title: Effects of therapeutic ultrasound on intramuscular blood circulation and oxygen dynamics.
abstract: OBJECTIVE
  This study aimed to clarify the effects of therapeutic ultrasound on intramuscular local blood circulation (and oxygen dynamics) using near-infrared spectroscopy (NIRS).
  
  
  METHODS
  The participants were 11 healthy males.
  
  
  METHODS
  All participants performed all three trials; (1) the ultrasound (US group), (2) without powered ultrasound (placebo group), and (3) rest (control group). Ultrasound was applied at 3 MHz, 1.0 W/cm(2), and 100% duty cycle for 10 minutes. Evaluation index were oxygenated, deoxygenated, and total hemoglobin (Hb) concentrations in the intramuscular and skin surface temperature (SST). The experimental protocol was a total of 40 minutes, that is, 10 minutes before trial (rest), 10 minutes during the trial (ultrasound, placebo, and control), and 20 minutes after trial (rest). The NIRS and SST data collected before and after the trial were divided into 5 minutes intervals for further analysis.
  
  
  RESULTS
  Oxygenated and total hemoglobin levels were significantly higher in the US group than in the placebo and control groups for the 20 minutes after ultrasound (p < 0.01). The SST was significantly higher in the US group than in the control for 15 minutes after ultrasound (p < 0.05), while it was significantly lower in the placebo group than in the US and control groups for 20 minutes after the trials (p < 0.01).
  
  
  CONCLUSIONS
  The effects of ultrasound were maintained for 20 minutes after the trial on intramuscular blood circulation and oxygen dynamics. These effects were caused by a combination of thermal and mechanical effects of the ultrasound.
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.|Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Katsuyuki
authors: K
authors: Morishita
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.
authors: Hiroshi
authors: H
authors: Karasuno
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.|Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Yuka
authors: Y
authors: Yokoi
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.
authors: Kazunori
authors: K
authors: Morozumi
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.|Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Hisayoshi
authors: H
authors: Ogihara
authors: Hokkaido Chitose Institute of Rehabilitation Technology, Hokkaido, Japan.
authors: Toshikazu
authors: T
authors: Ito
authors: Koriyama Institute of Health Sciences, Fukushima, Japan.|Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Takayuki
authors: T
authors: Fujiwara
authors: Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Tetsuya
authors: T
authors: Fujimoto
authors: Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors: Koji
authors: K
authors: Abe
keywords: local blood circulation; oxygen dynamics; ultrasound