Pulsed Electromagnetic Fields for Foot and Ankle CRPS — Do They Really Help?

Polish version: Pola elektromagnetyczne w CRPS stopy — czy naprawdę pomagają?

A randomized trial published on 9 September 2026 provides a positive signal for one specific pulsed electromagnetic field (PEMF) protocol used as an adjunct to exercise in patients with complex regional pain syndrome type I (CRPS-I) affecting the foot or ankle. Pain and functional scores were better in the PEMF group than with exercise alone through 12 months. The trial, however, included only 32 patients, used no sham procedure and no blinding, and enrolled patients after previous neridronate treatment. The device was supplied by its manufacturer, which also covered the publication fee, and two co-authors were employed by the company. The result is therefore interesting, but not strong enough to establish PEMF as a new standard treatment for CRPS.

Why is this study of interest?

CRPS-I remains one of the more difficult problems after limb injury or surgery. The clinical picture may include pain that is disproportionate to the original event, swelling, sensory disturbance, vasomotor and sweating abnormalities, and progressive loss of function. Treatment is usually multimodal, while the quality of evidence supporting many physical modalities remains low.

PEMF is not a new concept in CRPS. Earlier studies were small and did not show a convincing clinical effect. A positive randomized trial focused specifically on the foot and ankle, with follow-up extending to one year, therefore deserves attention—particularly because an earlier randomized study in hand CRPS-I found no added benefit from PEMF beyond rehabilitation.

Study question and methods

Covelli and colleagues enrolled 32 adults with CRPS-I of the foot or ankle. All had previously received an initial course of intravenous neridronate. Patients were then randomized to one of two strategies:

• PEMF at 1.5 mT and 75 Hz for 4 hours per day for 60 days, together with exercise for 30 minutes per day for 6 weeks,
• the same exercise program alone.

Assessments were performed at 3, 6 and 12 months. Outcomes included pain on a visual analogue scale (VAS), the AOFAS Ankle-Hindfoot score, allodynia and hyperalgesia, pain during passive movement, swelling, the Roles and Maudsley score, and use of non-steroidal anti-inflammatory drugs.

The public trial registry describes a parallel randomized design without blinding. No sham device was used, so the specific effect of electromagnetic stimulation could not be separated from expectation effects associated with receiving an additional treatment.

Results

Pain decreased and AOFAS scores improved from baseline in both groups at every follow-up point. The investigators also reported statistically significant advantages for PEMF over control at 3, 6 and 12 months for both VAS pain and AOFAS scores.

Resolution of allodynia, hyperalgesia and pain during passive movement was also more frequent in the PEMF group. At 3 months, non-steroidal anti-inflammatory drug use was lower, while Roles and Maudsley scores were more favorable at 6 and 12 months.

These findings are encouraging, but statistical significance alone does not show how large a benefit patients actually experienced. In such a small trial, absolute between-group differences, their uncertainty and their relationship to a clinically important change are particularly relevant. The result should not be reduced to the simple statement that “PEMF works for CRPS.”

Clinical interpretation for an orthopaedic surgeon

The persistence of the signal through 12 months is the most notable finding. If confirmed in a larger sham-controlled trial, it could suggest that a defined PEMF protocol may be a useful adjunct to rehabilitation in selected patients with lower-limb CRPS-I.

The scope of that conclusion must remain narrow. The study evaluated specific device parameters, a specific anatomical distribution of CRPS, and patients who had already received neridronate. The findings cannot automatically be generalized to other PEMF devices, other field strengths or frequencies, upper-limb CRPS, CRPS type II, or treatment without concurrent rehabilitation.

This distinction matters because a 2022 randomized trial by Cömertoğlu and colleagues involving 32 people with hand CRPS-I found no additional benefit from PEMF over a conventional rehabilitation program for any assessed outcome. The protocols differed in field parameters, anatomical site and treatment duration, so that earlier study does not directly contradict the new result. It does, however, show that efficacy has not been established for PEMF devices as a class.

Key limitations

• Very small sample: 32 patients can generate a clinically interesting signal, but this is not enough for a stable estimate of efficacy and safety across the heterogeneous CRPS population.
• No blinding or sham treatment: the experimental group received an obvious additional intervention, while several outcomes were subjective.
• Selected population: all patients had previously received neridronate, limiting generalizability to other treatment pathways.
• Intensive protocol: 4 hours of treatment every day for 60 days may be difficult to reproduce in routine practice and makes adherence an important issue.
• Multiple outcomes: with few participants and numerous comparisons, the risk of overinterpreting isolated positive findings increases.
• Manufacturer relationship: IGEA supplied the devices and funded the publication fee; two co-authors were company employees. The authors declared no conflict of interest, but these relationships should still be considered when interpreting the findings.

What could this change in practice—and what does it not prove?

At present, the study primarily supports the need for a larger multicenter trial with sham treatment, blinded outcome assessment and a prespecified minimal clinically important difference. Future studies should also examine CRPS duration, the precipitating event, previous treatment and actual exposure to PEMF separately.

The trial does not show that PEMF should enter routine CRPS care, does not establish a class effect irrespective of device parameters, and does not justify replacing early diagnosis, graded limb use, functional rehabilitation or multidisciplinary pain management. It is best viewed as a positive signal that requires independent confirmation in an area where previous evidence has been uncertain or negative.

References

1. Covelli I, Setti S, De Terlizzi F, et al. Pulsed electromagnetic fields (PEMFs) in complex regional pain syndrome type I (CRPS-I) of the foot: a randomised controlled trial. J Orthop Traumatol. Published 9 September 2026. DOI: 10.1186/s10195-026-00966-y.
2. Cömertoğlu İ, Güneş S, Elhan AH, Üstüner E, Kutlay Ş, Küçükdeveci AA. Effectiveness of pulsed electromagnetic field therapy in the management of complex regional pain syndrome type 1: A randomized-controlled trial. Turk J Phys Med Rehabil. 2022;68(1):107–116. DOI: 10.5606/tftrd.2022.9074.
3. Smart KM, Ferraro MC, Wand BM, O’Connell NE. Physiotherapy for pain and disability in adults with complex regional pain syndrome (CRPS) types I and II. Cochrane Database Syst Rev. 2022;5:CD010853. DOI: 10.1002/14651858.CD010853.pub3.

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Content prepared by: Tomasz Poboży - orthopaedic surgeon.