• Soft tissue injuries
• Joint dysfunction
• Osteoarthritis
• Periarthritis (non septic)
• Bursitis
• Tenosynovitis
• Musculoskeletal syndromes
  

PHYSIOLOGIC RESPONSES OF ULTRASOUND

GENERAL

• Increase collagen extensibility (increase range of motion).
• Decrease joint stiffness
• Increase pain threshold
• Decrease muscle spasms
• Increase metabolism of edema and exudates (decrease swelling)
• Increase nerve conduction velocities (promotes healthier nerves)
  

  CHEMICAL EFFECTS

• Vibration enhances chemical reactions
• Accelerates enzyme activity (promotes healing)
• Increases capillary permeability (Decreases swelling, will remove waste, and allows more blood, to reach injured areas.
• Increase ATP activity in skeletal activity. (Provides more chemical energy to muscles, to reduce fatigue)
• Serotonin released by platelets to increase the release of endogenous opiates. (A natural chemical produced in the body to reduce pain)
  

  BIOLOGICAL RESPONSES

• Increase fluid and nutrient transfer
• Increase phagocytic activity. (Reduces waste to the injured area and pathogens such as bacteria
• Increase sympathetic and parasympathetic stimulation. (Promotes a stronger immune response to the affected site).
  

  MECHANICAL RESPONSE

• Cavitation: Extreme power, duration or not moving sound head causes deformation of molecular structure. (Can burn the patient if not used properly. Low levels of cavitation stimulate cellular responses by reducing edema, and stimulate the mechanoreceptors.
• Micro-massage: moderate deformation, useful for mobilizing scar tissue, decrease muscle spasms, breaking up calcific deposits, etc. and is normally found at therapeutic levels.
• Tendon Extensibility: mechanical vibration acts on cementum that binds collagen causing fiber separation; can increase potential extensibility of tendons and connective tissue. (Increase ROM).
  

  THERMAL EFFECTS

• Most soft tissue such as muscle, skin, fat, and ligament absorb heat similarly.
• Alters blood flow to promote healing.
• Increases pain threshold (tolerate pain better).
• Enzymatic activity is increased which promote healing and repair of damage tissue.

WORKS CONSULTED
Prentice, Wm. Therapeutic Modalities in Sports Medicine. Times Mirror/Mosby, 1990. McDonland, D.CC.C.R.D. Heather A. Thieme, M.A.,A.T.C. Guide t o Therapeutic Modalities. 1991. Gersch, Merly. Electrotherapy in Rehabilitation. F.A. Davis Company. Philadelphia 1992.