Therapeutic ultrasound decreases mechano-growth factor messenger ribonucleic acid expression after muscle contusion injury

Arch Phys Med Rehabil. 2007 Jul;88(7):936-40. doi: 10.1016/j.apmr.2007.04.005.


Objective: To examine the influence of nonthermal ultrasound on mechano-growth factor (MGF) messenger ribonucleic acid (mRNA) expression after blunt trauma.

Design: A 2x4 factorial multivariate analysis of variance design.

Setting: University research laboratory.

Animals: Thirty-six 3- to 4-month-old male Wistar rats (mean weight, 280.8+/-21.5g). Thirty-two received a bilateral contusion injury to the gastrocnemius via a drop mass technique. Four were control animals.

Intervention: Ultrasound treatment (frequency, 3MHz; intensity, 0.3W/cm(2); continuous duty cycle) was started 24 hours postinjury and delivered for 5 minutes daily on 4 consecutive days. Treatment was on the left hindlimb and the contralateral right hindlimb was the nonultrasound control.

Main outcome measures: Muscle mass (in grams) and MGF mRNA expression as measured via real-time reverse transcriptase polymerase chain reaction.

Results: Ultrasound had no effect on muscle mass (F(1,28)=2.723, P=.110, 1-beta=.357, eta(2)=.089). Ultrasound treatments decreased MGF mRNA expression in the treated limb compared with the nontreated hindlimb (F(1,28)=6.605, P=.016, 1-beta=.699, eta(2)=.191).

Conclusions: The nonthermal ultrasound treatments resulted in decreased MGF mRNA expression after blunt trauma to the gastrocnemius muscles.

MeSH terms

  • Animals
  • Contusions / metabolism
  • Contusions / therapy*
  • Insulin-Like Growth Factor I / metabolism*
  • Male
  • Muscle, Skeletal / injuries
  • Muscle, Skeletal / metabolism*
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Wistar
  • Ultrasonic Therapy*


  • RNA, Messenger
  • mechano-growth factor, rat
  • Insulin-Like Growth Factor I