Temperature rise in human muscle during ultrasound treatments using flex-all as a coupling agent

• Published in: Journal of athletic training Vol. 33; no. 2; pp. 136 - 140
• Main Authors: Ashton, D F, Draper, D O, Myrer, J W
• Format: Journal Article
• Language: English
• Published: United States National Athletic Trainers Association 01.04.1998
• Subjects: Climate; Control Groups; Factor Analysis; Gender Differences; Muscular system; Original Research; Pharmaceuticals; Phonetics; Research Design; Sports injuries; Statistical Analysis; Temperature
• ISSN: 1062-6050; 1938-162X

To determine if Flex-all 454, as advertised, is effective as a thermal ultrasound couplant. Research design was a one-factor analysis of variance. Subjects received three (alternating order) ultrasound treatments (1 MHz at 1.5 W/cm(2) for 10 minutes) using the following couplants: 50% Flex-all mixed with 50% ultrasound gel; 100% ultrasound gel; and sham ultrasound with 100% Flex-all. Data were collected in a ventilated laboratory. Fifteen male and female students (mean age = 24.2 +/- 3.7 years). Muscle temperature was measured via hypodermic microprobes inserted 3 and 5 cm deep in the medial triceps surae. A visual analogue scale was used to measure perceived heat. At 3 cm, the increases for the gel, 50/50 mixture, and sham were 3.2 degrees C, 2.6 degrees C, and -0.82 degrees C, respectively. At 5 cm, the increases were 2.17 degrees C, 1.80 degrees C, and -0.50 degrees C, respectively. Subjects rated the sham treatment as mild heating (although the temperature dropped) and perceived treatments using the 50/50 mixture to be warmer than treatments using 100% gel couplant. Ultrasound treatments delivered with a 50/50 Flex-all/gel couplant felt warmer to subjects; however, identical treatments with 100% ultrasound gel produced higher muscle temperatures. Clinicians desiring optimal thermal effects should use 100% ultrasound gel as the couplant.