Journal of NeuroEngineering and Rehabilitation最新文献

{"title":"Ipsilateral inhibitory rTMS restores interhemispheric motor cortex balance and reduces phantom limb pain: an exploratory longitudinal nTMS mapping study.","authors":"Ghaith Altawalbeh, Eugen Ursu, Filippo Emanuele Colella, Maria Goldberg, Raimunde Liang, Axel Schröder, Sebastian Ille, Sandro M Krieg, Melissa Zavaglia, Amartya Ganguly, Chiara Negwer, Bernhard Meyer, Arthur Wagner","doi":"10.1186/s12984-026-02120-5","DOIUrl":"https://doi.org/10.1186/s12984-026-02120-5","url":null,"abstract":"<p><strong>Background: </strong>Phantom limb pain (PLP) is a debilitating condition associated with maladaptive neuroplastic changes following limb amputation. The prevailing neuromodulatory approach targets the deafferented contralateral motor cortex, yet interhemispheric imbalance is increasingly recognized as a central pathophysiological feature of PLP. We investigated whether inhibitory repetitive transcranial magnetic stimulation (rTMS) applied to the ipsilateral (unaffected) hemisphere could reduce PLP and induce measurable normalization of interhemispheric cortical asymmetry.</p><p><strong>Methods: </strong>Two individuals with traumatic right upper-limb amputation and severe PLP underwent a longitudinal study comprising a four-week baseline phase, an inhibitory 1 Hz rTMS intervention targeting the ipsilateral motor cortex, and a five-week follow-up phase. Serial navigated transcranial magnetic stimulation (nTMS) motor mapping of both hemispheres was performed before and after the intervention. A principal component analysis (PCA)-based spatial projection and Gaussian kernel regression pipeline was developed to quantify motor map area, center of gravity (CoG), mean motor evoked potential (MEP) amplitude, and signal amount bilaterally.</p><p><strong>Results: </strong>Both participants demonstrated clinically meaningful PLP reductions (66% and 33% relative decreases on the Visual Analog Scale [VAS]), sustained across the five-week follow-up. Serial nTMS mapping revealed enlarged residual limb motor representations in the affected hemisphere at baseline. Following rTMS, cortical area of the triceps representation in the affected hemisphere decreased by 67% and 61% in the two participants respectively, with concurrent normalization of interhemispheric differences in both representation area and signal amount. CoG shifts were modest (mean 3.28 mm), indicating focal map consolidation rather than wholesale topographic reorganization.</p><p><strong>Conclusions: </strong>These findings offer novel neurophysiological evidence suggesting that inhibitory rTMS targeting the ipsilateral motor cortex reduces PLP while concurrently normalizing interhemispheric motor map asymmetry. The results are consistent with a callosal disinhibition mechanism, whereby ipsilateral inhibition may facilitate adaptive reorganization of the deafferented hemisphere. The novel PCA-based bilateral mapping pipeline introduced here provides a quantitative framework for future controlled trials.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13474741/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148766549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction: An electrical stimulation intervention protocol to prevent disuse atrophy and muscle strength decline: an experimental study in rat.","authors":"Haiwang Shi, Fan Li, Fulong Zhang, Xiaobei Wei, Chengyi Liu, Rui Duan","doi":"10.1186/s12984-026-02117-0","DOIUrl":"10.1186/s12984-026-02117-0","url":null,"abstract":"","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13452098/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148697645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parkinsonian gait improvement through vibratory stride parameter feedback.","authors":"Paul Kirsch, Miriam Helbig, Dominic Rupar, Simon Baudrexel, Christian A Kell","doi":"10.1186/s12984-026-02113-4","DOIUrl":"10.1186/s12984-026-02113-4","url":null,"abstract":"<p><strong>Background: </strong>Hypokinetic gait increases morbidity and mortality of persons with Parkinson's disease and constitutes a major target symptom for therapy. Feedback on gait quality, e.g. by a physiotherapist, improves stride length and reduces shuffling. Wearable devices measuring gait parameters and providing feedback could improve parkinsonian gait during everyday life when no physiotherapist is available. Here, we report on the efficacy of a new device providing discreet vibratory feedback upon decreased stride length and increased shuffling.</p><p><strong>Methods: </strong>33 persons with Parkinson's disease, in two cohorts, received automatic vibratory feedback administered via a newly developed sensor-equipped insole when their stride length and heel strike angle decreased while walking a 730 m walking course. Gait of 14 persons with Parkinson's disease in the first cohort was investigated in OFF and ON medication state to allow for a comparison of the feedback effect with the effect of medication on stride length, heel strike angle and gait variability. In both cohorts, the effect of feedback on gait parameters was compared against a control walk without stimulation and was subjectively evaluated by the study participants. In the second cohort of 19 participants, the effect of feedback was additionally compared with vibration at random time points to investigate the efficacy of context-adequate feedback.</p><p><strong>Results: </strong>Both stride length and heel strike angle improved upon feedback to a degree that, on average, was close to the medication effect on parkinsonian gait. Stimulation at random time points showed intermediate values with non-significant improvements in gait parameters compared to control walks. Closed-loop feedback resulted in a less variable gait pattern compared to control walks. Persons with Parkinson's disease rated the feedback mode as subjectively useful.</p><p><strong>Conclusions: </strong>Our results demonstrate the use of closed-loop feedback can improve parkinsonian gait and suggest such a device could effectively complement the available approaches in the treatment of persons with Parkinson's disease.</p><p><strong>Trial registration: </strong>This trial was retrospectively registered in the German Clinical Trials Register (DRKS00038516) on 9 December 2025.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13430838/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148669751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eight weeks of focal muscle vibration shows improvements in muscle co-ordination and co-contraction in cerebral palsy children: a randomized control trial.","authors":"Moeez Ashfaque, Kiran Khushnood, Ganesh R Naik, Imran K Niazi, Imran Amjad, Amit N Pujari","doi":"10.1186/s12984-026-02066-8","DOIUrl":"10.1186/s12984-026-02066-8","url":null,"abstract":"<p><strong>Background: </strong>Muscle spasticity, impaired coordination and fatigue are common in cerebral palsy (CP) children. This study investigated frequency-specific effects of focal muscle vibration (FMV) on neuromuscular activation, fatigue, and agonist-antagonist coordination. We hypothesized that 8 weeks of FMV would improve lower limb muscle activation, reduce fatigue, and optimize co-contraction compared to control, with differential effects between 80 and 100 Hz stimulation.</p><p><strong>Methods: </strong>In a double-blind randomized controlled trial, 65 spastic diplegic CP children (GMFCS II-IV) were allocated to Control, 80 Hz, or 100 Hz FMV groups. Primary outcomes were EMG-derived muscle activation (RMS) and fatigue (median frequency; and fatigue index). Secondary outcomes included co-contraction index (CCI) between tibialis anterior (TA) and soleus (Sol). Assessments were conducted at baseline, 4, 8, and 12 weeks. Linear mixed-effects models evaluated Group, Time, and Group × Time effects, with Bonferroni-corrected post-hoc comparisons.</p><p><strong>Results: </strong>Significant group differences were observed primarily in the TA. In non-dominant leg, the 100 Hz group showed higher RMS compared to Control at 4 weeks (p = 0.027) and 8 weeks (p = 0.027) and compared to 80 Hz at 4 weeks (p = 0.045) and 8 weeks (p = 0.008). In dominant leg, 100 Hz also demonstrated higher RMS than Control at 8 weeks (p = 0.003). Fatigue analysis revealed significant time effects in soleus muscle (p ≤ 0.009), with 100 Hz group demonstrating more sustained MDF values in the dominant limb, suggesting improved fatigue resistance, whereas 80 Hz group showed greater fatigue-related declines. FI analysis further revealed significant Group × Time interactions in non-dominant Sol (p = 0.008), with 80 Hz differing from Control (p = 0.019) and 100 Hz (p = 0.008) at 8 weeks. For co-contraction, a significant group effect was observed in the non-dominant limb (p = 0.034), indicating differences between intervention and control groups, although post-hoc comparisons were not significant.</p><p><strong>Conclusion: </strong>FMV induces frequency-specific neuromuscular adaptations in CP children. 100 Hz stimulation appears more effective for enhancing short-term muscle activation and fatigue resistance, while 80 Hz may promote longer-term coordination changes. Trial registration Trial prospectively registered with United States clinical trial registry (clinicaltrials.gov), trial ID: NCT05751135.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13505169/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148818744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of anterioposterior weight-shift training with visual biofeedback for step length asymmetry and functional mobility in chronic stroke: a randomized controlled trial.","authors":"Jong Weon Lee, Yea Jin Jo, Yoon Su Baek, Seeun Kim, Jung Hoon Kim, Dae Hyun Kim, Jong Hyun Choi, Jong Bum Park, Deog Young Kim","doi":"10.1186/s12984-026-02030-6","DOIUrl":"https://doi.org/10.1186/s12984-026-02030-6","url":null,"abstract":"<p><strong>Background: </strong>Step length asymmetry is a specific and persistent characteristic of hemiparetic gait in patients with chronic stroke, typically resulting from impaired weight bearing and reduced propulsive force on the paretic side. This asymmetry leads to reduced walking efficiency and an increased risk of musculoskeletal complications. This study investigated the efficacy of an anterioposterior weight-shift training (AP training) system utilizing visual biofeedback to improve gait asymmetry in patients with chronic stroke.</p><p><strong>Methods: </strong>This randomized controlled trial enrolled 34 patients with chronic hemiplegic stroke who exhibited step-length asymmetry (step-length ratio > 1.1). Participants were randomized into an AP training group or a control group. Both groups received conventional gait training for 6 weeks, and the experimental group received additional AP training sessions (30 min, 3 times/week). The AP training system provided real-time visual biofeedback on the Center of Pressure trajectory and weight distribution. The primary outcome was the Step Length Asymmetry Index (SLAI). The secondary outcomes included plantar pressure distribution, temporospatial parameters, 3D kinematic/kinetic gait analysis, and energy consumption.</p><p><strong>Results: </strong>The AP training group demonstrated significant improvements in the SLAI compared with the control group (p < 0.05). Significant between-group differences favoring the intervention were also observed for swing time asymmetry, forefoot contact area, and pressure (p < 0.05). Three-dimensional gait analysis revealed an increased ankle dorsiflexion angle and hip extension moment on the affected side in the training group. While the self-selected walking speed showed no significant difference, the maximum safe walking speed significantly improved in the training group (p < 0.05). No significant between-group differences were observed in energy consumption (oxygen cost or oxygen rate).</p><p><strong>Conclusion: </strong>AP training may effectively improve step length asymmetry and paretic limb mechanics in patients with chronic stroke. By enhancing the anterior weight transfer and propulsive force, this intervention offers a targeted strategy for addressing established asymmetric gait patterns in the chronic phase of recovery. Trial details ClinicalTrial.gov Identifier NCT02207933.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149224315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visual feedback increases expiratory muscle training effort in Parkinson's disease: a randomised crossover trial.","authors":"Martin Srp, Katerina Dvorakova, Jan Muzik, Petra Janderova, Martin Sevcik, Vaclav Matys, Jakub Vitek, Radim Kliment, Martina Hoskovcova, Evzen Ruzicka","doi":"10.1186/s12984-026-02104-5","DOIUrl":"10.1186/s12984-026-02104-5","url":null,"abstract":"<p><strong>Background: </strong>Disorders of airway protection, including impaired cough and swallowing, are clinically important complications of Parkinson's disease. Expiratory muscle strength training (EMST) is an established non-pharmacological intervention targeting these deficits. The aim of this study was to evaluate the acute effect of visual feedback provided by the SpiroGym mHealth app on expiratory muscle activation during EMST in people with Parkinson's disease.</p><p><strong>Methods: </strong>We conducted a single-center, randomised, two-period crossover trial in people with Parkinson's disease. Participants performed EMST under two conditions, in randomised order: conventional EMST without visual feedback and EMST with real-time visual feedback provided by the SpiroGym app. Expiratory muscle activation was measured using surface electromyography of the abdominal muscles. The primary outcome was the within-participant difference in mean peak normalised internal oblique activity between conditions. Secondary outcomes included external oblique and rectus abdominis activity, associations with neuropsychiatric symptoms, and participant-reported usability ratings.</p><p><strong>Results: </strong>Twenty participants were randomised, and 19 completed the study and were included in the final analysis. No study-related adverse events occurred. Visual feedback significantly increased mean peak normalised internal oblique activity compared with no feedback (118.2 ± 36.4% vs. 90.5 ± 23.0% of reference voluntary contraction; p < 0.001; Cohen d = 0.95). Without feedback, internal oblique activation significantly declined from 100.1 ± 22.2% in the first set to 84.4 ± 25.5% in the fifth set, whereas it remained stable with feedback (120.3 ± 29.4% to 119.9 ± 40.6%). External oblique activation was also significantly higher with feedback (122.2 ± 38.1% vs. 100.9 ± 32.4%; p = 0.002; Cohen d = 0.66), while rectus abdominis activation did not differ significantly between conditions (105.2 ± 41.3% vs. 90.2 ± 36.1%; p = 0.06; Cohen d = 0.43). No significant associations between feedback responsiveness and depression, apathy, or anxiety were detected. Participants rated the visual feedback as easy to understand and helpful for EMST performance.</p><p><strong>Conclusions: </strong>Real-time visual feedback delivered by the SpiroGym app acutely increased and stabilized expiratory muscle activation during EMST in people with Parkinson's disease. Trial registration ClinicalTrials.gov NCT06942533, 1 May 2025.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13673806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal synchrony promotes motor recovery and ipsilesional cortical reorganization in BCI-based stroke rehabilitation: a randomized controlled trial.","authors":"Yu Wu, Qiumeng Dong, Jie Chen, Cong Huang, Ming Zhang","doi":"10.1186/s12984-026-02100-9","DOIUrl":"10.1186/s12984-026-02100-9","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;The therapeutic mechanisms of brain-computer interface (BCI) rehabilitation remain partially understood. Specifically, it is unclear whether functional gains are driven primarily by active neural engagement or strictly by the temporal contingency between motor intention and sensory feedback. This study aimed to deconstruct the BCI paradigm to isolate the specific contributions of these core components to functional recovery and cortical reorganization in subacute stroke.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;Seventy-seven subacute stroke patients were randomized into three intervention arms. Group C (synchronous) received robotic assistance strictly contingent on real-time detection of task engagement during motor imagery; Group B (asynchronous) performed identical motor imagery tasks but received temporally uncoupled robotic assistance; and Group A (sham) received sham motor imagery detection and preset passive robotic assistance. The intervention lasted for 3 weeks. The primary clinical outcome was Fugl-Meyer Assessment-Upper Extremity (FMA-UE) scores. Functional near-infrared spectroscopy (fNIRS) was included as an exploratory neuroimaging measure to provide preliminary information on cortical responses associated with the intervention.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Sixty-eight participants were included in the final analysis. After adjustment for baseline values, Group C showed significantly higher post-intervention FMA-UE scores than both Group A (adjusted mean difference = 7.47, 95% CI [1.94, 13.00], P = 0.004) and Group B (adjusted mean difference = 9.72, 95% CI [4.14, 15.30], P &lt; 0.001). Group C also showed significantly higher post-intervention MBI scores than both Group A (adjusted mean difference = 21.15, 95% CI [12.49, 29.81], P &lt; 0.001) and Group B (adjusted mean difference = 21.27, 95% CI [12.42, 30.12], P &lt; 0.001). Exploratory neuroimaging analyses showed that only the change in ipsilesional sensorimotor cortex laterality index during motor imagery was significantly correlated with motor improvement (ρ = 0.404, P = 0.002, q = 0.012), whereas no resting-state or task-related fNIRS group comparisons remained significant after false discovery rate correction.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Synchronous BCI training was associated with superior clinical improvement compared with asynchronous and sham conditions in subacute stroke. The benefit was observed only when robotic assistance was contingent on real-time task performance, despite all three groups receiving comparable device exposure and motor imagery instruction. The neuroimaging results remain exploratory and should be confirmed in larger studies with prospectively defined imaging endpoints. Trial registration This trial was registered under the Chinese Clinical Trial Registry (ChiCTR2400091197) and was prospectively registered on October 21, 2024. Ethics Approval: Approved by the Ethics Committee of Xuzhou Rehabilitation Hospital (XK-LSW-2024101","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A smart vision assistance system designed for the cybathlon 2024 vision assistance race to support individuals with visual impairments.","authors":"Simon Senoner, Simon Winkler, Lukas Neururer, Leon Ochtendung, Julia Jackermaier, Marcel Naderer, Bernhard Tschulnigg, Bernhard Hollaus, Yeongmi Kim","doi":"10.1186/s12984-026-02092-6","DOIUrl":"10.1186/s12984-026-02092-6","url":null,"abstract":"<p><p>Individuals with visual impairments continue to face challenges in performing everyday tasks, despite ongoing advances in assistive technologies. In the context of the Cybathlon 2024 Vision Assistance Race, we developed and evaluated a smart vision assistance system combining lightweight wearable hardware, multimodal sensing, and computer vision algorithms. This article presents the technical development process of the system, including hardware design, sensor integration, feedback mechanisms, real-time object detection and text recognition pipelines, and task-oriented interaction strategies adapted to the competition tasks. The system achieved reliable performance across most race tasks, although consistent results for the Forest task remained challenging. To investigate usability beyond the competition environment, we conducted a user study using simplified versions of selected race tasks. The study evaluated task completion time and success rate to assess how effectively the system could be used with minimal training. Results showed an average success rate of 93.46%, with reductions in task completion times for the evaluated tasks: Doorbell, Empty Seats, Grocery, Colours, and Touchscreen. This work serves as a technical report on the design, implementation, and evaluation of a Cybathon vision assistance system, providing insights into the integration of wearable hardware, multimodal feedback, and machine learning methods for assistive applications.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":" ","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13673871/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why inverse simulations overestimate optimal ankle exoskeleton assistance: the role of bi-articular coordination and joint stiffness.","authors":"Israel Luis, Elena M Gutierrez-Farewik, Maarten Afschrift","doi":"10.1186/s12984-026-02106-3","DOIUrl":"10.1186/s12984-026-02106-3","url":null,"abstract":"<p><strong>Background: </strong>Ankle-foot exoskeletons can reduce muscle activity and metabolic energy consumption during walking. Experimental studies consistently show that submaximal assistance, typically providing 40-60% of the biological plantarflexion moment, achieves the largest reductions in metabolic power. Inverse musculoskeletal simulations, which neglect factors such as comfort and balance, also predict that submaximal assistance is optimal, yet at higher levels than those observed experimentally. The biomechanical mechanisms underlying this submaximal assistance and its disagreement with experimental observations remain poorly understood.</p><p><strong>Methods: </strong>In this study, we addressed these questions using inverse simulations of walking and systematically examining muscle-tendon dynamics, metabolic power, and ankle joint stiffness across ten assistance levels (0-100% of the biological plantarflexion moment).</p><p><strong>Results: </strong>We found that the bi-articular role of the gastrocnemius limits the reduction of metabolic power at the highest levels of assistance. A sensitivity analysis modifying biceps femoris short head strength provided causal confirmation of this mechanism. We further show that increasing assistance substantially reduces ankle joint stiffness by up to 55%, primarily due to de-recruitment of the soleus.</p><p><strong>Conclusions: </strong>These findings identify both the explanation for submaximal assistance in inverse simulations and propose a missing control objective in exoskeleton simulation frameworks. Because standard effort-based cost functions do not penalize reductions in joint mechanical impedance, this trade-off between effort minimization and stiffness preservation may help explain why simulation-based optimal assistance exceeds experimentally observed values. Inverse simulation does not model robustness, for which impedance preservation may serve as a tractable formulation. Accounting for such a term might represent a new direction for more accurate prediction of optimal exoskeleton assistance.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":"23 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13386900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bypass neural interfaces for paralysis: clinical translation, challenges and future directions.","authors":"Marcus Jun Rui Lee, Ashton Kai Shun Tan, Yu Tung Lo, Charles Liu, Lei Jiang","doi":"10.1186/s12984-026-02082-8","DOIUrl":"10.1186/s12984-026-02082-8","url":null,"abstract":"<p><p>Advances in neural recording, real-time decoding and bioelectronic stimulation have enabled a new class of systems that re-establish functional communication across disrupted neural pathways. In the context of paralysis, these neural bypass interfaces link upstream neural intent to effector activation downstream of the lesion, effectively circumventing sites of injury within the nervous system to restore volitional movement. In this review, we define neural bypass interfaces as an emerging category of bioelectronic medicine, distinct from conventional brain-computer interfaces and neuromodulation technologies. We first outline key neurophysiological and systems-level considerations underlying bypass design, before tracing their evolution from bench to bedside. We then focus on the clinical translation challenges that govern real-world deployment, specifically signal stability and fidelity, stimulation performance, decoding robustness, closed-loop integration and long-term implant viability. Importantly, this review highlights two emerging directions that may shape the next generation of neural bypasses: the use of the spinal cord itself as a source of neural intent, and the development of bidirectional bypasses integrating sensory feedback to enable more adaptive, physiologically aligned control. Ultimately, neural bypasses may go beyond simply restoring movement to drive biological recovery, redefining neurorestorative therapies for paralysis.</p>","PeriodicalId":16384,"journal":{"name":"Journal of NeuroEngineering and Rehabilitation","volume":" ","pages":""},"PeriodicalIF":6.0,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13670714/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148549548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}