Biomed Eng Online. 2026 Feb 6. doi: 10.1186/s12938-026-01532-7. Online ahead of print.
ABSTRACT
BACKGROUND: The use of lower limb exoskeletons in clinical rehabilitation has expanded in recent years, offering potential benefits for walking recovery. However, current clinical evidence on their effectiveness remains inconclusive. Additionally, the way individuals adapt to these robotic devices and how this adaptation contributes to functional improvements is not yet fully understood. This study was intended to (1) investigate the safety and feasibility of the Fourier X2 exoskeleton for walking rehabilitation and (2) examine its effect on walking function following a rehabilitation program.
METHODS: A randomized controlled trial was undertaken with 46 individuals who had suffered a spinal cord injury (SCI) within the last year. Participants were randomly allocated into two groups: an intervention group (IG), which received gait training using the Fourier X2 exoskeleton, and a control group (CG), which underwent conventional gait training. Each participant completed 20 gait training sessions lasting one hour. The neurological impairment ranged from C2 to L4, with participants classified under the American Spinal Injury Association Impairment Scale (AIS) C or D. The treatment program involved 20 gait training sessions, each lasting one hour, utilizing the Fourier X2 exoskeleton. Safety was assessed by tracking adverse events, while pain and fatigue levels were measured using the Visual Analogue Scale (VAS). Functional outcomes were evaluated through the Lower Extremity Motor Score (LEMS), Walking Index for Spinal Cord Injury II (WISCI-II), Spinal Cord Independence Measure III (SCIM-III), and various walking assessments, including the 10-Meter Walk Test (10MWT), 6-Minute Walk Test (6MWT), and Timed Up and Go (TUG).
RESULTS: No major complications were observed during the study. Participants in the intervention group (IG) reported experiencing mild pain (1.7 cm, SD 1.1) and moderate fatigue (3.3 cm, SD 1.6) as measured by the Visual Analogue Scale (VAS, 0-10 cm range). Statistical analysis of WISCI-II scores showed notable progress in both the “group” effect (F = 17.82, p < 0.001) and the “group-time” interaction (F = 7.27, p = 0.03). Further post-hoc evaluations revealed that the IG achieved a significant improvement of 3.20 points (SD 2.16, p < 0.0001), whereas the control group (CG) demonstrated a minor, non-significant increase of 0.5 points (SD 1.31, p = 0.32). No other variables showed significant differences between the two groups.
CONCLUSIONS: The Fourier X2 exoskeleton is both safe and well-tolerated in clinical environments. Participants who received training with the device exhibited enhanced walking independence, as reflected in their WISCI-II scores.
TRIAL REGISTRATION: The Chinese Clinical Trial Register (ChiCTR) includes this study under registration number ChiCTR2000041186, dated December 21, 2020.
PMID:41652436 | DOI:10.1186/s12938-026-01532-7
