Cardiovascular

tDCS synchronous robotic training on lower-limb with post-stroke hemiplegia: a comparative study between synchronous and sequential group.

TL;DR

Synchronous tDCS-RT produced superior gait and functional benefits compared with sequential delivery, but did not differentially improve lower-limb motor impairment as measured by the FMA-LE on lower-limb with post-stroke hemiplegia.

Key Findings

No significant difference in Fugl-Meyer Assessment for Lower Extremities (FMA-LE) was found between the synchronous and sequential groups after treatment.

  • FMA-LE comparison between groups yielded F = 1.751, p = 0.191
  • Both groups received 40 minutes of treatment, five times a week, for two continuous weeks
  • This suggests tDCS delivery timing (synchronous vs. sequential) did not differentially improve lower-limb motor impairment as measured by FMA-LE
  • Baseline data showed no significant difference between groups before treatment (p > 0.05)

The synchronous tDCS-RT group showed superior hip flexion outcomes compared to the sequential group.

  • The 95% CI of hip flexion favored the synchronous group over the sequential group
  • The difference was statistically significant (p < 0.001)
  • Gait parameters were assessed using the Gait Watch three-dimensional gait analysis system before and after treatment
  • 30 participants were in each group after 4 dropouts from the original 64 enrolled

The synchronous tDCS-RT group demonstrated superior knee flexion outcomes compared to the sequential group.

  • The 95% CI of knee flexion favored the synchronous group (p < 0.001)
  • Knee flexion was measured using the Gait Watch three-dimensional gait analysis system
  • This finding suggests that concurrent application of tDCS during robotic training may better facilitate lower-limb gait kinematics

The synchronous group showed superior Functional Ambulation Category (FAC) scores compared to the sequential group after treatment.

  • FAC difference between groups was statistically significant (p < 0.001)
  • FAC was used to assess walking function in both groups
  • FAC was measured before and after the two-week intervention period

Step difference favored the synchronous tDCS-RT group over the sequential group after treatment.

  • Step difference outcome was significantly better in the synchronous group (p < 0.001)
  • Step difference was assessed as part of the Gait Watch three-dimensional gait analysis
  • Improved step difference in the synchronous group suggests more symmetrical gait following concurrent tDCS and robotic training

The synchronous tDCS-RT group demonstrated superior Modified Barthel Index (MBI) scores compared to the sequential group, indicating better activities of daily living (ADL) outcomes.

  • MBI difference between groups was statistically significant (p < 0.001)
  • MBI was used to assess activities of daily living in both groups
  • MBI was evaluated before and after the two-week treatment period
  • This suggests that timing of tDCS relative to robotic training influences functional independence beyond gait parameters

64 post-stroke hemiplegia patients were enrolled and allocated to synchronous or sequential groups, with 60 completing the study.

  • Patients were allocated into a synchronous group (tDCS concurrent with robotic training) and a sequential group (robotic training after tDCS ended)
  • 60 cases finished the study, with 30 in each group
  • All participants met specified inclusion and exclusion criteria
  • Both groups received 40 minutes of treatment, five times per week, for two consecutive weeks
  • Baseline data showed no significant between-group differences (p > 0.05)

What This Means

This research suggests that the timing of brain stimulation relative to robotic leg training matters for stroke recovery outcomes. The study compared two approaches in 60 post-stroke patients with weakness on one side of the body: one group received transcranial direct current stimulation (tDCS, a mild electrical brain stimulation) at the same time as robotic-assisted walking training, while the other group received the brain stimulation first and then did the robotic training afterward. Both approaches were delivered for 40 minutes a session, five days a week, over two weeks. The results showed that patients who received the brain stimulation and robotic training simultaneously had meaningfully better outcomes in several areas, including hip and knee bending during walking, step symmetry, walking ability (as measured by a standard clinical scale), and ability to perform daily activities. However, both groups showed similar improvements in a standard measure of lower-limb motor impairment (the Fugl-Meyer Assessment), meaning the timing difference did not change how much raw muscle control improved — only how that control translated into real-world walking and function. This research suggests that synchronizing brain stimulation with robotic rehabilitation, rather than delivering them one after the other, may produce better practical walking and daily living outcomes for stroke survivors. This could have implications for how rehabilitation sessions are scheduled and structured in clinical settings, though further research with larger samples and longer follow-up periods would help confirm these findings.

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Citation

Chen P, Sun J, Min Y, Zhang W, Li T. (2026). tDCS synchronous robotic training on lower-limb with post-stroke hemiplegia: a comparative study between synchronous and sequential group.. Annals of medicine. https://doi.org/10.1080/07853890.2026.2722430