A Novel Quantitative Spasticity Evaluation Method Based on Surface Electromyogram Signals and Adaptive Neuro Fuzzy Inference System

Decoding hand and wrist movement intention from chronic stroke survivors with hemiparesis using a user-friendly, wearable EMG-based neural interface

OBJECTIVE

Seventy-five percent of stroke survivors, caregivers, and health care professionals (HCP) believe current therapy practices are insufficient, specifically calling out the upper extremity as an area where innovation is needed to develop highly usable prosthetics/orthotics for the stroke population. A promising method for controlling upper extremity technologies is to infer movement intention non-invasively from surface electromyography (EMG). However, existing technologies are often limited to research settings and struggle to meet user needs.

APPROACH

To address these limitations, we have developed the NeuroLife® EMG System, an investigational device which consists of a wearable forearm sleeve with 150 embedded electrodes and associated hardware and software to record and decode surface EMG. Here, we demonstrate accurate decoding of 12 functional hand, wrist, and forearm movements in chronic stroke survivors, including multiple types of grasps from participants with varying levels of impairment. We also collected usability data to assess how the system meets user needs to inform future design considerations.

MAIN RESULTS

Our decoding algorithm trained on historical- and within-session data produced an overall accuracy of 77.1 ± 5.6% across 12 movements and rest in stroke participants. For individuals with severe hand impairment, we demonstrate the ability to decode a subset of two fundamental movements and rest at 85.4 ± 6.4% accuracy. In online scenarios, two stroke survivors achieved 91.34 ± 1.53% across three movements and rest, highlighting the potential as a control mechanism for assistive technologies. Feedback from stroke survivors who tested the system indicates that the sleeve's design meets various user needs, including being comfortable, portable, and lightweight. The sleeve is in a form factor such that it can be used at home without an expert technician and can be worn for multiple hours without discomfort.

SIGNIFICANCE

The NeuroLife EMG System represents a platform technology to record and decode high-resolution EMG for the real-time control of assistive devices in a form factor designed to meet user needs. The NeuroLife EMG System is currently limited by U.S. federal law to investigational use.

Effects of extracorporeal shock wave therapy on spasticity, walking and quality of life in poststroke lower limb spasticity: a systematic review and meta-analysis

OBJECTIVE

To determine the effects of extracorporeal shock wave therapy (ESWT) on lower limb function, walking, and quality of life in patients with lower limb poststroke spasticity.

DATA SOURCES

A comprehensive and systematic electronic database search of PubMed, Web of Science, ProQuest thesis Dissertation checks, Google Scholar was conducted from January 2010 to March 2022.

REVIEW METHOD

Initially, the bibliography was screened to identify randomized and nonrandomized controlled trials evaluating the effects of ESWT on lower limb spasticity and functional outcomes in stroke patients. Two reviewers independently screened the title and abstract, full-text articles, extracted data, and assessed the quality of the selected studies. The primary evaluation outcome was spasticity assessed by Modified Ashworth Scale (MAS), and the secondary outcomes were walking performance and quality of life measured on different scales.

DATA SYNTHESIS

Out of the total of 483 records, 15 studies (389 participants) were finally found eligible for inclusion. A meta-analysis was performed and beneficial effects of ESWT were observed in the experimental group compared with the control group on spasticity. MAS: Standard mean difference (SMD = 0.626), (95%CI = -0.133, 1.119), (p < 0.01), ROM: (SMD = 0.573), (95%CI = 0.074, 1.072), (p < 0.02). The result for before and after ESWT application on TUG: (SMD = 0.174), (95%CI=-0.151, 0.499), (p = 0.29). The results for walking performance were not significant and inconclusive which may be due to the heterogeneity of the studies included.

CONCLUSION

Evidence suggests that ESWT has promising effects in reducing spasticity and improving lower limb motor function. However, uncertainty exists regarding its effectiveness in walking performance.

Technology-assisted assessment of spasticity: a systematic review

BACKGROUND

Spasticity is defined as "a motor disorder characterised by a velocity dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks". It is a highly prevalent condition following stroke and other neurological conditions. Clinical assessment of spasticity relies predominantly on manual, non-instrumented, clinical scales. Technology based solutions have been developed in the last decades to offer more specific, sensitive and accurate alternatives but no consensus exists on these different approaches.

METHOD

A systematic review of literature of technology-based methods aiming at the assessment of spasticity was performed. The approaches taken in the studies were classified based on the method used as well as their outcome measures. The psychometric properties and usability of the methods and outcome measures reported were evaluated.

RESULTS

124 studies were included in the analysis. 78 different outcome measures were identified, among which seven were used in more than 10 different studies each. The different methods rely on a wide range of different equipment (from robotic systems to simple goniometers) affecting their cost and usability. Studies equivalently applied to the lower and upper limbs (48% and 52%, respectively). A majority of studies applied to a stroke population (N = 79). More than half the papers did not report thoroughly the psychometric properties of the measures. Analysis identified that only 54 studies used measures specific to spasticity. Repeatability and discriminant validity were found to be of good quality in respectively 25 and 42 studies but were most often not evaluated (N = 95 and N = 78). Clinical validity was commonly assessed only against clinical scales (N = 33). Sensitivity of the measure was assessed in only three studies.

CONCLUSION

The development of a large diversity of assessment approaches appears to be done at the expense of their careful evaluation. Still, among the well validated approaches, the ones based on manual stretching and measuring a muscle activity reaction and the ones leveraging controlled stretches while isolating the stretch-reflex torque component appear as the two promising practical alternatives to clinical scales. These methods should be further evaluated, including on their sensitivity, to fully inform on their potential.

Multimodal assessment of spasticity using a point-of-care instrumented glove to separate neural and biomechanical contributions

Accurate assessment of spasticity is crucial for physicians to select the most suitable treatment for patients. However, the current clinical practice standard is limited by imprecise assessment scales relying on perception. Here, we equipped the clinician with a portable, multimodal sensor glove to shift bedside evaluations from subjective perception to objective measurements. The measurements were correlated with biomechanical properties of muscles and revealed dynamic characteristics of spasticity, including catch symptoms and velocity-dependent resistance. Using the biomechanical data, a radar metric was developed for ranking severity in spastic knees and elbows. The continuous monitoring results during anesthesia induction enable the separation of neural and structural contributions to spasticity in 21 patients. This work delineated effects of reflex excitations from structural abnormalities, to classify underlying causes of spasticity that will inform treatment decisions for evidence-based patient care.

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Tool to shift from subjective scales to objective metrics in spasticity evaluation

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Develop a multifaceted metric to rank severity based on biomechanical properties

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Delineate effects of hyper-reflexes and structural abnormalities in spastic muscles

A Practical Post-Stroke Elbow Spasticity Assessment Using an Upper Limb Rehabilitation Robot: A Validation Study

Spasticity is a motor disorder characterised by a velocity-dependent increase in muscle tone, which is critical in neurorehabilitation given its high prevalence and potential negative influence among the post-stroke population. Accurate measurement of spasticity is important as it guides the strategy of spasticity treatment and evaluates the effectiveness of spasticity management. However, spasticity is commonly measured using clinical scales which may lack objectivity and reliability. Although many technology-assisted measures have been developed, showing their potential as accurate and reliable alternatives to standard clinical scales, they have not been widely adopted in clinical practice due to their low usability and feasibility. This paper thus introduces an easy-to-use robotic based measure of elbow spasticity and its evaluation protocol. Preliminary results collected with one post-stroke patient and one healthy control subject are presented and demonstrate the feasibility of the approach.

Effects of Functional Acupuncture on Upper Limb Spasticity After Ischemic Stroke: A Protocol for a Randomized Controlled Parallel Clinical Trial

Background

Upper limb spasticity (ULS) is a common complication after stroke, which seriously affects the quality of life and rehabilitation of patients. There are different treatment methods for post-stroke spasticity (PSS). Our group found that functional acupuncture (FA) can effectively improve forearm spasticity and hand dysfunction after stroke, but the efficacy of ULS needs to be further verified. Therefore, this subject has mainly used clinical randomized controlled trials to evaluate the clinical efficacy of FA in the treatment of ULS after ischemic stroke.

Method

This is a parallel design and randomized controlled trial. We selected 108 patients who met the predefined criteria and randomized them into two groups, the experimental group and the control group. The experimental group receives FA and routine rehabilitation treatment. The control group received traditional acupuncture (TA) and routine rehabilitation treatment. All patients received 20 courses of treatment for 4 weeks, and the modified Ashworth score (MAS), clinical neurological deficit score (CSS), Fugl-Meyer upper extremity function assessment (FMA-UE), and the Modified Barthel Index (MBI) scores were evaluated before and after treatment.

Discussion

This trial is mainly to study the clinical efficacy of FA in the treatment of ULS after ischemic stroke. It will not only provide a new idea for the clinical treatment of upper limb post-stroke spasticity (ULPSS) but also will provide effective experimental support and a theoretical basis for the clinic.

Trial registration

China Clinical Trials Registry No. ChiCTR2100050440. Registered on 27 August 27 2021.

A Data-Driven Investigation on Surface Electromyography Based Clinical Assessment in Chronic Stroke

Background: Surface electromyography (sEMG) based robot-assisted rehabilitation systems have been adopted for chronic stroke survivors to regain upper limb motor function. However, the evaluation of rehabilitation effects during robot-assisted intervention relies on traditional manual assessments. This study aimed to develop a novel sEMG data-driven model for automated assessment. Method: A data-driven model based on a three-layer backpropagation neural network (BPNN) was constructed to map sEMG data to two widely used clinical scales, i.e., the Fugl-Meyer Assessment (FMA) and the Modified Ashworth Scale (MAS). Twenty-nine stroke participants were recruited in a 20-session sEMG-driven robot-assisted upper limb rehabilitation, which consisted of hand reaching and withdrawing tasks. The sEMG signals from four muscles in the paretic upper limbs, i.e., biceps brachii (BIC), triceps brachii (TRI), flexor digitorum (FD), and extensor digitorum (ED), were recorded before and after the intervention. Meanwhile, the corresponding clinical scales of FMA and MAS were measured manually by a blinded assessor. The sEMG features including Mean Absolute Value (MAV), Zero Crossing (ZC), Slope Sign Change (SSC), Root Mean Square (RMS), and Wavelength (WL) were adopted as the inputs to the data-driven model. The mapped clinical scores from the data-driven model were compared with the manual scores by Pearson correlation. Results: The BPNN, with 15 nodes in the hidden layer and sEMG features, i.e., MAV, ZC, SSC, and RMS, as the inputs to the model, was established to achieve the best mapping performance with significant correlations (r > 0.9, P < 0.001), according to the FMA. Significant correlations were also obtained between the mapped and manual FMA subscores, i.e., FMA-wrist/hand and FMA-shoulder/elbow, before and after the intervention (r > 0.9, P < 0.001). Significant correlations (P < 0.001) between the mapped and manual scores of MASs were achieved, with the correlation coefficients r = 0.91 at the fingers, 0.88 at the wrist, and 0.91 at the elbow after the intervention. Conclusion: An sEMG data-driven BPNN model was successfully developed. It could evaluate upper limb motor functions in chronic stroke and have potential application in automated assessment in post-stroke rehabilitation, once validated with large sample sizes. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02117089.

Long-Term Efficacy of Extracorporeal Shock Wave Therapy on Lower Limb Post-Stroke Spasticity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The purpose of this systematic review and meta-analysis is to evaluate the long-term efficacy of Extracorporeal Shock Wave Therapy (ESWT) on reducing lower limb post-stroke spasticity in adults. A systematic electronic search of PubMed/ MEDLINE, Physiotherapy Evidence Database (PEDro), Scopus, Ovid MEDLINE(R), and search engine of Google Scholar was performed. Publications that ranged from January 2010 to August 2020, published in English, French, Spanish, Portuguese, and Italian language and available as full texts were eligible for inclusion and they were searched without any restrictions of country. The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and followed the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions. Two authors screened the references, extracted data, and assessed the risk of bias. The primary outcome was spasticity grade mainly assessed by the Modified Ashworth Scale (MAS). Secondary outcomes were passive range of motion (PROM), pain intensity, electrophysiological parameters, gait assessment, and adverse events. A total of seven recent randomized controlled trials (RCTs) were included in the systematic review and meta-analysis, and a beneficial effect on spasticity was found. The high level of evidence presented in this paper showed that ESWT ameliorates spasticity considering the parameters: MAS: standardized mean difference (SMD) = 0.53; 95% confidence interval (95% CI): (0.07-0.99); Modified Tardieu Scale (MTS): SMD = 0.56; 95% CI: (0.01-1.12); Visual Analogue Scale (VAS): SMD = 0.35; 95% CI: (-0.21-0.91); PROM: SMD = 0.69; 95% CI: (0.20-1.19). ESWT presented long-term efficacy on lower limb post-stroke spasticity, reduced pain intensity, and increased range of motion. The effect of this novel and non-invasive therapy was significant and the intervention did not present adverse events, proving a satisfactory safety profile.