Transcutaneous spinal cord stimulation for motor function and functional independence in patients with spinal cord injury: a systematic review.
TL;DR
Current evidence is insufficient to support the definitive efficacy of tSCS in individuals with SCI, and the findings suggest that tSCS may have beneficial effects on upper limb motor function as well as balance and postural control.
Abstract
Background
Spinal cord injury (SCI) can lead to severe impairments in motor, sensory, and autonomic functions, significantly affecting patients' functional independence and quality of life. Transcutaneous spinal cord stimulation (tSCS), as an emerging non-invasive neuromodulation technique, has shown potential in improving motor function. However, existing studies demonstrate substantial heterogeneity, and its clinical efficacy remains unclear.
Objective
To systematically evaluate the effects of tSCS on motor function and functional independence in individuals with SCI, and to explore the potential influence of patient characteristics and stimulation parameters on treatment outcomes.
Methods
A systematic search of PubMed, Web of Science, Cochrane Library, Embase, and Scopus was conducted from database inception to March 23, 2026. Eligible studies included randomized controlled trials (RCTs), non-randomized studies, and case series. Methodological quality was assessed using the revised Cochrane Risk of Bias tool (RoB 2) for RCTs, the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool, and the Joanna Briggs Institute (JBI) critical appraisal checklist for case series. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence. This review was registered in PROSPERO (registration number: CRD420251106919).
Results
A total of 25 studies (n = 353) were included, comprising 9 RCTs, 10 non-randomized studies, and 6 case series. Due to substantial heterogeneity in study design, patient characteristics, and intervention parameters, a qualitative synthesis was performed. The findings suggest that tSCS may have beneficial effects on upper limb motor function as well as balance and postural control. However, no consistent or stable improvements were observed in lower limb motor function, walking ability, functional independence, spasticity, or quality of life. According to the GRADE assessment, the overall certainty of evidence was very low. In terms of safety, tSCS was well tolerated, with no serious adverse events reported.
Conclusion
Current evidence is insufficient to support the definitive efficacy of tSCS in individuals with SCI. Although potential benefits have been observed in certain functional domains, the robustness of the evidence is limited by small sample sizes, methodological limitations, and substantial heterogeneity across studies. High-quality randomized controlled trials are needed to further establish its clinical effectiveness.