Magnetic field tissue repair (PEMF)

A coil generates a pulsed magnetic field through the treated region. The proposed mechanism is an effect on cell membrane activity and local circulation that supports tissue repair. Treatment is painless, requires no skin contact and can be applied through clothing and casts.

That last point is its practical advantage: it can be delivered to a region that cannot be touched, moved or loaded.

Delayed fracture healing, bone oedema, osteoarthritis pain, chronic soft tissue problems, and post-surgical swelling and pain. It is used in the early phase where active treatment is not yet possible.

It is avoided in pregnancy, in patients with pacemakers or implanted electronic devices, in active malignancy in the field, and where there is active bleeding.

For bone healing, pooled sham-controlled trials of bone stimulators, most of them PEMF, give moderate-quality evidence of fewer non-unions on X-ray, although the few trials that measured function found no difference 1. A Cochrane review limited to delayed union and non-union, however, found the evidence inconclusive 2. For osteoarthritis and soft tissue pain the evidence is weaker and the effect sizes are modest 3 4.

We use it where it fits, describe it as an adjunct, and do not present it as a primary treatment. Patients are entitled to know which category a treatment falls into before they pay for it.

Pulsed magnetic field therapy is widely offered and the evidence is limited and mixed. Some studies report pain improvement in osteoarthritis and better bone healing, but the osteoarthritis trials carry a high overall risk of bias and their gains may fall short of what patients would notice 5.

We use it as an adjunct where a patient finds it helpful and we do not build treatment plans around it. It is not offered as a treatment for systemic disease, and those claims exist in this field.

It appears in programmes as an optional adjunct chosen by preference, and it never displaces exercise, loading or hands-on work. If a session has to be dropped for time, this is the one.

We do not offer it for systemic disease, immune conditions or as a general wellness treatment, and those claims circulate widely in this field.

The trials that test this directly suggest it adds little. In a randomised, double-blind trial in shoulder impingement, patients who had active or placebo PEMF before the same strengthening programme finished with no difference between the groups in pain, function or strength 4. In knee osteoarthritis, pooled trials show short-term symptom relief compared with placebo but no advantage over other conservative treatments such as physiotherapy, and the gap between treated and control patients narrows as follow-up lengthens 3.

Exercise therefore remains the core of any plan for joint or tendon pain; PEMF, where it is used at all, sits alongside it as an optional extra.