Motor Complete Spinal Cord Injury Research Articles

Passive activity enhances residual control ability in patients with complete spinal cord injury

Abstract Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level. However, because of prolonged inactivity, initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway. A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation, as measured by surface electromyography. In this study, we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury. Eleven patients with chronic complete thoracic spinal cord injury were recruited. Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol. The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation. Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity, the difference was not statistically significant. These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.

A Sonomyography-Based Muscle Computer Interface for Individuals With Spinal Cord Injury.

Impairment of hand functions in individuals with spinal cord injury (SCI) severely disrupts activities of daily living. Recent advances have enabled rehabilitation assisted by robotic devices to augment the residual function of the muscles. Traditionally, electromyography-based muscle activity sensing interfaces have been utilized to sense volitional motor intent to drive robotic assistive devices. However, the dexterity and fidelity of control that can be achieved with electromyography-based control have been limited due to inherent limitations in signal quality. We have developed and tested a muscle-computer interface (MCI) utilizing sonomyography to provide control of a virtual cursor for individuals with motor-incomplete spinal cord injury. We demonstrate that individuals with SCI successfully gained control of a virtual cursor by utilizing contractions of muscles of the wrist joint. The sonomyography-based interface enabled control of the cursor at multiple graded levels demonstrating the ability to achieve accurate and stable endpoint control. Our sonomyography-based muscle-computer interface can enable dexterous control of upper-extremity assistive devices for individuals with motor-incomplete SCI.

Boldine Promotes Recovery of Function After Motor-Incomplete Spinal Cord Injury in Mice

Membrane channels such as connexins (Cx) and pannexins (Panx) are permeable to calcium ions and other small molecules such as ATP and glutamate. Release of ATP and glutamate through these channels is a key mechanism driving tissue response to traumas such as spinal cord injury (SCI). Boldine, an alkaloid isolated from the Chilean boldo tree, blocks both Cx hemichannels (HC) and Panx. To test if boldine could improve function after SCI, boldine or vehicle was administered to treat mice with a moderate severity contusion-induced SCI. Boldine led to greater spared white matter and increased locomotor function as determined by the Basso Mouse Scale and horizontal ladder rung walk tests. Boldine treatment reduced immunostaining for markers of activated microglia (Iba1) and astrocytic (GFAP) markers while increasing that for axon growth and neuroplasticity (GAP-43). RT-qPCR studies showed that boldine treatment reduced expression of chemokine Ccl2, cytokine IL-6 and microglial gene CD68, while increasing expression of the neurotransmission genes Snap25 and Grin2b, and Gap-43. Bulk RNA sequencing revealed that boldine modulated a large number of genes involved in neurotransmission in spinal cord tissue just caudal from the lesion epicenter at 14 days after SCI. Numbers of genes regulated by boldine was much lower at 28 days after injury. Furthermore, physical activity through treadmill training together with boldine showed an additive effect in recovery of function after SCI. Overall, our results indicate that boldine treatment ameliorates injury and spares tissue to increase locomotor function. DOD SCIRP SC170315; VA RR&D Service Grant B-2020-C; NIH GM54508 and GM137056. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effect of Circulating Extracellular Vesicles from Adults with Spinal Cord Injury on Pulmonary Artery Endothelial Cell Function

Spinal cord injury (SCI) is associated with an increased risk and prevalence of cardiopulmonary and cerebrovascular disease-related morbidity and mortality. Despite an improved understanding of the neurological and physical consequences associated with SCI, factors that initiate, promote and accelerate cardiopulmonary disease are poorly understood. It has become apparent that the increased incidence of pulmonary disorders in adults with chronic SCI is not solely due to worsening of traditional risk factors, but also involves ill-defined factors. Several studies have implicated circulating endothelial cell-derived microvesicles (EMVs) in the etiology of cardiopulmonary diseases. We have previously reported that circulating EMVs are elevated in adults with chronic SCI and the expression of their microRNA cargo promotes disease. Reduction in pulmonary nitric oxide (NO) bioavailability and increased endothelin (ET)-1 production underly many cardiopulmonary disorders associated with SCI. The experimental aim of this study was to determine the effect of EMVs isolated from adults with chronic tetraplegic SCI on pulmonary endothelial cell NO and ET-1 production. As part of an ongoing study, circulating EMVs (CD144-PE) were isolated (flow cytometry) from 7 non-injured adults (all male; age: 38±4 yr) and 7 motor complete SCI adults with tetraplegic SCI (male; 44±5 yr). All subjects were free of overt cardiometabolic disease. Human pulmonary artery endothelial cells (HPAECs) were cultured and separately treated with EMVs from each subject for 24 hr. Expression of intracellular NO and ET-1 proteins of interest was determined by capillary electrophoresis immunoassay. Circulating EMV concentrations were significantly higher (~200%) in SCI vs non-injured (154±36 vs 54±7 EMV/μL). Expression of p-eNOS (Ser1177), the primary activation site for eNOS, was ~30% lower (96.0±2.3 vs 140.7±8.9 AU; p<0.01) and p-eNOS (Thr495), primary inhibitory site, ~40% higher (40.7±1.7 vs 28.8±3.1 AU; p<0.01) in cells treated with EMVs from SCI vs non-injured. As a result, NO production was ~20% lower (6.5±0.3 vs 8.3±0.7 μmol/L; P=0.03) in HPAECs treated with EMVs from adults with SCI. SCI-associated EMVs also significantly increased (~70%) the expression of Big ET-1 (60.6±3.6 vs 36.1±2.7 AU) resulting in enhanced endothelial ET-1 production (884.0±22.9 vs 778.7±18.0 pg/mL). In conclusion, EMVs harvested from adults with SCI markedly reduced eNOS activation and NO production and increased ET-1 synthesis and release in pulmonary endothelial cells in vitro. Circulating EMVs represent a potential mechanistic factor underlying pulmonary disorders and increased disease risk with SCI. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Efficacy of Walking Adaptability Training on Walking Capacity in Ambulatory People With Motor Incomplete Spinal Cord Injury: A Multicenter Pragmatic Randomized Controlled Trial

Background and Objective Balance and walking capacity are often impaired in people with motor incomplete spinal cord injury (iSCI), frequently resulting in reduced functional ambulation and participation. This study aimed to assess the efficacy of walking adaptability training compared to similarly dosed conventional locomotor and strength training for improving walking capacity, functional ambulation, balance confidence, and participation in ambulatory people with iSCI. Methods We conducted a 2-center, parallel-group, pragmatic randomized controlled trial. Forty-one people with iSCI were randomized to 6 weeks of (i) walking adaptability training (11 hours of Gait Real-time Analysis Interactive Lab (GRAIL) training—a treadmill in a virtual reality environment) or (ii) conventional locomotor and strength training (11 hours of treadmill training and lower-body strength exercises). The primary measure of walking capacity was maximal walking speed, measured with an overground 2-minute walk test. Secondary outcome measures included the Spinal Cord Injury Functional Ambulation Profile (SCI-FAP), the Activities-specific Balance Confidence (ABC) scale, and the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P). Results No significant difference in maximal walking speed between the walking adaptability (n = 17) and conventional locomotor and strength (n = 18) training groups was found 6 weeks after training at follow-up (−0.05 m/s; 95% CI = −0.12-0.03). In addition, no significant group differences in secondary outcomes were found. However, independent of intervention, significant improvements over time were found for maximal walking speed, SCI-FAP, ABC, and USER-P restrictions scores. Conclusions. Our findings suggest that walking adaptability training may not be superior to conventional locomotor and strength training for improving walking capacity, functional ambulation, balance confidence, or participation in ambulatory people with iSCI. Trial Registration Dutch Trial Register; Effect of GRAIL training in iSCI.

Mild Intermittent Hypoxia Improves Autonomic Dysreflexia and Orthostatic Hypotension in a Participant with Motor Incomplete Spinal Cord Injury

Mild Intermittent Hypoxia Improves Autonomic Dysreflexia and Orthostatic Hypotension in a Participant with Motor Incomplete Spinal Cord Injury

Plasticity of Minute Ventilation, But Not Blood Pressure in Participants with Motor Incomplete Spinal Cord Injury

Plasticity of Minute Ventilation, But Not Blood Pressure in Participants with Motor Incomplete Spinal Cord Injury

Targeting Frequency of Gait Training in the Motor Complete Cervical Spinal Cord Injury Population: A case series

Targeting Frequency of Gait Training in the Motor Complete Cervical Spinal Cord Injury Population: A case series

Mild Intermittent Hypoxia Improves Hand Function in a Participant with Motor Incomplete Cervical Spinal Cord Injury

Mild Intermittent Hypoxia Improves Hand Function in a Participant with Motor Incomplete Cervical Spinal Cord Injury

Skin and not dorsal root stimulation reduces hypertonus in thoracic motor complete spinal cord injury: a single case report.

On demand and localized treatment for excessive muscle tone after spinal cord injury (SCI) is currently not available. Here, we examine the reduction in leg hypertonus in a person with mid-thoracic, motor complete SCI using a commercial transcutaneous electrical stimulator (TES) applied at 50 or 150 Hz to the lower back and the possible mechanisms producing this bilateral reduction in leg tone. Hypertonus of knee extensors without and during TES, with both cathode (T11-L2) and anode (L3-L5) placed over the spinal column (midline, MID) or 10 cm to the left of midline (lateral, LAT) to only active underlying skin and muscle afferents, was simultaneously measured in both legs with the pendulum test. Spinal reflexes mediated by proprioceptive (H-reflex) and cutaneomuscular reflex (CMR) afferents were examined in the right leg opposite to the applied LAT TES. Hypertonus disappeared in both legs but only during thoracolumbar TES, and even during LAT TES. The marked reduction in tone was reflected in the greater distance both lower legs first dropped to after being released from a fully extended position, increasing by 172.8% and 94.2% during MID and LAT TES, respectively, compared with without TES. Both MID and LAT (left) TES increased H-reflexes but decreased the first burst, and lengthened the onset of subsequent bursts, in the cutaneomuscular reflex of the right leg. Thoracolumbar TES is a promising method to decrease leg hypertonus in chronic, motor complete SCI without activating spinal cord structures and may work by facilitating proprioceptive inputs that activate excitatory interneurons with bilateral projections that in turn recruit recurrent inhibitory neurons.NEW & NOTEWORTHY We present proof of concept that surface stimulation of the lower back can reduce severe leg hypertonus in a participant with motor complete, thoracic spinal cord injury (SCI) but only during the applied stimulation. We propose that activation of skin and muscle afferents from thoracolumbar transcutaneous electrical stimulation (TES) may recruit excitatory spinal interneurons with bilateral projections that in turn recruit recurrent inhibitory networks to provide on demand suppression of ongoing involuntary motoneuron activity.

A direct spinal cord-computer interface enables the control of the paralysed hand in spinal cord injury.

The paralysis of the muscles controlling the hand dramatically limits the quality of life of individuals living with spinal cord injury (SCI). Here, with a non-invasive neural interface, we demonstrate that eight motor complete SCI individuals (C5-C6) are still able to task-modulate in real-time the activity of populations of spinal motor neurons with residual neural pathways. In all SCI participants tested, we identified groups of motor units under voluntary control that encoded various hand movements. The motor unit discharges were mapped into more than 10 degrees of freedom, ranging from grasping to individual hand-digit flexion and extension. We then mapped the neural dynamics into a real-time controlled virtual hand. The SCI participants were able to match the cue hand posture by proportionally controlling four degrees of freedom (opening and closing the hand and index flexion/extension). These results demonstrate that wearable muscle sensors provide access to spared motor neurons that are fully under voluntary control in complete cervical SCI individuals. This non-invasive neural interface allows the investigation of motor neuron changes after the injury and has the potential to promote movement restoration when integrated with assistive devices.

Effects of releasing ankle joint during electrically evoked cycling in persons with motor complete spinal cord injury.

Literature has shown that simulated power production during conventional functional electrical stimulation (FES) cycling was improved by 14% by releasing the ankle joint from a fixed ankle setup and with the stimulation of the tibialis anterior and triceps surae. This study aims to investigate the effect of releasing the ankle joint on the pedal power production during FES cycling in persons with spinal cord injury (SCI). Seven persons with motor complete SCI participated in this study. All participants performed 1min of fixed-ankle and 1min of free-ankle FES cycling with two stimulation modes. In mode 1 participants performed FES-evoked cycling with the stimulation of quadriceps and hamstring muscles only (QH stimulation), while Mode 2 had stimulation of quadriceps, hamstring, tibialis anterior, and triceps surae muscles (QHT stimulation). The order of each trial was randomized in each participant. Free-ankle FES cycling offered greater ankle plantar- and dorsiflexion movement at specific slices of 20° crank angle intervals compared to fixed-ankle. There were significant differences in the mean and peak normalized pedal power outputs (POs) [F(1,500) = 14.03, p < 0.01 and F(1,500) = 7.111, p = 0.008, respectively] between fixed- and free-ankle QH stimulation, and fixed- and free-ankle QHT stimulation. Fixed-ankle QHT stimulation elevated the peak normalized pedal PO by 14.5% more than free-ankle QH stimulation. Releasing the ankle joint while providing no stimulation to the triceps surae and tibialis anterior reduces power output. The findings of this study suggest that QHT stimulation is necessary during free-ankle FES cycling to maintain power production as fixed-ankle.

Effectiveness and efficiency of telerehabilitation on functionality after spinal cord injury: A matched case-control study.

Telerehabilitation in spinal cord injury (teleSCI) is a growing field that can improve access to care and health outcomes in patients with spinal cord injury (SCI). The clinical effectiveness of teleSCI is not known. To compare independence in activities of daily living and mobility capacity in patients following teleSCI and matched controls undergoing traditional rehabilitation. Matched case-control study. TeleSCI occurring in home setting (cases) versus traditional rehabilitation on inpatient unit (controls). Forty-two consecutive patients with SCI followed with teleSCI were compared to 42 historical rehabilitation inpatients (controls) matched for age, time since injury to rehabilitation admission, level of injury (paraplegia/tetraplegia), complete or incomplete injury, and etiology (traumatic/nontraumatic). The teleSCI group (n = 42) was also compared to the complete cohort of historical controls (n = 613). The teleSCI group followed home-based telerehabilitation (3.5 h/day, 5 days/week, 67 days average duration) and historical controls followed in-person rehabilitation. The Functional Independence Measure (FIM), the Spinal Cord Independence Measure (SCIM) and the Walking Index for Spinal Cord Injury (WISCI). We formally compared gains, efficiency and effectiveness. International Standards for Neurological Classification of Spinal Cord Injury and the American Spinal Injury Association Impairment Scale (AIS) were used. The teleSCI group (57.1% nontraumatic, 71.4% paraplegia, 73.8% incomplete, 52.4% AIS grade D) showed no significant differences compared with historical controls in AIS grades, neurological levels, duration, gains, efficiency and effectiveness in FIM, SCIM, or WISCI, although the teleSCI cohort had significantly higher admission FIM scores compared with the complete cohort of historical controls. TeleSCI may provide similar improvements in mobility and functional outcomes as traditional rehabilitation in medically stable patients (predominantly with paraplegia and motor incomplete SCI) when provided with appropriate support and equipment.

Robotic Postural Training With Epidural Stimulation for the Recovery of Upright Postural Control in Individuals With Motor Complete Spinal Cord Injury: A Pilot Study.

Activity-based training and lumbosacral spinal cord epidural stimulation (scES) have the potential to restore standing and walking with self-balance assistance after motor complete spinal cord injury (SCI). However, improvements in upright postural control have not previously been addressed in this population. Here, we implemented a novel robotic postural training with scES, performed with free hands, to restore upright postural control in individuals with chronic, cervical (n = 5) or high-thoracic (n = 1) motor complete SCI, who had previously undergone stand training with scES using a walker or a standing frame for self-balance assistance. Robotic postural training re-enabled and/or largely improved the participants' ability to control steady standing, self-initiated trunk movements and upper limb reaching movements while standing with free hands, receiving only external assistance for pelvic control. These improvements were associated with neuromuscular activation pattern adaptations above and below the lesion. These findings suggest that the human spinal cord below the level of injury can generate meaningful postural responses when its excitability is modulated by scES, and can learn to improve these responses. Upright postural control improvements can enhance functional motor recovery promoted by scES after severe SCI.

Brief High-Velocity Motor Skill Training Increases Step Frequency and Improves Length/Frequency Coordination in Slow Walkers With Chronic Motor-Incomplete Spinal Cord Injury

ObjectiveTo quantify spatiotemporal coordination during overground walking among persons with motor-incomplete spinal cord injury (PwMISCI) by calculating the step length (SL)/step frequency (SF) ratio (ie, the Walk Ratio [WR]) and to examine the effects of motor skill training (MST) on the relationship between changes in these parameters and walking speed (WS). DesignBetween-day exploratory analysis. SettingResearch laboratory in a rehabilitation hospital ParticipantsPwMISCI (N=26). Interventions3-day high-velocity MST. Main Outcome MeasuresOverground WS, SL, SF, and WR measured during the 10-Meter Walk Test. ResultsAmong the full sample, MST was associated with increases in WS, SL, SF, and a decrease in the WR. Relative change in WS and SF was higher among slow (ΔWS=↑46%, ΔSF=↑28%) vs fast (ΔWS=↑16%, ΔSF=↑8%) walkers. Change in the WR differed between groups (slow: ΔWR=↓10%; fast: ΔWR=0%). Twenty-six percent of the variability observed in ΔWR among slow walkers could be explained by ΔSF, while ΔSL did not contribute to ΔWR. Among fast walkers, ΔSL accounted for more than twice the observed ΔWR (43%) compared to ΔSF (15%). ConclusionsOn the whole, WR values among PwMISCI are higher than previous reports in other neurologic populations; however, values among fast walkers were comparable to noninjured adults. Slow walkers demonstrated greater variability in the WR, with higher values associated with slower WS. Following MST, increases in WS coincided with a decrease in the WR among slow walkers, mediated primarily through an effect on SF. This finding may point to a specific mechanism by which MST facilitates improvements in WS among PwMISCI with greater mobility deficits.

Peak Slope Ratio of the Recruitment Curves Compared to Muscle Evoked Potentials to Optimize Standing Configurations with Percutaneous Epidural Stimulation after Spinal Cord Injury.

Background: Percutaneous spinal cord epidural stimulation (pSCES) has effectively restored varying levels of motor control in persons with motor complete spinal cord injury (SCI). Studying and standardizing the pSCES configurations may yield specific motor improvements. Previously, reliance on the amplitude of the SCES-evoked potentials (EPs) was used to determine the correct stimulation configurations. Methods: We, hereby, retrospectively examined the effects of wide and narrow-field configurations on establishing the motor recruitment curves of motor units of three different agonist-antagonist muscle groups. Magnetic resonance imaging was also used to individualize SCI participants (n = 4) according to their lesion characteristics. The slope of the recruitment curves using a six-degree polynomial function was calculated to derive the slope ratio for the agonist-antagonist muscle groups responsible for standing. Results: Axial damage ratios of the spinal cord ranged from 0.80 to 0.92, indicating at least some level of supraspinal connectivity for all participants. Despite the close range of these ratios, standing motor performance was enhanced using different stimulation configurations in the four persons with SCI. A slope ratio of ≥1 was considered for the recommended configurations necessary to achieve standing. The retrospectively identified configurations using the supine slope ratio of the recruitment curves of the motor units agreed with that visually inspected muscle EPs amplitude of the extensor relative to the flexor muscles in two of the four participants. Two participants managed to advance the selected configurations into independent standing performance after using tonic stimulation. The other two participants required different levels of assistance to attain standing performance. Conclusions: The findings suggest that the peak slope ratio of the muscle agonists-antagonists recruitment curves may potentially identify the pSCES configurations necessary to achieve standing in persons with SCI.

Effectiveness of Body Weight-Supported Gait Training on Gait and Balance for Motor-Incomplete Spinal Cord Injuries: A Systematic Review with Meta-Analysis.

This review aims to analyse the effectiveness of body weight-supported gait training for improving gait and balance in patients with motor-incomplete spinal cord injuries. Relevant articles were systematically searched in electronic databases to identify randomised controlled trials of body weight-supported gait training (either with methods of robotic, manual, and functional electrical stimulation assistance) versus conventional physical therapy or no intervention. Subjects were >16 years-old with motor-incomplete spinal cord injury (AIS C or D). Primary outcomes were gait-related parameters (functionality, endurance, and speed) and balance. Quality of life was included as a secondary outcome. Articles were selected up to 31 December 2023. Fifteen studies met the inclusion criteria (n = 673). Nine studies used robotic assistance, four trials performed manual assistance, one study functional electrical stimulation assistance, and one trial performed the intervention without guidance. Robot-assisted body weight-supported gait training improved walking functionality (SMD = 1.74, CI 95%: 1.09 to 2.39), walking endurance (MD = 26.59 m, CI 95% = 22.87 to 30.31), and balance (SMD = 0.63, CI 95% = 0.24 to 1.02). Body weight-supported gait training is not superior to conventional physiotherapy in gait and balance training in patients with motor-incomplete spinal cord injury. However, body weight-supported gait training with robotic assistance does improve walking functionality, walking endurance, and balance, but not walking speed.

Comparison of One-Year Postinjury Mobility Outcomes Between Locomotor Training and Usual Care After Motor Incomplete Spinal Cord Injury.

To compare 1-year mobility outcomes of individuals with traumatic motor incomplete spinal cord injury (miSCI) who participated in standardized locomotor training (LT) within the first year of injury to those who did not. This retrospective case-control analysis conducted with six US rehabilitation hospitals used SCI Model Systems (SCIMS) data comparing 1-year postinjury outcomes between individuals with miSCI who participated in standardized LT to those who received usual care (UC). Participants were matched on age, gender, injury year, mode of mobility, and rehabilitation center. The primary outcome is the FIM Total Motor score. Other outcomes include the FIM Transfer Index, FIM Stairs, and self-reported independence with household mobility, community mobility, and stairs. LT participants reported significantly better FIM Total Motor (difference = 2.812, 95% confidence interval [CI] = 5.896, 17.282) and FIM Transfer Index scores (difference = 0.958, 95% CI = 0.993, 4.866). No significant between-group differences were found for FIM Stairs (difference = 0.713, 95% CI = -0.104, 1.530) or self-reported household mobility (odds ratio [OR] = 5.065, CI = 1.435, 17.884), community mobility (OR = 2.933, 95% CI = 0.868, 9.910), and stairs (OR = 5.817, 95% CI = 1.424, 23.756) after controlling for multiple comparisons. LT participants reported significantly greater improvements in primary and secondary measures of mobility and independence (FIM Total Motor score; FIM Transfer Index) compared to UC participants. Self-reported mobility outcomes were not significant between groups.

OVERGROUND ROBOTIC EXOSKELETON GAIT TRAINING INTENSITY IN PATIENTS WITH SCI

BACKGROUND High-intensity gait training during inpatient rehabilitation (IPR) promotes functional recovery following spinal cord injury (SCI) and may be achieved with overground robotic exoskeleton gait training (OEGT). Due to neuromuscular and autonomic impairments associated with SCI, assessing intensity through heart rate response and perceived exertion during gait training may be inaccurate. Wearable metabolic systems (WMS) have been used to directly measure intensity using oxygen consumption (VO2) with SCI. However, the use of WMS to assess OEGT intensity during OEGT in IPR is unexplored. PURPOSE: To describe the use of WMS to measure physiological intensity of OEGT in patients with motor incomplete SCI during IPR. METHODS This observational study included adults aged 18 to 85 admitted to IPR with diagnosis of motor incomplete SCI who were eligible to initiate OEGT. OEGT intensity, duration, and step count were assessed during 1 OEGT session performed within 1 week of gait training initiation following IPR admission. Intensity was assessed by rate of perceived exertion (RPE) and VO2. VO2 was measured using a WMS worn during OEGT and expressed in metabolic equivalents (METs). Moderate and high intensity were defined as ≥ 3 and ≥ 6 METs, respectively, with 2.7 mL/min/kg of VO2 = 1 MET. RESULTS 4 participants [3 males; 1 non-Hispanic white, 2 Hispanic white, 1 Black] were aged 52±8.4 years with a body mass index of 28.4±3.2. Participants’ SCI characteristics were 3 diagnosed ASIA Impairment Scale (AIS) C, 1 AIS D; 2 tetraplegia and 2 paraplegia admitted within 30.5 [range=8-56] days after SCI. Duration of OEGT sessions (n=4) was 15:57 [range=10:23-19:43] minutes and participants completed 512 [287-761] steps. RPE was 4 [2-6], VO2 was 7.3 [3.05-15.6], and METs were 2.72 [1.1-5.8]. Three participants achieved ≥3 METs and ≥6 METs for 79-89.6% and 4.2-54.8% of the OEGT session, respectively. VO2 was highest in the AIS D participant. CONCLUSIONS WMS use was demonstrated to feasibly obtain intensity data of OEGT in adults with SCI during IPR. Future research should consider the utility of WMS to assess the capacity of OEGT to promote high-intensity gait training in this population during IPR.

Clinical Delivery of Overground Exoskeleton Gait Training in Persons With Spinal Cord Injury Across the Continuum of Care: A Retrospective Analysis.

After spinal cord injury (SCI), inpatient rehabilitation begins and continues through outpatient therapy. Overground exoskeleton gait training (OEGT) has been shown to be feasible in both settings, yet its use as an intervention across the continuum has not yet been reported. This study describes OEGT for patients with SCI across the continuum and its effects on clinical outcomes. Medical records of patients with SCI who completed at least one OEGT session during inpatient and outpatient rehabilitation from 2018 to 2021 were retrospectively reviewed. Demographic data, Walking Index for Spinal Cord Injury-II (WISCI-II) scores, and OEGT session details (frequency, "walk" time, "up" time, and step count) were extracted. Eighteen patients [male (83%), White (61%), aged 37.4 ± 15 years, with tetraplegia (50%), American Spinal Injury Association Impairment Scale A (28%), B (22%), C (39%), D (11%)] completed OEGT sessions (motor complete, 18.2 ± 10.3; motor incomplete, 16.7 ± 7.7) over approximately 18 weeks (motor complete, 15.1 ± 6.4; motor incomplete, 19.0 ± 8.2). Patients demonstrated improved OEGT session tolerance on device metrics including "walk" time (motor complete, 7:51 ± 4:42 to 24:50 ± 9:35 minutes; motor incomplete, 12:16 ± 6:01 to 20:01 ± 08:05 minutes), "up" time (motor complete, 16:03 ± 7:41 to 29:49 ± 12:44 minutes; motor incomplete, 16:38 ± 4:51 to 23:06 ± 08:50 minutes), and step count (motor complete, 340 ± 295.9 to 840.2 ± 379.4; motor incomplete, 372.3 ± 225.2 to 713.2 ± 272). Across therapy settings, patients with motor complete SCI experienced improvement in WISCI-II scores from 0 ± 0 at inpatient admission to 3 ± 4.6 by outpatient discharge, whereas the motor incomplete group demonstrated a change of 0.2 ± 0.4 to 9.0 ± 6.4. Patients completed OEGT across the therapy continuum. Patients with motor incomplete SCI experienced clinically meaningful improvements in walking function.