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The use of exoskeleton robotic training and bowel/bladder function: A systematic review
, Brian Moriaritya,b, Ashwin Mathewa,b, Jason Noora,b, Het Chavdaa,b, Sudha Ramakrishnana,b, Max Sadlowskia,b, Ioannis Avramisa,b, Joseph Chavarriaa,b, James Rizkallaa,b,
⁎Corresponding author: James Rizkalla. james.rizkalla@bswhealth.org
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Received: ,
Accepted: ,
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.
1 Introduction
Spinal cord injury (SCI) is a life-altering condition with wide-ranging consequences, including persistent impairments in autonomic function. Among the most burdensome of these are neurogenic bowel and bladder dysfunctions, which affect approximately 70–80% of individuals with SCI.1 These complications not only pose medical risks such as infections, incontinence, and constipation, but also contribute significantly to decreased quality of life and psychological distress.2
Conventional management approaches, such as medications, digital stimulation, and transanal irrigation, often provide incomplete relief and may introduce complications with long-term use.3 Consequently, attention has increasingly turned to novel rehabilitative technologies, such as robotic exoskeletons, which offer the dual potential of restoring mobility and improving autonomic regulation.
Robotic exoskeletons have demonstrated promise in facilitating upright posture, ambulation, and improved cardiovascular and musculoskeletal health in individuals with SCI.4,5 Emerging evidence also suggests potential secondary benefits on bowel and bladder function, possibly mediated by improved pelvic floor stimulation, increased abdominal pressure during upright walking, and enhanced autonomic modulation. Juszczak et al. reported that 20% of participants noted improvements in bowel function and 9% in bladder control following regular exoskeleton training sessions.6
However, the literature on this topic remains controversial. Systematic reviews, including one by Tamburella et al. underscore the heterogeneity in study designs, the small sample sizes, and the variability in outcome measures used to assess bowel and bladder function.7 Despite encouraging preliminary findings, definitive conclusions about the efficacy of exoskeleton-assisted rehabilitation in improving autonomic function in SCI patients are yet to be drawn.
This study aims to systematically evaluate the role of robotic exoskeleton usage in bowel and bladder management for individuals with SCI, providing a structured analysis that may help inform clinical guidelines and future rehabilitative strategies.
2 Methods
2.1 Search
This study investigates the role of wearable exoskeletons in improving bowel and bladder function in individuals with spinal cord injuries (SCI). A systematic review was registered with PROSPERO and performed according to PRISMA guidelines using Covidence to screen articles from three electronic databases: Embase, Cochrane Library, and PubMed. Two authors conducted this search, with studies published in English between April 2012 and December 2024 being considered. The search criteria included “exoskeleton”, “bowel”, “bladder”, and “lower motor”, and used Boolean operators for our search protocol. Both authors performed a further review to ensure no relevant articles were excluded. A third author mediated discrepancies in search inclusions. The search was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines (see Flow Chart).
Our inclusion criteria involved original research studies involving adult patients (≥18 years) with SCI who experienced bowel and/or bladder dysfunction (in addition to other extremity weakness) and received interventions using wearable robotic exoskeletons. Studies were excluded if they involved pediatric populations, did not assess bowel/bladder outcomes, or were not original research (e.g., reviews, meta-analyses, protocols).
An initial search yielded 77 articles from Covidence. We initially screened by title and abstract. Of these, 42 studies were excluded: 22 for addressing unrelated endpoints and 20 for being meta-analyses or for incompatible study protocols. Thirty-five studies proceeded to full-text review. An additional 21 studies were excluded for lacking relevant endpoints or failing to meet the inclusion criteria. A total of fourteen studies met all criteria and were included in the final analysis. This process is demonstrated in the PRISMA flowchart.
2.2 Inclusion and exclusion criteria
2.2.1 Inclusion criteria
Studies that measured the effects of exoskeleton systems on bowel/bladder management in SCI were included in this study. We included peer-reviewed studies for which the full text was available for analysis. Our primary endpoints were improvement in bowel/bladder management. We focused on studies that reported Bowel/Bladder Surveys Pre/Post exoskeleton usage. These measures would help determine whether exoskeletons improved bowel/bladder function from the patient's perspective.
2.2.2 Exclusion criteria
Studies that used more than one experimental group were excluded. Studies that did not measure the above functional outcomes were excluded. Studies that had patients with multifactorial injuries were also excluded. We also excluded studies that did not meet our patient population characteristics, including those that did not report bowel/bladder functional outcomes in their experimental groups.
2.3 Data collection
Reviewers extracted data from each study, including bowel and bladder functionality surveys. We collected the type of experimental intervention used, i.e., the kind of exoskeleton and the nature of the control group, such as overground therapy. We collected additional demographic measures, including participants' ages in both the experimental and control groups. Other important measures included sample size, study type, intervention type, control methods, and country of origin. We have displayed this information in the demographics table (Table 1). Regarding the population, the patients were mainly chronic injuries, >6 months, and injuries involving the lower cervical and thoracolumbar levels of injury. Although there was overlap in patient demographics across studies, the studies were heterogeneous overall, with different exoskeleton devices used and varying intervention durations.
| Demographics: | Country | Study Design | Level of Evidence | Age(in years)Mean, (SD), [range] | Sample Size (Male) | Intervention measures | Outcome measure | Course (acute <6 months), (chronic >6 months) | Degree of Injury |
| Juszcak 2018 | USA | Cross-Sectional/Survey-Based Observational Studies | IV | 35 (13) | 45 (37) | Indego Powered Exoskeleton | Self-reported assessments of pain, bowel or bladder function | chronic | T3-L2 |
| Morrison 2018 | USA | Observational Cohort | III | 41 (15) | 69 (49) | Manually assisted locomotor training (LT) | Self-Reported Assessments of Bowel or Bladder Functions | chronic | 50 cervical, 19 thoracic |
| Gorman 2021 | USA | RCT | I | [18-65] | 50 (38) | ReWalk, Ekso | Self-Reported Assessments of Bowel or Bladder Functions | chronic | C1-C8, T1-T12 |
| Brinkemper 2023 | Germany | Cross-Sectional/Survey-Based Observational Studies | IV | 47 (14) | 13 (9) | HAL | Self-Reported Assessments of Bowel or Bladder Functions | 13 acute, 22 chronic | thoracolumbar |
| Kim 2021 | South Korea | Non-Randomized Interventional | IV | 48 [35-63] | 10 (7) | H-MEX | Self-Reported Assessments of Bowel or Bladder Functions | chronic | C6-L1, one cervical level |
| Chun 2020 | USA | Observational Cohort | III | 48 [38-63] | 10(9) | Rewalk | Self-Reported Assessments of Bowel or Bladder Functions | chronic | T2-T11 |
| Williams 2021 | Canada | RCT | I | 32 [24-49] | 4(4) | EKSO, Lokomat | Self-Reported Assessments of Bowel or Bladder Functions | chronic | cervical and thoracic |
| vanNes 2024 | Netherlands | Non-Randomized Interventional | IV | 36-median [24-57] | 21 (13) | ReWalk | Self-Reported Assessments of Bowel or Bladder Functions | chronic | T1-L1 |
| Hu 2024 | China | RCT | I | [20-60] | 8 (−) | AIDER | Self-Reported Assessments of Bowel or Bladder Functions | acute | T2-L1 |
| Kerdraon 2021 | France | Observational Cohort | III | 34(9) | 11 (9) | Atalantae | Self-Reported Assessments of Bowel or Bladder Functions | chronic | T5-T12 |
| Baunsgaard 2018 | Denmark | Observational Cohort | III | 35.8, median [27.5-52.6], IQR | 52 (36) | Ekso | Self-Reported Assessments of Bowel or Bladder Functions | 25 acute, 27 chronic | cervical (C1-C8, motor incomplete), (C7-C8 motor complete). Thoracolumbar (T1-L2) |
| Sale 2018 | Italy | Non-Randomized Interventional, Quasi-experimental | II | 43 [21-67] | 8(6) | Ekso | Self-Reported Assessments of Bowel or Bladder Functions | chronic | C7-L2 |
| Esquenazi 2012 | USA | Non-Randomized Interventional | IV | 38 [18-55] | 12 (8) | ReWalk | Self-Reported Assessments of Bowel or Bladder Functions | chronic | C7 - T12 |
| Zeilig 2012 | Israel | Case Series | IV | 33 [25-48] | 6(6) | ReWalk | Self-Reported Assessments of Bowel or Bladder Functions | chronic | T5-T12 |
Outcome variables/Measured: The primary outcomes of interest were bowel quality surveys and bladder quality surveys.
2.4 Quality assessment
To assess article quality, two reviewers applied the ROBINS-I criteria to assess risk of bias. The risk of bias for the articles is shown in Fig. 1. We have also conducted a GRADE assessment to further evaluate the quality of the studies' responses. Fig. 2.1-2.2 for bowel GRADE and Fig. 3.1-3.2 for bladder GRADE.
The table indicated that all articles used had some degree of bias; however, none showed extreme bias when our reviewers appraised them.
2.5 Statistical analysis
We conducted a cumulative analysis to provide an overview of exoskeleton use and autonomic functioning. The primary outcomes for measurement were survey reports on bowel/bladder impact after exoskeleton use. We collected the data from the 14 articles. We used R to fit a random-effects model for proportions. We used a p-value of <0.05 and a 95% confidence interval. See Fig. 4.1-4.3 for Bowel Random Forest Plots and Fig. 6.1-6.3 for Bladder Random Forest Plots.
3 Results
3.1 Study characteristics
A table that provides supplementary information on the scoring type, exoskeleton used, number of participants, average age, country of origin, and the number of male/female participants.
3.2 Bowel results
Thirteen studies have reported bowel outcomes using surveys, involving a total of 269 patients. Based on cumulative data on qualitative bowel outcomes, there seems to be a beneficial aspect, at least for a subset of the population. (Fig. 5). Furthermore, this is demonstrated by the random-effects model of proportions used in our meta-analysis. This model was based on patient-reported outcomes for bowel function. Fig. 4.1-4.3. A significant proportion of participants had either beneficial or neutral outcomes in bowel management after exoskeleton use.
3.3 Bladder results
Six studies examined bladder function using surveys, involving a total of 157 patients. Based on cumulative data on qualitative bladder outcomes, there appears to be a benefit, at least for a subset of the population. (Fig. 7). Furthermore, this is demonstrated by the random-effects model of proportions used in our meta-analysis. This model was based on patient-reported outcomes for bladder function. Fig. 6.1-6.3. A significant proportion of participants had either beneficial or neutral outcomes in bladder management after exoskeleton use.
3.4 Conclusions from studies
Based on the study conclusions included in this systematic review, current evidence from these pilot studies and clinical trials suggests that exoskeleton-assisted walking (EAW) offers potential benefits for bowel and bladder management in individuals with spinal cord injury (SCI). However, the effects are modest and variable. Improvements in bowel functions, such as reduced evacuation time, normalisation of stool consistency, and subjective satisfaction, were observed across several studies, particularly in individuals with motor-complete injuries and those participating in longer, high-frequency training programs. While bladder outcomes were less consistent, some users reported reduced urinary incontinence and improved satisfaction with bladder care. In addition to these functional gains, EAW consistently demonstrated reductions in spasticity, improved user tolerance and efficiency, and potential enhancements in secondary health outcomes that may facilitate greater community participation. However, limitations including small sample sizes, short intervention durations, and reliance on subjective measures underscore the need for larger, long-term studies. Overall, these findings support the therapeutic potential of EAW as part of comprehensive neurorehabilitation strategies to improve autonomic function and quality of life in the SCI population.
4 Discussion
This systematic review highlights the emerging role of exoskeleton-assisted devices in addressing bowel and bladder dysfunction in individuals with spinal cord injury (SCI). While improvements in mobility and musculoskeletal health have been shown to benefit from robotic rehabilitation, the potential for exoskeletons to influence autonomic function, particularly bowel and bladder control, represents an important and increasingly relevant area of interest. Across the studies included in this analysis, bowel-related outcomes were more consistently reported and showed a modest but encouraging trend toward improvement. Bladder outcomes may have potential for improvement; however, more exploration is needed, as the reported outcomes were less robust and variable.
Bowel-related improvements were documented across multiple study designs, with several investigations demonstrating shorter evacuation times, more regular stool consistency, and increased satisfaction with bowel routines. Chun et al. (2020) reported that 50–80% of participants experienced improvements in bowel function, including increased bowel movement frequency. Brinkemper et al. (2023) similarly found significant reductions in the Wexner Incontinence Score among chronic SCI patients. They noted additional improvements in bowel satisfaction with constipation, using the Cleveland Clinic Constipation Scoring System. Improvements in stool consistency were also frequently reported; for example, Chun et al. (2020) observed that 8 of 10 participants had better stool consistency and 7/10 reported better bowel function relating to quality of life following exoskeleton training.
In a three-centre crossover randomised controlled trial, Gorman et al. (2021) reported that 24% of participants. Hu et al. (2024) reported improvements in bowel management, including decreased enema use and increased bowel movement frequency, after 8 weeks of exoskeleton-assisted walking. Additionally, Hu et al. demonstrated alterations in gut microbiota composition following training, suggesting a potential mechanistic link between exoskeleton-assisted locomotion and the brain-gut axis.
Individuals with motor-complete injuries may get more benefit. Across several studies (Brinkemper et al., 2023; Chun et al., 2020; Gorman et al., 2021), participants with more severe baseline bowel dysfunction tended to exhibit greater improvements. This is consistent with the hypothesis that exoskeleton-assisted walking can provide autonomic stimulation for bowel and bladder management in individuals with severe injuries.
By contrast, bladder outcomes were less consistent and generally weaker across studies. Brinkemper et al. (2023) reported subjective improvements in bladder sensation and incontinence in approximately 23% of acute patients and 31% of chronic patients. In addition, Juszczak et al. (2018) found that 9% of individuals noted improved bladder control with no reports of deterioration. Early work by Esquenazi et al. (2012) also documented improvements in bladder functioning.
Secondary benefits that may indirectly support autonomic improvements were widely reported. Several studies reported reduced spasticity following exoskeleton use (Baunsgaard et al., 2018; Juszczak et al., 2018; Morrison et al., 2018), with improvements in balance and user confidence also common. These factors can facilitate greater consistency in physical activity engagement and may contribute to downstream autonomic regulation.
Despite these encouraging findings, the available literature has several limitations. Across studies, sample sizes were small, follow-up periods were short, and nearly all outcomes were self-reported, particularly for bowel and bladder function. Heterogeneity in device type, training protocol, and measurement tools further complicates cross-study comparison. Importantly, no study consistently employed validated autonomic outcome measures such as the Neurogenic Bowel Dysfunction Score or standardised urodynamic testing.
Taken together, the evidence synthesised here suggests that exoskeleton-assisted walking holds promise as a therapeutic modality for improving bowel and, to a lesser degree, bladder function in individuals with SCI. Although the findings predominantly originate from small-scale, heterogeneous studies, the consistency of bowel-related improvements across multiple exoskeleton platforms and training paradigms is noteworthy. Integrating exoskeleton-based interventions into broader neurorehabilitation frameworks may provide additional autonomic benefits, particularly for individuals with chronic immobility and persistent autonomic dysfunction.
Future research should employ larger randomised controlled trials with standardised autonomic outcome measures, more extended follow-up periods, and diverse participant populations. Mechanistic studies, including those examining microbiome modulation, colonic motility, and autonomic neural pathways, are also needed to clarify how exoskeleton-assisted walking may influence bowel and bladder function. Strengthening methodological rigour will be essential for determining the long-term impact of exoskeletons on autonomic recovery and overall quality of life for individuals living with SCI.
5 Conclusion
This review suggests that exoskeleton-assisted devices may offer more than just mobility gains for individuals with spinal cord injury (SCI); they may also support improvements in bowel and, to a lesser extent, bladder function. While bowel-related outcomes, such as reduced evacuation time, improved consistency, and greater patient satisfaction, were the most consistently reported benefits, bladder outcomes were less clear and varied across studies. Still, some participants did report positive changes in continence and overall management. These findings, particularly among individuals with motor-complete injuries and those participating in higher-frequency or longer-duration training, point to a meaningful therapeutic potential. However, the current evidence base is limited by small sample sizes, short follow-up durations, and a lack of standardised autonomic outcome measures. Looking ahead, more robust, long-term studies are needed to understand better how exoskeleton devices might be integrated into everyday rehabilitation and whether their benefits for bowel and bladder function can translate into lasting improvements in independence and quality of life. Furthermore, with further research supporting exoskeleton use and its positive impact on bowel and bladder function, it can significantly improve the quality of life for patients with SCI, as rehab can incorporate these devices that offer additional bowel and bladder benefits.
Ethical statement
None.
Patients consent
None.
Credit author statement
Thomas Jacob: Conceptualization, Data Curation, Formal Analysis, Investigation, Methodology, Writing Original Draft, Writing-Review and Editing.
Ashwin Matthew: Data Curation, Formal Analysis.
Jason Noor: Data Curation.
Het Chavda: Data Curation.
Max Sadlowski: Data Curation.
Sudha Ramakrishnan: Data Curation.
Dr. Brian Moriarity: Writing Original Draft, Writing-Review and Editing.
Dr. James Rizkalla: Project Administration, Conceptualization, Writing -Review and Editing, Supervision.
Dr. Ioannis Avramis: Project Administration, Supervision.
Dr. Joseph Chavarria: Project Administration, Supervision.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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