# Transcranial direct current stimulation combined with exercise therapy for chronic low back pain: a systematic review and meta-analysis

## TL;DR

Combining transcranial direct current stimulation with exercise therapy modestly reduces chronic low back pain, but more research is needed to confirm and optimize this approach.

## Contribution

This study provides the first meta-analysis on the additive effects of tDCS and exercise for chronic low back pain.

## Key findings

- tDCS combined with exercise significantly reduced pain intensity in adults with chronic low back pain.
- Functional improvements were not statistically significant, but longer intervention duration may enhance outcomes.
- Certainty of evidence was moderate for pain and low for function based on GRADE assessment.

## Abstract

Chronic low-back pain (CLBP) is a leading cause of disability, with current treatments offering only modest benefits. Transcranial direct-current stimulation (tDCS) may enhance exercise therapy by modulating cortical excitability and pain-inhibitory pathways. This systematic review and meta-analysis quantified the additive effect of combining tDCS with structured exercise in adults with CLBP.

We searched PubMed, Web of Science, CENTRAL, Embase, and CNKI up to 25 September 2025. Randomized controlled trials (RCTs) comparing active tDCS plus identical exercise therapy vs. sham tDCS plus the same exercise in adults with CLBP (≥ 12 weeks) were included. Risk of bias was assessed using Cochrane RoB 2.0. Weighted mean difference (WMD) and standardized mean difference (SMD) were calculated for pain and function, respectively.

GRADE was used to assess certainty.

Five RCTs (n = 195) were included. For pain intensity (4 studies, n = 173), tDCS showed a significant additive effect (WMD = −0.99, 95% CI: −1.68 to −0.31, p = 0.006, I2 = 60.1%). For physical function (five studies, n = 195), the effect was favorable but non-significant (SMD = −0.65, 95% CI: −1.87 to 0.57, p = 0.28, I2 = 90.7%). Meta-regression indicated intervention duration significantly moderated functional outcomes (β = 0.56, p < 0.001). GRADE certainty was moderate for pain and low for function.

Anodal tDCS combined with exercise provides a modest but significant additional reduction in pain intensity for CLBP. Longer intervention duration may enhance functional outcomes. Clinical significance should be interpreted cautiously. Larger, well-designed trials are needed to confirm these findings and optimize stimulation parameters.

https://www.crd.york.ac.uk/PROSPERO/view/CRD420251151315, identifier CRD420251151315.