The Effect and Dose-Response of Functional Electrical Stimulation Cycling Training on Spasticity in Individuals With Spinal Cord Injury: A Systematic Review With Meta-Analysis

Consumer views of functional electrical stimulation and robotic exoskeleton in SCI rehabilitation: A mini review

BACKGROUND

Functional electrical stimulation (FES) and robotic exoskeletons represent emerging technologies with significant potential for restoring critical physical functions such as standing and walking-functions that are most susceptible after spinal cord injury (SCI). However, the further development and successful integration of these technologies into clinical practice and daily life require a deep understanding of consumer perspectives.

OBJECTIVE

This review synthesizes consumer perspectives from a diverse range of technology stakeholders, including medical service providers, researchers, and persons affected by SCI-those living with SCI and their caregivers. By capturing this diverse range of perspectives, the review aims to describe the real-world implications, challenges, and expectations associated with FES and robotic exoskeleton technologies.

METHODS

Relevant literature was primarily identified through a search in EBSCO, SCOPUS, and Web of Science. The authors supplemented the search by reviewing reference lists including appropriate articles identified by the authors. The PICO question guiding this process was defined as P (persons with SCI and caregivers, researchers, clinicians, and developers), I (use of FES or robotic exoskeletons), C (technology users compared to non-users), and O (stakeholder perspectives and experiences). Each identified article underwent a thorough appraisal, after which findings were summarized to present consumers' viewpoints on FES and robotic exoskeleton technologies.

RESULTS

The review focuses on key areas such as perceived benefits, limitations, implementation barriers, and consumer expectations. The benefits identified are multifaceted, extending from physical improvements, such as enhanced mobility and muscle strength, to psychological gains including increased confidence and sense of independence. However, these technologies also face perceived limitations, often related to accessibility, cost, and usability challenges. Beyond technical issues, implementation barriers are related to factors like insurance coverage and the need for specialized training for both users and providers. Consumer expectations include hope for technological advancements, increased accessibility and affordability, and a desire for more personalized and adaptable solutions tailored to the unique needs of individuals with SCI.

CONCLUSION

This comprehensive overview of consumer perspectives offers insights into the needs and preferences of the end-users, which are essential for creating user-centric technology and effectively translating research findings into clinical practice.

Early functional proprioceptive stimulation in high spinal cord injury: a pilot study

Introduction

The first months following a spinal cord injury (SCI) are crucial for promoting recovery. However, patients with high SCIs often require prolonged stays in intensive care units (ICUs), delaying optimal rehabilitation due to limited resources. This study examined the safety, feasibility, and effects on spasticity and muscle atrophy of an early rehabilitation technique using non-invasive sensory stimulation and called functional proprioceptive stimulation (FPS).

Materials and methods

Ten SCI patients were included in this randomized pilot study, with five receiving early FPS and five receiving sham stimulation. Both groups were treated using the Vibramoov, consisting of 12 computer-synchronized vibrators placed on the lower limbs. Treatment sessions lasted 30 min, four times a week, for up to 8 weeks. Spasticity was assessed using the Modified Ashworth Scale, Tardieu Scale, Spinal Cord Assessment Tool for Spastic Reflexes, and a patient self-evaluation with a visual analog scale. Muscle atrophy was evaluated through ultrasonography of rectus femoris thickness and cross-sectional area. The duration of the follow-up period ranged from 6 months to 1 year.

Results

Treatment began early, with a median of 4 days post-injury for both groups. The number of adverse events was similar between groups, with none linked to the intervention. No medium-term effects on spasticity or muscle atrophy could be identified. However, our results show a tendency toward a beneficial short-term effect of FPS on spasticity, observed for all spasticity measurements.

Discussion

This pilot study shows that early FPS is feasible and safe for SCI as early as the intensive care unit stage. We demonstrated that FPS induced a transient relaxation and spasticity reduction that could potentially enhance a rehabilitation session administered shortly after it, but larger studies are needed to determine the medium and long-term effects.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT05094752).

Transcutaneous spinal cord stimulation combined with robotic-assisted body weight-supported treadmill training enhances motor score and gait recovery in incomplete spinal cord injury: a double-blind randomized controlled clinical trial

BACKGROUND

Although transcutaneous spinal cord stimulation (tSCS) has been suggested as a safe and feasible intervention for gait rehabilitation, no studies have determined its effectiveness compared to sham stimulation.

OBJECTIVE

To determine the effectiveness of tSCS combined with robotic-assisted gait training (RAGT) on lower limb muscle strength and walking function in incomplete spinal cord injury (iSCI) participants.

METHODS

A randomized, double-blind, sham-controlled clinical trial was conducted. Twenty-seven subacute iSCI participants were randomly allocated to tSCS or sham-tSCS group. All subjects conducted a standard Lokomat walking training program of 40 sessions (5 familiarization sessions, followed by 20 sessions combined with active or sham tSCS, and finally the last 15 sessions with standard Lokomat). Primary outcomes were the lower extremity motor score (LEMS) and dynamometry. Secondary outcomes included the 10-Meter Walk Test (10MWT), the Timed Up and Go test (TUG), the 6-Minute Walk test (6MWT), the Spinal Cord Independence Measure III (SCIM III) and the Walking Index for Spinal Cord Injury II (WISCI-II). Motor evoked potential (MEP) induced by transcranial magnetic stimulation (TMS) were also assessed for lower limb muscles. Assessments were performed before and after tSCS intervention and after 3-weeks follow-up.

RESULTS

Although no significant differences between groups were detected after the intervention, the tSCS group showed greater effects than the sham-tSCS group for LEMS (3.4 points; p = 0.033), 10MWT (37.5 s; p = 0.030), TUG (47.7 s; p = 0.009), and WISCI-II (3.4 points; p = 0.023) at the 1-month follow-up compared to baseline. Furthermore, the percentage of subjects who were able to walk 10 m at the follow-up was greater in the tSCS group (85.7%) compared to the sham group (43.1%; p = 0.029). Finally, a significant difference (p = 0.049) was observed in the comparison of the effects in the amplitude of the rectus femoris MEPs of tSCS group (- 0.97 mV) and the sham group (- 3.39 mV) at follow-up.

CONCLUSIONS

The outcomes of this study suggest that the combination of standard Lokomat training with tSCS for 20 sessions was effective for LEMS and gait recovery in subacute iSCI participants after 1 month of follow-up. Trial registration ClinicalTrials.gov (NCT05210166).

Industry-Scalable Reusable Textile Electrodes for Neurostimulation Applications

Neurostimulation delivers electrical pulses to modulate neuromuscular activity. Commonly used in medical interventions from pain relief to rehabilitation, neurostimulation typically uses manually placed hydrogel electrodes over the treated region. However, this method limits interventions requiring frequent, long-term daily use. To address this, novel fully textile electrodes are developed using industrial programmable knitting machines. These electrodes are designed to be washable, reusable, flexible, and breathable, with embedded interconnects. Textile electrodes are made of yarns with stainless steel and PEDOT-coated stainless steel conductive components. The electrodes' performance are compared with gel electrodes, characterizing impedance, sensorimotor stimulation thresholds, recruitment of induced movements, sensation levels, and perceived sensations. The effects of residential wash cycles and continuous use duration are also investigated. The proposed electrodes are found to perform similarly to hydrogel electrodes in all characterized metrics. No degradation in electrode performance is found after at least 30 wash cycles. Electrodes remained functionally intact after 1000 cycles of stretch loading at 50% of break strain. The textile electrodes consistently induced comfortable sensorimotor responses for at least six hours after donning. The proposed textile electrodes offer a novel and effective solution for neurostimulation interventions, paving the way for integration into smart garments and long-term wearable health technologies.

Professionals' Perspectives of Smart Stationary Bikes in Rehabilitation: Qualitative Study

Background

Stationary bikes are used in numerous rehabilitation settings, with most offering limited functionalities and types of training. Smart technologies, such as artificial intelligence and robotics, bring new possibilities to achieve rehabilitation goals. However, it is important that these technologies meet the needs of users in order to improve their adoption in current practice.

Objective

This study aimed to collect professionals' perspectives on the use of smart stationary bikes in rehabilitation.

Methods

Twelve health professionals (age: mean 43.4, SD 10.1 years) completed an online questionnaire and participated in a semistructured interview regarding their needs and expectations before and after a 30-minute session with a smart bike prototype.

Results

A content analysis was performed with inductive coding. Seven main themes emerged: (1) bike functionalities (cycling assistance, asymmetric resistance, and forward and backward cycling), (2) interface between bike and users (simple, user-friendly, personalized, with written reminders during training), (3) feedback to users (user and performance data), (4) training programs (preprogrammed and personalized, and algorithmic programs), (5) user engagement (telerehabilitation, group sessions, music, and automatic suggestion of training), (6) the bike as a physical device (dimensions, comfort, setup, screen, etc), and (7) business model (various pricing strategies, training for professionals, and after-sales service).

Conclusions

This study provides an interpretive understanding of professionals' perspectives regarding smart stationary bikes and is the first to identify the expectations of health professionals regarding the development of future bikes in rehabilitation.

Electrodiagnosis for mitigating false-negative non-responsiveness in electrical evoked contractions: A case series exploring probable polyneuromyopathy induced by nonuse

INTRODUCTION

The revised international standards for neurological classification of spinal cord injury (ISNCSCI) have facilitated the documentation of non-spinal cord injury-related impairments, such as chronic peripheral nerve injuries and muscle weakness due to immobility. This advancement addresses potential biases in muscle strength examinations. Utilizing electrically evoked contractions from paralyzed muscles, enhanced by electrodiagnosis, holds promise in identifying false-negative diagnoses of non-responsiveness to neuromuscular electrical stimulation. This concept prompts the exploration of polyneuromyopathy arising from nonuse in paralyzed muscles.

CASE SERIES PRESENTATION

To substantiate our hypothesis, we recruited nine participants for a case series aimed at elucidating the potential benefits of incorporating the stimulus electrodiagnostic test (SET) to mitigate non-responsiveness during preparation for functional electrical stimulation (FES)-assisted cycling. In our convenience sample (n = 5), we conducted neurological mapping based on ISNCSCI and applied SET on the quadriceps. The SET guided optimal dosimetry for evoking contractions and revealed responses similar to those observed in peripheral neuropathies, with α coefficients equal to or lower than 2.00. This observation is likely attributable to nonuse of paralyzed muscles, indicative of an ongoing polyneuropathy in individuals with chronic spinal cord injury (SCI).

DISCUSSION

Among the nine initially recruited subjects, seven exhibited responsiveness to neuromuscular electrical stimulation (78% responsiveness), with two participants excluded based on exclusion criteria. In the final five reported cases, all displayed α coefficient values indicating impaired neuromuscular accommodation, and one presented no α coefficient within the normal range. The inclusion of electrodiagnosis appears effective in averting non-responsiveness, suggesting the presence of ongoing polyneuropathies in paralyzed muscles.

AAPM&R consensus guidance on spasticity assessment and management

BACKGROUND

The American Academy of Physical Medicine and Rehabilitation (AAPM&R) conducted a comprehensive review in 2021 to identify opportunities for enhancing the care of adult and pediatric patients with spasticity. A technical expert panel (TEP) was convened to develop consensus-based practice recommendations aimed at addressing gaps in spasticity care.

OBJECTIVE

To develop consensus-based practice recommendations to identify and address gaps in spasticity care.

METHODS

The Spasticity TEP engaged in a 16-month virtual meeting process, focusing on formulating search terms, refining research questions, and conducting a structured evidence review. Evidence quality was assessed by the AAPM&R Evidence, Quality and Performance Committee (EQPC), and a modified Delphi process was employed to achieve consensus on recommendation statements and evidence grading. The Strength of Recommendation Taxonomy (SORT) guided the rating of individual studies and the strength of recommendations.

RESULTS

The TEP approved five recommendations for spasticity management and five best practices for assessment and management, with one recommendation unable to be graded due to evidence limitations. Best practices were defined as widely accepted components of care, while recommendations required structured evidence reviews and grading. The consensus guidance statement represents current best practices and evidence-based treatment options, intended for use by PM&R physicians caring for patients with spasticity.

CONCLUSION

This consensus guidance provides clinicians with practical recommendations for spasticity assessment and management based on the best available evidence and expert opinion. Clinical judgment should be exercised, and recommendations tailored to individual patient needs, preferences, and risk profiles. The accompanying table summarizes the best practice recommendations for spasticity assessment and management, reflecting principles with little controversy in care delivery.

The effect of electrical stimulation on skin vulnerability to irritants

PURPOSE

Electrical stimulation (ES) is a widely used technique in the medical field for various purposes. The effect of ES on several skin properties has been investigated; however, its effect on skin vulnerability to irritants remains unknown. This study aimed to investigate the effects of ES application on skin vulnerability to external irritants.

MATERIALS AND METHODS

An experimental study on 12 healthy male subjects (Mean ± SD, 22.9 ± 3.6 years) who completed the study. The subjects were free of skin abnormalities in the volar aspect of both forearms. Three areas were allocated to each forearm and marked as areas 1, 2, and A in the treated forearm, and areas 3, 4, and B in the control forearm. ES was applied to the volar aspect of the treated forearm for 30 min three times a week, for 2 weeks. The effect of ES on skin vulnerability was investigated using 5% and 0.5% sodium lauryl sulfate (SLS) patches applied to both treated and control forearms. The skin response to irritants was evaluated using transepidermal water loss (TEWL) and a visual erythema score 24 h after patch removal.

RESULTS

Compared to the control forearm, ES increased skin permeability and erythema in response to external irritants (SLS), as measured by the visual analog score (Z = 2.75, p = 0.006) and TEWL (p < 0.05), respectively.

CONCLUSIONS

ES escalates skin reactions to low concentrations of irritant substances, such as SLS, in the area between the two electrodes. This emphasizes the use of this substance, and similar irritants should be avoided in areas treated with ES.

Neuroinflammation in the Evolution of Motor Function in Stroke and Trauma Patients: Treatment and Potential Biomarkers

Neuroinflammation has a significant impact on different pathologies, such as stroke or spinal cord injury, intervening in their pathophysiology: expansion, progression, and resolution. Neuroinflammation involves oxidative stress, damage, and cell death, playing an important role in neuroplasticity and motor dysfunction by affecting the neuronal connection responsible for motor control. The diagnosis of this pathology is performed using neuroimaging techniques and molecular diagnostics based on identifying and measuring signaling molecules or specific markers. In parallel, new therapeutic targets are being investigated via the use of bionanomaterials and electrostimulation to modulate the neuroinflammatory response. These novel diagnostic and therapeutic strategies have the potential to facilitate the development of anticipatory patterns and deliver the most beneficial treatment to improve patients' quality of life and directly impact their motor skills. However, important challenges remain to be solved. Hence, the goal of this study was to review the implication of neuroinflammation in the evolution of motor function in stroke and trauma patients, with a particular focus on novel methods and potential biomarkers to aid clinicians in diagnosis, treatment, and therapy. A specific analysis of the strengths, weaknesses, threats, and opportunities was conducted, highlighting the key challenges to be faced in the coming years.

Rehabilitation of spinal patients with diseases and injury of the cervical spine in the early and late postoperative period (analysis of russian and foreign recommendations)

Despite the success of modern conservative therapy of severe spinal instability, surgical methods still retain their importance in the treatment of this pathology, but even the most successful operation may be in vain without subsequent adequate rehabilitation. This report summarizes the features of rehabilitation of patients after surgery for injuries of the cervical spine using methods and means of physiofunctional treatment.

Application of Vagus Nerve Stimulation in Spinal Cord Injury Rehabilitation

Spinal cord injury (SCI) is a prevalent devastating condition causing significant morbidity and mortality, especially in developing countries. The pathophysiology of SCI involves ischemia, neuroinflammation, cell death, and scar formation. Due to the lack of definitive therapy for SCI, interventions mainly focus on rehabilitation to reduce deterioration and improve the patient's quality of life. Currently, rehabilitative exercises and neuromodulation methods such as functional electrical stimulation, epidural electrical stimulation, and transcutaneous electrical nerve stimulation are being tested in patients with SCI. Other spinal stimulation techniques are being developed and tested in animal models. However, often these methods require complex surgical procedures and solely focus on motor function. Vagus nerve stimulation (VNS) is currently used in patients with epilepsy, depression, and migraine and is being investigated for its application in other disorders. In animal models of SCI, VNS significantly improved locomotor function by ameliorating inflammation and improving plasticity, suggesting its use in human subjects. SCI patients also suffer from nonmotor complications, including pain, gastrointestinal dysfunction, cardiovascular disorders, and chronic conditions such as obesity and diabetes. VNS has shown promising results in alleviating these conditions in non-SCI patients, which makes it a possible therapeutic option in SCI patients.

Electrical Stimulation Exercise for People with Spinal Cord Injury: A Healthcare Provider Perspective

Electrical stimulation exercise has become an important modality to help improve the mobility and health of individuals with spinal cord injury (SCI). Electrical stimulation is used to stimulate peripheral nerves in the extremities to assist with muscle strengthening or functional activities such as cycling, rowing, and walking. Electrical stimulation of the peripheral nerves in the upper extremities has become a valuable tool for predicting the risk of hand deformities and rehabilitating functional grasping activities. The purpose of this paper is to provide healthcare providers perspective regarding the many rehabilitation uses of electrical stimulation in diagnosing and treating individuals with SCI. Electrical stimulation has been shown to improve functional mobility and overall health, decrease spasticity, decrease the risk of cardiometabolic conditions associated with inactivity, and assist in the diagnosis/prognosis of hand deformities in those with tetraplegia. Studies involving non-invasive stimulation of the spinal nerves via external electrodes aligned with the spinal cord and more invasive stimulation of electrodes implanted in the epidural lining of the spinal cord have demonstrated improvements in the ability to stand and enhanced the stepping pattern during ambulation. Evidence is also available to educate healthcare professionals in using functional electrical stimulation to reduce muscle spasticity and to recognize limitations and barriers to exercise compliance in those with SCI. Further investigation is required to optimize the dose-response relationship between electrical stimulation activities and the mobility and healthcare goals of those with SCI and their healthcare providers.

Neurophysiological and clinical outcome measures of the impact of electrical stimulation on spasticity in spinal cord injury: Systematic review and meta-analysis

This systematic review and meta-analysis aims to determine whether non-invasive electrical stimulation (ES) is effective at reducing spasticity in people living with spinal cord injury (SCI). PubMed, Web of Science, Scopus and Cochrane Central Register of Controlled Trials databases were searched in April 2022. Primary outcome measures were the Ashworth scale (AS), Modified Ashworth scale (MAS), Pendulum test and the Penn spasm frequency scale (PSFS). Secondary outcomes were the Hoffman (H)- reflex, motor-evoked potentials (MEPs) and posterior-root reflexes (PRRs). A random-effects model, using two correlation coefficients, ( C o r r = 0.1 , C o r r = 0.2 ) determined the difference between baseline and post-intervention measures for RCTs. A quantitative synthesis amalgamated data from studies with no control group (non-RCTs). Twenty-nine studies were included: five in the meta-analysis and 17 in the amalgamation of non-RCT studies. Twenty studies measured MAS or AS scores, 14 used the Pendulum test and one used the PSFS. Four measured the H-reflex and no studies used MEPs or PRRs. Types of ES used were: transcutaneous electrical nerve stimulation (TENS), transcutaneous spinal cord stimulation (TSCS), functional electrical stimulation (FES) cycling and FES gait. Meta-analyses of 3 studies using the MAS and 2 using the Pendulum test were carried out. For MAS scores, non-invasive ES was effective at reducing spasticity compared to a control group (p = 0.01, C o r r = 0.1 ; p = 0.002, C o r r = 0.2 ). For Pendulum test outcomes, there was no statistically significant difference between intervention and control groups. Quantitative synthesis of non-RCT studies revealed that 22 of the 29 studies reported improvement in at least one measure of spasticity following non-invasive ES, 13 of which were statistically significant (p < 0.05). Activation of the muscle was not necessary to reduce spasticity. Non-invasive ES can reduce spasticity in people with SCI, according to MAS scores, for both RCT and non-RCT studies, and Pendulum test values in non-RCT studies. This review could not correlate between clinical and neurophysiological outcomes; we recommend the additional use of neurophysiological outcomes for future studies. The use of TSCS and TENS, which did not induce a muscle contraction, indicate that activation of afferent fibres is at least required for non-invasive ES to reduce spasticity.

Advanced Equipment Development and Clinical Application in Neurorehabilitation for Spinal Cord Injury: Historical Perspectives and Future Directions

Partial to complete paralysis following spinal cord injury (SCI) causes deterioration in health and has severe effects on the ability to perform activities of daily living. Following the discovery of neural plasticity, neurorehabilitation therapies have emerged that aim to reconstruct the motor circuit of the damaged spinal cord. Functional electrical stimulation (FES) has been incorporated into devices that reconstruct purposeful motions in the upper and lower limbs, the most recent of which do not require percutaneous electrode placement surgery and thus enable early rehabilitation after injury. FES-based devices have shown promising results for improving upper limb movement, including gripping and finger function, and for lower limb function such as the ability to stand and walk. FES has also been employed in hybrid cycling and rowing to increase total body fitness. Training using rehabilitation robots is advantageous in terms of consistency of quality and quantity of movements and is particularly applicable to walking training. Initiation of motor reconstruction at the early stage following SCI is likely to advance rapidly in the future, with the combined use of technologies such as regenerative medicine, brain machine interfaces, and rehabilitation robots with FES showing great promise.