Neurology · Medical Literature
Development and Upgrade of a Robot That Enables Three-Dimensional Trunk Motion and Lower Limb Exercise for Stroke Patients: A Pilot Clinical Investigation Including a User Feasibility Test.
Abstract
Stroke impairs functional independence including gait ability. While robot-aided rehabilitation techniques have been developed, there is a need for a robotic system that promotes three-dimensional (3D) movement of the trunk and gait ability while providing automatic function evaluation and individually optimized prescriptions for stroke patients. To assess the efficacy and safety of a novel trunk and lower limb robotic system for patients with hemiplegia due to chronic stroke. This study employed a single-arm, before-after trial design conducted in an institutional setting. Twenty individuals (eight males; mean age, 52.3 ± 11.8 years) with hemiplegia resulting from chronic stroke (≥ 12 months postonset) who showed no change in the Functional Ambulation Category (FAC) for at least 2 months prior to baseline were enrolled. Participants underwent robot-assisted training using a system composed of trunk, upright, and lower extremity modules. Each participant received 30-min sessions, 5 days per week, for 4 weeks. The robotic system provided real-time kinematic motion data to support rehabilitation exercises. Primary outcomes included changes in functional evaluation and performance scores from baseline to postintervention. Additionally, a feasibility survey was administered to assess user satisfaction and identify areas for system improvement. In all patients, the functional scores did not differ significantly between baseline and 1 month after the robotic intervention. However, there were improvements in the performance scores of lateral and forward bending of the trunk while sitting, forward bending ability during sit-to-stand activity, weight transfer, and lateral and forward bending of the trunk while standing 1 month after the intervention (p < 0.05). The user experience survey showed satisfaction in 16 of 20 patients due to the easy and safe operation of the robot. The proposed robotic system was safe and convenient to use and was associated with improvements in selected kinematic parameters.
Clinical relevance
In adults with chronic post-stroke hemiplegia whose functional ambulation has plateaued, does a novel multimodule robotic system enabling three-dimensional trunk motion and lower-limb exercise improve functional and kinematic outcomes over a 4-week training program? __SNAPSHOT__ {"studyDesign":"Single-arm, before-after pilot clinical trial with a supplementary user feasibility survey","setting":"Institutional rehabilitation setting; CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea","sampleSize":"n=20 (8 male, 12 female; mean age 52.3 ± 11.8 years); no comparator arm","population":"Adults with hemiplegia resulting from chronic stroke (≥12 months post-onset) who demonstrated no change in Functional Ambulation Category (FAC) for at least 2 months prior to enrollment — i.e., a functionally stable, plateaued chronic stroke cohort","intervention":"Robot-assisted training using a multimodule system comprising trunk, upright, and lower extremity modules; 30-minute sessions, 5 days per week, for 4 weeks (approximately 20 sessions total); the system provided real-time kinematic motion data to support and guide rehabilitation exercises","comparator":"Not applicable — single-arm design with no active or sham comparator","primaryOutcome":"Changes in functional evaluation scores and robotic performance scores from baseline to post-intervention (1 month); a user feasibility and satisfaction survey was also administered","followUp":"1 month (immediate post-intervention assessment only; no long-term follow-up reported)","fundingSource":"Not reported in the available abstract"}
Key findings
The primary functional outcome scores (specific scales not fully enumerated in the available abstract, but inclusive of standard functional evaluation instruments) did not differ significantly between baseline and 1 month post-intervention across all 20 participants. However, statistically significant improvements (p < 0.05) were observed in robotic performance scores for: lateral and forward bending of the trunk while sitting, forward bending ability during sit-to-stand activity, weight transfer, and lateral and forward bending of the trunk while standing. The authors concluded the system was safe and convenient to use and was associated with improvements in selected kinematic parameters. Absolute effect sizes, confidence intervals, between-group comparisons, NNT/NNH, and specific scale scores (e.g., FAC, Berg Balance Scale, Fugl-Meyer) are not reported in the available abstract. Adverse event rates and their nature are not quantified in the abstract. All reported p-values derive from within-group before-after comparisons in the absence of a control arm.
Practice implications
This study established preliminary feasibility and safety of a novel 3D trunk and lower-limb robotic rehabilitation system in a small cohort of functionally plateaued chronic stroke survivors. It demonstrated statistically significant within-group improvements in robot-measured kinematic performance scores for trunk mobility (lateral and forward bending in sitting and standing) and sit-to-stand mechanics after 4 weeks of intensive daily training. However, it did not establish efficacy on standard functional outcome measures — the primary functional evaluation scores were not significantly changed — and no causal inference is possible due to the single-arm design with no comparator group. The absence of a control arm means observed kinematic gains cannot be attributed to the robotic intervention versus natural variation, regression to the mean, or therapist contact time. The population was narrowly defined (chronic, plateaued hemiplegia, mean age ~52 years), limiting generalizability to subacute stroke, older adults, or those with more severe or less severe impairments. User feasibility and satisfaction data were collected but are not quantified in the abstract. Whether the observed kinematic gains translate into meaningful functional improvements in activities of daily living, gait independence, or quality of life remains unestablished. NOTE: This summary is based on abstract-level data only; full-text review may reveal additional outcome data, statistical details, and methodological information not captured here. __LIMITATIONS__ Single-arm before-after design with no comparator group precludes causal attribution of any observed changes to the robotic intervention,Very small sample size (n=20) substantially limits statistical power and precision; the study is explicitly a pilot investigation,No long-term follow-up; only immediate post-intervention (1-month) data available, so durability of any observed gains is unknown,Primary functional outcome scores were not significantly improved, raising questions about the clinical meaningfulness of kinematic performance gains,Kinematic performance scores are system-specific, robot-derived surrogate endpoints whose relationship to validated functional scales (FAC, BBS, FMA-LE, mBI) or patient-reported outcomes is not established,Plateau criterion (no FAC change for ≥2 months) reduces but does not eliminate the possibility of spontaneous recovery contributing to observed changes,Selection bias likely; institutionally recruited, relatively young (mean ~52 years) chronic stroke population may not represent community-dwelling or older stroke survivors,Potential ceiling/floor effects not characterized given that baseline functional scores are not reported in the abstract,Blinding was not possible given the single-arm design; assessor blinding status is not reported,Funding source is not reported, limiting assessment of potential conflicts of interest,Abstract-only access limits full appraisal of statistical methods, completeness of adverse event reporting, dropout rates, and feasibility survey methodology __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This small, uncontrolled pilot study found that a novel 3D trunk and lower-limb robotic system was safe and feasible in functionally plateaued chronic stroke patients, with statistically significant within-group improvements in robot-derived kinematic performance scores for trunk mobility, but no significant change in primary functional outcome measures. The absence of a control arm and the small sample size prevent any conclusions about therapeutic efficacy. Larger randomized controlled trials with validated functional endpoints and long-term follow-up are required before this system can be considered for clinical adoption.