Repetitive transcranial magnetic stimulation paired with a 3D-printed ankle-foot orthosis for ankle-foot dysfunction among older adults following subacute stroke: clinical findings and exploratory neurophysiological analyses.
Zhang Y, Chen H, et al. • Frontiers in neurology • 2026
Adding rTMS to a custom 3D-printed ankle-foot orthosis produced greater improvements in ankle mobility, muscle recruitment, balance and walking than 3D-printed AFO alone or conventional rehabilitation in older adults with subacute stroke, alongside indirect evidence of increased ipsilesional corticospinal excitability, though mechanistic explanations remain exploratory hypotheses.
Key Findings
Methods
Sixty older adults with ankle-foot dysfunction after subacute stroke were randomized to three parallel four-week rehabilitation arms and assessed at baseline and post-intervention.
Groups were conventional-only rehabilitation, 3D-printed AFO therapy, and combined rTMS plus 3D-printed AFO (n = 20 per group).
Outcomes were ankle active range-of-motion (AROM), resting motor threshold (RMT), integrated surface EMG (iEMG), Clinical Spasticity Index (CSI), FMA-LE, Berg Balance Scale (BBS), and 10-Metre Walking Test (10MWT).
Assessments were done at baseline and at four weeks post-intervention.
Results
All three study arms showed significant within-group functional improvements after treatment.
The abstract reports noticeable within-group improvements in all three arms (p < 0.001).
Improvements were seen on the measured clinical endpoints following the four-week intervention.
Results
The combined rTMS plus 3D-printed AFO group achieved greater functional improvement than the standalone 3D-printed AFO or conventional rehabilitation groups.
Between-group differences favoring combined therapy were reported as p < 0.05.
Combined therapy brought measurable improvements in ankle mobility, muscle recruitment, balance and walking performance compared with single-modality approaches.
Results
The conventional rehabilitation group showed the weakest magnitude of functional recovery across measured endpoints.
This was observed relative to both the 3D-printed AFO and the combined rTMS-AFO groups.
All groups nonetheless improved within-group (p < 0.001).
Results
Clinical benefits in the combined group occurred alongside elevated excitability within the ipsilesional corticospinal tract.
Excitability was assessed via indirect physiological readouts such as resting motor threshold (RMT) and iEMG.
The neurophysiological analyses were exploratory and no direct neural measurements were obtained.
Conclusions
Mechanistic explanations involving sensorimotor integration and afferent-efferent circuit regulation are exploratory hypotheses, not demonstrated mechanisms.
Direct neural measurements were not obtained in the study.
The authors state that further independent research is needed to test these mechanistic assumptions.
What This Means
This study tested whether adding a form of non-invasive brain stimulation, repetitive transcranial magnetic stimulation (rTMS), to a custom 3D-printed ankle-foot brace could help older adults recover ankle and foot function after a stroke. Sixty older adults in the subacute phase after stroke were randomly assigned to one of three groups of 20: conventional rehabilitation only, a 3D-printed brace, or the brace plus rTMS. They were assessed before and after four weeks of treatment on ankle movement, muscle activity, spasticity, lower-limb motor function, balance and walking speed.
All three groups improved significantly over the four weeks. However, the group that received both rTMS and the 3D-printed brace improved more than the other two groups, and the conventional rehabilitation group improved the least. The combined group also showed signs of increased excitability in the brain-to-muscle pathway on the stroke-affected side, measured through indirect indicators.
This research suggests that combining brain stimulation with a custom brace may offer added benefit over either approach alone for ankle-foot problems after stroke. The authors caution that the explanations for why it works, such as improved integration of sensory and motor signals, are only hypotheses because the brain was not measured directly. The study was small and four weeks long, so independent follow-up research is needed to confirm and explain the findings.
Zhang Y, Chen H, Xu R, Zhu L, Song S, Zhu W. (2026). Repetitive transcranial magnetic stimulation paired with a 3D-printed ankle-foot orthosis for ankle-foot dysfunction among older adults following subacute stroke: clinical findings and exploratory neurophysiological analyses.. Frontiers in neurology. https://doi.org/10.3389/fneur.2026.1859162