A recent investigation published in JAMA Network Open demonstrates that integrating transcutaneous electrical nerve stimulation (TENS) with standard physical therapy significantly reduces movement-evoked pain and fatigue in patients with fibromyalgia. Led by Kathleen A. Sluka, PT, PhD, FAPTA, professor of physical therapy and rehabilitation science at the University of Iowa Carver College of Medicine, alongside colleagues across 28 outpatient clinics in six health systems, the pragmatic trial evaluated the clinical utility of non-pharmacologic nerve stimulation in a real-world setting.
Clinical Trial Methodology and Cohort Characteristics
The multi-center study accrued participants between February 1, 2021, and September 31, 2024. A total of 459 patients with fibromyalgia were randomly assigned to either physical therapy combined with daily TENS or physical therapy alone. Data from 384 participants (mean age, 53 years; standard deviation, 15) were evaluated in the final analysis, comprising 191 individuals in the TENS cohort and 193 in the control cohort. Participants in the control arm crossed over to receive TENS following day 60 during a trial extension phase.
The intervention protocol required participants to apply TENS to the upper and lower back for two hours daily. The stimulation parameters utilized a modulating frequency of “2 to 125 Hz for 100 to 180 microseconds at a strong but comfortable intensity.”
| Parameter | TENS + Physical Therapy Group | Physical Therapy Only Group |
| Analyzed Cohort Size ($N$) | 191 | 193 |
| Mean Age (Years) | 53 (SD, 15) | 53 (SD, 15) |
| Daily Application Protocol | 2 hours daily (Upper/lower back) | Standard physical therapy only |
| Day 60 Movement-Evoked Pain Difference | Group mean difference, 1.2 ($95\% \text{ CI}, 1.6 \text{ to } 0.7$; $d=0.46$) | Reference baseline |
| Patient Global Impression of Change Improvement | 72% reporting improvement | 51% reporting improvement |
| Responder Analysis ($\ge 30\%$ pain reduction) | 41% of participants | 13% of participants ($P < .001$) |
| Day 180 Adherence & Utility | 81% found helpful; 55% used daily | Crossover phase initiated |
Trial Results and Secondary Outcomes
At the 60-day assessment, patients in the TENS group demonstrated marked improvements in movement-evoked pain compared to those receiving physical therapy alone. Furthermore, responder analyses indicated that 41% of participants in the TENS group achieved a $30\%$ or greater reduction in movement-evoked pain, compared to only $13\%$ in the control group ($P < .001$). Improvements were also observed in resting pain and overall fatigue metrics. No serious adverse events were reported throughout the study period.
Investigator Insights and Rationale
Addressing the rationale behind the study during an interview, Dr. Sluka explained:
“Fibromyalgia is associated with movement pain. This interferes with participation in exercise programs, which we know are the primary treatment in fibromyalgia. It also stops people from doing daily activities.”
She further elaborated on the neurobiological mechanisms targeted by the intervention:
“We also know that fibromyalgia is associated with increased excitability in the nervous system and a loss of ability for the nervous system to inhibit pain. TENS reduces movement-evoked pain, one of the few treatments that directly targets this. TENS also increases pain inhibition in the nervous system and reduces excitability in the nervous system.”
Discussing the broader clinical implications of non-pharmacologic modalities, Dr. Sluka noted:
“People with all types of chronic pain, including fibromyalgia, need a variety of safe and effective treatments to help manage their pain. Non-drug treatments like TENS provide additional options for people. Drugs all come with side effects, some worse than others. Treatments like TENS and other non-drug treatments have minimal side effects that are all quite minor, making them incredibly safe.”
Expert Perspective in Rheumatology
Evaluating the trial within the context of contemporary rheumatology, Leonard H. Calabrese, DO, professor of medicine at the Cleveland Clinic Lerner College of Medicine, noted that noninvasive bioelectric and neurostimulation strategies represent a potential paradigm shift. While acknowledging that emerging technologies like vagal nerve stimulation face ongoing debate and varied clinical adoption rates, Dr. Calabrese emphasized that empirical validation of outpatient, noninvasive modalities such as TENS offers a vital pathway to managing complex chronic pain and systemic fatigue without pharmaceutical burdens.
Zero-CLS Interactive Widget Code for WordPress (Soledad Theme)
To prevent Cumulative Layout Shift (CLS) on WordPress sites utilizing the Soledad theme, the widget container below employs explicit CSS containment and a fixed minimum height.
HTML
<div class="tens-fibro-calculator-wrapper" style="contain: layout size style; min-height: 440px; width: 100%; box-sizing: border-box;">
<div id="tensCalculator" class="soledad-custom-widget" style="background: #ffffff; border: 1px solid #dcdcdc; padding: 24px; border-radius: 8px; box-shadow: 0 4px 6px rgba(0,0,0,0.02);">
<h3 style="margin-top: 0; font-size: 18px; color: #111; font-weight: 700;">TENS Therapy Response Estimator</h3>
<p style="font-size: 14px; color: #555; line-height: 1.5;">Estimate clinical response probabilities for fibromyalgia patients integrating daily TENS with physical therapy based on trial outcomes.</p>
<div style="margin-bottom: 15px;">
<label for="cohortSizeInput" style="display: block; font-weight: 600; font-size: 13px; color: #333; margin-bottom: 6px;">Total Patient Cohort Size:</label>
<input type="number" id="cohortSizeInput" value="100" style="width: 100%; padding: 10px; box-sizing: border-box; border: 1px solid #ccc; border-radius: 4px; font-size: 14px;" />
</div>
<button onclick="calculateTensOutcomes()" style="background: #0056b3; color: #fff; border: none; padding: 10px 18px; border-radius: 4px; cursor: pointer; font-weight: 600; font-size: 14px;">Calculate Projected Responders</button>
<div id="widgetOutputArea" style="margin-top: 20px; font-size: 14px; color: #222; min-height: 60px; line-height: 1.6;">
<em>Enter a patient population size above to calculate expected clinical responders.</em>
</div>
</div>
</div>
<script>
function calculateTensOutcomes() {
const cohort = parseInt(document.getElementById('cohortSizeInput').value) || 0;
const pgiImproved = Math.round(cohort * 0.72);
const strictResponders = Math.round(cohort * 0.41);
document.getElementById('widgetOutputArea').innerHTML = `
<strong>Projected Clinical Outcomes for ${cohort} Patients:</strong><br>
โข Patient Global Impression of Change (PGI-C) Improvement (~72%): <strong>${pgiImproved} patients</strong><br>
โข $\ge 30\%$ Movement-Evoked Pain Reduction (~41%): <strong>${strictResponders} patients</strong>
`;
}
</script>
Zero-CLS Clinical Trial Summary HTML Code
HTML
<div class="clinical-trial-summary-box" style="contain: layout size style; min-height: 320px; width: 100%; font-family: inherit; border-left: 4px solid #0056b3; background: #fdfdfd; padding: 22px; box-shadow: 0 2px 5px rgba(0,0,0,0.04); box-sizing: border-box;">
<h4 style="margin: 0 0 12px 0; font-size: 18px; color: #1a1a1a; font-weight: 700;">Trial Design & Key Takeaways Summary</h4>
<ul style="margin: 0; padding-left: 20px; font-size: 14px; color: #333; line-height: 1.7;">
<li><strong>Study Design:</strong> Pragmatic, multi-center randomized trial across 28 outpatient clinics in 6 health systems.</li>
<li><strong>Intervention Protocol:</strong> Transcutaneous electrical nerve stimulation (TENS) applied to the upper and lower back for 2 hours daily during physical activity.</li>
<li><strong>Primary Finding:</strong> Significant reduction in movement-evoked pain at day 60 compared to physical therapy alone ($d = 0.46$).</li>
<li><strong>Responder Rate:</strong> 41% of the TENS group achieved $\ge 30\%$ pain reduction vs. 13% in controls ($P < .001$).</li>
<li><strong>Long-Term Adherence:</strong> At 180 days, 81% of participants reported TENS was helpful, with 55% maintaining daily use and no serious adverse events recorded.</li>
</ul>
</div>
