). The falls were attributed to programming errors in the first generation Ekso device in 2 cases and to a crutch malfunction in the 3rd case. The authors concluded that, “Powered exoskeletons allow patients with SCI to safely ambulate in real-world settings at a physical activity intensity conducive to prolonged use and known to yield health benefits.”  However, this conclusion is weakened by the fact that the majority of studies took place in the investigational setting.

A small cohort study involving 5 subjects with traumatic C7-T10 SCI and minimal spasticity was published by Karelis and others in 2017. All subjects underwent a 6-week long training period involving 3, 3-hour long training sessions per week with the Ekso device. No changes in the American Spinal Injury Association Impairment Scale (AIS) were reported following completion of the training sessions. Significant changes were noted for leg and appendicular lean body mass, and total leg and appendicular fat mass. Total BMI increased significantly. No serious injuries were reported.

Kozlowski (2017) reported the findings of the first study involving the use of a powered exoskeleton device in 5 subjects with multiple sclerosis (MS). This cohort study involved individuals with Expanded Disability Status Scale (EDSS) scores ranging from 5.5 to 7.0, medically stable, fit the ReWalk device, could tolerate standing for 30 minutes, and at least 1 year since their last relapse. Evaluations were taken at baseline and at weeks 1, 4, 8 (baseline period), 12 and 16 (intervention period) and at week 20 (follow-up). Subjects underwent 3, 30- to 90-minute training sessions per week for a total of 24 sessions. The study originally enrolled 13 subjects, but 2 failed screening and 6 withdrew, either due to transportation issues or device-related pain. A total of 5 subjects completed a minimum of 20 walking sessions. The investigators commented that regression of progress was noted with gaps in the training interval that exceeded 4 days, but losses were usually regained within  a single session. Learnability was considered high, with most participants attaining walking and sitting well within the 24-session limit. No serious adverse events were reported, but skin issues were common, with 151 events per 1000 hours of exposure to training. Qualitative postural improvements were reported for 4 of the 5 subjects. No overall improvement was reported with regard to the Neuro-QOL and Patient Reported Outcome Measurement and Information System (PROMIS) tools.

In 2017, Molteni published the results of the first study investigating the use of a powered exoskeleton device in subjects who had experienced a stroke. This study involved 23 subjects who were trained to use the Ekso device in 12, 1-hour long sessions over 4 weeks (3 sessions per week). The authors stratified their findings by subject condition, with 12 subacute (< 180 days from acute event) and 11 chronic (> 180 days from acute event). For the subacute subjects, the total scores on the motricity index (MI) revealed significant improvements at 6 and 12 weeks (p=0.008 and p=0.001, respectively). MI measures for hip and knee at 6 and 12 weeks also demonstrated significant benefits (p=0.008 and p=0.002 for hip, p=0.013 and p=0.008 for knee, respectively). Improvements in the MI ankle level were significant at 12 weeks. The Trunk Control Test (TCT) showed significant changes at both 6 and 12 weeks (p=0.008 and p=0.004, respectively). The Functional Ambulation Scale (FAC) had similar results (p=0.001 for both 6 and 12 weeks). Ambulation was achieved in 2 nonambulatory subjects. No significant improvements were noted in the 10MWT or in the number of steps. Finally, for this group, significant improvements were reported in walking velocity and the 6MWT at both 6 and 12 weeks (p=0.023 and p=0.008 for velocity, respectively and p=0.016 and p=0.004 for 66MWT, respectively). In the chronic group, no significant changes were found on the Ashworth scale, which measures lower limb spasticity. With respect to MI scores, the total score did show significant improvements at 6 and 12 weeks (p=0.016 and p=0.008, respectively), but only at the hip level (p=0.016 for both time points), but not at the knee or ankle levels. No significant changes were reported for the TCT, 10MWT, or steps taken. Findings on the FAC were significantly improved at 12 weeks (p=0.031), walking velocity improved significantly as well at both time points (p=0.016 for both), as did the results of the 6MWT (p=0.016 and p=0.031, respectively).

Tefertiller and others (2017) reported on a case series study involving 32 subjects with T4 and lower spinal cord injury. All subjects underwent training sessions with the Indego device 3 times weekly over 8 weeks and a single follow-up phone call 1 week after the completion of the training sessions. All subjects completed the trial. A total of 11 device-related adverse events were reported, including minor skin abrasions, joint edema, and bruising. A total of 2 moderate adverse events occurred, a trochanteric blister and a sprained ankle. No differences between mid-study and final measurements of indoor and outdoor 10MWT speeds were noted (p=0.081 and p=0.62, respectively). On the 10MWT, from the mid-study to final measurements, average indoor walking speed improved by 0.06 m/s (SD=0.07). Outdoor walking speed improved by 0.05 m/s (SD=0.08). Walking distance on the 6MWT from the mid-study to final measurements increased for all participants, with an average 151 m.

Bach Baunsgaard (2018) reported the results of a case series study of 52 subjects with spinal cord injury who were evaluated using the Ekso (n=8) and Ekso GT (n=44) devices. Subjects had either motor complete injury from C7 to L2 or motor incomplete injury from C1 to L2. The study involved gait training sessions scheduled 3 times weekly over 8 weeks and then followed for an additional 4 weeks. Subjects completing at least 16 of the 24 scheduled were included in the analysis. A total of 8 subjects (15.4%) dropped out of the study, and another was excluded due to spasticity unassociated with the treatment, leaving 42 evaluable subjects (80.8%) in the final analysis. The authors reported that time to get out of the seated position, 10MWT, and number of steps taken all increased significantly during the 8-week training period (p<0.001 for all measures). Rate of perceived exertion, as measured with the Borg Scale, significantly improved as well (p=0.001). Perhaps most importantly, in the group of recently injured subjects (time since injury < 1 year), the number that had gait function increased from 5 to 14 after the 8-week period, and to 15 after the additional 4-week follow-up period. A single subject in the chronically injured group (time since injury ≥ 1 year) acquired gait function at the time of follow-up. The authors noted no serious adverse events were experienced, but did report “a number of skin issues.”  These issues were not further described in the article. They concluded that training with the Ekso and Ekso GT devices was generally safe and feasible in a heterogeneous sample of persons with SCI and that they may provide benefits for gait function and balance.

Hayes and colleagues (2018) published the results of a systematic review of robotic exoskeleton devices used in gait training of individuals with spinal cord injuries. They included 12 studies, including 3 involving overground trials and 9 involving treadmill trials. The primary outcome measures reported were walking speed and walking distance. They reported that the use of treadmill or overground based robotic exoskeleton-assisted gait training did not result in an increase in walking speed beyond that of conventional gait training. Furthermore, they stated that no studies reviewed enabled large enough improvements to enable community ambulation.

In 2019, Sczesny-Kaiser reported the results of the HALESTRO study (HAL-Exoskeleton STROke study). A total of 18 subjects that had incomplete hemiparesis as a result of a stroke were enrolled for 6 weeks of HAL®-assisted (Cyberdyne, Tsukuba, Japan), supervised, body-weight supported treadmill training (BWSTT). The subjects also received conventional physiotherapy (CPT) for 6 weeks in this crossover study. There were no significant differences between the HAL-BWSTT and CPT group for the 10MWT (p=0.071), 6MWT (p=0.840), or TUG, (p=0.835). The authors reported that HAL-BWSTT did not significantly improve walking function or balance abilities when compared with CPT. While the combination of therapies shows promise, further studies are needed to evaluate net health outcomes. The study was small and lacked sufficientfollow-up needed to assess durable or continued improvement in motor capabilities as compared to standard of care.

Xiang and colleagues (2021) reported the results of a single-center, randomized controlled pilot study exploring the effects of exoskeleton-assisted walking (EAW) on pulmonary function and walking parameters compared to conventional rehabilitation training in individuals with SCI. The study involved 18 individuals, previously diagnosed with an SCI, who were randomized to receive either EAW or conventional training delivered as 50 to 60 minute sessions, 4 times per week for 4 weeks. Regarding pulmonary function parameters after training, significantly greater values were observed for forced vital capacity (FVC, p=0.041), FVC% (p=0.012), and forced expiratory volume in 1 second (FEV1, p=0.013) in the EAW group compared to the conventional treatment group. Differences in values for forced expiratory flow, peak expiratory flow, and maximal voluntary ventilation were not statistically significant. Only 10 participants completed the final 6MWT, of which 2 were in the conventional treatment group. There was no difference in lower extremity motor score. The results of this study suggest EAW has the potential to improve some pulmonary function parameters among this group of individuals with SCI, although the clinical significance is uncertain. Interpretation of study results is limited by the overall sample size and proportion of participants lost to follow-up.

Androwis and colleagues (2021) published the results of a randomized controlled pilot study evaluating the effects of 4 weeks of robotic exoskeleton-assisted exercise rehabilitation (REAER) compared to conventional gait training in individuals with substantial disability due to MS. The experimental condition involved supervised and progressive overground walking using the Ekso-GT robotic exoskeleton. The outcomes of interest were the effects of REAER on functional mobility (assessed by TUG), walking endurance (assessed by 6MWT), cognitive processing speed ([CPS], assessed by Symbol Digit Modalities Test [SDMT]), and brain connectivity (assessed by thalamocortical resting-state functional connectivity [RSFC] on fMRI). The study involved 10 individuals with substantial MS-related neurological disability. Although there were large improvements in functional mobility in the REAER group based on effect size estimates, there was no significant between-group difference in functional mobility (p=0.06) or walking endurance. There was a significant between-group difference in cognitive processing speed (p=0.02) and brain connectivity (p<0.01) in favor of the REAER group. Though the improvements in some individuals in this study population are promising, additional evidence in appropriately powered trials of sufficient duration is needed to confirm the durable effects of REAER on mobility and cognition in individuals with substantial MS-related disability.

Berriozabalgoitia and colleagues (2021) reported the results of a randomized controlled trial evaluating the use of overground robotic training in addition to a conventional outpatient physical therapy program in individuals with MS. The study involved 36 individuals with Expanded Disability Status Scale score between 4.5 and 7, and the need for assistive devices for walking outdoors. Participants were randomized to a conventional physical therapy program consisting of individualized, weekly, 1-hour sessions (control group, n=14) or conventional therapy plus overground gait training (OR group, n=18). Overground gait training consisted of a twice-weekly, individualized and progressive intervention for 3 months using the Ekso wearable exoskeleton. The primary outcome was performance on the 10MWT. Secondary variables included the Short Physical Performance Battery, TUG, and Modified Fatigue Impact Scale. There were no statistically significant between-group differences regarding the 10MWT. In the OR group, there was significant improvement on the TUG test (p=0.049, medium effect size) without an increase in fatigue perception. However, no time per group interactions were observed for any variable.

The American Heart Association and the American Stroke Association published guidelines for adult stroke rehabilitation and recovery in 2016 (Winstein, 2016). This document addressed the use of robotic and electromechanics-assisted training devices, and concluded that “Overall, although robotic therapy remains a promising therapy as an adjunct to conventional gait training, further studies are needed to clarify the optimal device type, training protocols, and patient selection to maximize benefits.”

In 2017, the Cochrane Library published a report assessing electromechanical-assisted training for walking after stroke (Mehrholz, 2017). This report concluded:

People who receive electromechanical-assisted gait training in combination with physiotherapy after stroke are more likely to achieve independent walking than people who receive gait training without these devices. We concluded that seven patients need to be treated to prevent one dependency in walking. Specifically, people in the first three months after stroke and those who are not able to walk seem to benefit most from this type of intervention. The role of the type of device is still not clear. Further research should consist of large definitive pragmatic phase III trials undertaken to address specific questions about the most effective frequency and duration of electromechanical-assisted gait training as well as how long any benefit may last.

On June 26, 2014, the U.S. Food and Drug Administration (FDA) cleared the ReWalk robotic lower body exoskeleton device with the following approved indications:

…is intended to enable individuals with spinal cord injury at levels T7-L5 to perform ambulatory functions with supervision of a specifically trained companion in accordance with the user assessment and training certification program. The device is also intended to enable individuals with spinal cord injury at levels T4-T6 to perform ambulatory functions in rehabilitation institutions in accordance with the user assessment and training certification program. The ReWalk™ is not intended for sports or stair climbing.

On February 26, 2016, the FDA cleared the Indego powered lower extremity exoskeleton, which is

…intended to enable individuals with spinal cord injury at levels T7 to L5 to perform ambulatory functions with supervision of a specially trained companion in accordance with the user assessment and training certification program. The device is also intended to enable individuals with spinal cord injury at levels T4 to T6 to perform ambulatory functions in rehabilitation institutions in accordance with the user assessment and training certification program. The Indego is not intended for sports or stair climbing.

On July 19, 2016, the FDA cleared the Ekso (version 1.1) and Ekso GT (version 1.2) powered lower extremity exoskeleton, saying that these devices are:

…intended to perform ambulatory functions in rehabilitation institutions under the supervision of a trained physical therapist for the following population:

The therapist must complete a training program prior to use of the device. The devices are not intended for sports or stair climbing.

The FDA cleared HAL for Medical Use (Lower Limb Type) on December 17, 2017 with the following approved indications:

…intended for individuals with spinal cord injury at levels C4 to L5 (ASIA C, ASIA D) and T11 to L5 (ASIA A with Zones of Partial Preservation, ASIA B), who exhibit sufficient residual motor and movement-related functions of the hip and knee to trigger and control HAL.
…intended to temporarily help improve ambulation upon completion of the HAL gait training intervention. HAL must be used with a Body Weight Support system. HAL is not intended for sports or stair climbing. HAL gait training is intended to be used in conjunction with regular physiotherapy.
…intended to be used inside medical facilities while under trained medical supervision in accordance with the user assessment and training certification program.

Published evidence addressing the clinical utility and beneficial health outcomes of robotic lower body exoskeleton devices is limited to small studies. There is insufficient evidence to evaluate long-term durability, or tolerability, or assess improvements in net health outcomes.

Background/Overview

Robotic lower body exoskeleton devices are intended to allow individuals with loss of lower limb function to ambulate on their own. When used, the device is worn outside clothing and consists of an upper-body harness, lower-limb braces, motorized joints, ground-force sensors, a tilt sensor, a locomotion-mode selector, and a backpack carrying a computerized controller and rechargeable battery. Using a wireless remote control worn on the wrist, the user commands the device to stand up, sit down, or walk. The device is strapped to the user at the waist, alongside each lower limb, and at the feet. Ordinary crutches are also utilized to help maintain stability.

There are several FDA approved robotic lower body exoskeleton devices on the market, including the ReWalk exoskeleton, Ekso, Ekso GT, Indego, and the ExoAtlet-II (ExoAtlet Asia Co. Ltd., Denver, CO). The FDA-approved indications for these devices include use by individuals with hemi- and paraplegia due to spinal cord injuries or stroke when accompanied by a specially trained caregiver. They may also be used in rehabilitation institutions. None of these types of devices are intended for sports or climbing stairs. For some of these devices, candidates must retain upper-limb strength and mobility to manage stabilizing crutches.

Coding

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Investigational and Not Medically Necessary:

HCPCS

 

 

K1007

Bilateral hip, knee, ankle, foot device, powered, includes pelvic component, single or double upright(s), knee joints any type, with or without ankle joints any type, includes all components and accessories, motors, microprocessors, sensors

 

L2999

Lower extremity orthoses, not otherwise specified [when specified as a powered robotic lower body exoskeleton device]

 

 

 

 

ICD-10 Diagnosis

 

 

All diagnoses

 

References

Peer Reviewed Publications:

  1. Androwis GJ, Sandroff BM, Niewrzol P, et al. A pilot randomized controlled trial of robotic exoskeleton-assisted exercise rehabilitation in multiple sclerosis. Mult Scler Relat Disord. 2021; 51:102936.
  2. Asselin PK, Avedissian M, Knezevic S, et al. Training persons with spinal cord injury to ambulate using a powered exoskeleton. J Vis Exp. 2016; (112):54071. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4927801/. Accessed on April 4, 2022.
  3. Asselin P, Knezevic S, Kornfeld S, et al. Heart rate and oxygen demand of powered exoskeleton-assisted walking in persons with paraplegia. J Rehabil Res Dev. 2015; 52(2):147-158.
  4. Bach Baunsgaard C, Vig Nissen U, Katrin Brust A, et al. Gait training after spinal cord injury: safety, feasibility and gait function following 8 weeks of training with the exoskeletons from Ekso Bionics. Spinal Cord. 2018; 56(2):106-116.
  5. Benson I, Hart K, Tussler D, van Middendorp JJ. Lower-limb exoskeletons for individuals with chronic spinal cord injury: findings from a feasibility study. Clin Rehabil. 2016; 30(1):73-84.
  6. Berriozabalgoitia R, Bidaurrazaga-Letona I, Otxoa E, et al. Overground robotic program preserves gait in individuals with multiple sclerosis and moderate to severe impairments: a randomized controlled trial. Arch Phys Med Rehabil. 2021; 102(5):932-939.
  7. Esquenazi A, Lee S, Packel AT, Braitman L. A randomized comparative study of manually assisted versus robotic-assisted body weight supported treadmill training in persons with a traumatic brain injury. PM R. 2013; 5(4):280-290.
  8. Esquenazi A, Talaty M, Packel A, Saulino M. The ReWalk powered exoskeleton to restore ambulatory function to individuals with thoracic-level motor-complete spinal cord injury. Am J Phys Med Rehabil. 2012; 91(11):911-921.
  9. Evans N, Hartigan C, Kandilakis, et.al. Acute cardiorespiratory and metabolic responses during exoskeleton-assisted walking overground among persons with chronic spinal cord injury. Top Spinal Cord Inj Rehab. 2015; 21(2):122-132.
  10. Fineberg DB, Asselin P, Harel NY, et al. Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia. J Spinal Cord Med. 2013; 36(4):313-321.
  11. Hartigan C, Kandilakis C, Dalley S, et al. Mobility outcomes following five training sessions with a powered exoskeleton. Top Spinal Cord Inj Rehabil. 2015; 21(2):93-99.
  12. Hayes SC, James Wilcox CR, Forbes White HS, Vanicek N. The effects of robot assisted gait training on temporal-spatial characteristics of people with spinal cord injuries: a systematic review. J Spinal Cord Med. 2018; 41(5):529-543.
  13. Karelis AD, Carvalho LP, Castillo MJ, et al. Effect on body composition and bone mineral density of walking with a robotic exoskeleton in adults with chronic spinal cord injury. J Rehabil Med. 2017; 49(1):84-87.
  14. Kozlowski AJ, Bryce TN, Dijkers MP. Time and effort required by persons with spinal cord injury to learn to use a powered exoskeleton for assisted walking. Top Spinal Cord Inj Rehabil. 2015; 21(2):110-121.
  15. Kozlowski AJ, Fabian M, Lad D, Delgado AD. Feasibility and safety of a powered exoskeleton for assisted walking for persons with multiple sclerosis: a single-group preliminary study. Arch Phys Med Rehabil. 2017; 98(7):1300-1307.
  16. Lonini L, Shawen M, Scanlon K, et.al. Accelerometry-enabled measurement of walking performance with a robotic exoskeleton: a pilot study. J Neuroeng Rehab. 2016; 13(35):142-149.
  17. Miller LE, Zimmermann AK, Herbert WG. Clinical effectiveness and safety of powered exoskeleton-assisted walking in patients with spinal cord injury: systematic review with meta-analysis. Med Devices (Auckl). 2016; 9:455-466.
  18. Molteni F, Gasperini G, Gaffuri M, et al. Wearable robotic exoskeleton for over-ground gait training in sub-acute and chronic hemiparetic stroke patients: preliminary results. Eur J Phys Rehabil Med. 2017; 53(5):676-684.
  19. Platz T, Gillner A, Borgwaldt N, et al. Device-training for individuals with thoracic and lumbar spinal cord injury using a powered exoskeleton for technically assisted mobility: achievements and user satisfaction. Biomed Res Int. 2016; 2016:8459018. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005562/. Accessed on April 4, 2022.
  20. Sczesny-Kaiser M, Trost R, Aach M, et al. A randomized and controlled crossover study investigating the improvement of walking and posture functions in chronic stroke patients using HAL exoskeleton - the HALESTRO study (HAL-Exoskeleton STROke study). Front Neurosci. 2019; 13:259. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6450263/pdf/fnins-13-00259.pdf. Accessed on April 4, 2022.
  21. Stampacchia G, Rustici A, Bigazzi S, et al. Walking with a powered robotic exoskeleton: subjective experience, spasticity and pain in spinal cord injured persons. NeuroRehabilitation. 2016; 39(2):277-283.
  22. Talaty M, Esquenazi A, Briceno JE. Differentiating ability in users of the ReWalk(TM) powered exoskeleton: an analysis of walking kinematics. IEEE Int Conf Rehabil Robot. 2013; 2013:6650469. Available at: https://ieeexplore.ieee.org/document/6650469. Accessed on April 4, 2022.
  23. Tefertiller C, Hays K, Jones J, et al. Initial outcomes from a multicenter study utilizing the Indego powered exoskeleton in spinal cord injury. Top Spinal Cord Inj Rehabil. 2018; 24(1):78-85.
  24. Xiang XN, Zong HY, Ou Y, et al. Exoskeleton-assisted walking improves pulmonary function and walking parameters among individuals with spinal cord injury: a randomized controlled pilot study. J Neuroeng Rehabil. 2021; 18(1):86.
  25. Yang A, Asselin P, Knezevic S, et al. Assessment of in-hospital walking velocity and level of assistance in a powered exoskeleton in persons with spinal cord injury. Top Spinal Cord Inj Rehabil. 2015; 21(2):100-109.
  26. Zeilig G, Weingarden H, Zwecker M, et al. Safety and tolerance of the ReWalk™ exoskeleton suit for ambulation by people with complete spinal cord injury: a pilot study. J Spinal Cord Med. 2012; 35(2):96-101.

Government Agency, Medical Society, and Other Authoritative Publications:

  1. Mehrholz J, Thomas S, Werner C, et al. Electromechanical-assisted training for walking after stroke. Cochrane Database of Systematic Reviews 2017;(5):CD006185.
  2. Spungen AM, Asselin P, Fineberg DB, et al.; VA Rehabilitation Research and Development National Center of Excellence for the Medical Consequences of Spinal Cord Injury. Exoskeletal-assisted walking for persons with motor-complete paraplegia. Research and Technology Organization, Human Factors, and Medicine Panel: North Atlantic Treaty Organization; 2013.
  3. U.S. Food and Drug Administration (FDA). 510(k) Premarket Notification Database. Ekso and Ekso GT. No. K143690. Richmond, CA: FDA. April 01, 2016. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf14/K143690.pdf. Accessed on April 4, 2022.
  4. U.S. Food and Drug Administration (FDA). 510(k) Premarket Notification Database. HAL for Medical Use (Lower Limb Type). No. K171909. Tsukuba, Japan. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf17/K171909.pdf. Accessed on April 4, 2022.
  5. U.S. Food and Drug Administration (FDA). 510(k) Premarket Notification Database. Indego. No. K171334. Austin, TX. Available at: https://www.accessdata.fda.gov/cdrh_docs/pdf17/K171334.pdf. Accessed on April 4, 2022.
  6. U.S. Food and Drug Administration (FDA). Premarket Notification Database. ReWalk. No. K131798. Marlborough, MA. Available at: https://www.accessdata.fda.gov/cdrh_docs/reviews/DEN130034.pdf. Accessed on April 4, 2022.
  7. Winstein CJ, Stein J, Arena R, et al. Guidelines for adult stroke rehabilitation and recovery. A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2016; 47(6):e98-e169.
Index

Ekso
Ekso GT
ExoAtlet
HAL for Medical Use-Lower Limb
Indego
ReWalk
Trexo

The use of specific product names is illustrative only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.

Document History

Status

Date

Action

Reviewed

05/12/2022

Medical Policy & Technology Assessment Committee (MPTAC) review. Updated Rationale, Background, References, and Index sections.

Reviewed

05/13/2021

MPTAC review. Updated Rationale and References sections.

 

10/01/2020

Updated Coding section with 10/01/2020 HCPCS changes; added K1007.

Reviewed

05/14/2020

MPTAC review. Updated Rationale, References, and Index sections.

Reviewed

08/22/2019

MPTAC review. Updated Rationale and References sections.

Reviewed

09/13/2018

MPTAC review. Updated Rationale and References sections.

Reviewed

11/02/2017

MPTAC review. The document header wording updated from “Current Effective Date” to “Publish Date.” Updated Rationale and References sections.

Reviewed

11/03/2016

MPTAC review. Updated References section.

Reviewed

11/05/2015

MPTAC review. Updated Rationale and Reference sections. Removed ICD-9 codes from Coding section.

New

11/13/2014

MPTAC review. Initial document development.

 


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