Not all magnetic therapy is the same.

How extracorporeal magnetotransduction therapy differs from PEMF in frequency, field strength and evidence, and where the MAGNETOLITH® ultra+ fits in an MSK clinic.

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STORZ MEDICAL MAGNETOLITH ultra+ EMTT device

Most MSK clinicians have a view on magnetic therapy, and it is usually a sceptical one. That is fair. The category is crowded with low-powered mats and handheld units making big promises on thin evidence.

So when the STORZ MEDICAL MAGNETOLITH® ultra+ gets filed under “PEMF”, it is worth asking whether the label fits. It doesn’t, quite. EMTT uses electromagnetic pulses, as PEMF does, but the signal differs in two ways that matter clinically: how fast the field oscillates, and how strong it gets.

Same family, different signal

PEMF is a broad term. It covers any device that drives current through a coil to produce a magnetic field that switches on and off. In clinical use the frequency is usually below 100 Hz, with field strengths between 0.1 and 30 mT, delivered as square, triangular or sawtooth waveforms.1 That leaves a lot of room. A fracture-healing stimulator and a consumer wellness mat can both fairly call themselves PEMF.

EMTT sits at the high-energy end. Each pulse from the MAGNETOLITH® oscillates at 100 to 300 kHz, with a field strength of 80 mT, and pulses are delivered at up to 10 per second.2 STORZ quotes a penetration depth of up to 18 cm.3 Rapidly alternating magnetic pulses induce small electrical currents in tissue, and cells convert that stimulus into a biological response.4

PEMF Low frequency, low amplitude EMTT Each pulse oscillates at 100 to 300 kHz One pulse
Not to scale. Within every EMTT pulse, a much stronger field swings back and forth many thousands of times a second.

Two numbers that change everything

The current induced in tissue depends on how quickly a field changes, not only on how strong it is. EMTT is faster by around a thousandfold and stronger by a wide margin. A 2026 systematic review found efficacy appears sensitive to electromagnetic dose, with low-intensity protocols below about 5 mT often hard to tell apart from placebo.6

Frequency

Logarithmic scale2,5

PEMF EMTT ×1,000 1 Hz100 Hz10 kHz1 MHz

Field strength

Millitesla, typical clinical range1,2

PEMF, up to 30 80 mT 0255075100

Head to head

PEMF

Frequency
Usually below 100 Hz
Field strength
Usually 0.1 to 30 mT
Pulse rate
Varies by device
Session length
Varies by device and protocol
Parameters
Highly variable across devices and studies
Evidence
Large and long-standing, but mixed
Undressing
Depends on device

EMTT

Frequency
100 to 300 kHz within each pulse
Field strength
80 mT
Pulse rate
Up to 10 pulses per second
Session length
5 to 20 minutes
Parameters
One defined device, set on a touchscreen
Evidence
Newer, including sham-controlled RCTs
Undressing
Not needed

What the evidence says

PEMF has decades of research behind it, going back to Bassett’s work in the 1970s.7 The difficulty is the spread. Studies use such different parameters that firm conclusions are hard to draw. A 2026 meta-analysis of PEMF in knee osteoarthritis found statistically significant improvements, but noted they may not reach the threshold for clinical meaningfulness, and that results depended on amplitude and frequency.8 In a randomised trial comparing shockwave, low-level laser and PEMF in knee OA, all three helped in the short term, though PEMF’s gains were the least pronounced.9

EMTT’s evidence base is younger, but it has been tested against sham, and it has grown steadily.

2017
Non-specific low back pain13
Prospective randomised controlled trial.
2018
Rotator cuff tendinopathy13
Randomised trial of EMTT and shockwave in 86 patients.
2018
Chronic aseptic osteitis pubis14
Prospective series of nine athletes after failed conservative care.
2022
Bone marrow stem cells16
Laboratory study showing stimulation of human mesenchymal stem cells.
2023
Shoulder tendinopathy12
Double-blind, placebo-controlled trial, 43 patients.
2024
Bone healing15
Gene upregulation and accelerated matrix mineralisation.
2025
Knee OA, rotator cuff, lumbar spine10
Double-blind, sham-controlled RCT, 126 patients. Results favoured EMTT in all three conditions.

Side effects were minor: slight skin reddening and mild discomfort during treatment, reported more often with EMTT than with sham.11

Bone and joint conditions

Osteo presentations are where EMTT’s research is most interesting for MSK clinics.

Knee osteoarthritis10

One of three conditions in the 126-patient sham-controlled trial, with results favouring EMTT.

Lumbar spondyloarthrosis10

Also included in the same trial, alongside knee OA and rotator cuff enthesopathy.

Osteitis pubis14

Four 15-minute sessions at 80 mT were associated with reduced pain in athletes who had failed conservative care. A small series, but a condition with few good options.

In the lab, EMTT has been shown to upregulate genes linked to bone formation and to accelerate matrix mineralisation,15 and to stimulate human bone marrow mesenchymal stem cells.16 PEMF has its own long history in delayed union and non-union fractures, osteoarthritis and osteoporosis,1 and EMTT builds on that foundation at a much higher energy.

EMTT treatment of a woman's knee with the MAGNETOLITH ultra+

Five to twenty minutes. Fully clothed. A different dose reaching the tissue.

In the treatment room

The practicalities are where EMTT tends to win clinicians over. Sessions take 5 to 20 minutes depending on the indication and settings.2 Patients don’t need to undress, which helps with comfort and privacy. Settings are adjusted on the touchscreen, and the unit moves between rooms on its integrated trolley.17

It also sits comfortably alongside shockwave. STORZ MEDICAL positions EMTT as a complement to ESWT, and combined use has been studied in rotator cuff tendinopathy.13 For clinics already running shockwave, EMTT adds a second option for the same patient groups: chronic tendinopathy, knee osteoarthritis and persistent low back pain.

As with any electromagnetic therapy, screen for active implanted devices such as pacemakers, and check the full contraindications in the instructions for use.

Where it fits

Already offering shockwave

A complementary modality that draws on the same referral base and the same conversations with patients.

Chronic caseload that has plateaued

Something new to bring to degenerative presentations that haven’t moved with conservative care.

Underwhelmed by PEMF before

EMTT is a genuinely different treatment, at a different dose. It deserves a fresh look.

Thinking about adding EMTT to your clinic?

Get in touch for a MAGNETOLITH® ultra+ brochure and pricing, or read more about the device and how it works.

Request a brochure and pricing Explore EMTT
Sources (17)
  1. Hu H, et al. Promising application of Pulsed Electromagnetic Fields (PEMFs) in musculoskeletal disorders. 2020. View source
  2. STORZ MEDICAL. MAGNETOLITH® ultra+ product information. View source
  3. STORZ MEDICAL MAGNETOLITH® product listing (Enovis). View source
  4. STORZ MEDICAL. EMTT: scientific basis, clinically tested. View source
  5. Paolucci T, et al. Electromagnetic field therapy: a rehabilitative perspective in the management of musculoskeletal pain. A systematic review. J Pain Res. 2020. View source
  6. Contemporary advances (2015 to 2026) in EMTT and PEMF for musculoskeletal disorders: a systematic review of dosimetry and clinical response. Biomedicines. 2026. View source
  7. Flatscher J, et al. Pulsed Electromagnetic Fields (PEMF): physiological response and its potential in trauma treatment. Int J Mol Sci. 2023. View source
  8. Chang Y-S, Lin C-Y, Huang W-C. Pulsed electromagnetic field therapy in people with knee osteoarthritis: a systematic review and meta-analysis. Medicina. 2026. View source
  9. Comparison of short-term effects of ESWT, low-level laser therapy and PEMF in knee osteoarthritis: a randomised controlled study. PEDro. View source
  10. Hollander K, Burgkart R, von Eisenhart-Rothe R, Vester J, Gerdesmeyer L. Extracorporeal magnetotransduction therapy (EMTT) for management of musculoskeletal disorders: a double-blind, placebo-controlled, randomised trial. 2025. View source
  11. STORZ MEDICAL. EMTT: non-invasive treatment option for chronic pain. View source
  12. Ringeisen M, et al. Prospective double blinded placebo controlled trial of high energetic magneto transduction therapy in shoulder joint enthesiopathies. Sports Orthop Traumatol. 2023;39(2):212. View source
  13. STORZ MEDICAL. EMTT publications, including Krath et al. (low back pain) and Klüter et al. (EMTT and shockwave in rotator cuff tendinopathy). View source
  14. Klüter T, et al. Electromagnetic transduction therapy in patients with chronic aseptic osteitis pubis. J Orthop Res Ther. 2018;3(12):1113. View source
  15. Extracorporeal magnetotransduction therapy as a new form of electromagnetic wave therapy: from gene upregulation to accelerated matrix mineralization in bone healing. Biomedicines. 2024. View source
  16. Stimulation of human bone marrow mesenchymal stem cells by electromagnetic transduction therapy (EMTT). 2022. View source
  17. STORZ MEDICAL. Supercharge your tissue: the new MAGNETOLITH® ultra+. View source