Effects of different intensity training with a lower limb exoskeleton robot on walking function in people with subacute stroke: a randomized controlled trial.

backgroundLower limb exoskeleton robots provide quantifiable training to overcome the intensity limitations of conventional rehabilitation for post-stroke gait dysfunction. Employing a 2 × 2 factorial design, this study aimed to systematically compare the therapeutic effects of four fixed intervention regimens (combined by two robot-assisted walking training speeds [high vs. routine] and two single-session durations [long vs. routine]) on lower limb walking function recovery in people with subacute stroke.

methodsThis was a randomized, assessor-blind, parallel-group controlled trial with an exploratory framework. A total of 60 people with subacute stroke were enrolled from Shanghai Yangzhi Rehabilitation Hospital between January and November 2024. Participants were randomly assigned to four groups via local computer-generated 1:1:1:1 sequence (sealed opaque envelopes for allocation concealment): T1S1 (0.2 m/s, 20 min), T1S2 (0.5 m/s, 20 min), T2S1 (0.2 m/s, 50 min), and T2S2 (0.5 m/s, 50 min). All groups received the same 40 min of conventional rehabilitation plus exoskeleton-assisted gait training, 5 sessions/week for 3 weeks (15 sessions total). Assessments pre- and post-intervention included clinical measures-10-Meter Walk Test (10MWT), Fugl-Meyer Assessment of Lower Extremity (FMA-LE), 6-Minute Walk Distance (6MWD), Rivermead Mobility Index (RMI) and spatiotemporal gait parameters (gait speed, gait cycle time, double support phase time, swing phase time, step length, and gait asymmetry). For the blinding design, participants and treating therapists had no blinding, whereas outcome assessors and statisticians were kept blinded.

resultsFifty-eight participants completed the study with high training adherence (2 withdrew due to discharge ). No serious adverse events occurred during the intervention. The incidence of non-serious adverse events was 17.2% (10/58), and all participants showed good tolerance and adherence to training. Post-randomization: 15 per group initially, with 15 (T1S1), 15 (T1S2), 13 (T2S1), 15 (T2S2) in primary outcome analysis. Analysis of clinical outcomes showed: (1) All groups showed significant improvements in all clinical outcomes after the intervention (P < 0.05); (2) Significant between-group differences in 10MWT (P<0.001), FMA-LE (P = 0.006), 6MWD (P < 0.001), and RMI (P = 0.038). Post-hoc analysis indicated that the T1S2, T2S1, and T2S2 groups showed greater improvement in 10MWT and FMA-LE than T1S1; T2S1 and T2S2 were superior to T1S1 in 6MWD; and T2S2 outperformed T1S1 in RMI (all P < 0.05). Spatiotemporal gait analysis revealed: (1) Significant post-intervention reductions in gait cycle time and increases in gait speed across all groups. The T1S2, T2S1, and T2S2 groups also exhibited significant improvements in double support phase time, spatiotemporal gait asymmetry, swing phase time and step length on the unaffected limb (P < 0.05); (2) Significant between-group differences in gait speed, gait cycle time, double support phase time, gait spatial asymmetry, and step length on the unaffected limb (P < 0.05). The T2S2 group demonstrated the greatest improvement in gait speed, surpassing all other groups. All three experimental groups (T1S2, T2S1, T2S2) showed better outcomes than T1S1 in double support phase time, step length on the unaffected limb, and gait spatial asymmetry, while T2S1 and T2S2 were superior in gait cycle time (P < 0.05).

conclusionThis study demonstrates that the synergistic load of "high-speed and long-duration" appears preferable among the tested 2 × 2 regimen combinations for improving walking recovery post-stroke. People with poorer walking ability should prioritize prolonged training to build walking endurance, while those with better function should emphasize high-speed training to enhance walking speed and quality, thereby showing potential benefits in improving patients' ability of daily activities and participation. Trial registration ChiCTR2400080118, on 22 January 2024, https://www.chictr.org.cn/ .