Pulsed electromagnetic field (PEMF) therapy is a treatment modality for horses in which pulses of electromagnetic fields are directed at specific parts of the body. Research suggests that PEMF can improve bone healing rates, regenerate and protect cartilage cells, and reduce pain and inflammation.

PEMF Therapy in Horses

The use of pulsed electromagnetic field (PEMF) therapy originated when researchers discovered stress applied to a bone during weight bearing induced an electrical current within the bone cells.

Researchers found these electrical currents enable bone tissues to sense mechanical forces, stimulating tissue remodeling (bone regeneration and structural changes) to better compensate for load bearing.

PEMF therapy leverages this concept by producing an electrical current within the tissue, with the hypothesis that the stimulation will trigger tissue remodeling without having to apply additional mechanical stress to the bone.

How PEMF Works

PEMF technology uses magnetic fields to create electrical currents within tissues. This makes it different from other therapies that pulse waves through the tissues such as shockwave therapy or therapeutic ultrasound. This allows PEMF treatment to affect deeper tissues that other therapies cannot access using standard treatment methods. [3]

Effects on Tissue

Research on the impact of PEMF therapy on equine tissues is limited, but there are several studies from human medical literature. These studies report variable efficacy, with one review showing that only 51% of PEMF studies identified cellular changes.

  • Increased bone production (osteogenesis)

  • Increased regeneration of cartilage cells

  • Improved cartilage cell survival in joint tissues

  • Anti-inflammatory effects in treated tissues

  • Proliferation of stem cells.

Anti-inflammatory Changes

Studies show that PEMF may have an anti-inflammatory effect. PEMF treatment can decrease the activity of neutrophils, a major inflammatory cell in the immune system. [ Decreasing the activity of these cells can have a protective effect on structural cells within the joint capsule.

Additionally, other studies show PEMF treatment can decrease levels of prostaglandin in a treated area. Prostaglandin is a major inflammatory protein that plays a role in the pain sensation associated with inflammation. By decreasing prostaglandin levels in an area, PEMF may reduce pain perception and improve comfort.

Stem Cell Proliferation

There is considerable research into the effect of PEMF on stem cells. Studies show PEMF can stimulate stem cells to transform into osteoblasts and chondrocytes. As stem cell therapy is an increasingly popular treatment for lameness in horses, these findings suggest that PEMF therapy may have a synergistic effect with stem cell treatment.

Uses

Each machine produces a slightly different electromagnetic field, which may have a different effect depending on the treatment area, frequency of treatment, and duration of treatment session. Therefore, standardizing PEMF treatment protocols is difficult in both human and equine medicine.

Parameters of the electromagnetic fields that vary between machines include:

  • Intensity of the magnetic field

  • Duration of the pulses

  • Frequency of the pulses

  • Shape of the electromagnetic pulse

Some machines allow practitioners to adjust these settings to produce a desired effect. There are currently few studies describing ideal PEMF treatment protocols for different conditions, so most practitioners use previous experience and anecdotal evidence to design a treatment protocol for each case.

Joint Disease

Some medical practitioners use PEMF as part of treatment protocols for patients with arthritis. One review paper evaluating 11 human clinical studies showed pain associated with arthritis decreased after PEMF treatment, with additional improvements in physical function and joint stiffness.

Another review of medical literature revealed that half of the studies assessing PEMF therapy’s effectiveness on arthritis showed positive results. The researchers concluded that PEMF is a safe and effective method to relieve pain and improve function in the short term for arthritis patients.

Wound Healing

Some studies from medical literature show increased wound healing rates when PEMF is part of the treatment protocol. One study showed patients with chronic foot ulcers had an 18% reduction in wound size compared to 10% reduction in untreated patient

Side Effects

There are few reports of side effects from PEMF therapy. This treatment is considered safe for most horses.

PEMF treatment should not be directly applied locally to areas with known or obvious:

  • Metal bone implants

  • Tumors

  • Open wounds

  • Sites of infection or inflammation, particularly of joints

Additionally, pregnant mares should not receive PEMF treatment.

Summary

Pulsed electromagnetic field (PEMF) therapy is a promising treatment modality for horses with compelling evidence from human medical literature. It may be beneficial to support rehab and recovery for a number of muscular and skeletal injuries in horses.

  • PEMF involves treating an area with pulses of electromagnetic fields to stimulate tissue healing and proliferation

  • PEMF may improve bone healing rates, reduce inflammation, and control pain

  • More scientific research is necessary to determine optimum treatment protocols and efficacy in horses

  • PEMF has few reported side effects and is considered safe for most horses