title: Muscle and tendon heating rates with therapeutic ultrasound in horses.
abstract: OBJECTIVE
  To (1) determine the temperature change in equine tendon and muscle during therapeutic ultrasound and (2) develop guidelines for treating horses for muscular or tendinous injury using therapeutic ultrasound.
  
  
  METHODS
  Experimental, in vivo study.
  
  
  METHODS
  Adult horses (n = 10).
  
  
  METHODS
  Thermistors were inserted in the superficial and deep digital flexor tendons (SDFT and DDFT) of the thoracic limbs of 10 adult horses. On the left, 3.3 MHz therapeutic continuous ultrasound was done for 10 minutes at an intensity of 1.0 W/cm(2) and for the right thoracic limb at 1.5 W/cm(2). Thermistors were placed at 1 cm, 4 cm, and 8 cm depths in the epaxial muscles of the same 10 horses, for a 20-minute treatment at a frequency of 3.3 MHz and intensity of 1.5 W/cm(2). Temperature was recorded before, during, and after treatment. Data were statistically analyzed.
  
  
  RESULTS
  Mean temperature rise was 3.5°C in the SDFT and 2.5°C in the DDFT at the end of the 1.0 W/cm(2) treatment (P = .94) and 5.2°C in the SDFT and 3.0°C in the DDFT at the end of the 1.5-W/cm(2) treatment (P = .48). Mean temperature rise in epaxial musculature was 1.3°C at a depth of 1.0 cm, 0.7°C at 4.0 cm, and 0.7°C at 8 cm.
  
  
  CONCLUSIONS
  The SDFT and DDFT are heated to a therapeutic temperature using a frequency of 3.3 MHz and intensity of 1.0 W/cm(2). The epaxial muscles are not heated to a therapeutic temperature using a frequency of 3.3 MHz and an intensity of 1.5 W/cm(2).
authors: Department of Large Animal Surgery, University of Tennessee Equine Medical Center, Knoxville, TN, USA. lmontgom98@gmail.com
authors: Leslie
authors: L
authors: Montgomery
authors: Sarah B
authors: SB
authors: Elliott
authors: H Steve
authors: HS
authors: Adair
mesh_terms: D000818:Animals; D001831:Body Temperature; D005260:Female; D006736:Horses; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000293:injuries; D013708:Tendon Injuries / Q000000981:diagnostic imaging / Q000662:veterinary*; D013710:Tendons / Q000502:physiology*; D013821:Thermometers / Q000662:veterinary; D014464:Ultrasonic Therapy / Q000662:veterinary*; D014463:Ultrasonography