The Thermal Influence of an Electromagnetic Field with a Radio Frequency Depending on the Type of Electrode Used

Diathermy is a method used in physiotherapy based on obtaining an increase in temperature by supplying energy from the electromagnetic field to the tissues. The aim of this retrospective work, based on the data included in a medical documentation, was to assess the dynamics of temperature changes on the body surface after the application of a high-frequency electromagnetic field depending on the type of electrode used. In order to generate a radio frequency electromagnetic field, an INDIBA ACTIV(®) CT9 was used. In order to measure the temperature, an HT-17 thermovision camera was used, enabling measurements within the range of −20 to 300 °C, with an accuracy of ±2% or 2 °C. The participants consisted of 30 healthy subjects (15 women and 15 men) who were physiotherapy students in the Faculty of Public Health in the Silesian Medical University in Katowice, Poland; they were divided into two comparative groups (A and B). It was found that the differences between the groups were not significant in the measurements carried out before using the electrode (p = 0.84; Mann–Whitney U test). On the other hand, at 0, 5 and 15 min, statistically significant differences were noted in the tissue temperature between the groups, depending on the electrode used (p = 0.00; Mann–Whitney U test). Based on the obtained results, it can be concluded that with the extension of the observation time, the tissue temperature increased (for Group A, Me 30.40 °C vs. 34.90 °C; for Group B, Me 30.70 °C vs. 35.20 °C). Our study confirmed that the use of both a capacitive and resistive electrode during treatment with the use of a high-frequency electromagnetic field statistically significantly increased the surface temperature of the area to which the therapy was applied. The results of the study can be used in clinical practice by physiotherapists to optimize the conditions of therapy.