JMIR Publications

ABSTRACT

Background:

Spinal cord injury (SCI) affects millions of people worldwide and often results in impaired lower limb function and reduced mobility. Transcutaneous spinal cord stimulation (tSCS) has emerged as a promising neuromodulation technique that shows potential for enhancing motor recovery and walking ability in individuals with SCI. However, the effectiveness of tSCS for lower limb rehabilitation in this population remains unclear due to limited evidence from small sample sizes, heterogeneous protocols, and lack of long-term follow-up data.

Objective:

The primary objective of this systematic review and meta-analysis is to determine the effectiveness of tSCS, compared to sham stimulation, no intervention, or other active interventions, for improving lower limb motor function in individuals with SCI. Secondary objectives are to evaluate the effects of tSCS on walking ability (including speed, distance, and independence), spasticity, quality of life, and safety outcomes.

Methods:

This systematic review will be conducted according to the Cochrane Handbook for Systematic Reviews of Interventions and reported following the PRISMA 2020 statement. We will search electronic databases (PubMed, Web of Science, Embase, CINAHL, MEDLINE, Cochrane Library, PEDro, and Scopus) from inception to August 2025, along with grey literature, trial registries, and hand-searching of key journals. We will include randomized controlled trials, quasi-RCTs, and non-randomized studies (case series with ≥5 participants) that evaluate the effects of tSCS applied over the spinal region on lower limb rehabilitation outcomes in adults with traumatic or non-traumatic SCI. The primary outcome will be lower limb motor function assessed by validated measures such as the Lower Extremity Motor Score (LEMS). Secondary outcomes will include walking ability, balance, functional independence, spasticity, quality of life, and adverse events. Two reviewers will independently screen studies, extract data, and assess risk of bias using the RoB 2 and ROBINS-I tools. Data will be synthesized using random-effects meta-analysis if appropriate, with planned subgroup analyses examining injury level (cervical vs. thoracic vs. lumbosacral), injury completeness (AIS A vs. B-D), stimulation site (cervical vs. thoracic vs. lumbosacral), and co-intervention effects (tSCS alone vs. tSCS plus training), along with sensitivity analyses to explore heterogeneity. The certainty of evidence will be evaluated using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation).

Results:

This is a protocol paper describing the planned methodology for the systematic review. The search strategy has been developed and the protocol has been registered with PROSPERO (CRD420250652270), with results expected by October 2025.

Conclusions:

This comprehensive systematic review and meta-analysis will address an important gap in the current literature by providing the first focused evaluation of tSCS effectiveness for lower limb rehabilitation in individuals with SCI. The results will inform clinical practice guidelines and guide future research directions in tSCS for SCI rehabilitation. Clinical Trial: Prospero CRD420250652270