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J Athl Train. 1998 Apr-Jun; 33(2): 136–140.
PMCID: PMC1320400

Temperature Rise in Human Muscle During Ultrasound Treatments Using Flex-All as a Coupling Agent

Douglas F. Ashton, MS, ATC,* David O. Draper, EdD, ATC, and J. William Myrer, PhD



To determine if Flex-all 454, as advertised, is effective as a thermal ultrasound couplant.

Design and Setting:

Research design was a one-factor analysis of variance. Subjects received three (alternating order) ultrasound treatments (1 MHz at 1.5 W/cm2 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°C, 2.6°C, and -0.82°C, respectively. At 5 cm, the increases were 2.17°C, 1.80°C, and -0.50°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.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Lehmann JF, DeLateur BJ, Warren CG, Stonebridge JB. Heating of joint structures by ultrasound. Arch Phys Med Rehabil. 1968 Jan;49(1):28–30. [PubMed]
  • Draper DO, Sunderland S, Kirkendall DT, Ricard M. A comparison of temperature rise in human calf muscles following applications of underwater and topical gel ultrasound. J Orthop Sports Phys Ther. 1993 May;17(5):247–251. [PubMed]
  • Dyson M, Pond JB, Joseph J, Warwick R. The stimulation of tissue regeneration by means of ultrasound. Clin Sci. 1968 Oct;35(2):273–285. [PubMed]
  • Lehmann JF, Stonebridge JB, deLateur BJ, Warren CG, Halar E. Temperatures in human thighs after hot pack treatment followed by ultrasound. Arch Phys Med Rehabil. 1978 Oct;59(10):472–475. [PubMed]
  • KUITERT JH. Ultrasonic energy as an adjunct in the management of radiculitis and similar referred pain. Am J Phys Med. 1954 Feb;33(1):61–65. [PubMed]
  • Griffin JE. Transmissiveness of ultrasound through tap water, glycerin, and mineral oil. Phys Ther. 1980 Aug;60(8):1010–1016. [PubMed]
  • Warren CG, Koblanski JN, Sigelmann RA. Ultrasound coupling media: their relative transmissivity. Arch Phys Med Rehabil. 1976 May;57(5):218–222. [PubMed]
  • Cameron MH, Monroe LG. Relative transmission of ultrasound by media customarily used for phonophoresis. Phys Ther. 1992 Feb;72(2):142–148. [PubMed]
  • Kramer JF. Ultrasound: evaluation of its mechanical and thermal effects. Arch Phys Med Rehabil. 1984 May;65(5):223–227. [PubMed]
  • Draper DO, Sunderland S. Examination of the law of grotthus-draper: does ultrasound penetrate subcutaneous fat in humans? J Athl Train. 1993 Fall;28(3):246–250. [PMC free article] [PubMed]
  • Draper DO, Castel JC, Castel D. Rate of temperature increase in human muscle during 1 MHz and 3 MHz continuous ultrasound. J Orthop Sports Phys Ther. 1995 Oct;22(4):142–150. [PubMed]
  • Price DD, McGrath PA, Rafii A, Buckingham B. The validation of visual analogue scales as ratio scale measures for chronic and experimental pain. Pain. 1983 Sep;17(1):45–56. [PubMed]
  • Rimington SJ, Draper DO, Durrant E, Fellingham G. Temperature changes during therapeutic ultrasound in the precooled human gastrocnemius muscle. J Athl Train. 1994 Dec;29(4):325–327. [PMC free article] [PubMed]
  • Reid DC, Cummings GE. Efficiency of ultrasound coupling agents. Physiotherapy. 1977 Aug;63(8):255–257. [PubMed]
  • Byl NN. The use of ultrasound as an enhancer for transcutaneous drug delivery: phonophoresis. Phys Ther. 1995 Jun;75(6):539–553. [PubMed]
  • Machluf M, Kost J. Ultrasonically enhanced transdermal drug delivery. Experimental approaches to elucidate the mechanism. J Biomater Sci Polym Ed. 1993;5(1-2):147–156. [PubMed]
  • McElnay JC, Benson HA, Harland R, Hadgraft J. Phonophoresis of methyl nicotinate: a preliminary study to elucidate the mechanism of action. Pharm Res. 1993 Dec;10(12):1726–1731. [PubMed]
  • Steinsträsser I, Merkle HP. Dermal metabolism of topically applied drugs: pathways and models reconsidered. Pharm Acta Helv. 1995 Apr;70(1):3–24. [PubMed]
  • Ciccone CD, Leggin BG, Callamaro JJ. Effects of ultrasound and trolamine salicylate phonophoresis on delayed-onset muscle soreness. Phys Ther. 1991 Sep;71(9):666–678. [PubMed]
  • Hogan RD, Burke KM, Franklin TD. The effect of ultrasound on microvascular hemodynamics in skeletal muscle: effects during ischemia. Microvasc Res. 1982 May;23(3):370–379. [PubMed]
  • Balmaseda MT, Jr, Fatehi MT, Koozekanani SH, Lee AL. Ultrasound therapy: a comparative study of different coupling media. Arch Phys Med Rehabil. 1986 Mar;67(3):147–150. [PubMed]
  • Docker MF, Foulkes DJ, Patrick MK. Ultrasound couplants for physiotherapy. Physiotherapy. 1982 Apr;68(4):124–125. [PubMed]
  • Oakley EM. Application of continuous beam ultrasound at therapeutic levels. Physiotherapy. 1978 Jun;64(6):169–172. [PubMed]

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