CRPS: What the Evidence Says
— and Why It Says No to PEMF.

August 2026 · 11 min read · Clinical Evidence Review

The Short Answer

PEMF is not indicated for Complex Regional Pain Syndrome. A Cochrane systematic review covering 18 randomised controlled trials and 739 participants states explicitly that there is low to very-low quality evidence that pulsed electromagnetic field therapy, compared with placebo, is not effective for treating short-term pain in CRPS Type I (PubMed 26905470). The only randomised controlled trial that tested the question directly — 32 patients with CRPS-I of the hand — found that adding PEMF to a conventional rehabilitation programme produced no additional benefit in pain, grip strength, oedema, dexterity or hand function, at the end of therapy or at one-month follow-up (PubMed 35949961).

We publish this because the patients are already in the clinic. CRPS develops after a fracture, sprain or surgery — which means the person sitting in front of a physiotherapist with "stubborn post-fracture pain" is the person at risk. The clinically and commercially valuable skill here is recognition, not treatment.

What Is CRPS?

Complex Regional Pain Syndrome is severe, persistent pain in one limb that is out of proportion in intensity and duration to the injury that triggered it. It usually follows a fracture, sprain or surgery, and sometimes only a minor injury. It is described as arising from a maladaptive pro-inflammatory response, disturbed sympathetically-mediated vasomotor control, and maladaptive peripheral and central neuronal plasticity.

Two types, and the old names are still in circulation. CRPS Type I (the common form) has no identifiable nerve lesion and was previously called Reflex Sympathetic Dystrophy or algodystrophy. CRPS Type II involves a confirmed nerve lesion and was previously called causalgia. The distinction matters for one blunt reason: the entire rehabilitation evidence base concerns Type I only — in the Cochrane review, no trial in CRPS Type II met the inclusion criteria.

How Common Is It After a Fracture?

A meta-analysis of nine studies found the incidence of CRPS after radius fractures ranging from 0.19% to 13.63%, with open fractures, an associated ulnar fracture, female sex and high BMI identified as risk factors (PubMed 37209231). The spread in that range is itself informative: CRPS is diagnosed inconsistently, and under-recognition is the norm rather than the exception.

For the Philippine market this is not an abstract number. A high road-traffic injury burden, a large post-surgical orthopedic population and a growing stroke-rehabilitation cohort all feed the same pipeline of limb trauma — and the clinics receiving those patients are largely not screening for CRPS at all.

The Budapest Criteria — How CRPS Is Actually Diagnosed

The diagnosis is entirely clinical. There is no blood test and no scan that confirms or excludes CRPS. Under the Budapest Criteria, the patient must report symptoms in all four categories and demonstrate signs on examination in at least two:

The practical rule for a clinic, in one sentence: a post-fracture or post-surgical patient whose pain is getting worse rather than better over time, in whom light touch hurts, and whose limb looks or feels different from the other side in colour, temperature or sweating, is a patient who needs a referral — not another treatment session.

What Do Imaging and Tests Show?

No imaging finding diagnoses CRPS. Imaging is used mainly to exclude other causes: non-union, an occult fracture, infection, deep vein thrombosis or failed fixation. Two associated findings are worth knowing:

• Plain radiograph — patchy osteopenia of the affected limb, an uneven juxta-articular thinning of bone that usually appears only after several weeks.
• MRI — bone marrow oedema signal and soft-tissue oedema in the early phase. This is non-specific: it also appears in avascular necrosis, transient osteoporosis and stress fracture, so it diagnoses nothing on its own.

A review from the Rizzoli Orthopedic Institute notes that CRPS-I presents with a clinical picture resembling localised osteoporosis, alongside increased release of pro-inflammatory neuropeptides and cytokines (PubMed 28934787) — which is precisely where the laboratory rationale for testing PEMF in this indication came from.

Differential Diagnosis: What Else Causes Pain Like This After an Injury?

What the Research Says About PEMF in CRPS

The clinical evidence is negative, and it is clearer here than in most indications. This is everything that exists, in order of weight:

• Cochrane review 2016 (updated 2022), CD010853 — 18 RCTs, 739 participants, covering the full range of physiotherapy interventions in CRPS. It reports low to very-low quality evidence that PEMF versus placebo is not effective for short-term pain in CRPS-I, alongside tactile discrimination training and ultrasound-guided stellate ganglion block. No CRPS Type II trial met the inclusion criteria (PubMed 26905470).
• Cömertoğlu et al. 2022, Turkish Journal of Physical Medicine and Rehabilitation, Ankara University — the only dedicated RCT. 32 patients with CRPS-I of the hand, randomised to conventional rehabilitation alone (n=16) or conventional rehabilitation plus PEMF at 8 Hz and 3.2 mT (n=16), 20 sessions across four weeks. Both groups improved significantly in pain, grip and pinch strength, hand oedema, dexterity and hand activities — but no statistically significant between-group difference was found on any outcome, either at the end of therapy or at one-month follow-up (PubMed 35949961).
• Pagani et al. 2017, Pain Physician, Rizzoli Orthopedic Institute — rationale only. An analysis of 44 in-vitro and in-vivo studies. PEMF increased osteoclast apoptosis, osteoblast viability, bone matrix calcification and antioxidant protein levels, and decreased pro-inflammatory cytokines. The authors state explicitly that clinical trial data are scarce and that PEMF parameters are not standardised (PubMed 28934787). This is a rationale, not clinical evidence.
• Notarnicola et al. 2021, Journal of Biological Regulators and Homeostatic Agents, University of Bari — a study of predictors of responsiveness to biostimulation treatments (PEMFs and/or shockwaves) in CRPS-I of the ankle (PubMed 34155875). Full disclosure: some of its authors are affiliated with a PEMF device manufacturer, and no abstract is available on PubMed — so we quote no figures from it. It is listed only to confirm it exists and does not change the picture set by the review and the RCT.

What Do the Clinical Guidelines Recommend?

The consistent principle is that CRPS is managed multidisciplinarily and fast, and that the primary goal is restoring function rather than reducing pain in isolation. Several anchors emerge from the literature:

• Early recognition is the single highest-impact intervention. The longer the diagnosis is delayed, the more entrenched the syndrome becomes and the poorer rehabilitation outcomes are.
• Preserving movement comes first. Prolonged immobilisation and total avoidance of limb use make the condition worse. Treatment is graded, controlled activation — even when uncomfortable.
• Pharmacological management and a pain clinic lead the programme, not physical modalities. Physiotherapy and occupational therapy work inside that framework.
• Perioperative vitamin C is the most-studied preventive intervention. A meta-analysis of eight studies found a reduced rate of CRPS-I with an odds ratio of 0.33 (95% CI 0.17–0.63), consistent across distal radius, ankle and foot surgery and across 500 mg and 1 g doses (PubMed 34961681). For balance: a more recent 2024 meta-analysis of eight studies found a positive direction but no statistical significance, and detected publication bias (PubMed 39447383). This is a prescribing decision for the treating surgeon or physician alone.
• PEMF does not appear as a recommended intervention anywhere in this chain — a statement we publish despite being the importer of the technology.

If Not PEMF, Then What Does Work?

The two approaches that came out best in the Cochrane review belong to the same family: brain-directed rehabilitation, aimed at correcting the distorted representation of the limb in the central nervous system rather than treating the tissue.

• Graded Motor Imagery — a three-stage programme of limb laterality recognition, imagined movement and finally mirror therapy. Across two trials and 49 participants it improved pain and functional disability at six-month follow-up versus usual care plus physiotherapy.
• Mirror therapy — two trials, 72 participants, in patients with CRPS-I after stroke: clinically meaningful improvement in pain and function at six months versus a covered-mirror placebo.
• Graded limb loading, progressive desensitisation to touch, and occupational therapy — the functional core of the programme.
• Pharmacological management and blocks in a pain clinic — at the physician's discretion.

⚠️ The quality of evidence here is also very low, and Cochrane says so explicitly. The difference between these approaches and PEMF is not that they are proven — it is that they are the direction the available evidence points, whereas PEMF was tested directly and found not effective.

What Should a Clinic Actually Do?

The protocol here is a recognition-and-referral protocol, not a treatment protocol:

1. Flag the file. Any patient after a fracture, sprain or limb surgery who reports worsening rather than improving pain over time is flagged for review — not automatically continued into another treatment block.
2. One screening question filters most cases: "Does light contact with the skin — a sleeve, a bedsheet, running water — hurt?" A yes is allodynia, and it does not characterise tendinopathy.
3. Compare both limbs on examination — colour, temperature to touch, sweating, swelling, hair and nails. Document in writing and with a photograph, because the findings fluctuate through the day.
4. Refer to the treating physician, an orthopedic surgeon or a pain clinic — the same week. Send the documentation and an explicit statement that CRPS is suspected.
5. Continue graded movement in the meantime. Do not immobilise the limb while waiting for the appointment.
6. Do not start a PEMF course for this indication. If the patient is already in a course for the underlying orthopedic injury, the decision to continue passes to the physician leading the plan.

⚠️ One practical caveat specific to this condition: patients with allodynia may not tolerate the weight of a coil, or even a bedsheet, on the limb. That is a further, entirely practical reason why routine local physical therapy is inappropriate here before a pain-clinic-led plan is in place.

How the Approaches Compare

Who Is This For?

• Post-surgical and post-fracture orthopedic patients — the largest at-risk group, and the one already inside physiotherapy clinics.
• Road-traffic injury patients — crush injuries, fracture-dislocations and nerve injuries from the Philippines' high traffic-accident burden.
• Post-stroke patients — shoulder-hand syndrome, a CRPS Type I presentation associated with shoulder subluxation and immobilisation.
• Any patient with a limb that looks or feels different from the other side after an injury, regardless of how minor the original injury was.

Contraindications for PEMF Therapy

• Cardiac pacemaker, implanted defibrillator or any active implanted electronic device
• Pregnancy
• Active epilepsy — neurological consultation required
• Active malignancy — there is no scientific evidence for this contraindication; it is observed for insurance reasons
• Acute infection in the treatment area
• Active bleeding or uncontrolled coagulation disorder

⚠️ Safety is not efficacy. That a treatment is safe is no reason to give it in an indication where it was tested and found not effective — particularly when doing so can delay the correct diagnosis.

Frequently Asked Questions

Does PEMF help complex regional pain syndrome?

No. A Cochrane review of 18 randomised trials and 739 participants found PEMF no more effective than placebo for short-term pain in CRPS-I, and the only dedicated RCT found that adding it to rehabilitation produced no additional benefit. We state this despite importing the technology, because the information sits in a public review that any orthopedic surgeon can check.

What is recommended instead?

Graded motor imagery and mirror therapy performed best in the same Cochrane review — 49 and 72 participants respectively, with clinically meaningful improvement in pain and function at six months, at very low quality of evidence. Alongside them: graded limb activation, occupational therapy, and pharmacological management led by a pain clinic.

Can CRPS be prevented after surgery?

A meta-analysis of eight studies found perioperative vitamin C associated with a reduced CRPS-I rate at an odds ratio of 0.33, consistently across distal radius, ankle and foot surgery. A more recent 2024 meta-analysis found a positive direction without statistical significance and detected publication bias. This is a decision for the treating surgeon; do not self-supplement.

How quickly does CRPS need to be diagnosed?

Outcome measures in the Cochrane review were assessed at 6 and 12 months, so the timescale is months rather than weeks. The variable that matters most is how quickly treatment begins. A diagnosis made in the third week after symptom onset is not the same clinical situation as one made in the fifth month.

Is the pain psychological?

No. CRPS is a recognised, defined physiological syndrome with international diagnostic criteria and objective signs that can be seen and measured — temperature differences, colour change, swelling and bone changes on radiograph. That some effective treatments work through the brain does not mean the pain is imagined; it means the system processing pain is part of the problem.

Clinic Investor Takeaway

This page is the clearest illustration of the model PainFree operates. A clinic that recognises CRPS early and returns the patient to the referring surgeon with proper documentation becomes a standing referral destination for that surgeon. A clinic that instead runs twelve futile sessions loses the patient, loses the referrer, and is asked afterwards why nobody noticed. In a Philippine market where CRPS is almost universally under-recognised, that recognition capability is a differentiator that costs nothing to acquire and is worth considerably more than the sessions it forgoes.

PEMF's indications — fracture healing, post-surgical orthopedic rehabilitation, chronic musculoskeletal pain — are documented elsewhere on this site, each with its own evidence. Knowing where the line falls is what makes the rest of the catalogue credible. 70+ Israeli clinics serving a population of 9M — now expanding to the Philippines.

References

• Smart KM, Wand BM, O'Connell NE. Physiotherapy for pain and disability in adults with complex regional pain syndrome (CRPS) types I and II. Cochrane Database of Systematic Reviews 2016;2:CD010853 (updated 2022) — PubMed 26905470
• Cömertoğlu İ, Güneş S, Elhan AH, et al. Effectiveness of pulsed electromagnetic field therapy in the management of complex regional pain syndrome type 1: A randomized-controlled trial. Turkish Journal of Physical Medicine and Rehabilitation 2022;68(1):107-116 — PubMed 35949961
• Pagani S, Veronesi F, Aldini NN, Fini M. Complex Regional Pain Syndrome Type I, a Debilitating and Poorly Understood Syndrome. Possible Role for Pulsed Electromagnetic Fields: A Narrative Review. Pain Physician 2017;20(6):E807-E822 — PubMed 28934787
• Notarnicola A, Covelli I, Moretti L, et al. Predictors of responsiveness to biostimulation treatments (PEMFs and/or shockwaves) in patients with complex regional pain syndrome type I of the ankle. Journal of Biological Regulators and Homeostatic Agents 2021;35(3):1087-1095 — PubMed 34155875
• Lorente A, Mariscal G, Lorente R. Incidence and risk factors for complex regional pain syndrome in radius fractures: meta-analysis. Archives of Orthopaedic and Trauma Surgery 2023;143(9):5687-5699 — PubMed 37209231
• Seth I, Bulloch G, Seth N, et al. Effect of Perioperative Vitamin C on the Incidence of Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis. Journal of Foot and Ankle Surgery 2022;61(4):748-754 — PubMed 34961681
• Ranjbar Moghaddam M, Nasiri-Formi E, Merajikhah A. Efficacy of vitamin C supplementation in preventing and treating complex regional pain syndrome type I (CRPS-I) in Orthopedic patients: A systematic review and meta-analysis. International Journal of Orthopaedic and Trauma Nursing 2024;55:101140 — PubMed 39447383

Hebrew version of this article: painfree.org.il. This article is not medical advice and is not a substitute for diagnosis, treatment or follow-up by a treating physician.