Effect of robotic gait training on cardiorespiratory system in incomplete spinal cord injury

Effect of robot-assisted stair climbing training as part of a rehabilitation program to improve pulmonary function, gait performance, balance, and exercise capacity in a patient after severe coronavirus disease 2019: a case report

BACKGROUND

Severe coronavirus disease 2019 (COVID-19) infection may decrease respiratory and physical functions.

OBJECTIVE

To evaluate whether robot-assisted stair climbing training (RASCT) would improve pulmonary and physical functions in a patient post-severe COVID-19 infection.

CASE DESCRIPTION

A 48-year-old woman who had experienced severe COVID-19 underwent a 6-week inpatient rehabilitation. She persistently exhibited impaired pulmonary and physical functions, including walking and balance impairment. We provided a 30-min outpatient RASCT biweekly for 6 weeks.

OUTCOMES

After training, maximal inspiratory and maximal expiratory pressures improved from 81 and 74 cmH2O to 104 and 81 cmH2O, respectively. The walking speed improved from 1.15 to 1.21 m/s. In balance ability, physical performance battery score and timed up-and-go test improved from 8 to 11 s and 10.89 to 9.95 s, respectively. Regarding exercise capacity, the 6-min walk test distance improved from 453 to 482 m, and the number of 1-min sit-to-stand test improved from 20 to 23, with improved pulse rate and saturation level. The physical and psychological domain scores of the World Health Organization Quality-of-Life Scale-BREF improved from 44 to 63 and 69 to 81, respectively; Falls Efficacy Scale-International scores improved from 38 to 21.

CONCLUSION

RASCT, as part of a rehabilitation plan, was feasible and effective for this patient after severe COVID-19 infection.

Effects of robot-assisted gait training on cardiopulmonary function and lower extremity strength in individuals with spinal cord injury: A systematic review and meta-analysis

CONTEXT

Robot-assisted gait training (RAGT) has been increasingly adopted in many rehabilitation facilities for walking function and activity in individuals with spinal cord injury (SCI). However, the effectiveness of RAGT on lower extremity strength and cardiopulmonary function, especially static pulmonary function, have not been clearly outlined.

OBJECTIVE

Determine the effect of RAGT on cardiopulmonary function and lower extremity strength in SCI survivors.

METHODS

Eight databases were systematically searched for randomized controlled trials comparing RAGT with conventional physical therapy or other non-robotic therapies for survivors with SCI. Study selection required lower extremity strength decline after SCI at baseline. The overall effects of RAGT were calculated using a meta-analytic method. Begg's test was used to assess the risk of publication bias.

RESULTS

The pooled analysis demonstrated that RAGT may have a positive effect for individuals with SCI on lower extremity strength enhancing (n = 408; standardized mean difference [SMD]  =  0.81; 95% confidence interval [CI] = 0.14-1.48) and cardiopulmonary endurance(n = 104; standardized mean difference [SMD]  =  2.24; 95% confidence interval [CI] = 0.28-4.19). However, no significant effect was established on static pulmonary function. No publication bias was observed according to the Begg's test.

CONCLUSIONS

RAGT may be a useful technique for improving lower limb strength and cardiovascular endurance in SCI survivors. The usefulness of RAGT in enhancing static pulmonary function was not demonstrated by the study. However, these results should be interpreted with caution, given the low number of selected studies and subjects. Clinical studies with large sample sizes will be necessary in the future.

Exercise and aerobic capacity in individuals with spinal cord injury: A systematic review with meta-analysis and meta-regression

BACKGROUND

A low level of cardiorespiratory fitness [CRF; defined as peak oxygen uptake ([Formula: see text]O2peak) or peak power output (PPO)] is a widely reported consequence of spinal cord injury (SCI) and a major risk factor associated with chronic disease. However, CRF can be modified by exercise. This systematic review with meta-analysis and meta-regression aimed to assess whether certain SCI characteristics and/or specific exercise considerations are moderators of changes in CRF.

METHODS AND FINDINGS

Databases (MEDLINE, EMBASE, CENTRAL, and Web of Science) were searched from inception to March 2023. A primary meta-analysis was conducted including randomised controlled trials (RCTs; exercise interventions lasting >2 weeks relative to control groups). A secondary meta-analysis pooled independent exercise interventions >2 weeks from longitudinal pre-post and RCT studies to explore whether subgroup differences in injury characteristics and/or exercise intervention parameters explained CRF changes. Further analyses included cohort, cross-sectional, and observational study designs. Outcome measures of interest were absolute (A[Formula: see text]O2peak) or relative [Formula: see text]O2peak (R[Formula: see text]O2peak), and/or PPO. Bias/quality was assessed via The Cochrane Risk of Bias 2 and the National Institute of Health Quality Assessment Tools. Certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random effects models were used in all meta-analyses and meta-regressions. Of 21,020 identified records, 120 studies comprising 29 RCTs, 67 pre-post studies, 11 cohort, 7 cross-sectional, and 6 observational studies were included. The primary meta-analysis revealed significant improvements in A[Formula: see text]O2peak [0.16 (0.07, 0.25) L/min], R[Formula: see text]O2peak [2.9 (1.8, 3.9) mL/kg/min], and PPO [9 (5, 14) W] with exercise, relative to controls (p < 0.001). Ninety-six studies (117 independent exercise interventions comprising 1,331 adults with SCI) were included in the secondary, pooled meta-analysis which demonstrated significant increases in A[Formula: see text]O2peak [0.22 (0.17, 0.26) L/min], R[Formula: see text]O2peak [2.8 (2.2, 3.3) mL/kg/min], and PPO [11 (9, 13) W] (p < 0.001) following exercise interventions. There were subgroup differences for R[Formula: see text]O2peak based on exercise modality (p = 0.002) and intervention length (p = 0.01), but there were no differences for A[Formula: see text]O2peak. There were subgroup differences (p ≤ 0.018) for PPO based on time since injury, neurological level of injury, exercise modality, and frequency. The meta-regression found that studies with a higher mean age of participants were associated with smaller changes in A[Formula: see text]O2peak and R[Formula: see text]O2peak (p < 0.10). GRADE indicated a moderate level of certainty in the estimated effect for R[Formula: see text]O2peak, but low levels for A[Formula: see text]O2peak and PPO. This review may be limited by the small number of RCTs, which prevented a subgroup analysis within this specific study design.

CONCLUSIONS

Our primary meta-analysis confirms that performing exercise >2 weeks results in significant improvements to A[Formula: see text]O2peak, R[Formula: see text]O2peak, and PPO in individuals with SCI. The pooled meta-analysis subgroup comparisons identified that exercise interventions lasting up to 12 weeks yield the greatest change in R[Formula: see text]O2peak. Upper-body aerobic exercise and resistance training also appear the most effective at improving R[Formula: see text]O2peak and PPO. Furthermore, acutely injured, individuals with paraplegia, exercising for ≥3 sessions/week will likely experience the greatest change in PPO. Ageing seemingly diminishes the adaptive CRF responses to exercise training in individuals with SCI.

REGISTRATION

PROSPERO: CRD42018104342.

Effects of walking training on risk markers of cardiovascular disease in individuals with chronic spinal cord injury

OBJECTIVE

To investigate the effects of an 8-week walking training program on glycemic control, lipid profile, and inflammatory markers in individuals with chronic spinal cord injury (SCI).

DESIGN

A pilot, single-group, pretest-posttest study.

SETTING

A neuromuscular research laboratory.

PARTICIPANTS

Eleven participants with chronic SCI.

INTERVENTION

An 8-week walking training program using a treadmill, a body weight-supported system, and an assistive gait training device.

OUTCOME MEASURES

Levels of glycated hemoglobin (HbA_1c), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), and interleukin-6 were assessed before and after the walking training.

RESULTS

Following the walking training, there was a statistically significant decrease in HbA_1c level (P<0.01) of uncertain clinical significance. The lipid profile improved after training, as shown by a statistically and clinically significant increase in HDL-C level (P<0.01) and a statistically significant decrease in LDL-C level (P<0.1) of no clinical significance. The ratio of LDL-C to HDL-C was significantly reduced (P<0.01). In regard to inflammatory markers, concentrations of IL-6 showed a significant reduction after training (P=0.05) of unknown clinical significance, while those of CRP trended to decrease (P=0.13).

CONCLUSION

The findings of this pilot study suggest that an 8-week walking training program may produce favorable changes in risk markers of cardiovascular disease in individuals with chronic SCI as shown by clinically meaningful improvements in HDL-C, and small changes in the right direction, but uncertain clinical significance, in HbA1c, LDL-C and IL-6. A randomized controlled trial is needed to compare the effects of walking training on these outcome measures with those of other exercise modalities suitable for this population, and to see if more prolonged exercise exposure leads to favorable parameters of significant size to justify the exercise modality.

Robot-assisted gait training in individuals with spinal cord injury: A systematic review for the clinical effectiveness of Lokomat

BACKGROUND

Spinal cord injury (SCI) is a critical medical condition that causes numerous impairments leading to accompanying disability. Robotic-assisted gait training (RAGT) offers many advantages, including the capability to increase the intensity and total duration of training while maintaining a physiological gait pattern. The effects of the RAGT 'Lokomat' on various impairments following SCI remain unclear.

OBJECTIVES

This review was conducted to examine the impacts of the RAGT 'Lokomat' on the impairments following SCI.

METHODS

We searched PubMed, SCOPUS, PEDro, REHABDATA, MEDLINE, EMBASE, and web of science from inception to January 2021. Experimental studies examining the effects of the Lokomat on the impairments following incomplete SCI were selected. The methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Sixteen studies were met the inclusion criteria. Thirteen were randomized controlled trials, two were clinical trials, and one was a pilot study. The scores on the PEDro scale ranged from two to eight, with a median score of six. The results showed evidence for the beneficial effects of the Lokomat on many motor impairments following incomplete SCI.

CONCLUSIONS

The Lokomat may improve gait speed, walking distance, strength, range of motion, and mobility after incomplete SCI. There is insufficient evidence for the effect of the Lokomat on balance, depression, cardiorespiratory fitness, and quality of life. The effects of the Lokomat on the lower extremity spasticity were limited.

Energy cost and psychological impact of robotic-assisted gait training in people with spinal cord injury: effect of two different types of devices

BACKGROUND

In the last years, there has been an intense technological development of robotic devices for gait rehabilitation in spinal cord injury (SCI) patients. The aim of the present study was to evaluate energy cost and psychological impact during a rehabilitation program with two different types of robotic rehabilitation systems (stationary system on a treadmill, Lokomat, and overground walking system, Ekso GT).

METHODS

Fifteen SCI patients with different injury levels underwent robot-assisted gait training sessions, divided into 2 phases: in the first phase, all subjects completed 3 sessions both Lokomat and Ekso GT. Afterwards, participants were randomly assigned to Lokomat or the Ekso for 17 sessions. A questionnaire, investigating the subjective psychological impact (SPI) during gait training, was administered. The functional outcome measures were oxygen consumption (VO₂), carbon dioxide production (VCO₂), metabolic equivalent of task (MET), walking economy, and heart rate (HR).

RESULTS

The metabolic responses (7.73 ± 1.02 mL/kg/min) and MET values (3.20 ± 1.01) during robotic overground walking resulted to be higher than those during robotic treadmill walking (3.91 ± 0.93 mL/kg/min and 1.58 ± 0.44; p < 0.01). Both devices showed high scores in emotion and satisfaction. Overground walking resulted in higher scores of fatigue, mental effort, and discomfort while walking with Lokomat showed a higher score in muscle relaxation. All patients showed improvements in walking economy due to a decrease in energy cost with increased speed and workload.

CONCLUSIONS

Overground robotic-assisted gait training in rehabilitation program needs higher cognitive and cardiovascular efforts than robot-assisted gait training on a treadmill.

Cardiac, Autonomic, and Cardiometabolic Impact of Exercise Training in Spinal Cord Injury: A QUALITATIVE REVIEW

INTRODUCTION

Direct and indirect effects of spinal cord injury lead to important cardiovascular (CV) complications that are further increased by years of injury and the process of "accelerated aging." The present review examines the current evidence in the literature for the potential cardioprotective effect of exercise training in spinal cord injury.

REVIEW METHODS

PubMed and Web of Science databases were screened for original studies investigating the effect of exercise-based interventions on aerobic capacity, cardiac structure/function, autonomic function, CV function, and/or cardiometabolic markers. We compared the effects in individuals <40 yr with time since injury <10 yr with those in older individuals (≥40 yr) with longer time since injury (≥10 yr), reasoning that the two can be considered individuals with low versus high CV risk factors.

SUMMARY

Studies showed similar exercise effects in both groups (n = 31 in low CV risk factors vs n = 15 in high CV risk factors). The evidence does not support any effect of exercise training on autonomic function but does support an increased peripheral blood flow, improved left ventricular mass, higher peak cardiac output, greater lean body mass, better antioxidant capacity, and improved endothelial function. In addition, some evidence suggests that it can result in lower blood lipids, systemic inflammation (interleukin-6, tumor necrosis factor α, and C-reactive protein), and arterial stiffness. Training intensity, volume, and frequency were key factors determining CV gains. Future studies with larger sample sizes, well-matched groups of subjects, and randomized controlled designs will be needed to determine whether high-intensity hybrid forms of training result in greater CV gains.

Effect of Body Weight-Supported Treadmill Training on Cardiovascular and Pulmonary Function in People With Spinal Cord Injury: A Systematic Review

Objective: To assess the current evidence with regard to the effects of body weight-supported treadmill training (BWSTT) on cardiovascular and pulmonary function in people with spinal cord injury (SCI) with a focus on outcomes of heart rate (HR), blood pressure (BP), and respiratory parameters. Methods: A systematic literature search was conducted through MEDLINE/PubMed, the Cumulative Index to Nursing and Allied Health Literature, and Physiotherapy Evidence Database. Clinical trials involving adults with SCI and focusing on the effects of BWSTT on HR, BP, and respiratory measurements were included. The quality of included studies was assessed using the Downs and Black scale. The level of evidence of each study was identified using the Spinal Cord Injury Rehabilitation Evidence system. Results: Nine studies that met inclusion criteria were evaluated and included in this review. Overall, the quality index of all included studies was low. All studies scored less than 21 out of 28 on the Downs and Black scale. The level of evidence varied from level 2 to level 4. Level 4 evidence supports the use of BWSTT to decrease resting and exercise HR and improve heart rate variability. The use of BWSTT to improve respiratory parameters after SCI is supported by one study with level 2 evidence. The evidence that supports the use of BWSTT to improve resting BP is inconclusive. Conclusion: There has been low to moderate evidence to support the use of BWSTT in individuals with SCI to improve cardiovascular and pulmonary health. Future randomized controlled trials are needed to investigate the effect of BWSTT on cardiovascular and pulmonary function in people with SCI and compare BWSTT to other physical rehabilitation interventions.

Exercise-Induced Alterations in Sympathetic-Somatomotor Coupling in Incomplete Spinal Cord Injury

The aim of this study was to understand how high- and low-intensity locomotor training (LT) affects sympathetic-somatomotor (SS) coupling in people with incomplete spinal cord injury (SCI). Proper coupling between sympathetic and somatomotor systems allows controlled regulation of cardiovascular responses to exercise. In people with SCI, altered connectivity between descending pathways and spinal segments impairs sympathetic and somatomotor coordination, which may have deleterious effects during exercise and limit rehabilitation outcomes. We postulated that high-intensity LT, which repeatedly engages SS systems, would alter SS coupling. Thirteen individuals (50 ± 7.2 years) with motor incomplete spinal cord injuries (American Spinal Injury Association Impairment Scale C or D; injury level >T6) participated in a locomotor treadmill training program. Patients were randomized into either a high-intensity (high-LT; 70-85% of maximum predicted heart rate; n = 6) group or a low-intensity (low-LT; 50-65% of maximum predicted heart rate; n = 7) group and completed up to 20 LT training sessions over 4-6 weeks, 3-5 days/week. Before and after taining, we tested SS coupling by eliciting reflexive sympathetic activity through a cold stimulation, noxious stimulation, and a mental math task while we measured tendon reflexes, blood pressure, and heart rate. Participants who completed high- versus low-LT exhibited significant decreases in reflex torques during triggered sympathetic activity (cold: -83 vs. 13%, p < 0.01; pain: -65 vs. 54%, p < 0.05; mental math: -43 vs. 41%; p < 0.05). Mean arterial pressure responses to sympathetic stimuli were slightly higher following high- versus low-LT (cold: 30 vs. -1.5%; pain: 6 vs. -12%; mental math: 5 vs. 7%), although differences were not statistically significant. These results suggest that high-LT may be advantageous to low-LT to improve SS coupling in people with incomplete SCI.

miR-34a alleviates spinal cord injury via TLR4 signaling by inhibiting HMGB-1

The aim of the present study was to investigate the effect of microRNA (miR)-34a on spinal cord injury (SCI)-induced inflammation and the possible underlying mechanisms. The results indicated that miR-34a expression was downregulated in a rat model of SCI compared with the control group. Furthermore, miR-34a knockdown was demonstrated to aggravate inflammation, inhibit cell proliferation and enhance apoptosis in an in vitro model of SCI. MiR-34a inhibition was demonstrated to upregulate the expression of inducible nitric oxide synthase and nitric oxide, as well as inducing the expression of toll-like receptor 4 (TLR4) and high mobility group box-1 (HMGB-1) in an in vitro model of SCI. TLR4 inhibitor reduced the effects of miR-34a downregulation on inflammation and cell growth in SCI. Together, these results suggest that miR-34a is able to alleviate SCI via inhibiting HMGB-1 expression in TLR4 signaling.

Robotic assisted gait as a tool for rehabilitation of individuals with spinal cord injury: a systematic review

BACKGROUND

Spinal cord injury (SCI) is characterized by a total or partial deficit of sensory and motor pathways. Impairments of this injury compromise muscle recruitment and motor planning, thus reducing functional capacity. SCI patients commonly present psychological, intestinal, urinary, osteomioarticular, tegumentary, cardiorespiratory and neural alterations that aggravate in chronic phase. One of the neurorehabilitation goals is the restoration of these abilities by favoring improvement in the quality of life and functional independence. Current literature highlights several benefits of robotic gait therapies in SCI individuals.

OBJECTIVES

The purpose of this study was to compare the robotic gait devices, and systematize the scientific evidences of these devices as a tool for rehabilitation of SCI individuals.

METHODS

A systematic review was carried out in which relevant articles were identified by searching the following databases: Cochrane Library, PubMed, PEDro and Capes Periodic. Two authors selected the articles which used a robotic device for rehabilitation of spinal cord injury.

RESULTS

Databases search found 2941 articles, 39 articles were included due to meet the inclusion criteria. The robotic devices presented distinct features, with increasing application in the last years. Studies have shown promising results regarding the reduction of pain perception and spasticity level; alteration of the proprioceptive capacity, sensitivity to temperature, vibration, pressure, reflex behavior, electrical activity at muscular and cortical level, classification of the injury level; increase in walking speed, step length and distance traveled; improvements in sitting posture, intestinal, cardiorespiratory, metabolic, tegmental and psychological functions.

CONCLUSIONS

This systematic review shows a significant progress encompassing robotic devices as an innovative and effective therapy for the rehabilitation of individuals with SCI.

Robot-assisted gait training (Lokomat) improves walking function and activity in people with spinal cord injury: a systematic review

Abstract

Robot-assisted gait training (RAGT) after spinal cord injury (SCI) induces several different neurophysiological mechanisms to restore walking ability, including the activation of central pattern generators, task-specific stepping practice and massed exercise. However, there is no clear evidence for the optimal timing and efficacy of RAGT in people with SCI. The aim of our study was to assess the effects of RAGT on improvement in walking-related functional outcomes in patients with incomplete SCI compared with other rehabilitation modalities according to time elapsed since injury. This review included 10 trials involving 502 participants to meta-analysis. The acute RAGT groups showed significantly greater improvements in gait distance, leg strength, and functional level of mobility and independence than the over-ground training (OGT) groups. The pooled mean difference was 45.05 m (95% CI 13.81 to 76.29, P = 0.005, I² = 0%; two trials, 122 participants), 2.54 (LEMS, 95% CI 0.11 to 4.96, P = 0.04, I² = 0%; three trials, 211 participants) and 0.5 (WISCI-II and FIM-L, 95% CI 0.02 to 0.98, P = 0.04, I² = 67%; three trials, 211 participants), respectively. In the chronic RAGT group, significantly greater improvements in speed (pooled mean difference = 0.07 m/s, 95% CI 0.01 to 0.12, P = 0.01, I² = 0%; three trials, 124 participants) and balance measured by TUG (pooled mean difference = 9.25, 95% CI 2.76 to 15.73, P = 0.005, I² = 74%; three trials, 120 participants) were observed than in the group with no intervention. Thus, RAGT improves mobility-related outcomes to a greater degree than conventional OGT for patients with incomplete SCI, particularly during the acute stage. RAGT treatment is a promising technique to restore functional walking and improve locomotor ability, which might enable SCI patients to maintain a healthy lifestyle and increase their level of physical activity.

Trial registration

PROSPERO (CRD 42016037366). Registered 6 April 2016.

Long-Term Training with a Brain-Machine Interface-Based Gait Protocol Induces Partial Neurological Recovery in Paraplegic Patients

Brain-machine interfaces (BMIs) provide a new assistive strategy aimed at restoring mobility in severely paralyzed patients. Yet, no study in animals or in human subjects has indicated that long-term BMI training could induce any type of clinical recovery. Eight chronic (3–13 years) spinal cord injury (SCI) paraplegics were subjected to long-term training (12 months) with a multi-stage BMI-based gait neurorehabilitation paradigm aimed at restoring locomotion. This paradigm combined intense immersive virtual reality training, enriched visual-tactile feedback, and walking with two EEG-controlled robotic actuators, including a custom-designed lower limb exoskeleton capable of delivering tactile feedback to subjects. Following 12 months of training with this paradigm, all eight patients experienced neurological improvements in somatic sensation (pain localization, fine/crude touch, and proprioceptive sensing) in multiple dermatomes. Patients also regained voluntary motor control in key muscles below the SCI level, as measured by EMGs, resulting in marked improvement in their walking index. As a result, 50% of these patients were upgraded to an incomplete paraplegia classification. Neurological recovery was paralleled by the reemergence of lower limb motor imagery at cortical level. We hypothesize that this unprecedented neurological recovery results from both cortical and spinal cord plasticity triggered by long-term BMI usage.

Effects of aerobic exercise training on fitness and walking-related outcomes in ambulatory individuals with chronic incomplete spinal cord injury

Study Design

Single group, pretest-posttest study.

Objectives

To determine the effects of a non-task-specific, voluntary, progressive aerobic exercise training (AET) intervention on fitness and walking-related outcomes in ambulatory adults with chronic motor-incomplete SCI.

Setting

Rehabilitation research center.

Methods

Ten ambulatory individuals (50% female; 57.94 ± 9.33 years old; 11.11 ± 9.66 years post injury) completed voluntary, progressive moderate-to-vigorous intensity AET on a recumbent stepper three days per week for six weeks. The primary outcome measures were aerobic capacity (VO_2peak) and self-selected overground walking speed (OGWS). Secondary outcome measures included: walking economy, six-minute walk test (6MWT), daily step counts, Walking Index for Spinal Cord Injury (WISCI-II), Dynamic Gait Index (DGI), and Berg Balance Scale (BBS).

Results

Nine participants completed all testing and training. Significant improvements in aerobic capacity (P=0.011), OGWS (P=0.023), the percentage of VO_2peak utilized while walking at self-selected speed (P=0.03), and daily step counts (P=0.025) resulted following training.

Conclusions

The results indicate that total-body, voluntary, progressive AET is safe, feasible, and effective for improving aerobic capacity, walking speed, and select walking-related outcomes in an exclusively ambulatory SCI sample. This study suggests the potential for non-task-specific aerobic exercise to improve walking following incomplete SCI and builds a foundation for further investigation aimed at the development of exercise based rehabilitation strategies to target functionally limiting impairments in ambulatory individuals with chronic SCI.

Energy expenditure and heart rate responses to increased loading in individuals with motor complete spinal cord injury performing body weight-supported exercises

OBJECTIVE

To examine acute metabolic and heart rate responses in individuals with motor complete spinal cord injury (SCI) during stepping and standing with body weight support (BWS).

DESIGN

Cohort study.

SETTING

Therapeutic exercise research laboratory.

PARTICIPANTS

Nonambulatory individuals with chronic, motor complete SCI between T5 and T12 (n=8) and healthy, able-bodied controls (n=8).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Oxygen consumption (V˙o2) and heart rate.

RESULTS

Individuals with motor complete SCI performed standing and stepping exercises in a BWS system with manual assistance of lower body kinematics. V˙o2 and heart rate responses were assessed in relation to level of BWS. Weight support was provided by an overhead lift at high (≥50% BWS) or low (20%-35% BWS) levels during stepping and standing. Although participants with motor complete SCI were unable to stand or step without assistance, levels of V˙o2 and heart rate were elevated by 38% and 37%, respectively, when load was maximized during stepping (ie, low BWS). Participants without an SCI (able-bodied group) had a similar acute response to exercise. None of the participants met the target range for V˙o2 response in any of the tasks. However, stepping was sufficient to enable half of the participants in the SCI group to attain the target range for heart rate response to exercise.

CONCLUSIONS

Individuals with motor complete SCI exhibit cardiovascular responses during body weight-supported exercise. Findings indicate that body weight-supported stepping provides a minimal cardiovascular challenge for individuals with paraplegia. Emphasis on low weight support during locomotor training can trigger additional heart rate adaptations.