The findings advance the translation of soft robotic exo-suits from the laboratory to the clinic and may motivate future controlled efficacy trials.
Louis N. Awad, PT, DPT, PhD
Results from a multi-site clinical trial (NCT03499210) of ReWalk Robotics’ ReStore exo-suit demonstrated to be safe and reliable for use during post-stroke gait rehabilitation, while providing targeted assistance to both paretic ankle plantarflexion and dorsiflexion during treadmill and over ground walking.1,2
Led by study investigator Louis N. Awad, PT, DPT, PhD, director, Neuromotor Recovery Laboratory, Boston University, the data showed that there were no device-related falls or serious adverse events (AEs) reported among the 36 study participants who completed all 5 training days with the device. Device-related AEs occurred in less than 10% of study visits and the majority of AEs did not require intervention or treatment or considered mild in severity. The most frequent device-related AEs were pain the lower extremity (11 events) and skin abrasions (7 events).
"Physical therapists have historically relied on passive assistive devices to help patients with post-stroke hemiparesis walk safely. As an active assistive device, the ReStore soft robotic exo-suit offers new opportunities to retrain walking after stroke,” Awad said in a statement.1
Regardless of their reliance on ancillary assistive devices, after 5 days of walking practice with the device, participants increased both their device-assisted (0.10 ±0.03 m/s) and unassisted (0.07 ±0.03 m/s) maximum walking speeds (P <.05). Additionally, 64% of the study participants achieved the small meaningful change of 0.05 m/s, 36% increased by 0.10 m/s and 17% surpassed the 0.16 m/s threshold after 5 days of practice with the ReStore suit.
In total, 16 of the 36 study participants (44.4%) required the use of an Ankle Foot Orthosis (AFO) or cane during the walking evaluations. There were no reported differences between the exo-suit-assisted or unassisted maximum walking speed increases across these participant subsets.
“This multi-site clinical trial builds on this prior work by presenting safety, reliability, and feasibility data related to the use of the technology by licensed physical therapists to support post-stroke rehabilitation,” Awad and colleagues concluded.
The multi-site clinical trial originally included 44 users with post-stroke hemiparesis who completed up to 5 days of training with the ReStore on the treadmill and over ground. Of these individuals, 60% had an ischemic stroke and 41% were right hemiparetic. Their average age was 54.8 years, they were 7.3 years post-stroke, and had walked with an average comfortable walking speed of 0.82 m/s.
Researchers noted that 73% of the study population had customarily used passive assistive technology such as AFOs, canes or walkers for community mobility. Of the 44 original participants, 8 withdrew early from the study, leaving 36 for data analysis.
Safety and device reliability across all training activates were considered primary and secondary endpoints of the study. Exploratory evaluation of the effect of multiple exposures to using the device on users’ maximum walking speeds with and without the device was also conducted prior to and following the 5 training visits.
Clinical feasibility was also assessed using 2 custom questionnaires, with each question scored on a scale from 1 to 5. In the first questionnaire, patients answered on all planned visits and activities, with a score of 1 indicating “very satisfied,” and a score of 5 indicating “not satisfied at all.” The other questionnaire was provided to the 14 licensed physical therapists who operated the ReStore across each study site, with a score of 5 indicating “strongly agree” and a score of 1 indicating “strongly disagree.”
Research from this study was primarily done to support the company’s successful application in June 2019, where it became the first soft exo-suit device granted clearance by the FDA. The company also received CE Marking for the device in May 2019. According to ReWalk, the system consists of a soft, garment-like design connected to a waist pack and mechanical cables that allow the patient’s affected leg to be lifted in synchronized timing with their natural walking pattern. Although it applies force to the individual’s body, it does not restrict movement, and provides targeted assistance during forward propulsion and ground clearance. The device also records data that can be shared with a health care provider to further inform treatment and rehabilitations strategies.3
1. ReWalk announces publication of ReStore powered exo-suit clinical study results [news release]. Marlborough, MA: ReWalk Robotics. Published June 22, 2020. Accessed June 23, 2020. prnewswire.com/news-releases/rewalk-announces-publication-of-restore-powered-exo-suit-clinical-study-results-301081340.html
2. Awad LN, Esquenazi A, Francisco GE, Nolan KJ, Jayaraman A. The ReWalk ReStore soft robotic exosuit: a multisite clinical trial of the safety, reliability, and feasibility of exosuit-augmented post-stroke gait rehabilitation. J Neuroeng Rehabil. 2020;17:80. doi: 10.1186/s12984-020-00702-5
3. FDA issues clearance for the ReStore™ Exo-Suit, the first soft robotic system for stroke therapy [news release]. Marlborough, MA: ReWalk Robotics Ltd. June 4, 2019. Accessed June 24, 2020. prnewswire.com/news-releases/fda-issues-clearance-for-the-restore-exo-suit-the-first-soft-robotic-system-for-stroke-therapy-300861824.html