Hyperthermia induced by microwave diathermy in the management of muscle and tendon injuries ## Abstract Introduction: Hyperthermia induced by microwave diathermy raises the temperature of deep tissues from 41 degrees C to 45 degrees C using electromagnetic power. Microwave diathermy is used in the management of superficial tumours with conventional radiotherapy and chemotherapy and, recently, its use has been successfully extended to physical medicine and sports traumatology in Central and Southern Europe. Methods: We searched the literature for relevant studies. Most of the published studies in these fields have used 434 and 915 microwave diathermy, as these wavelengths are most effective. Results: Hyperthermia induced by microwave diathermy into tissue can stimulate repair processes, increase drug activity, allow more efficient relief from pain, help in the removal of toxic wastes, increase tendon extensibility and reduce muscle and joint stiffness. Moreover, hyperthermia induces hyperaemia, improves local tissue drainage, increases metabolic rate and induces alterations in the cell membrane. Conclusions: The biological mechanism that regulates the relationship between the t