Stroke survivors often suffer from upper limb spasticity and impaired motor function. This review seeks to: (1) explore the efficacy of neural mobilization, particularly using the Upper Limb Neurodynamic Test 1 (ULNT1), in modulating electromyographic (EMG) activity of muscles; (2) examine its role in reducing spasticity and improving functional outcomes; and (3) outline the current state of knowledge, identifying existing gaps and directions for future research. A comprehensive literature review was conducted, focusing on studies that implemented ULNT1 and EMG analysis in post-stroke patients. The included studies varied in participant characteristics, methodologies, and outcome measures. The results demonstrated that neural mobilization has the potential to reduce EMG activity in spastic muscles and modify pain perceptions. However, results regarding the improvement of range of motion and functional outcomes were mixed. Neural mobilization and electromyographic analysis show promise for improving post-stroke rehabilitation. However, further research is required to confirm these benefits, with more rigorous methodologies and larger sample sizes.
Los sobrevivientes de un accidente cerebrovascular a menudo sufren de espasticidad en el miembro superior y disfunción motora. Esta revisión tiene como objetivos: 1) explorar la eficacia de la movilización neural, particularmente mediante el Test neurodinámico del miembro superior 1 (ULNT1), en la modulación de la actividad electromiográfica de los músculos; 2) examinar su papel en la reducción de la espasticidad y en la mejora de los resultados funcionales y 3) delinear el estado actual del conocimiento, identificando las brechas existentes y las direcciones para futuras investigaciones. Se llevó a cabo una revisión exhaustiva de la literatura, centrándose en estudios que implementaron el ULNT1 y el análisis electromiográfico en pacientes tras un ictus. Los estudios incluidos variaron en características de los participantes, metodologías y medidas de resultado. Los resultados demostraron que la movilización neural tiene el potencial de reducir la actividad electromiográfica en músculos espásticos y modificar las percepciones del dolor. Sin embargo, los resultados respecto a la mejora del rango de movimiento y de los resultados funcionales fueron mixtos. La movilización neural y el análisis electromiográfico muestran un potencial prometedor para mejorar la rehabilitación tras un ictus. No obstante, se requiere más investigación con metodologías más rigurosas y tamaños de muestra más grandes para confirmar estos beneficios.
Stroke stands as one of the primary causes of long-term disability worldwide, significantly impacting the quality of life of affected individuals and posing a considerable challenge for rehabilitation professionals.1–4 The spasticity and motor dysfunctions that arise as a consequence of a stroke can severely limit an individual's functionality and independence, making the exploration of effective and innovative therapeutic strategies imperative.5,6 Neural mobilization, employing specific techniques to mobilize the nervous system and enhance its functionality, has gained attention as a potential approach to mitigate post-stroke neuromuscular implications.1,7–9 The present scoping review was conducted following the Joanna Briggs Institute (JBI) methodology18 for scoping reviews. The present study seeks to explore the efficacy of neural mobilization, particularly through the use of the Upper Limb Neurodynamic Test 1 (ULNT1), in modulating the electromyographic activity of muscles and potentially influencing spasticity and muscle functionality in post-stroke patients. The ULNT1, aiming to assess and mobilize the median nerve, has been employed in various clinical contexts and has shown promise in inducing positive changes in nerve and muscle function.9–14 However, its applicability and efficacy in the context of post-stroke rehabilitation remain areas worthy of further exploration and confirmation through empirical research.7,15,16 This review aims to examine existing literature regarding the employment of neural mobilization in post-stroke patients, with a particular focus on electromyographic analysis of involved muscles and associated functional outcomes. The goal is to outline the current state of knowledge, identify existing gaps in the literature, and provide insights for future research that may further elucidate the role and efficacy of neural mobilization in post-stroke rehabilitation. Through a thorough and critical analysis of existing studies, this review aspires to contribute to the ongoing dialogue in the scientific and clinical community17 regarding optimal strategies to address the challenges of neurological rehabilitation and enhance functional outcomes and quality of life for stroke-affected patients. This scoping review approach is justified as the topic of neural mobilization in post-stroke rehabilitation remains underexplored. A scoping review allows mapping of the existing evidence to identify gaps in knowledge and provide directions for future research. Given the complexity of the topic and the diversity of interventions, this approach is well-suited to synthesize available findings comprehensively without focusing on the quality of evidence.
MethodsThis scoping review adhered to the PRISMA-ScR19 (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) Checklist to ensure rigor and transparency in reporting. Each subsection, including eligibility criteria, search strategy, study selection, and data synthesis, has been addressed in alignment with the checklist to provide a structured and comprehensive overview of the existing evidence.
Review questionWe formulated the following research question: “How effective is neural mobilization, specifically utilizing the Upper Limb Neurodynamic Test 1 (ULNT1), in modulating electromyographic activity and improving functional outcomes in the biceps brachii muscle of individuals experiencing post-stroke spasticity and motor dysfunction?”.
Eligibility criteriaStudies were eligible for inclusion if they met the following Population, Concept, and Context (PCC) criteria.
PopulationThe population consists of adults who have experienced a stroke and demonstrate spasticity, with particular attention to those experiencing spasticity and motor impairments in the upper limb. This includes individuals with varying degrees of spasticity following a stroke, often measured by clinical tools such as the Modified Ashworth Scale. The focus is on motor impairments in the upper limb, where patients may exhibit difficulty in muscle control, increased muscle tone, or stiffness, commonly associated with post-stroke recovery.
ConceptThe concept focuses on neural mobilization, specifically utilizing the Upper Limb Neurodynamic Test 1 (ULNT1). ULNT1 is a specific test aimed at mobilizing the median nerve, which is one of the major nerves affecting upper limb function. The test and subsequent interventions are intended to reduce neural tension, with the hypothesis that neural mobilization may decrease spasticity and improve motor function. Studies employing this specific technique were sought, with emphasis on the electromyographic analysis of affected muscles to track changes in muscle activity before and after the intervention.
ContextThe intervention had to be administered in a rehabilitation center, clinical setting, hospital, or any other healthcare facility. These are environments where post-stroke rehabilitation programs are often delivered, ensuring that the interventions are applied in real-world settings by healthcare professionals trained in neurorehabilitation. This context ensures that studies included in the review reflect practical clinical applications, rather than experimental or non-clinical environments. Only studies that fulfilled all three criteria (Population, Concept, and Context) were considered eligible for inclusion in the review.
Exclusion criteriaStudies that did not meet the specific PCC criteria were excluded.
Search strategyAn initial limited search of MEDLINE was performed through the PubMed interface to identify articles on the topic and then the index terms used to describe the articles were used to develop a comprehensive search strategy for MEDLINE. The search strategy, which included all identified keywords and index terms, was adapted for use in Cochrane Central, Scopus, PEDro. Searches were conducted on 23 July 2024 with no date limitation.
MEDLINE (PubMed): (stroke[MeSH Terms] OR cerebrovascular accident[MeSH Terms] OR “post-stroke” OR “cerebrovascular accident” OR “brain infarction”) AND (spasticity[MeSH Terms] OR muscle spasticity[MeSH Terms] OR “upper limb spasticity” OR “spastic paralysis”) AND (“neural mobilization” OR “nerve mobilization” OR “neurodynamic mobilization” OR “Upper Limb Neurodynamic Test 1” OR ULNT1) AND (rehabilitation centers OR rehabilitation[MeSH Terms] OR hospitals OR clinical settings OR healthcare facility).
Scopus: (TITLE-ABS-KEY(stroke OR “cerebrovascular accident” OR “brain infarction” OR “post-stroke”)) AND (TITLE-ABS-KEY(spasticity OR “muscle spasticity” OR “upper limb spasticity”)) AND (TITLE-ABS-KEY(“neural mobilization” OR “nerve mobilization” OR “neurodynamic mobilization” OR “Upper Limb Neurodynamic Test 1” OR ULNT1)) AND (TITLE-ABS-KEY(rehabilitation OR “rehabilitation center” OR hospital OR “clinical setting” OR “healthcare facility”)).
PEDro (Physiotherapy Evidence Database): (stroke OR cerebrovascular accident OR brain infarction OR post-stroke) AND (spasticity OR muscle spasticity OR upper limb spasticity) AND (“neural mobilization” OR “nerve mobilization” OR “neurodynamic mobilization” OR “Upper Limb Neurodynamic Test 1” OR ULNT1).
Cochrane Central: (stroke OR “cerebrovascular accident” OR “brain infarction” OR “post-stroke”) AND (spasticity OR “muscle spasticity” OR “upper limb spasticity”) AND (“neural mobilization” OR “nerve mobilization” OR “neurodynamic mobilization” OR “Upper Limb Neurodynamic Test 1” OR ULNT1) AND (rehabilitation OR “rehabilitation center” OR hospital OR “clinical setting” OR “healthcare facility”).
The search strategy was documented and adapted for each database in accordance with PRISMA-ScR guidelines to ensure replicability.
Study selectionAfter completing the search strategy, the results were collected and imported into Zotero. Duplicates were removed using Zotero's deduplication tool, resulting in a unique set of records. This file was then made available for further processing. The selection process involved two levels of screening using Rayyan QCRI. First, in the “title and abstract screening” phase, two authors independently reviewed the articles. Discrepancies were resolved by a third author. The aim was to assess relevance to the research question. The selection process followed the PRISMA-ScR flow, with screening conducted at two levels: title/abstract and full-text review by two independent reviewers. Discrepancies were resolved through consensus or a third reviewer.
Data extraction and data synthesisData extraction was conducted using a pre-designed form based on the JBI (Joanna Briggs Institute) tool, tailored for this scoping review. Key details extracted included authors, publication year, country, study design, patient characteristics, interventions, outcomes, and any additional relevant information. Descriptive analyses were performed to summarize the characteristics of the included studies, with results presented in numerical format using frequencies and percentages. The search decision process, including the number of articles identified, screened, assessed for eligibility, and included in the review, was systematically mapped for transparency. The extracted data were summarized in Table 1, offering a clear and structured overview of the main characteristics and findings, facilitating easy comparison and analysis across the studies.
Summary of key findings from included studies.
| Authors and year | Population | Intervention | Outcomes | Results |
|---|---|---|---|---|
| Godoi et al., 2010 | 5 stroke patients (4 men, 1 woman), mean age: 52.8±11 years, Grade 1 and +1 spasticity (MAS). | ULNT1 applied, followed by EMG analysis of biceps brachii muscle (90° flexion and full extension). | EMG activity | Statistically significant decrease in EMG activity of the biceps brachii (p≤0.05). |
| Castilho et al., 2012 | 6 adults (4 men, 2 women), mean age: 54.16±7.9 years, with spasticity in elbow flexors. | ULNT1 (wrist oscillations for 3min, repeated 3 times, 1-min rest)+EMG analysis. | EMG activity | 17% decrease in flexion and 11% in extension; not statistically significant (p=0.27, 0.30). |
| Villafañe et al., 2012 | 76-Year-old man with severe upper limb spasticity (9 months post-stroke). | Combined therapy: BoNT-A (2 sessions)+neurodynamic mobilization (5x/week for 6 months). | ROM, spasticity, pain, anxiety/depression | ROM improved (shoulder, elbow, forearm, wrist); 71% spasticity reduction; 87% pain reduction; decreased HADS scores. |
| Díez Valdés et al., 2019 | 32 patients (20 men, 12 women), mean age: 60.09 years, with acquired brain injury (hemiparesis). | ULNT1 for median nerve with structural differentiation (cervical side bending). | ROM, pain, functional status | ROM differences between limbs; pain/discomfort reported; variable STD results (positive/negative). |
BoNT-A: Botulinum toxin type A; EMG: electromyography; HADS: Hospital Anxiety and Depression Scale; MAS: Modified Ashworth Scale; NM: neurodynamic mobilization; NRS: Numeric Rating Scale; ROM: range of motion; RMS: root mean square; STD: structural differentiation; ULNT1: Upper Limb Neurodynamic Test 1.
As presented in the PRISMA 2020 flow-diagram (Fig. 1), from 23 records identified by the initial literature searches, 19 were excluded and 4 articles were included (Table 1).
The results of this scoping review are structured into five key domains to provide a comprehensive synthesis: electromyographic activity, range of motion, spasticity, pain, and anxiety and depression. This structured approach allows for a clearer understanding of the impact of neural mobilization and its associated outcomes in post-stroke rehabilitation.
Electromyography (EMG)- •
Godoi et al., 201012: This study demonstrated a significant decrease in EMG activity in the biceps brachii muscle following the application of the Upper Limb Neurodynamic Test 1 (ULNT1). Participants, who exhibited Grade 1 or +1 spasticity according to the Modified Ashworth Scale, showed a statistically significant reduction in muscle activity (p≤0.05) during full elbow extension post-intervention. This suggests that ULNT1 can effectively reduce muscle hyperactivity related to post-stroke spasticity.
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Castilho et al., 201210: In this study, six adults with stroke sequelae and spasticity in the elbow flexor muscles underwent neural mobilization on the unaffected limb. The intervention resulted in a reduction of EMG activity by 17% during flexion and 11% during extension of the biceps brachii. However, these decreases were not statistically significant (p=0.27 for flexion, p=0.30 for extension). This indicates that while neural mobilization shows potential in reducing muscle activity, further research is needed to confirm its efficacy.
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Villafañe et al., 201220: In this case report, a 76-year-old male with severe upper limb spasticity following a stroke experienced marked improvements in range of motion (ROM) after receiving combined therapy of Botulinum toxin type A (BoNT-A) and neurodynamic mobilization. Shoulder ROM, elbow ROM, forearm supination, and wrist extension all improved significantly throughout the six-month treatment, and these gains were sustained during the follow-up period. The combined approach suggests that pairing BoNT-A with neural mobilization can be effective for improving upper limb mobility in patients with severe spasticity.
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Díez Valdés et al., 201911: In a study of 32 patients with acquired brain injuries, differences in ROM between the affected and unaffected limbs were observed during the performance of ULNT1. The neurodynamic test revealed ROM limitations in the affected limbs, highlighting the importance of ROM assessment in neurodynamic testing. The study also reported that patients experienced varying levels of discomfort during the procedure, which could influence ROM outcomes.
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Villafañe et al., 201220: The same patient from Villafañe et al.’s case report experienced a 71% reduction in spasticity as measured by the Modified Ashworth Scale (MAS). This significant reduction occurred after a combined treatment of BoNT-A and neurodynamic mobilization. The reduction in muscle tone highlights the potential effectiveness of combining pharmacological and manual therapy interventions to manage severe spasticity in post-stroke patients.
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Villafañe et al., 201220: Pain was significantly reduced by 87% after six months of combined BoNT-A and neurodynamic mobilization therapy, as measured by the Numeric Rating Scale (NRS). The patient reported consistent pain relief throughout the treatment and during follow-up, indicating long-term benefits of the combined therapeutic approach in managing both spasticity and pain post-stroke.
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Díez Valdés et al., 201911: In the study involving 32 brain-injured patients, some participants reported pain and discomfort during the ULNT1 test, especially in the affected limbs. This suggests that neurodynamic tests can provoke pain responses in some patients, which should be carefully monitored during clinical assessments.
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Villafañe et al., 201220: In addition to physical improvements, the patient in this study also showed significant reductions in anxiety and depression, as measured by the Hospital Anxiety and Depression Scale (HADS). These psychological benefits were sustained during follow-up, indicating that the combined treatment approach had a positive impact on the patient's mental health alongside physical improvements.
The application of the Upper Limb Neurodynamic Test 1 (ULNT1) and the electromyographic analysis of the biceps brachii muscle showed a statistically significant decrease in electromyographic activity in a sample of five post-stroke individuals.10,12 This suggests that ULNT1 might have a positive impact in modulating muscle activity and potentially managing spasticity.21–25 However, it is crucial to consider the sample size and the need for further research to validate these findings in a broader population. Neural mobilization (ULNT1) showed a reduction in electromyographic activity of the biceps brachii muscle, the changes were not statistically significant. This raises pertinent questions regarding the consistency and reliability of neural mobilization interventions, and whether these can be influenced by factors such as the severity of spasticity and the time elapsed since the stroke event.10,14 The case of the 76-year-old who received combined therapy of Botulinum toxin type A (BoNT-A) and neurodynamic mobilization (NM) highlighted notable improvements in various parameters, including ROM, spasticity, and pain. This combined approach might suggest that integrating different therapeutic modalities may offer an optimal path to address the multiple challenges presented by spasticity and post-stroke dysfunctions. Lastly, the use of the ULNT1 neurodynamic test and structural differentiation (STD) in a sample of 32 patients offered a complex look at the efficacy of these techniques in treating acquired brain injuries. The variety of outcomes measured, ranging from pain and discomfort during the test to measurements of functional status, underscores the importance of a holistic approach in assessing and treating patients with brain injuries. In summary, while each of the explored interventions offers valuable insights and potential therapeutic paths for treating spasticity and post-stroke motor dysfunctions, the variability and complexity of the results highlight the need for further exploration and experimentation. Personalizing interventions, taking into account the specificities and individual needs of patients, and integrating various therapeutic strategies might emerge as key elements in the future of post-stroke rehabilitation.26–30 Future research should, therefore, aim to consolidate these findings, further exploring the synergies between different intervention modalities and optimizing therapeutic strategies to maximize functional outcomes and the quality of life of post-stroke patients. Although the quality of evidence was not formally assessed, it is worth noting that the included studies exhibited variations in sample sizes, methodologies, and intervention protocols. These factors may influence the reliability and generalizability of the findings. Future studies should aim for larger samples and standardized protocols to strengthen the evidence base.
LimitationsHowever, there are several limitations. The small sample sizes and lack of participant diversity limit the generalizability of the findings. Additionally, some observed changes, such as reductions in electromyographic activity, did not reach statistical significance, raising questions about the reliability of the interventions. The long-term impact of these interventions on functional outcomes and quality of life remains largely unexplored, and the variability in protocols across studies complicates comparisons and synthesis of findings. Finally, the underlying mechanisms through which these interventions affect neuromuscular dynamics and functional recovery are not fully understood, indicating the need for more robust and methodologically sound research.
Implications for clinical practiceNavigating post-stroke rehabilitation requires a patient-centered, research-driven approach that integrates multiple therapeutic modalities. Clinicians should focus on tailoring interventions to the patient's unique needs and progress, ensuring a personalized and adaptive treatment plan. Collaboration across healthcare disciplines is key to optimizing outcomes, especially when managing complex post-stroke conditions like spasticity and motor dysfunction.
Practically, it is crucial to engage patients in their rehabilitation, enhancing their motivation and adherence through education and involvement in decision-making. Safety and comfort during interventions, particularly for pain management, must be prioritized. Additionally, leveraging technology – such as assessment tools and tele-rehabilitation platforms – can support remote monitoring and improve the real-world application of therapeutic benefits.
ConclusionsThe exploration into various therapeutic interventions for post-stroke rehabilitation, including neural mobilization and electromyographic analysis, has unveiled potential avenues for enhancing patient outcomes, particularly in addressing spasticity and muscle function. While preliminary findings indicate possible benefits, such as improved range of motion and reduced electromyographic activity, the lack of statistical significance in some outcomes and the limitations posed by sample size and diversity necessitate cautious interpretation. Future research endeavors should prioritize larger, more diverse participant samples, and long-term follow-up studies to substantiate the clinical relevance and sustainability of observed benefits.
Ethical approvalNot applicable.
FundingNone declared.
