Pulsed Electromagnetic Field Therapy (PEMF)

Original Editor - Malisha van der Berg Top Contributors - Malisha van der Berg, Vidya Acharya and Alexandra Stead  

Introduction

Pulsed Electromagnetic Field Therapy (PEMF) therapy is a non-invasive, non-thermal physical modality that delivers low-frequency, low-intensity electromagnetic fields to biological tissues through external coil applicators.  Originally developed in the 1970s for non-union fracture healing, PEMF has since demonstrated therapeutic potential in a wide variety of musculoskeletal and neurological conditions.

PEMF operates via a control unit that sends specific electrical currents through insulated coils, generating a pulsed magnetic field. These electromagnetic pulses trigger a physiological cascade at the cellular level stimulating the body’s natural regenerative pathways. Biological effects are achieved through electromagnetic signalling rather than heat, distinguishing PEMF from modalities such as therapeutic ultrasound or shortwave diathermy.

PEMF has received FDA clearance for non-union bone fracture healing. It is increasingly used as both a standalone and adjunctive treatment in physiotherapy and orthopaedic rehabilitation.

PEMF use is supported by evidence for the following conditions:

• Bone fractures and non-union healing
• Osteoarthritis (OA): knee, hip, hand, and cervical spine
• Osteoporosis
• Tendinopathy and tendon disorders
• Non-specific low back and neck pain
• Fibromyalgia
• Neuropathic pain: spinal/radicular and peripheral
• Multiple sclerosis-related fatigue
• Post-surgical rehabilitation, including post-ACDF cervical fusion
• Neurogenic heterotopic ossification (NHO) prophylaxis following spinal cord injury
• Foot and ankle soft tissue injuries: ankle sprain, Achilles tendinopathy, calcaneal spurs

PEMF is also used in veterinary physiotherapy for musculoskeletal conditions in horses, dogs and cats, including pain management and tissue healing. For further information, see Modalities Used in Animal Physiotherapy.

Despite widespread clinical use, PEMF currently lacks standardised treatment protocols. Physiotherapists should apply PEMF selectively, with clear clinical rationale and measurable outcome goals.

Physical Properties of PEMF

Understanding PEMF’s physical parameters is essential before using this modality. Unlike many electrophysical agents where settings are standardised, PEMF devices vary considerably in waveform, frequency, intensity, and coil configuration. Selecting inappropriate parameters is one of the primary reasons for inconsistent results in the literature.

Electromagnetic Induction

The physical output of PEMF devices is governed by Faraday’s law of electromagnetic induction, whereby time-varying magnetic fields induce an electric field within target tissues, driving ion movement that initiates biological signalling cascades.

The magnitude of the induce current is determined by the Pulse Gradient, which is the speed at which the electromagnetic field rises and falls, measured in Tesla per second (T/s). The steeper the gradient, the stronger the induced current and the deeper it can penetrate into biological tissue. This gradient is shaped by three interdependent physical properties: frequency; intensity; and waveform shape. Coil geometry governs the spatial distribution of the resulting magnetic field in tissue. Each is addressed in turn below.

Frequency

Frequency refers to the number of electromagnetic pulses delivered per second, measured in Hertz (Hz), and is one of the most clinically significant parameters. There are two distinct frequency concepts and should not be confused:

1. Pulse repetition frequency: Pulses delivered per second; the most commonly reported in clinical studies.
2. Field (carrier) frequency: The frequency of the signal within each pulse, often in kHz-MHz range. Pulsed radiofrequency (PRF) devices operates at these carrier frequencies 1kHz and above

The following frequencies are mentioned in the literature, but should be interpreted cautiously considering the heterogeneity across studies:

• 0.1–500 Hz have been shown to stimulate currents in tissues with measurable biological effects.
  • 1–100 Hz classified as Extremely low frequency (ELF) is the most widely used clinical range producing musculoskeletal and anti-inflammatory effects.
  • Frequencies below 60 Hz influences cell transcription and DNA synthesis, relevant for tissue healing and regenerative applications.
    • 15 Hz is the specific resonance point for maximal osteogenic response and bone healing.

• Frequencies above 100 Hz have been associated with higher cellular response rate and faster pain relief in vitro and clinical studies.
• Frequencies above 1 kHz, PRF, are neuromodulatory and applicable in radicular and neuropathic pain conditions.

The frequency selectivity of PEMF reflects the resonance behaviour of cellular ion transport systems: Particularly calcium-channel gating kinetics, which respond selectively to specific oscillatory inputs.

Intensity (Magnetic Flux Density)

Intensity measured in Tesla (T), milliTesla (mT; 1mT=0.001T) or Gauss in older literature (G; 1G=0.1mT) describes the strength of the magnetic field delivered to the tissue. It is a critical parameter as tissue penetration depth increases with intensity. Reported ranges span from 0.001G to over 100 mT, with some devices reaching up to 1T.

• Ultra low intensity (0.001G-1.5G) modulates systemic pain and autonomic effects via whole-body delivery, applicable for widespread chronic pain, fibromyalgia, fatigue.

• Low intensity (0.1-10 mT) is associated with analgesic and anti-inflammatory effects.
• Medium intensity (10 mT-30mT) produces structural tissue effects and enhances collagen organisation for soft tissue repair and tendon healing.
• High intensity (30–150 mT) has been associated with osteogenic gene expression for structural bone, cartilage and tendon repair. 80-150mT has shown superior outcomes for non-specific low back pain (LBP).
• Very high intensity (>150mT-0.1T) is where the biological window effect kicks in, meaning that biological effects plateau or become inhibitory.Although some studies have proven the effectiveness in OA protocols.

Pulse Shape and Duration

PEMF fields deliver discrete electromagnetic bursts rather than a continuous signal. Waveform shape varies by device and may be sinusoidal, square, triangular or trapezoidal. These different waveforms each produce distinct induced current profiles in tissue and contribute to heterogeneity across clinical studies.

• Sinusoidal waves are most commonly used in whole-body mat devices.
• Square waves are characterised by steep rises and falls, producing short high-intensity fields.
• Triangular waves produce weaker electromagnetic fields of longer duration, and are associated with the highest cellular response rate in in vitro studies.
• Asymmetric burst waveforms consists of asymmetrical bipolar pulses repeating at 15Hz and are the most extensively validated configuration in orthopaedic applications.

Waveform shape is rarely reported in clinical studies, representing a substantial methodological gap given its direct influence on biological effectiveness.

Session Duration

Reported session durations range from 6 minutes to 12 hours per day.

• 20–30 minute sessions are optimal for most musculoskeletal pain conditions.
  • Cellular signalling pathways become saturated after approximately 30 minutes of electromagnetic exposure.
  • This effect is consistent with receptor downregulation kinetics in calcium-calmodulin signalling.

• Bone fracture healing protocols require much longer daily exposures (≥6-8 hours/day), targeting structural remodelling

Total treatment duration across conditions ranges from 2 weeks to 12 weeks.

Coil Type and Delivery Mode

Coil geometry determines the spatial distribution of the magnetic field in target tissue and should be matched to the clinical indication.

Coil Type, Magnetic Field Induced, Field Distribution and Clinical Implications

Coil Type	Solenoid	Helmholtz	Flat spiral
Field Induced	Solenoid coil magnetic field	Helmholtz coil magnetic field	Flat spiral coil
Field Distribution	Non-Linear: ~50% drop at coil ends vs centre	Uniform across intervening volume	Concentrated at surface with rapid depth drop-off
Clinical Implications	Best for localised single-joint treatment with centre of coil over target	Multi-site or whole-body treatment.	Suited to superficial tissue

PEMF can be delivered via different applicator types:

1. Localised coil applicators are placed directly over the target tissue and are used for conditions such as:
   • Bone fractures  
   • Knee, hip or wrist OA
   • Shoulder impingement
   • Tendinopathy
2. Whole-body mat devices, deliver electromagnetic field across the entire body;
   • Fibromyalgia
   • MS-related fatigue

Parameter Summary Table

Parameter	Ulta-low/ Whole body	Low (Analgesic/Anti-inflammatory	Medium (Tissue Repear)	High (Stuctural/Bone)
Frequency	0.1-83Hz	1-100Hz (ELF)	1-100Hz	ELF (<100Hz); PRF for LBP
Intensity	0.004-1.5G	0.1-10mT	10-30mT	30-150mT
Primary Effect	Systemic pain modulation; autonomic	Analgesia; anti-inflammatory	Collagen organisation; chondrocyte proliferation	Osteogenesis; fracture healing; structural repair
Waveform	Sinusoidal most common	Variable; asymmetric burst	Variable	Asymmetric burst
Delivery mode	Whole-body mat	Localised coil or mat	Localised coil	Localised coil
Session duration	8-40min	20-30min	20-30min	≥6-8 hours/day (Fracture); 20-60min other

Proposed Mechanisms of Action

The following mechanisms have been proposed primarily based on in vitro and animal studies:

• PEMF produces its therapeutic effects through a cascade of interconnected molecular and cellular events. The mechanisms are not yet completely clarified, but the following have been consistently implicated across the literature:
  1. First messenger:
     • PEMF signal acts on the plasma membrane
     • Voltage-gated calcium channels (VGCC’s) open in response to membrane depolarisation
     • Calcium (Ca²⁺) enters the cell
  2. Second messenger:
     • Elevated cytosolic calcium activates calmodulin.
     • Calmodulin upregulates the expression of osteogenic genes including:
       • fibroblast growth factor (FGF-2),
       • osteocalcin (OCN),
       • TGF-β,
       • Bone Morphogenetic Proteins (BMP),  
       • alkaline phosphatase (ALP)
     • The calcium-calmodulin complex also activates nitric oxide synthase (NOS), driving downstream NO-mediated vasodilation and tissue repair.
     • Following video explains how first and secondary messengers work in the intracellular signalling pathway:

Key Signalling Pathways Activated:

Signalling Pathway	Main Effect
TGF-β / SMAD (Growth factors)	Chondrogenic differentiation and BMP upregulation.
MAPK / ERK	Promotes cellular proliferation and anti-inflammatory response.
Wnt / β-catenin	Stimulates osteoblast differentiation and chondrogenesis, relevant to osteoarthritis and fracture healing.
PI3K / AKT / mTOR	Promotes cartilage repair and stem cell differentiation.
Adenosine receptor (A2A and A3) stimulation	Promotes chondrocyte proliferation and extracellular matrix synthesis, contributing to the analgesic and chondroprotective effects observed in osteoarthritis.
NF-κB pathway inhibition	Suppresses the downstream transcription of pro-inflammatory cytokines, representing a key anti-inflammatory mechanism of PEMF.
Ca2+/nitric oxide/cGMP/protein kinase G pathway	Downstream signalling cascade and vasodilation.
Notes: Chondrogenic differentiation: Stem cells transforming into chondrocytes that produce collogen type II, proteoglycans, and extracellular matrix, creating a favourable cellular environment for cartilage maintenance and repair. BMP upregulation: Signalling proteins that regulates repair across bone, cartilage, tendon, and muscle. Cellular proliferation: Increased osteoblasts, chondrocytes and mesenchymal stem cells. Meaningful in early and middle stages of tissue healing where increased cell numbers are needed to improve recovery.

Clinical Evidence by Condition

In the following video, Jeffrey Peng MD, answers questions on the effectiveness of PEMF and highlights some of the evidence done:

Current evidence on PEMF summarised.

Summary of Evidence for PEMF by Condition Reported in the Reviews by Rajalekshmi and Agrawal., 2024 and Flatscher et al., 2023

Condition / Application	Reported Effects of PEMF	Level of Evidence	Key Findings / Outcomes
Bone Fracture Healing / Non-Union Fractures	Accelerated fracture healing; increased callus formation; improved biomechanical strength; reduced radiographic and clinical healing time	Strongest evidence; FDA-approved indication; animal, RCT and clinical evidence	Improved callus mineralisation and faster healing in delayed/non-union fractures.
Osteoporosis / Osteopenia	Improved bone mineral density (short-term); enhanced bone strength; reduced bone loss; pain relief; possible equivalence to alendronate in some parameters	Moderate evidence; animal studies, meta-analyses and RCTs; FDA approval for osteoporosis not yet granted	Improved BMD and bone turnover markers when PEMF was combined with medication.
Osteoarthritis (OA)	Significant pain relief; reduced inflammation and synovitis; improved stiffness and physical function (WOMAC/VAS scores); reduced cartilage degeneration	Moderate evidence; multiple meta-analyses of RCTs (up to 11 trials, 614 patients)	Significant pain reduction vs baseline. More effective than placebo for short-term symptom relief, but not consistently superior to physiotherapy or conservative management.
Cartilage Repair / Articular Cartilage	Enhanced cartilage regeneration and extracellular matrix deposition; improved chondrogenic differentiation	Experimental and tissue-engineering evidence	Improved cartilage repair and chondrogenic differentiation in scaffold and hydrogel studies.
Tendinopathy / Tendon Healing	Improved collagen organisation; reduced inflammation; enhanced tendon healing	Emerging evidence; mainly animal and in vitro studies	Improved tendon histology and fibre organisation in Achilles tendinopathy models.
Rotator Cuff Repair	Improved tendon-to-bone healing and collagen organisation	Limited preclinical and clinical evidence	Rat studies showed improved biomechanical elasticity and collagen organisation after rotator cuff repair.
Muscle Regeneration	Increased myoblast proliferation; enhanced muscle regeneration; improved cell migration	Primarily preclinical evidence	PEMF promoted skeletal muscle cell proliferation and regenerative responses in vitro. Effects on mesenchymal stem cells extend several days post-exposure.
Muscle Hypertrophy (HIFEM)	Increased muscle fibre density and muscle size	Experimental animal evidence	Porcine models showed increased muscle mass density and muscle fibre size.
Meniscal Healing	Improved fibrocartilage regeneration; reduced degeneration	Animal evidence	PEMF-treated groups demonstrated superior meniscal healing and less degeneration than controls.
Chronic Neck Pain	Symptom improvement comparable to standard physiotherapy	Clinical evidence with mixed outcomes	No additional benefit compared with sham PEMF when added to conventional physiotherapy.
Chronic Low Back Pain (CLBP)	Pain reduction; improved functional outcomes and quality of life	Moderate clinical evidence	PEMF combined with conventional physiotherapy improved pain and quality of life similarly to IFC therapy.
Flexor Tendon Repair Rehabilitation	Improved pinch grip strength; improved ADL outcomes	Limited clinical evidence	Improved pinch grip and patient-reported outcomes when added to exercise therapy.
Wound Healing	Pain relief post-surgery; reduced swelling; improved closure of chronic diabetic foot ulcers	Low: small sample sizes, sparse high-quality studies	14 sessions over 3 weeks (12 Hz, 1.2 mT) showed 18% wound size reduction vs 10% in controls. Strauch et al.: supports post-surgical use for pain and oedema.
Neurology (TMS / Alzheimer’s / Depression)	Reduced neuroinflammation; vasodilatory effects improving blood circulation; symptom improvement in neurodegenerative disease	Low-Moderate: clinical trials exist but limited in scope	promising results for Alzheimer’s, including reduced inflammation and vasodilation.
Oncology	Stable disease in some patients; pain reduction; possible anti-tumour effects	Preliminary: very small studies, no controlled trials	hepatocellular carcinoma patients reported complete pain resolution. No adverse events were reported. The evidence remains highly experimental.
Cellular / General (In Vitro)	Modulation of apoptosis, proliferation, and differentiation across multiple cell types	In vitro / preclinical: extensive but inconsistent	only 51% of 2,421 human cell experiments showed measurable changes. Frequencies >100 Hz and flux densities 1–10 mT were most effective. Triangular waveforms produced the highest cellular response (78%) vs square waves (~40%).

Summary of Systematic Reviews and Meta-Analyses on The Effectiveness of PEMF

Condition	Reported Effects of PEMF	Level of Evidence	Parameters Used
Acute fractures, delayed union, and non-union (various sites: tibia, scaphoid, radius, mandible, vertebra, femur).	Increased number of cases achieving complete fracture healing; reduced time to healing; moderate pain relief; SUCRA rankings: 67.6% for healing rate, 58.7% for healing time, 42.9% for pain relief	Moderate, 10 RCTs included; some concerns around heterogeneity (I² = 75% for healing rate); mostly low-to-moderate risk of bias	Requires ≥8 h/day over 45–60 days for significant effect
Acute bone fractures (femoral diaphysis, scaphoid, mandibular).	No significant effect on bone healing in any of the 3 RCTs; contradictory pain results (one study showed significant pain reduction at 7 and 14 days; another showed none); one study showed transient improvement in wrist range of motion at 24 weeks and grip strength at 12 weeks only	Low, only 3 RCTs, 197 patients total; high heterogeneity across fracture types, protocols and outcomes; one study rated high risk of bias; no meta-analysis performed	Not standardised; varied across studies and devices; no consensus protocol reported
Shoulder Impingement Syndrome.	Reduced short-term pain; improved short-term and long-term functional capacity; no significant long-term pain reduction	High (pain short-term, functional capacity short- and long-term); Moderate (pain long-term)	Frequency: 3–50 Hz; Intensity: 20mT–85G; Sessions: 20–30 min/session, 2–5×/week; Duration: 3–4 weeks
Osteoarthritis (primarily knee; also cervical, hand, ankle)	Reduced short-term pain; improved physical function/disability; no consistent benefit for stiffness or quality of life; cervical OA showed minimal benefit	Low to moderate (most included reviews rated low/medium quality; only 2–5 of 10 reviews showed significant positive effects on pain; 5 of 10 showed positive functional outcomes)	Frequency: 0.1 Hz–27 MHz; Intensity: 3.4 mcT–105 mT; Duration: 6 min–12 h/day; Treatment period: 10–45 days; 1–3 sessions/day
Knee Osteoarthritis.	Early (18–21 day) WOMAC-pain reduction; later (1 month) improvements in stiffness and daily activity; no significant overall VAS pain or total WOMAC improvement; no improvement in objective functional measures (TUG, FTSST); effects dependent on device parameters	Low-to-moderate (7/9 RCTs rated high overall risk of bias; statistically significant findings did not meet MCID thresholds for clinical meaningfulness)	Amplitude: 0.0001–105 mT; Frequency: 4–1000 Hz
Osteoarthritis (primarily knee 77%; also lumbar spine, cervical spine, lower limbs, hemophilic arthropathy).	Significant pain reduction; improved physical function; improved quality of life; reduced NSAID/analgesic use (26% reduction); improved stiffness and disability scores; both short- and long-term benefits observed	Low-to-moderate (17 RCTs, n=1197; predominantly RCT design but high device and protocol heterogeneity; no pooled statistical meta-analysis performed; variable risk of bias)	Frequency: 6 Hz–27 MHz; Intensity: 10–100+ mT (up to 1000 Gauss); Duration: 15–90 days (median 52.5 days); Session length: 10 min–12 h/day; multiple device types used
Osteochondral lesions of the talus (OLT) treated with microfracture.	No significant additional benefit over microfracture alone; lowest SUCRA ranking among all adjunctive therapies for both AOFAS and VAS scores	Low to moderate quality (1 RCT included)	Not reported in this review
Degenerative cervical spondylosis (DCS) post cervical spine fusion (ACDF).	Significantly improved fusion rates at 6 months (83.6% PEMF vs 68.6% control, p<0.05); no significant difference in VAS pain, SF-12, NDI, or adverse events at 12 months	Level II (one prospective multicenter RCT.); GRADE score B	Not reported in this review
Neurogenic heterotopic ossification (NHO) prophylaxis following spinal cord injury (SCI).	0% NHO incidence in PLIMF group vs 33.3% in control group; statistically significant difference (p<0.04)	Single RCT; low risk of bias on Cochrane RoB 2 tool	Frequency: 25 Hz; Intensity: 10 miliTesla (mT); Session duration: 30-minute; Treatment duration 5x/week for 4 weeks
Non-specific low back pain (acute, subacute, and chronic)	Pain reduction and improved physical function, especially as adjunct to conventional physical therapy; PEMF alone showed mixed results vs. placebo; no serious adverse events reported; comparable effectiveness to NSAIDs and interferential current therapy	Low-to-moderate (9 RCTs, n=420; mean PEDro score 7.2/10; 5/9 studies showed significant results; substantial heterogeneity prevented meta-analysis; no long-term follow-up in any study)	Frequency: 3–50 Hz; Intensity: 2–150 mT; Session duration: 10–30 min; Frequency of sessions: 2–7×/week; Treatment duration: 2–13 weeks
Broad musculoskeletal pain conditions: knee osteoarthritis (8 studies), low back pain (4 studies), fibromyalgia (3 studies), shoulder impingement syndrome (2 studies), chronic neck pain, patellofemoral pain, plantar fasciitis, hand OA.	Generally positive effects on pain reduction and functional improvement, particularly for knee OA, shoulder impingement, LBP, and fibromyalgia; results inconsistent, several studies showed no significant difference vs. placebo, especially when PEMF was added to existing physical therapies (TENS, ultrasound, hot pack).	Moderate: 21 RCTs included; PEDro scores averaged 7.57/10 with only 4 studies rated low quality; 4 studies rated high risk of bias; no meta-analysis performed; significant heterogeneity in protocols	Frequency: 1 Hz to 85 kHz (most effective 1–100 Hz); intensity: 0.1 mT to 820 mT (most commonly <30 mT); session duration: 5 min to 4 hours; frequency of sessions: 1–5 per week; treatment duration: 7 days to 12 weeks
Neuropathic pain (diabetic peripheral neuropathy k=5, spinal/radicular pain k=3, carpal tunnel syndrome k=1).	Large significant analgesic effect for spinal/radicular pain; no significant reduction for peripheral neuropathy; no significant QoL improvement; PEMF as adjuvant to pharmacotherapy consistently superior to pharmacotherapy alone; excellent safety profile (0.6% adverse events, identical to sham)	Low (GRADE) for both subgroups; 4/9 RCTs low risk of bias, 3/9 some concerns, 2/9 high risk; extreme heterogeneity (I²=92.8%); global significance lost after publication bias adjustment	Frequency: ELF (<100 Hz) to radiofrequency (27.12 MHz); Session duration: 10–120 min; Treatment period: 10 days–18 weeks
Fibromyalgia (FM); chronic widespread pain with cognitive and emotional involvement, in adults ≥18 years with pain ≥3 months.	Significant short-term pain reduction at 1–3 months (16–55% pain reduction from baseline); no significant effect at ≥3 months; no significant improvement in functional outcomes (FIQ) at ≥3 months; improvements also noted in fatigue, stiffness, and quality of life in some studies	Low: 6 RCTs, 279 patients total; I² = 68% for 1–3 month pain scores; 3 of 6 trials had at least one high-risk bias domain; GRADE rated low quality for pain outcomes and very low for functional outcomes	Intensity: 400 nT to 400 μT (median 100 μT); frequency: 0.1 Hz to 83.3 MHz (median 33.3 Hz); session duration: 8–40 min (mean 23.6 min); treatment course: 3–84 days
Multiple Sclerosis (fatigue)	Significant reduction in fatigue severity; no significant improvement in quality of life or depressive symptoms; good safety profile with no serious adverse events	Moderate (fatigue); Low (QoL and depressive symptoms)- per GRADE; 6/7 RCTs rated high risk of bias	Low-frequency electromagnetic fields; treatment durations 3–12 weeks; includes both standard PEMF and BEMER devices
Foot & ankle soft tissue injuries (ankle sprain, Achilles tendinopathy, calcaneal spurs)	Significant pain reduction in 3/4 studies; physical function improvement in 1/3 studies	Low: heterogeneous PEMF parameters, mixed acute/chronic conditions; risk of bias; detected publication bias.	Frequency 3–100 Hz; intensity 1–80 mT; session duration 10–60 min; 1 session to 8 weeks total

Evidence Conclusion from tables:

• Strongest clinical evidence supports PEMF for bone fracture healing and osteoarthritis pain relief.
• Benefits for low back pain, shoulder impingement, and fibromyalgia are mostly short term and strongest when PEMF is used alongside conventional therapy.
• Evidence for tendon, muscle, and cartilage applications remains largely preclinical
• Neurological, neuropathic pain, and oncological applications are still exploratory
• Marked variation in device settings, treatment protocols, and outcome measures limits firm conclusions and cross-study comparison.

Treatment Protocols

The following table summarise evidence-based PEMF treatment parameters for physiotherapy practice. They should be used as clinical guidance rather than fixed prescriptions, given the current lack of universally standardised protocols.

PEMF Treatment Protocol Parameters by Condition

Condition	Frequency	Intensity	Session Duration	Sessions per Week	Treatment Duration
Bone Fracture Healing / Non-Union	ELF range (<100Hz)	35 µT (0.35G) – 0.03 T	Varied	Daily	≥8 hrs/day over 45–60 days recommended; 8–29 weeks for non-union
Osteoporosis / Osteopenia	ELF range (<100Hz)	35 µT (0.35G)– 0.03 T	30-60min	Daily or 5×/week	Short-term protocols < 3 months; long-term unclear
Osteoarthritis (General)	0.1 Hz – 27 MHz	3.4 µT (0.034G) – 105 mT	6 min – 12 hrs/day	1–3×/day	10–45 days
Knee Osteoarthritis	4–1,000 Hz (>100 Hz associated with faster pain relief)	0.0001–105 mT (>1 mT associated with better stiffness and function)	20-30min	Daily or 5×/week	Minimum 3-4 weeks; benefits in stiffness and function seen at 1 month
Osteoarthritis (Cianni et al.)	6 Hz – 27 MHz	10–100+ mT	10 min – 12 hrs/day	Daily preferred as adjunct to PT	15–90 days (median 52.5 days)
Shoulder Impingement Syndrome	3–50 Hz	20 mT – 85 G (>10 mT associated with functional benefit)	20–30 min/session	2–5×/week	3–4 weeks
Tendinopathy (Achilles, rotator cuff, and flexor tendon)	1-100 Hz	10-30 mT	20-30 min	3- 5×/week	4-12weeks
Low Back Pain	3–50 Hz	2–150 mT (80–150 mT associated with better outcomes)	10–30 min	2–7×/week	2–13 weeks
Broad Musculoskeletal Pain	1 Hz – 85 kHz (most effective 1–100 Hz)	0.1–820 mT (most commonly <30 mT)	5 min – 4 hrs	1–5×/week	7 days – 12 weeks
Fibromyalgia	0.1 Hz – 83.3 MHz (median 33.3 Hz)	400 nT – 400 µT (median 100 µT)	8–40 min (mean 23.6 min)	3-5×/week	3–84 days
Neuropathic Pain	ELF (<100 Hz) for peripheral; higher up to 27.12 MHz for spinal/radicular pain	Low-Moderate, Not uniformly reported	10–120 min	Daily or 5×/week as adjunct to pharmacotherapy	10 days – 18 weeks
Multiple Sclerosis (Fatigue)	Low frequency ELF range	Low intensity,Not uniformly reported	20-30 min	3-5×/week	3–12 weeks; 8 weeks greatest fatigue benefit
Neurogenic Heterotopic Ossification	25 Hz	10 mT	30 min	5×/week	4 weeks
Wound Healing	12 Hz	1.2 mT	30 min	Daily (14 sessions)	3 weeks
Cervical Spine Fusion (ACDF)	ELF Range	Low-Moderate	30-60 min	Daily	Improved fusion rates at 6 months; up to 12 months follow-up

Where specified, PEMF is typically delivered through solenoid or flat paddle coils placed over the target tissue, while whole-body mat systems are used for more widespread conditions such as fibromyalgia and low back pain. Localised ring or wrap-around coils are preferred for joint-specific applications, including the knee and shoulder.

Application in Physiotherapy Practice

PEMF should be used within a broader rehabilitation plan, with appropriate patient selection, informed parameter choice, active rehabilitation, and ongoing outcome monitoring.

Adverse Effects and Safety Profile

PEMF is generally well tolerated, and no serious adverse events were reported in the musculoskeletal systematic reviews. However, there was a mention in the review conducted by Lara-Reyers et al. (2026) that adverse event rates have been reported at 0.6% and were identical to sham groups in some controlled trails.

Patient Selection

PEMF should only be used where evidence supports its effectiveness and once all contraindications have been excluded. Evidence-supported conditions are listed in the Introduction.

Patient selection should be based on both the available clinical evidence and the individual’s clinical presentation. The following notes highlight some selection considerations from the literature reviewed:

• NHO prophylaxis following SCI is based on a single small RCT (n=29) and should be considered exploratory.
• Use PEMF as an adjunct within a multimodal plan for fibromyalgia, as effects are unlikely to persist beyond 3 months.
• PEMF should not be used as a standalone intervention for spinal or radicular neuropathic pain.
• Coordinate with neurological management team before using PEMF for MS-related fatigue.

Contraindications

Contraindications to PEMF include:

• Implanted electronic devices (e.g., pacemakers, deep brain stimulators). Risk of electromagnetic interference
• Active malignancy at or near the treatment site. Evidence is currently insufficient to confirm safety; clinical caution is advised.
• Pregnancy. Safety has not been established and use is not recommended.

Precautions

Precautions for the use of PEMF include:

• Epilepsy: effects on seizure threshold are unclear.
• Active infection or open wounds at the treatment site.
• Orthostatic hypotension, especially in fibromyalgia populations.
• Paediatric patients : specialist guidance only

Integration with Other Physiotherapy Interventions

Evidence suggests that PEMF provides no additional benefit when combined with other therapeutic modalities such as TENS or ultrasound in the same session. It is most effective as a standalone passive modality, followed by or combined with active exercise therapy.

1. Combine PEMF with exercise therapy, especially for low back pain, osteoarthritis, and post-surgical rehabilitation.
2. Use PEMF before exercise when pain relief is needed to facilitate movement.
3. Use PEMF after exercise when the goal is recovery, inflammation reduction, or tissue repair, especially after surgery or in tendinopathy.

Do not present PEMF as a substitute for exercise; it supports healing but does not replace active rehabilitation.

Practitioners should record the device model and all treatment parameters used during each session to facilitate audit processes and outcome monitoring. Caution is advised when applying evidence from one device type to another, as variability between devices is a recognised limitation within the current evidence base.

Goal Setting and Outcome Measures

Set clear, measurable goals before starting PEMF and plan reassessment from the outset.

• Do not use outcome evaluation scores alone, monitor functional improvement as well.
• For pain on the Visual Analogue Scale (VAS), a change of 15–20 mm on a 100 mm scale is a useful benchmark for response.

Recommended outcome measures by condition:

Condition	Recommended Outcome Measure
Osteoarthritis (knee, hip, hand)	WOMAC, VAS/NRS, TUG, FTSST
Low back pain	ODI, VAS/NRS, Patient-Specific Functional Scale
Shoulder impingement syndrome	DASH, SPADI, VAS/NRS
Fibromyalgia	FIQ, NRS, fatigue scales
MS-related fatigue	FSS, Modified Fatigue Impact Scale (MFIS)
Neuropathic pain	NRS, DN4, Patient Global Impression of Change
Fracture / bone healing	Radiological assessment, return to function milestones
Post-surgical rehabilitation	Condition-specific functional outcome tool plus patient-reported goals

Goal-setting guidance

Guidance in setting goals for the use of PEMF:

• Establish a baseline measurement before the first PEMF session
• Set a realistic short-term goal: for most conditions, initial reassessment should occur at 3 weeks.
• Set a medium-term goal: full reassessment at 6 weeks, with a decision to continue, modify, or cease PEMF based on clinical response.
• For fibromyalgia, set explicit expectations that effects are time-limited to approximately 3 months and build discharge planning into the treatment from the outset.

Ensure goals are patient-centred: frame outcomes in terms of functional activity, participation, and quality of life rather than pain scores alone, consistent with the ICF framework for physiotherapy practice.

Home and Commercial Use of PEMF Devices

Portable and wearable devices are now widely available for purchase by the general public, ranging from whole-body mats to localised joint wraps and handheld applicators. While this increases patient access, it also introduces clinical risks if devices are used without professional guidance.

Physiotherapists can support patients who wish to use PEMF devices at home or who are already doing so. Guidance should include:

• Confirming the absence of contraindications.
• Advising patients to choose devices with clearly stated technical specifications such as frequency and intensity parameters.
• Recommending session durations consistent with evidence-based protocols (typically 20–30 minutes for musculoskeletal conditions).
• Advising patients that consumer devices have a typically lower intensity than clinical devices and may produce more modest effects.
• Encouraging patients to continue with their active rehabilitation programme alongside any home device use, and NOT TO substitute PEMF for prescribed exercise.
• Monitoring patient-reported outcomes at follow-up appointments to assess whether home use is contributing to functional goals.

Regulatory considerations

Patients should be advised to select devices that hold appropriate regulatory approval in their country (e.g. MHRA in the UK, TGA in Australia, FDA clearance in the United States). Devices sold as wellness products rather than medical devices may not be subject to the same standards of evidence or safety.

Physiotherapists should not formally endorse specific commercial brands, but can advise patients on what features to look for when evaluating a device.

Limitations and Clinical Cautions

Physiotherapists should consider the following limitations when using PEMF:

• Lack of standardised protocols: devices and settings vary widely, research findings may not apply directly across clinical devices.
• Statistical significance may not equal clinical benefit; interpret changes in terms of meaningful functional improvement.
• Effects may be time limited, especially in fibromyalgia, and long-term follow-up is scarce; PEMF is not curative.
• Device variability is high; document the device, model, and settings used at each session for audit and outcome tracking.
• Publication bias may inflate reported effects.
• Evidence quality is often low to moderate, with frequent risk of bias; discuss this uncertainty honestly with patients.
• Regulatory status varies by country; practitioners should verify that their device holds appropriate regulatory approval from their national medical device authority (e.g., MHRA in the UK, TGA in Australia) before clinical use.

Resources

• Regulatory guidance can be found at:
  • MHRA (UK)
  • TGA (Australia)
  • FDA (USA)