A magnetic field is a space formed when magnetic forces act around a magnet, current, or changing electric field, and is used in various types of medical devices. Its uses are very wide, ranging from magnetic resonance imaging (MRI) to pulsed magnetic medical devices for pain relief.

When a magnetic field is applied to an area where the body's bioelectric current flows in a certain direction (internal circulation), a new magnetic field is generated in that area, and bioelectric current energy is concentrated in that area, stimulating nerves and cells. This principle has effects such as reducing chronic inflammation in painful areas, strengthening blood circulation, and strengthening muscles.