Textile-based Wearable to Monitor Heart Activity in Paediatric Population: A Pilot Study.

Background: Cardiac monitoring for children with heart disease still employs common clinical techniques that require visits to hospital either in an ambulatory or inpatient setting. Frequent cardiac monitoring, such as heart rate monitoring, can limit children's physical activity and quality of life. The main objective of this study is to evaluate the performance of a textile-based device (SKIIN) in measuring heart rate (HR) in different tasks: lying down, sitting, standing, exercising, and cooling down. Methods: Twenty participants including healthy children and children with heart disease were included in this study. The difference between the HRs recorded by the SKIIN was compared with a reference electrocardiogram collection by normalized root mean squared error. Participants completed a questionnaire on their experience wearing the textile device with additional parental feedback on the textile device collected. Results: Participants had the median age of 14 years (range: 10-17 years), with body mass index 23.1 ± 3.8 kg/m2 and body surface area 1.70 ± 0.25 m2. The HR recorded by SKIIN and reference system significantly changes between tasks (P < 0.001), while not significantly different from each other (P > 0.05). The normalized root mean squared error was 3.8% ± 3.0% and 3.6% ± 3.7% for healthy and the heart disease groups, respectively. All participants found the textile device non-irritating and easy to wear. Conclusions: This study provides proof of concept that HR can be robustly and conveniently monitored by smart textiles, with similar accuracy to standard-of-care devices.

Contexte: Encore aujourd'hui, la surveillance cardiaque chez les enfants atteints de cardiopathie repose sur des techniques cliniques courantes qui doivent être réalisées à l'hôpital, en soins ambulatoires ou en contexte d'hospitalisation. Chez les enfants, la surveillance cardiaque répétée, comme c'est le cas pour la fréquence cardiaque (FC), peut limiter leurs activités physiques et leur qualité de vie. La présente étude évalue principalement la performance d'un dispositif textile (SKIIN) dans la mesure de la FC pendant différentes tâches : en position couchée, en position assise, en position debout, pendant l'activité physique et pendant le retour au calme. Méthodologie: Vingt participants, y compris des enfants en santé et des enfants présentant une cardiopathie, ont été inclus dans l'étude. La différence entre la FC enregistrée par le dispositif SKIIN et la FC mesurée par une électrocardiographie (ECG) de référence a été comparée à l'aide de la racine de l'erreur quadratique moyenne normalisée (REQMN). Les participants ont rempli un questionnaire sur leur expérience avec le dispositif textile, et les commentaires des parents sur ce dispositif ont été recueillis. Résultats: Les participants avaient un âge médian de 14 ans [10-17 ans], un indice de masse corporelle de 23,1 ± 3,8 kg/m2 et une surface corporelle de 1,70 ± 0,25 m2. La FC enregistrée par le système SKIIN et le système de référence variait significativement d'une tâche à l'autre (p < 0,001), mais il n'y avait pas de différence significative entre les deux systèmes (p > 0,05). La REQMN était de 3,8 ± 3,0 % pour le groupe en santé et de 3,6 ± 3,7 % pour le groupe présentant une cardiopathie. Tous les participants ont trouvé que le dispositif textile ne causait pas d'irritation et qu'il était facile à porter. Conclusions: Cette étude démontre que les textiles intelligents permettent de surveiller la FC de façon fiable et pratique, avec une exactitude semblable à celle des dispositifs de référence.

Identifying priorities for balance interventions through a participatory co-design approach with end-users.

BACKGROUND: Most individuals living with spinal cord injuries/diseases (SCI/D) or stroke experience at least one fall each year; hence, the development of interventions and technologies that target balance control is needed. The purpose of this study was to identify and explore the priorities for balance-focused interventions and technologies from the perspectives of end-users to assist with the design of an intervention that combines functional electrical stimulation (FES) with visual feedback training for standing balance. METHODS: Two individuals with SCI/D, one individual with stroke, two physical therapists (PT) and one hospital administrator were recruited. Participants attended three focus group meetings that followed a participatory co-design approach. A semi-structured interview guide, developed from the FAME (Feasibility, Appropriateness, Meaningfulness, Effectiveness, Economic Evidence) framework, was used to lead the discussion, querying participants' experiences with balance deficits and interventions, and FES. Meetings were audio-recorded and transcribed verbatim. An iterative and reflexive inductive thematic analysis was applied to the transcripts by three researchers. RESULTS: Four themes were identified: (1) Balance is meaningful for daily life and rehabilitation. Participants acknowledged various factors influencing balance control and how balance deficits interfered with participation in activities. End-users stressed the importance of continuing to work on one's balance after discharge from hospital-based rehabilitation. (2) Desired characteristics of balance interventions. Participants explained that balance interventions should be tailored to an individual's unique needs and goals, relevant to their lives, balance their safety and risk, and be engaging. (3) Prior experiences with FES to inform future therapeutic use. Participants with stroke or SCI/D described initial apprehension with FES, but experienced numerous benefits that motivated them to continue with FES. Challenges with FES were mentioned, including wires, cost, and time of set up. (4) Potential role of FES in balance interventions. Participants felt that FES would complement balance interventions; however, they had not experienced this combination of therapies previously. CONCLUSIONS: End-users described how their experiences with balance deficits, rehabilitation, and FES informed their priorities for balance interventions. The findings inform the design and implementation of future balance interventions for individuals with SCI/D or stroke, including an intervention involving FES and visual feedback training.

Design and optimization of a sustainable and resilient mask supply chain during the COVID-19 pandemic: a multi-objective approach.

Wearing a mask or a face covering became mandatory in indoor public spaces to reduce the spread of coronavirus disease 2019 (COVID-19). The Ontario government (i.e., a province of Canada) encouraged medical supply producers to switch their operations to produce personal protective equipment (e.g., masks) during the COVID-19 pandemic. In this regard, there are several uncertain parameters (e.g., operational costs, market demand, and capacity levels of facilities) affecting the performance of producers in a medical supplies market. In this study, we propose a flexible optimization model to configure a robust mask supply chain network under uncertainty. Furthermore, companies are supposed to undertake their operations based on sustainable manners, in compliance with provincial policy, in Ontario. Therefore, the proposed flexible optimization model is extended to a robust multi-objective model to investigate sustainable strategies in a mask supply chain network design problem. The applicability of this model is demonstrated for the Greater Toronto Area, Canada.

Exploring textile-based electrode materials for electromyography smart garments.

INTRODUCTION: In recent years, electromyography (EMG) has been increasingly studied for wearable applications. Conventional gel electrodes for electrophysiological recordings have limited use in everyday applications such as prosthetic control or muscular therapy at home. This study investigates the efficacy and feasibility of dry-contact electrode materials employed in smart textiles for EMG recordings. METHODS: Dry-contact electrode materials were selected and implemented on textile substrates. Using these electrodes, EMG was recorded from the forearm of able-bodied subjects. 25% and 50% isometric maximum voluntary contractions were captured. A comparative investigation was performed against gel electrodes, assessing the effect of material properties on signal fidelity and strength compared. RESULTS: When isolating for electrode surface area and pressure, 31 of the 40 materials demonstrated strong positive correlations in their mean PSD with gel electrodes (r > 95, p < 0.001). The inclusion of ionic liquids in the material composition, and using raised or flat electrodes, did not demonstrate a significant effect in signal quality. CONCLUSIONS: For EMG dry-contact electrodes, comparing the performance against gel electrodes for the application with the selected material is important. Other factors recommended to be studied are electrodes' durability and long-term stability.

A Mass-Producible Washable Smart Garment with Embedded Textile EMG Electrodes for Control of Myoelectric Prostheses: A Pilot Study.

Electromyography (EMG) is the resulting electrical signal from muscle activity, commonly used as a proxy for users' intent in voluntary control of prosthetic devices. EMG signals are recorded with gold standard Ag/AgCl gel electrodes, though there are limitations in continuous use applications, with potential skin irritations and discomfort. Alternative dry solid metallic electrodes also face long-term usability and comfort challenges due to their inflexible and non-breathable structures. This is critical when the anatomy of the targeted body region is variable (e.g., residual limbs of individuals with amputation), and conformal contact is essential. In this study, textile electrodes were developed, and their performance in recording EMG signals was compared to gel electrodes. Additionally, to assess the reusability and robustness of the textile electrodes, the effect of 30 consumer washes was investigated. Comparisons were made between the signal-to-noise ratio (SNR), with no statistically significant difference, and with the power spectral density (PSD), showing a high correlation. Subsequently, a fully textile sleeve was fabricated covering the forearm, with 14 textile electrodes. For three individuals, an artificial neural network model was trained, capturing the EMG of 7 distinct finger movements. The personalized models were then used to successfully control a myoelectric prosthetic hand.

Modeling and Reproducing Textile Sensor Noise: Implications for Textile-Compatible Signal Processing Algorithms.

Smart textiles provide an opportunity to simultaneously record various electrophysiological signals, e.g., ECG, from the human body in a non-invasive and continuous manner. Accurate processing of ECG signals recorded using textile sensors is challenging due to the very low signal-to-noise ratio (SNR). Signal processing algorithms that can extract ECG signals out of textile-based electrode recordings, despite low SNR are needed. Presently, there are no textile ECG datasets available to develop, test and validate these algorithms. In this paper we attempted to model textile ECG signals by adding the textile sensor noise to open access ECG signals. We employed the linear predictive coding method to model different features of this noise. By approximating the linear predictive coding residual signals using Kernel Density Estimation, an artificial textile ECG noise signal was generated by filtering the residual signal with the linear predictive coding coefficients. The synthetic textile sensor noise was added to the MIT-BIH Arrhythmia Database (MITDB), thus creating Textile-like ECG dataset consisting of 108 trials (30 min each). Furthermore, a Python code for generating textile-like ECG signals with variable SNR was also made available online. Finally, to provide a benchmark for the performance of R-peak detection algorithms on textile ECG, the five common R-peak detection algorithms: Pan & Tompkins, improved Pan & Tompkins (in Biosppy), Hamilton, Engelse, and Khamis, were tested on textile-like MITDB. This work provides an approach to generating noisy textile ECG signals, and facilitating the development, testing, and evaluation of signal processing algorithms for textile ECGs.

Evaluation of dry textile electrodes for long-term electrocardiographic monitoring.

BACKGROUND: Continuous long-term electrocardiography monitoring has been increasingly recognized for early diagnosis and management of different types of cardiovascular diseases. To find an alternative to Ag/AgCl gel electrodes that are improper for this application scenario, many efforts have been undertaken to develop novel flexible dry textile electrodes integrated into the everyday garments. With significant progresses made to address the potential issues (e.g., low signal-to-noise ratio, high skin-electrode impedance, motion artifact, and low durability), the lack of standard evaluation procedure hinders the further development of dry electrodes (mainly the design and optimization). RESULTS: A standard testing procedure and framework for skin-electrode impedance measurement is demonstrated for the development of novel dry textile electrodes. Different representative electrode materials have been screen-printed on textile substrates. To verify the performance of dry textile electrodes, impedance measurements are conducted on an agar skin model using a universal setup with consistent frequency and pressure. In addition, they are demonstrated for ECG signals acquisition, in comparison to those obtained using conventional gel electrodes. CONCLUSIONS: Dry textile electrodes demonstrated similar impedance when in raised or flat structures. The tested pressure variations had an insignificant impact on electrode impedance. Looking at the effect of impedance on ECG signals, a noticeable effect on ECG signal performance metrics was not observed. Therefore, it is suggested that impedance alone is possibly not the primary indicator of signal quality. As well, the developed methods can also serve as useful guidelines for future textile dry-electrode design and testing for practical ECG monitoring applications.

Multichannel ECG recording from waist using textile sensors.

BACKGROUND: The development of wearable health monitoring systems is garnering tremendous interest in research, technology and commercial applications. Their ability of providing unique capabilities in continuous, real-time, and non-invasive tracking of the physiological markers of users can provide insights into the performance and health of individuals. Electrocardiogram (ECG) signals are of particular interest, as cardiovascular disease is the leading cause of death globally. Monitoring heart health and its conditions such as ventricular disturbances and arrhythmias can be achieved through evaluating various features of ECG such as R-peaks, QRS complex, T-wave, and P-wave. Despite recent advances in biosensors for wearable applications, most of the currently available solutions rely solely on a single system attached to the body, limiting the ability to obtain reliable and multi-location biosignals. However, in engineering systems, sensor fusion, which is the optimal integration and processing of data from multiple sensors, has been a common theme and should be considered for wearables. In recent years, due to an increase in the availability and variety of different types of sensors, the possibility of achieving sensor fusion in wearable systems has become more attainable. Sensor fusion in multi-sensing systems results in significant enhancements of information inferences compared to those from systems with a sole sensor. One step towards the development of sensor fusion for wearable health monitoring systems is the accessibility to multiple reliable electrophysiological signals, which can be recorded continuously. RESULTS: In this paper, we develop a textile-based multichannel ECG band that has the ability to measure ECG from multiple locations on the waist. As a proof of concept, we demonstrate that ECG signals can be reliably obtained from different locations on the waist where the shape of the QRS complex is nearly comparable with recordings from the chest using traditional gel electrodes. In addition, we develop a probabilistic approach-based on prediction and update strategies-to detect R-peaks from noisy textile data in different statuses, including sitting, standing, and jogging. In this approach, an optimal search method is utilized to detect R-peaks based on the history of the intervals between previously detected R-peaks. We show that the performance of our probabilistic approach in R-peak detection is significantly better than that based on Pan-Tompkins and optimal-threshold methods. CONCLUSION: A textile-based multichannel ECG band was developed to track the heart rate changes from multiple locations on the waist. We demonstrated that (i) the ECG signal can be detected from different locations on the waist, and (ii) the accuracy of the detected R-peaks from textile sensors was improved by using our proposed probabilistic approach. Despite the limitations of the textile sensors that might compromise the quality of ECG signals, we anticipate that the textile-based multichannel ECG band can be considered as an effective wearable system to facilitate the development of sensor fusion methodology for pervasive and non-invasive health monitoring through continuous tracking of heart rate variability (HRV) from the waist. In addition, from the commercialization point of view, we anticipate that the developed band has the potential to be integrated into garments such as underwear, bras or pants so that individuals can use it on a daily basis.

Garments for functional electrical stimulation: Design and proofs of concept.

INTRODUCTION: Repeated use of functional electrical stimulation can promote functional recovery in individuals with neurological paralysis. We designed garments able to deliver functional electrical stimulation. METHODS: Shirts and pants containing electrodes knitted with a conductive yarn were produced. Electrodes were moistened with water before use. Stimulation intensity at four thresholds levels (sensory, movement, full range of motion, and maximal), stimulation comfort, and electrical properties of the interface were tested in one able-bodied subject with garment electrodes and size-matched conventional gel electrodes. The pants and shirt were then used to explore usability and design limitations. RESULTS: Compared to gel electrodes, fabric electrodes had a lower sensory threshold (on forearm muscles) but they had a higher maximal stimulation threshold (for all tested muscles). The stimulation delivery was comfortable when the garment electrodes were recently moistened; however, as the electrodes dried (within 9 to 18 min) stimulation became unpleasant. Inconsistent water content in the fabric electrodes caused inconsistent intensity thresholds and inconsistent voltage necessary to apply a desired stimulation current. Garments' tightness and impracticality of electrode lead necessitate further design improvement. CONCLUSIONS: Fabric electrodes offer a promising alternative to gel electrodes. Further work involving people with paralysis is required to overcome the identified challenges.

Variability of vibrations produced by commercial whole-body vibration platforms.

OBJECTIVE: Whole body vibration has been studied in populations experiencing neuromuscular degradation, including the elderly and individuals with neurological disorders, but methodological standardization is required to clarify its therapeutic effects. The characteristics of the vibrations actually delivered by commercial platforms are rarely measured or reported. Our objective was to quantify the vibrations (frequency, amplitude and peak acceleration) produced by several commercial platforms across different settings. METHODS: Laser and accelerometer recordings were used to measure the vibrations of 7 vibration platforms. Four loads (0 kg, 45 kg, 68 kg, 91 kg) and 3 vibration frequencies were used (30 Hz, 40 Hz, 50 Hz), totaling 12 combinations. RESULTS: In all platforms, vibration amplitude and peak acceleration varied as a function of the load used (p < 0.001 in all cases). In most platforms, the actual frequency of vibration differed from the intended frequency (actual/intended ratio ranging from 0.83 to 1.19), as a function of load and frequency. These results imply that subjects of different weights could be receiving different vibrations. CONCLUSION: Investigators should characterize and report the vibrations actually delivered in their studies, in order to increase the quality of evidence in whole body vibration studies.

Muscle activity, cross-sectional area, and density following passive standing and whole body vibration: A case series.

OBJECTIVE: To investigate the effects of intermittent passive standing (PS) and whole body vibration (WBV) on the electromyography (EMG) activity, cross-sectional area, and density of lower extremity muscles in individuals with chronic motor complete spinal cord injury (SCI). DESIGN: Case series. METHODS: Seven adult men with chronic (≥2 years), thoracic motor complete (AIS A-B) SCI completed a 40-week course of thrice-weekly intermittent PS-WBV therapy, in a flexed knee posture (160°), for 45 minutes per session at a frequency of 45 Hz and 0.6-0.7 mm displacement using the WAVE(®) Pro Plate, with an integrated EasyStand™ standing frame. EMG was measured in major lower extremity muscles to represent muscle activity during PS-WBV. The cross-sectional area and density of the calf muscles were measured using peripheral quantitative computed tomography at the widest calf cross-section (66% of the tibia length) at pre- and post-intervention. All measured variables were compared between the pre- and post-intervention measurements to assess change after the PS-WBV intervention. RESULTS: PS-WBV acutely induced EMG activity in lower extremity muscles of SCI subjects. No significant changes in lower extremity EMG activity, muscle cross-sectional area, or density were observed following the 40-week intervention. CONCLUSIONS: Although acute exposure to PS-WBV can induce electrophysiological activity of lower extremity muscles during PS in men with motor complete SCI, the PS-WBV intervention for 40 weeks was not sufficient to result in enhanced muscle activity, or to increase calf muscle cross-sectional area or density.

Effect of whole-body vibration on lower-limb EMG activity in subjects with and without spinal cord injury.

OBJECTIVE: Traumatic spinal cord injury (SCI) results in substantial reductions in lower extremity muscle mass and bone mineral density below the level of the lesion. Whole-body vibration (WBV) has been proposed as a means of counteracting or treating musculoskeletal degradation after chronic motor complete SCI. To ascertain how WBV might be used to augment muscle and bone mass, we investigated whether WBV could evoke lower extremity electromyography (EMG) activity in able-bodied individuals and individuals with SCI, and which vibration parameters produced the largest magnitude of effect. METHODS: Ten male subjects participated in the study, six able-bodied and four with chronic SCI. Two different manufacturers' vibration platforms (WAVE(®) and Juvent™) were evaluated. The effects of vibration amplitude (0.2, 0.6 or 1.2 mm), vibration frequency (25, 35, or 45 Hz), and subject posture (knee angle of 140°, 160°, or 180°) on lower extremity EMG activation were determined (not all combinations of parameters were possible on both platforms). A novel signal processing technique was proposed to estimate the power of the EMG waveform while minimizing interference and artifacts from the plate vibration. RESULTS: WBV can elicit EMG activity among subjects with chronic SCI, if appropriate vibration parameters are employed. The amplitude of vibration had the greatest influence on EMG activation, while the frequency of vibration had lesser but statistically significant impact on the measured lower extremity EMG activity. CONCLUSION: These findings suggest that WBV with appropriate parameters may constitute a promising intervention to treat musculoskeletal degradation after chronic SCI.

Whole-body vibration during passive standing in individuals with spinal cord injury: effects of plate choice, frequency, amplitude, and subject's posture on vibration propagation.

BACKGROUND: To date, few pharmacologic or rehabilitation interventions for sublesional osteoporosis (SLOP) or low bone mass of the hip and knee regions after spinal cord injury (SCI) have produced significant or sustained increases in lower extremity bone mineral density. Whole body vibration (WBV) is a potential intervention for the prevention and/or treatment of SLOP. OBJECTIVE: To identify the optimal WBV conditions (ie, plate, frequency, amplitude, and subject posture) among men with chronic SCI during passive standing and facilitate the implementation and future evaluation of the efficacy of WBV and passive standing for prevention and treatment of SLOP in men with SCI. DESIGN: This phase 0 device development study assessed the lower extremity propagation characteristics of WBV in men with and without SCI by using a variety of a priori specified plates, frequencies, amplitudes, and postures that facilitate lower extremity vibration absorption while minimizing vibration propagation to the head. SETTING: A tertiary SCI rehabilitation center in Toronto, Canada. PARTICIPANTS: Healthy men with chronic paraplegia (n = 5) and those without SCI (n = 7), ages 20-50 years, weight 68-113 kg, and height 168-188 cm. INTERVENTIONS: An EasyStand standing frame (Altimate Medical Inc, Morton, MN) was fitted onto 2 commercially available vibration platforms: WAVE (WAVE Manufacturing Inc, Windsor, Ontario, Canada) and Juvent (Juvent Medical Inc, Somerset, NJ). Accelerometers were attached to the participants' forehead, hip, knee, and ankle to measure vibration propagation. Vibration parameters evaluated were posture (knee angles of 140°, 160°, and 180° [180° for Juvent only]), vibration frequency (25 Hz, 35 Hz, and 45 Hz), and vibration amplitude (0.6 mm and 1.2 mm [WAVE only]). The subjects were exposed to all combinations of posture, frequencies, and amplitudes during the experiments (total parameter combinations: 12 WAVE and 9 Juvent). MAIN OUTCOME MEASUREMENTS: Peak-to-peak vibration and transmissibility of vibration were recorded and computed for each accelerometer at the tested locations. RESULTS: Variations in frequency generated the most noticeable changes in propagation characteristics, followed by variations in knee angle and amplitude. CONCLUSIONS: WBV therapy delivered with use of the WAVE platform with a knee angle of 140°, plate frequency of 45 Hz, and amplitude of 1.2 mm met our a priori criteria for the "optimal WBV condition." Future studies should evaluate the therapeutic efficacy of the WAVE platform by using these parameters to maintain or augment bone mass among persons with SCI and SLOP.

Relationship between clinical assessments of function and measurements from an upper-limb robotic rehabilitation device in cervical spinal cord injury.

Upper limb robotic rehabilitation devices can collect quantitative data about the user's movements. Identifying relationships between robotic sensor data and manual clinical assessment scores would enable more precise tracking of the time course of recovery after injury and reduce the need for time-consuming manual assessments by skilled personnel. This study used measurements from robotic rehabilitation sessions to predict clinical scores in a traumatic cervical spinal cord injury (SCI) population. A retrospective analysis was conducted on data collected from subjects using the Armeo Spring (Hocoma, AG) in three rehabilitation centers. Fourteen predictive variables were explored, relating to range-of-motion, movement smoothness, and grip ability. Regression models using up to four predictors were developed to describe the following clinical scores: the GRASSP (consisting of four sub-scores), the ARAT, and the SCIM. The resulting adjusted R(2) value was highest for the GRASSP "Quantitative Prehension" component (0.78), and lowest for the GRASSP "Sensibility" component (0.54). In contrast to comparable studies in stroke survivors, movement smoothness was least beneficial for predicting clinical scores in SCI. Prediction of upper-limb clinical scores in SCI is feasible using measurements from a robotic rehabilitation device, without the need for dedicated assessment procedures.

Effect of a robotic rehabilitation device on upper limb function in a sub-acute cervical spinal cord injury population.

Robotic rehabilitation devices have been suggested as a tool to increase the amount of rehabilitation delivered after a neurological injury. Clinical robotic rehabilitation studies of the upper extremity have generally focused on stroke survivors. We present the results of a multi-center pilot study where an upper-limb robotic rehabilitation device (Armeo Spring®, Hocoma AG) was incorporated into the rehabilitation program of 12 subjects with sub-acute cervical spinal cord injury (motor level C4-C6, AIS A-D). Outcomes were measured using two tests of upper extremity function: ARAT and GRASSP. The change in scores for the arm receiving the Armeo training were not statistically significant when compared to the arm not receiving the Armeo training at discharge from therapy and over follow up assessments (8.7 +/- 2.9 compared to 7.4 +/- 2.5 for ARAT at discharge, p = 0.98, and 13.0 +/- 3.2 compared to 13.3 +/- 3.3 for GRASSP at discharge, p = 0.69). Nevertheless, subjects with some minimal (partial) hand function at baseline had a significantly larger increase in GRASSP scores than subjects with no minimal hand function preserved at baseline (19.3 +/- 2.4 compared to 6.6 +/- 4.7, p = 0.02). This suggests that the initial functional capabilities of patients can influence the benefits measured after robotic rehabilitation training and heterogeneous subject populations should be avoided in early phase studies.

Acute effects of whole body vibration during passive standing on soleus H-reflex in subjects with and without spinal cord injury.

Whole-body vibration (WBV) is being used to enhance neuromuscular performance including muscle strength, power, and endurance in many settings among diverse patient groups including elite athletes. However, the mechanisms underlying the observed neuromuscular effects of WBV have not been established. The extent to which WBV will produce similar neuromuscular effects among patients with neurological impairments unable to voluntarily contract their lower extremity muscles is unknown. We hypothesized that modulation of spinal motorneuronal excitability during WBV may be achieved without voluntary contraction. The purpose of our study was to describe and compare the acute effects of WBV during passive standing in a standing frame on the soleus H-reflex among men with and without spinal cord injury (SCI). In spinal cord intact participants, WBV caused significant inhibition of the H-reflex as early as 6s after vibration onset (9.0+/-3.9%) (p<0.001). The magnitude of the H-reflex gradually recovered after WBV, but remained significantly below initial values until 36s post-WBV (57.5+/-22.0%) (p=0.01). Among participants with SCI, H-reflex inhibition was less pronounced with onset 24 s following WBV (54.2+/-18.7%) (p=0.03). The magnitude of the H-reflex fully recovered after 60s of WBV exposure. These results concur with prior reports of inhibitory effects of local vibration application on the H-reflex. Our results suggest that acute modulation of spinal motoneuronal excitability during WBV can be achieved in the absence of voluntary leg muscle contractions. Nonetheless, WBV has implications for rehabilitation service delivery through modulation of spinal motoneuronal excitability in individuals with SCI.