Volume 98, December 2025, Pages 234-238Author links open overlay panel, , , AbstractBackground

Transcutaneous Electrical Nerve Stimulation (TENS) is established for chronic lower back pain but less studied in acute settings. This study evaluated the efficacy of cross-channel TENS for acute lower back pain in the emergency department (ED).

Methods

This single-blinded, randomized controlled trial enrolled ED patients aged 18–59 with acute lower back pain and Emergency Severity Index scores of 4 or 5. Participants were randomized to receive either active or placebo cross-channel TENS. The primary outcome was change in pain scores on a 100 mm visual analog scale (VAS) after 30 min of treatment. A clinically meaningful difference was defined as ≥13 mm. Secondary outcomes included the proportion of patients with clinically significant improvement, patient satisfaction (0–10 scale), and placebo effect assessment. Power analysis was based on a standard deviation of 15 mm, requiring a sample size of 42.

Results

Forty-two subjects completed the study (22 active, 20 placebo). Median pain reduction was 17 mm (IQR 6–29.5) in the active group and 5.5 mm (IQR 1.75–18.25) in the placebo group (difference: 11.5 mm; P = .06). Clinically significant improvement occurred in 68 % of the active group vs. 30 % of the placebo group (P = .03). Median satisfaction was 8 in both groups (P = .81).

Conclusions

Although overall pain reduction was not statistically significant between groups, a higher proportion of patients receiving active TENS achieved clinically meaningful relief. Patient satisfaction was high in both groups. Cross-channel TENS may be a useful adjunct in managing acute lower back pain in lower acuity ED patients. Future studies should explore TENS impact on length of stay and broader ED applications.

Section snippetsBackground

Acute lower back pain remains one of the most common reasons for emergency department (ED) visits globally and is a leading contributor to short-term disability [[1], [2], [3], [4]]. These encounters contribute substantially to healthcare utilization and costs, especially among working-age adults. Amid growing concerns over opioid overuse and the limited long-term efficacy of conventional pharmacologic treatments, clinical guidelines increasingly endorse nonpharmacologic strategies for pain

Study design and oversight

This was a single-center, prospective, single-blinded, randomized controlled trial conducted in the ED of a U.S. military treatment facility. The primary objective was to assess whether active cross-channel TENS led to greater reductions in acute lower back pain compared with placebo TENS immediately following a 30-min treatment session.

This study's protocol (#C.2020.144d) was approved by the Department of Defense Regional Health Command-Central Institutional Review Board in accordance with

Results

Between April 1 and May 15, 2023, 42 participants were enrolled and randomized into either the active TENS group (n = 22) or the placebo TENS group (n = 20). No participants withdrew, and all completed the assigned intervention. Baseline characteristics were similar across groups; Table 1 contains further demographic data of the patient population.

The primary outcome was the change in pain scores as measured on a 100-mm VAS before and after the 30-min TENS application. Table 2 and Fig. 3 show

Discussion

In this single-blinded, randomized controlled trial of adult patients presenting to a military ED with acute lower back pain, application of cross-channel TENS did not yield a statistically significant difference in pain reduction compared to placebo. However, a greater proportion of participants in the active TENS group achieved a clinically meaningful reduction in pain, suggesting a potential therapeutic benefit in this population. Specifically, 68 % of participants in the active group

Conclusions

A higher proportion of patients receiving active TENS achieved statistically significant and clinically meaningful relief. However, when comparing the amount of pain reduction between the active and placebo TENS groups, there was not a significant difference. Both active and placebo groups reported high satisfaction. Cross-channel TENS may serve as a useful adjunct for acute lower back pain management in low-acuity ED settings, warranting further study in larger, more diverse populations.

CRediT authorship contribution statement

Brian J. Ahern: Writing – review & editing, Writing – original draft, Methodology, Investigation, Formal analysis, Data curation. Cheryl L. Miller: Writing – review & editing, Writing – original draft, Visualization, Validation, Formal analysis. Joshua B. Somma: Writing – review & editing, Writing – original draft, Visualization, Validation, Resources, Methodology, Investigation, Formal analysis, Data curation. Daniel Mackey: Writing – review & editing, Writing – original draft, Supervision,

Declaration of competing interest

The views expressed in this publication are those of the authors and do not reflect the official policy or position of William Beaumont Army Medical Center, Department of the Army, Defense Health Agency, or the US Government.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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