Heat distribution in the lower leg from pulsed short-wave diathermy and ultrasound treatments

• Published in: Journal of athletic training 2000-01, Vol.35 (1), p.50-55
• Main Authors: Garrett, C L, Draper, D O, Knight, K L
• Format: Article
• Language: English
• Subjects: Climate; Error of Measurement; Heat; Legs; Original Research; Scientific Concepts; Sports medicine; Tissues; Ultrasonic imaging
• ISSN: 1062-6050; 1938-162X

To compare tissue temperature rise and decay after 20-minute diathermy and ultrasound treatments. We inserted 3 26-gauge thermistor microprobes into the medial aspect of the anesthetized triceps surae muscle at a depth of 3 cm and spaced 5 cm apart. Eight subjects received the diathermy treatment first, followed by the ultrasound treatment. This sequence was reversed for the remaining 8 subjects. The diathermy was applied at a frequency of 27.12 MHz at the following settings: 800 bursts per second, 400-microsecond burst duration, 850-microsecond interburst interval, peak root mean square amplitude of 150 W per burst, and an average root mean square output of 48 W per burst. The ultrasound was delivered at a frequency of 1 MHz and an intensity of 1.5 W/cm(2) in the continuous mode for 20 minutes over an area of 40 times the effective radiating area. The study was performed in a ventilated research laboratory. Sixteen (11 men, 5 women) healthy subjects (mean age = 23.56 +/- 4.73 years) volunteered to participate in this study. We recorded baseline, final, and decay temperatures for each of the 3 sites. The average temperature increases over baseline temperature after pulsed short-wave diathermy were 3.02 degrees C +/- 1.02 degrees C in site 1, 4.58 degrees C +/- 0.87 degrees C in site 2, and 3.28 degrees C +/- 1.64 degrees C in site 3. The average temperature increases over baseline temperature after ultrasound were only 0.17 degrees C +/- 0.40 degrees C, 0.09 degrees C +/- 0.56 degrees C, and -0.43 degrees C +/- 0.41 degrees C in sites 1, 2, and 3, respectively. The temperature dropped only 1 degrees C in 7.65 +/- 4.96 minutes after pulsed short-wave diathermy. We conclude that pulsed short-wave diathermy was more effective than 1-MHz ultrasound in heating a large muscle mass and resulted in the muscles' retaining heat longer.