Application of shortwave diathermy to lower limb increases arterial blood flow velocity and skin temperature in women: a randomized controlled trial

• Published in: Revista brasileira de fisioterapia (São Carlos (São Paulo, Brazil)) Brazil)), 2017-03, Vol.21 (2), p.127-137
• Main Authors: Sousa, Natanael Teixeira Alves De, Guirro, Elaine Caldeira De Oliveira, Calió, João Guilherme, Queluz, Mariane Cristina De, Guirro, Rinaldo Roberto De Jesus
• Format: Article
• Language: English
• Subjects: Blood Flow Velocity; Diathermy; Diathermy - methods; Female; Heating; Humans; Knee - physiopathology; Knee Joint - physiopathology; Lower Extremity; Original Research; Pain Management; Physical therapy modalities; Randomized Controlled Trials as Topic; Range of Motion, Articular; Skin Temperature
• ISSN: 1413-3555; 1809-9246
• DOI: 10.1016/j.bjpt.2017.03.008

•The velocity of popliteal artery flow remained unchanged with MWD and increased with SWD, remaining above baseline even 20min after application.•Despite changes in blood flow velocity, no correlation was found between the temperature variation and arterial blood flow.•SWD and MWD both increase skin temperature, but only SWD increased it for over 20min after the end of application.•The temperature was greater in the areas under the MWD and SWD electrodes.•The position of the knee interfered with the skin temperature of the hamstring only after 10min of SWD application. Shortwave diathermy (SWD) and microwave diathermy (MWD) are frequently used by physical therapists to treat musculoskeletal conditions. The therapeutic benefits are usually associated with an increase in tissue temperature; however, there is no consensus on the changes in blood flow. 1) To evaluate the behavior of temperature and arterial blood flow after the application of SWD and MWD to the lower limb of healthy women aged 18–30 and 2) to assess whether changes in limb positioning can influence SWD response. Among the subjects analyzed, 40 women were eligible to participate in the trial and were randomly allocated to the SWD group or the MWD group. Each group received 20min of diathermy. After receiving the interventions, all patients crossed over to the other group, but the devices were detuned (sham). SWD was applied to the posterior compartment of the thigh and leg, with the knee in 0° and 90° of flexion, and the MWD applied to the posterior thigh. Skin temperature evaluation (digital infrared thermography) and assessment of blood flow velocity (Doppler ultrasound) were performed immediately before and 10 and 20min after the application. Arterial blood flow increased after SWD diathermy (vs. Sham), but not after MWD diathermy. SWD promoted skin heating at the end of therapy in all areas analyzed, remaining above baseline even 20min after the end of the application. MWD diathermy promoted skin heating in the posterior thigh, reflecting a rise in the temperature of the popliteal fossa area that remained for 10min after the end of the application. The increase in arterial blood flow velocity depends on the size of the heating area, since it was only observed in the application of the SWD. However, after 20min of application, the position of the lower leg did not affect the heating.