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<< TillbakaÖverskrift | A comparison of human muscle temperature increases during 3-MHz continuous and pulsed ultrasound with equivalent temporal average intensities |
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Upplaga | 7 |
Sidor | 395-401 |
Överskrift | A comparison of human muscle temperature increases during 3-MHz continuous and pulsed ultrasound with equivalent temporal average intensities |
Beskrivning | STUDY DESIGN: A repeated-measure crossover design was used. The independent variable was the type of ultrasound (pulsed or continuous) and the dependent variable was intramuscular temperature. OBJECTIVE: To compare changes in intramuscular temperature resulting from the use of pulsed ultrasound versus continuous ultrasound with an equivalent spatial average temporal average (SATA) intensity. BACKGROUND: There is a lack of research on the heat-generating capabilities of pulsed ultrasound within human muscle. METHODS AND MEASURES: The subjects were 16 healthy volunteers (mean age +/- SD, 21.3 +/- 2.5 years). Each subject was treated with pulsed ultrasound (3 MHz, 1.0 W/cm2, 50% duty cycle, for 10 minutes) and continuous ultrasound (3 MHz, 0.5 W/cm2, for 10 minutes) during a single testing session. Tissue temperature returned to baseline and stabilized between treatments and treatment order was randomized. Tissue temperature was measured every 30 seconds using a 26-gauge needle microprobe inserted at a depth of 2 cm in the left medial gastrocnemius muscle. Data were analyzed using a linear mixed model. RESULTS: Treatment with continuous ultrasound produced a mean (+/-SD) temperature increase of 2.8 degrees C +/- 0.8 degrees C above baseline. Treatment with pulsed ultrasound produced a mean (+/-SD) temperature increase of 2.8 degrees C +/- 0.7 degrees C above baseline. Statistical analysis revealed no significant differences in either the extent or rate of temperature increases between the 2 modes of ultrasound application. CONCLUSION: Pulsed ultrasound (3 MHz, 1.0 W/cm2, 50% duty cycle, for 10 minutes) produces similar intramuscular temperature increases as continuous ultrasound (3 MHz, 0.5 W/cm2, for 10 minutes) at a 2-cm depth in the human gastrocnemius. Spatial average temporal average intensity is an important consideration when selecting pulsed ultrasound parameters intended to deliver nonthermal effects. |
Källa | The Journal of orthopaedic and sports physical therapy |
Publicerad | 2004 |
Författare | Brand KG., Brody LT, Draper DO, Fellingham GW, Gallo JA |