Ultrasound Uses in Physical Therapy
Ultrasound: A Brief Introduction
One of the most effective means of pain relief and healing therapy in medical practice today is ultrasound (US). Before its use within the medical community, ultrasound (under the title of SONAR) was used by the military with resounding effect for locating underwater objects and/or ships. It was this success that led to ultrasound finding its way into many commercial applications such as checking the structural integrity of manufactured goods, small scale/delicate cleaning (i.e. jewelry), and humidifying air. It is the medical use of ultrasound, however, that is most appreciated by millions of medical personnel and patients the world over. A short list of medical uses for ultrasound includes:
Medical Uses for Ultrasound:
- Diagnostic imaging: I'm sure most of you have seen those precious sonograms of your new baby in utero. Well, a sonogram utilizes ultrasound technology. Other medical imaging applications utilizing ultrasound include heart, prostate, and other internal organ imaging.
- Monitoring Speed of Body Fluids: Ultrasound medical equipment is often used to gauge the speed of certain body fluids, from the blood in your veins and into the brain. Peripheral blood flow, defined as circulation outside the brain, heart, spinal cord, and optic nerve, can also be monitored to check for dangerous blood clots or other circulation problems.
- Breaking Apart Internal Objects: Such as kidney stones and gall stones for non-surgical removal.
- Bone Regeneration: Ultrasound has been shown to increase bone healing within certain parameters and medical situations.
- Tissue Healing: The positive effects of ultrasound on the healing process, especially in the sense of difficult wounds, have been well documented. Other types of tissues that benefit from ultrasound are tendon and ligament injuries.
- Creating Deep Heat: Used with great success in clinics worldwide, ultrasound is one of the primary modalities for creating deep tissue heat leading to pain relief, increased circulation, and overall increased healing.
What is Ultrasound?
Ultrasound in its simplest terms is a type of sound; defined as the transferring of energy from one source to another by the vibration of molecules, for instance a mouth to an ear. The difference between the sound we hear and ultrasound, however, is that the human ear cannot hear ultrasound. Ultrasound frequencies are, for lack of a better term, above (ultra) the range of the human ear.
By definition, ultrasound is any sound frequency above 20 kHz (or 20,000 cycles/waves per second). The possibilities for ultrasound frequencies are many. For the purpose of this hub, however, therapeutic ultrasound frequencies are between 1 and 3 Mhz (or, 1-3 Million cycles per second); each having a specific therapeutic use: thermal (heat-producing) and non-thermal (non-heat-producing).
The thermal qualities of ultrasound are produced when the ultrasound waves are absorbed at the molecular level while the non-thermal qualities are created by ultrasound waves at the cellular level; both results have medical uses.
Thermal US uses include:
- Pre-heating tissues for stretching, i.e. tendons, muscles, joint capsules, etc: Quite often, tissue shortening and tightening, referred to as joint and muscle contracture, results due to long periods of immobilization following chronic disease, injury, scarring, paralysis, etc. If allowed to remain immobile, these temporary contractures may become permanent leading to added patient disability. Ultrasound is used to increase heat in affected tissues leading to increased elasticity, easier tissue stretching, and ranging.
- Increasing local circulation: Increased circulation is an effect of increased heat, and since ultrasound increases heat, the subsequent increase in blood and lymph circulation adds to the healing process of various types of wounds be they arterial, venous, diabetic neuropathies, or pressure ulcers.
- Treating muscle spasms: In much the same way ultrasound is used for increasing circulation to improve healing, higher levels of heat are used to control muscle pain and spasm.
- Pain control in chronic pain: Similar to controlling muscle pain, ultrasound has been shown to control pain associated with various chronic conditions.
- Metabolic effects: Increased circulation leads to increased cellular metabolism which leads to improved Oxygen delivery (which has its own catalog of benefits) and Calcium resorption for bone healing.
- Nerve conduction: Another benefit of increased heat is increased nerve conduction velocity which leads to a decreased firing rate of alpha motor neurons, the neurons most responsible for muscle spasm.
Non-Thermal Ultrasound Uses:
Non-Thermal US uses are:
- Facilitate healing in the inflammatory and proliferative phases following soft tissue injury
- Bone healing
- Wound healing
- Healing tendon injuries
- Enhance transdermal-drug penetration: PHONOPHORESIS
- Ultrasound can cause cell membrane destabilization. An unstable membrane can:
- Increase skin and cell permeability: For easier diffusion of medications such as corticosteroids.
- Increase intracellular calcium: Increases bone healing
- Increase mast cell production: Assists in the inflammatory and proliferation stages of wound healing
Ultrasound Treatment Poll:
What types of conditions have you had treated with ultrasound
Ultrasound: A Brief Conclusion
Ultrasound is a well-tested modality for the treatment of pain, certain types of healing, increased medication diffusion (Phonophoresis), inflammation, and creating deep heat. The process is painless, effective, and a mainstay in almost every physical therapy clinic.
With continuing research, ultrasound will more than likely expand its therapeutic boundaries to reach new patients and medical conditions; leading to a very bright future for its practice.
