How Ultrasound Works
- What is Ultrasound Therapy and how does it work?
Ultrasound is a therapeutic treatment method utilizing sound waves to treat pain, inflammation and muscle spasm. Ultrasound therapy has been used by physical therapists and chiropractors since the 1940s. Therapeutic Ultrasound is a method of stimulating tissue beneath the skin’s surface using sound waves. This high frequency massage has sound waves typically between 800,000Hz and 2,000,000Hz. The sound cannot be heard by humans.
Ultrasound waves are applied to tissues using a round-headed wand or transducer. Ultrasound gel is used on the skin in order to reduce friction and act as a conductor of the ultrasonic waves. The waves are generated by a piezoelectric effect caused by the vibration of crystals within the head of the wand or probe. The ultrasonic waves that pass through the skin cause a vibration of the local tissues. This vibration or cavitation can cause a deep heating locally though usually no sensation of heat will be felt by the patient.
Sound waves are pulsed at the area causing your pain at millions of times per second. These waves stimulate your joints, ligaments, tendons, muscles and other tissues providing targeted pain relief without drugs or surgery. Ultrasound waves do the following:
- Add Heat: The sound waves penetrate the skin and surface layers and cause the soft tissue to vibrate, producing gentle healing vibrations within the affected area that soothe inflammation and relieve pain.
- Increase Blood Flow: Ultrasound waves also cause tissues to relax and increase blood flow to help reduce local swelling and chronic inflammation. Increased blood flow also delivers more oxygen and nutrients to the tissue, removes cell waste and aids healing.
- Enhances Absorption of Analgesics and Anti-inflammatory Agents: Ultrasound can also be used to evoke phonophoresis. This is a non-invasive way of enhancing the absorption of analgesics and anti-inflammatory agents to tissues below the skin using ultrasonic waves.
- Decreases Trigger Point Pain: Ultrasound works by decreasing the pain and sensitivity associated with muscular trigger points. Studies have demonstrated trigger points to be important causes of headache, back ache and all types of muscular and soft tissue “overuse” syndromes.
Ultrasound therapy has been shown to cause increases in tissue relaxation, local blood flow, and scar tissue and adhesion breakdown. The effect of the increase in local blood flow can be used to help reduce local swelling and chronic inflammation, and, according to some studies, promote bone fracture healing. Ultrasound enhances the body’s natural healing process and can reduce irritation to nerve roots.
Click HERE to browse our selection of Portable Ultrasound Machines. These wonderful pain therapy systems are portable medical-grade ultrasound devices used to relieve pain and promote healing.
- Where can I find out more information about Ultrasound Therapy?
The Association for Medical Ultrasound has a great website with tons of scientific research and information concerning ultrasound modalities. View their website by clicking here. We encourage you to read their publication Journal of Ultrasound in Medicine, carried by most libraries.
NBC and iVillage have a great page on Ultrasound Therapy. Check it out here and also see their related pages on “Thermotherapy” and “Ultrasound & Pain Disorders.”
You can also read an article about ultrasound from a well known plastic surgeon by clicking here.
Wikipedia has two good articles on Ultrasound therapy. One is “Therapeutic Ultrasound” and the other is “Ultrasound.” We have reviewed these articles and found them to be correct but note that the text displayed on Wikipedia is always changing.
Ultrasound Pain Relief
3. What can Ultrasonic Therapy be used for?
The Portable Ultrasound Machines offered at EZUltrasound.com can be used to treat yourself, in the comfort of your own home, to help relieve aliments and injuries including:
- Arthritis Pain Relief: Osteoarthritis, Rheumatoid arthritis,
Juvenile Rheumatoid Arthritis, Psoriatic arthritis
- Sciatic Nerve Pain Relief
- Foot Pain: Plantar Fasciitis, ankle sprain
- Wound Care
- Poor Circulation
- Neck Pain, Shoulder Pain, Sharp Back Pain, Upper Back Pain,
Lower Back Pain, Middle Back Pain, Chronic Pain, Shingles Pain,
Knee Pain, Gout pain, Nerve pain, Dr Franks Pain Relief, Joint Pain,
Muscle Pain, Ankle Pain, Hand Pain, Phantom Limb Pain
- Knee Injury, Back Injury, Rotator Cuff Injury, Ankle Injury, Elbow Injury
- Impingement: Nerve Impingement, Shoulder Impingement
- Tendonitis: Achilles tendonitis
- Bursitis: Hip Bursitis, Knee Bursitis
- Herniated Disc Treatment
- Neck Strain, Neck Spasms, Neck Relief, Pain Calf, Running Pain,
Back Headache, Strained Muscle
- Blood Bruises, Torn Foot, Calf Cramps, Muscle Stiffness, Torn Muscle
- Bone Fractures, Broken Tibia, Broken Wrist, Broken Elbow, Bone Break
- Pulled Muscles: Pulled Calf Muscle, Pull Groin, Pull Hamstring
- Reiters Syndrome, Myofascial Pain Syndrome, Complex Regional
Pain Syndrome, Carpal Tunnel Syndrome
- Frozen Shoulder, Ankylosing Spondylitis, Fibromyalgia, TMJ Disorder
- Many, many MORE!!
- (Not for the treatment of malignancies)
4. What frequency of ultrasound should I used for pain relief and injuries?
In physical therapy, therapeutic ultrasound is conducted at a relatively low frequency using ultrasonic sound waves to speed healing in injured joint or muscle tissue. The frequency used for sports injuries, chronic inflammation, arthritis and trauma is typically 1 MHz. At this frequency, the waves tend to travel through tissue with high water or low protein content, and to bounce off cartilage and bone. They are absorbed primarily by connective tissue: ligaments, tendons, and fascia (and also by scar tissue).
Since ultrasound waves are different lengths, some penetrate further into the skin than others. Typically, the ultrasonic frequency is the inverse of the ultrasound wave length, meaning the lower the frequency (ex. 1Mhz), the longer the wave, and vice versa.
Therapeutic ultrasound has two types of benefit:
- Thermal effects involve energy being absorbed from the ultrasonic waves and heating the tissue. If the tissue is heated to 40 to 45 °C (104 to 113 °F), it can enter a state of hyperaemia (increased blood flow), which speeds healing and reduces chronic inflammation.
- Added effects result from the vibration of the tissue causing microscopic air bubbles to form, which transmit the vibrations in a way that directly stimulates cell membranes. This physical stimulation appears to enhance cell-repair effects of the inflammatory response.
So, an increase in temperature over baseline muscle temperature of 36° C (100° F) to 37°C (101° F) accelerates the metabolic rate in tissue. Also, the depth at which your specific tissue, bone, or muscle injury or other ailment is located determines which frequency you should use, since each frequency of ultrasound waves penetrate to a different depth.
A 1Mhz ultrasound machine has the longest ultrasonic waves that penetrate up to 4 cm (1.6″) into the skin. 1 Mhz ultrasound therapy is typically recommended for any acute or chronic injuries & pain. Just a few of the conditions that can be treated with 1 Mhz ultrasound are listated above in Question 3, “What can Ultrasonic Therapy be used for?” Since the 1 Mhz intensity penetrates the furthest, it is ideal for bone injuries and arthritis treatment.
A 3Mhz ultrasound massager has average length ultrasound waves that penetrate up to 2 cm (0.8″) into the body. Therefore, it treats only the most superficial of tendon injuries and is not nearly as versatile as 1Mhz ultrasound therapy. Some prefer to start with a milder intensity ultrasound, such as 3Mhz, and work their way up to a higher intensity ultrasound, such as 1Mhz, but this often not necessary.
A 5Mhz ultrasound therapy machine has the shortest ultrasonic waves that penetrate 0.5 cm (0.2″) into the skin. Therefore, it is usually recommended for skin & facial rejuvenation, fat removal, cellulite, scars & scar tissue, sunburn, bruises, superficial cuts & scrapes (although these claims have not been substantiated). The 5 Mhz ultrasonic intensity typically does not penetrate deeply enough to affect the tendons or large body tissues, so it is not effective at treating injuries.
Please view our “Ultrasound Frequency Comparison” chart below as an easy reference:
(Disclaimer: Always follow the advise or prescription of your doctor or physical therapist when choosing the proper ultrasonic massager.)
5. Who can and cannot use therapeutic ultrasound massagers?
Ultrasound therapy has been used for years by the most elite athletes. Ultrasound therapy is what enables them to get quickly back to their sport or game after an injury. Until recently, ultrasonic therapy was only available to those who could afford expensive, professional-grade machines or daily access to a chiropractor or physical therapist. Now, at EZUltrasound.com, everyone can benefit from access to the exact same technology, as often as necessary, at a fraction of the price with our portable ultrasound machines.
Whether you’re a senior citizen, an athlete or just someone experiencing pain, ultrasound therapy is safe to use and is a great treatment option for many of your aches and pains. However, there are some people and certain conditions that cannot and should not be treated with ultrasound. Ultrasound therapy should not be used for the treatment of malignancies nor in the region with malignant tumors.
- Do not use on people with poor arterial circulation.
- Do not use over area with bleeding or infections.
- Do not use over the eyes.
- Do not use on someone who is pregnant.
- Do not use for patients with demand type cardiac pacemakers.
- Do not use over the carotid sinus nerves or arteries.
- Do not use over the laryngeal or pharyngeal muscles.
- Do not use on children under 18 years old without the express recommendation or supervision of a physician.
The use of ultrasound is NOT recommended:
- Over organs (stomach, liver, lungs, spleen, bowels, heart, kidneys)
- Over the pelvis, abdomen and lumbar (lower back) region in pregnant or potentially pregnant females
- Over highly ultrasound-sensitive organs (eyes, ears, ovaries, testicles, brain, spinal cord)
- Over mucous membranes (mouth, nose, rectum/anus, vagina)
- On patients with pace-makers or electronic implants
- On patients with phlebitis, deep venous thromboses
- On patients with haemophilia/bleeding disorders
- On areas with poor circulation
- On patients with spina bifida or surgical laminectomies of the spine
- For 6 months after treatment with radioactive dyes
- On tissue and/or bone with active infection
- Over areas suspected to be cancerous or pre-cancerous
- Over de-sensitized (numb, hypoaesthesia) areas of the skin (eg. diabetic neuropathy)
- Over open sores or lesions
- In the front of the upper neck (thyroid region)
- Over joints or tissues that have been injected with medication, within the last 3 months
- Over plastic or cement implants
- Directly over the skull or bony prominences (i.e. bony part of elbow)
- Over growth plates in children under 18 years of age
- On tissues that have been pre-treated with hold or cold therapies
- Are there any side effects with therapeutic ultrasound?
No adverse effects with ultrasound therapy have ever been documented. Ultrasound has been used in the medical community for more than 60 years! Ultrasound therapy, unlike painkillers or other drug treatments, has not been shown to interact with systemic medications or to be habit-forming.
We advise that people with pacemakers and other electronic implants do NOT use ultrasound for obvious reasons. Ultrasound should not be performed directly over replacement joints, metal implants or on the skull or throat.
Ultrasound Machine Usage
7. How do I use my Physical Therapy Ultrasound Machine?
Refer to your specific ultrasonic unit’s user manual for exact instructions, but in general, follow the below procedures:
- Connect power cord to outlet.
- Connect AC adapter to power cord.
- Apply a generous amount of gel to skin at desired treatment area.
- Switch on the power. If power signal light is on, start to use the Physical Therapy Ultrasound Machine.
- Place the ultrasound head on the skin and move it slowly over the target area in a circular motion or in linear strokes at a rate of about 1 inch per second. DO NOT stop moving treatment head while in use.
- Use special care on bony prominences to avoid discomfort.
- Most units automatically power off in 10-15 minutes but, if desired, the power can be turned off sooner by pushing the ON/OFF switch to OFF.
- After using the ultrasonic massager, clean skin with water and towel to remove gel.
- Wipe excess conductive gel off the treatment head with a damp cloth. Disinfect treatment head with antiseptic wipe. Do not ever immerse treatment head in water or solvent.
- When power shuts off, leave unit off for 30 minutes before restarting unit.
- After every treatment, disconnect AC adaptor from power source.
- Do not hit or damage the treatment head or drop the unit on the floor.
8. Do I have to use ultrasound gel with my portable ultrasound machine?
Yes,a gel is needed to conduct the ultrasonic waves deep into the skin because air is a very poor conductor. When applied directly to the skin, an ultrasound head cannot effectively transfer the sound waves into the body. Conductive gel is hyper-ionic so it conducts the ultrasound waves better than any other medium. The ultrasound gel is a MUST and makes it possible for the ultrasonic energy to travel into your body. Ultrasound therapy without gel is ineffective.
Scientific research shows that the percentage of ultrasound waves that transmit in the air is 0%, 50% in water, 60% in distilled water, 70% in glue matter, and above 80% in ultrasound specific conductive gel.
You cannot use water, oil or lotion instead of gel with you ultrasonic massager. Not using ultrasound gel with your device will, in most cases, void the device’s warranty and possibly damage the sound head of the ultrasound unit. The ultrasound waves will build up on the outside surface of your skin and often times cause a mild burn or irritation if not used with proper ultrasound gel.
Click HERE to buy your ultrasound conductive gel from EZUltrasound.com.
- What does ultrasound therapy feel like and how will I know if the ultrasound unit is working?
When using ultrasound therapy, you should feel no sensation from the ultrasound waves. The ultrasonic therapy waves are also invisible to human eyes. If you do feel heat from the sound head at any time during use, increase the treatment area and speed of application and ensure you are using enough ultrasound gel. It is possible you may feel a slight cooling or warming sensation on the skin from applying the conductive ultrasound gel. If the light on your therapeutic ultrasonic massager is on, then your unit is working.
The portable ultrasound machines provided here at EZUltrasound.com emit a deep micro-vibration so rapid, that it can not be seen or felt on the surface of your skin. So don’t think your ultrasonic massager isn’t working! If you want to check to see if your ultrasound unit is working, try the following:
- Plug ultrasound device into outlet.
- Put a couple drops of water or alcohol on the metal head of the massager.
- Touch a finger to the metal with one hand while holding the portable ultrasound machine with your other hand.
- Turn the ultrasonic device on for only a couple second, then promptly turn off.
- You should see the water or alcohol rapidly vibrate, indicating the ultrasound machine is working! If not, please contact us at sales@EZUltrasound.com or 1-888-772-4047.
Please, only perform this test very occasionally so as not to damage your home ultrasound machine.
Ultrasound Machine Treatments
- How often and for how long do I administer my ultrasound treatment?
The typical length of treatment for your home ultrasound machine should take from 5-15 minutes. The ultrasound therapy should be used no more than twice a day on a specific body part and for no longer than 15 minutes (all of our ultrasound units have an auto shut-off after 30 minutes as a safety precaution). Generally, chiropractors and physical therapists recommend using therapeutic ultrasound daily or every other day on the desired area for the first two to three weeks. After which, if your pain has lessened, you can reduce the frequency of your ultrasound treatments to 3-4 days per week.Even after the pain is gone, it is recommended that the ultrasound therapy continue once or twice a week to ensure that the pain doesn’t recur.
Before using your portable ultrasound massager, apply a generous layer of conductive gel onto the treatment area. Then place the ultrasonic head onto the skin and turn on. Move the ultrasonic massager in a small, circular motion using firm pressure, avoiding bony areas on the body. The area you are treating should be about 2 inches in diameter. Always keep the head of the ultrasonic device flat against your skin and do not lift the unit off the treatment area during application.
During the treatment the head of the ultrasound probe should be kept in constant motion, so no discomfort is experienced. If the probe is held in one place for more than a few seconds, a build up of sound energy can result and become uncomfortable.
As always, read your specific ultrasound model’s manual for complete instructions on usage.
11. How long unit I notice results from Ultrasound Therapy?
You should notice pain relief immediately after you begin treatment. If you use ultrasound consistently and as per the user manual indicates, your pain should gradually lessen over a 2-3 week period. After you’ve relieved your pain, you should continue to treat yourself once or twice a week to ensure that your pain does not return.
Results, of course, do vary and depend on the nature and severity of your ailment and we cannot guarantee results. We recommend that you consult with your doctor, chiropractor or physical therapist to determine the optimum treatment schedule for you and your condition.
- What is Phonophoresis?
Phonophoresis, also known as sonophoresis, is the use of ultrasound to enhance the delivery of topically applied drugs. Effectively, medicines contained within or under the ultrasound gel are pushed by the sound waves of the ultrasound and driven deep below the skin. Phonophoretically administered medications can penetrate the body at a much deeper level than those massaged by hand over the surface of the skin. Naturally based pain relieving and anti-inflammatory ingredients are driven deep into the tissue with ultrasound application – delivering pain relief EXACTLY where you need it.
The duration of the treatment, and the need to adhere to a specific dosage, is also a large consideration. Obviously, the longer ultrasound is used over a topical phonophoretic drug, the more medication is delivered and the deeper it goes. Drugs that require very exact doses, like insulin for example, cannot be controlled accurately enough to be delivered via Phonophoresis. Many natural analgesics and anti-inflammatory drugs are excellent candidates for phonophoretic application though.
One of the greatest benefits to delivering medications via phonophoresis is that the medication can be delivered locally to a desired area. Oral pain killers and anti-inflammatory drugs are introduced to the entire body in equal amounts. Even if you only need pain relief in your tennis elbow, or an anti-inflammatory in your swollen bursa, when using oral medications, you end up drugging your entire body – including your brain, your heart, and your lungs – even if they might not need the drug. With phonophoresis, the part of the body that receives the medication is the precise part of your body that needs it.
Coming soon… EZUltrasound.com Medicated Phonophoresis Ultrasound Gel!
- Where is phonophoresis typically used and what conditions is it used to treat?
Phonophoresis is most commonly used by Physical Therapists and Chiropractors for the treatment of localized physical injuries. As a very cutting edge technology, phonophoresis is currently being studied for the use of a vast array of medications.
Phonophoresis is used to treat:
- post-injury conditions (dislocations, distortions of joints, inflammation of muscles, tendons, etc)
- pain in rheumatic diseases
- low-back pain of neurological origin (e.g. root pain, discopathies, sciatica)
- Bursitis and similar inflammatory ailments
- Carpal Tunnel Syndrome
- Foot/Toe Sprains/Achilles Sprains and Strains
- Ankle/Knee/Calf/Neck Sprains and Strains
- Hip Sprains, Thigh Sprains/Strains
- Ligament Strains
- Post – Exercise Recovery (when the workout goes a bit too far)
- Plantar Fascitis (Heel Spurs)
- Rheumatoid Arthritis
- Shoulder Capulitis
- Supraspinatus / Infraspinatus injuries
- Tarsal Tunnel Syndrome
- Tendonitis (acute or chronic)
- Tennis Elbow, Golfers Elbow,
- Tension Headaches
- Upper and Lower Back Strains
- Wrist/ Hand/Elbow/Shoulder Sprains and Strains
- Where can I find out more information about phonophoresis?Please refer to the following articles:
Different Types of Ultrasound
- How does therapeutic ultrasound differ from diagnostic ultrasound?
Therapeutic ultrasound differs from diagnostic ultrasound, which uses less-intense sound waves to create images of internal structures.
In physics, all acoustic energy with a frequency above human hearing (20,000 hertz or 20 kilohertz) is termed “ultrasound.” Typical diagnostic sonographic scanners operate in the frequency range of 2 to 18 megahertz, hundreds of times greater than the limit of human hearing.
Diagnostic ultrasonography is used to discern issues deep within the body. By bouncing and measuring high frequency sound waves, audio “images” can be created. Ultrasound-based diagnostic imaging helps doctors visualize tendons, muscles, joints, organs, and more. And of course, diagnostic ultrasound is used during pregnancy to visualize the developing baby.
Therapeutic ultrasound, on the other hand, operates in the frequency range of 0.7 to 3.3 MHz and is used to bring heat into the body at point of injury or inflammation. A commonly used modality in physical therapy and sports medicine for rehabilitation because it stimulates the repair of soft tissue injuries and also relieves pain.
16. How does a home ultrasound machine compare to the one used by my physical therapist/ doctor?
Home Ultrasound Therapy using a portable ultrasound machine can be very effective, just as effective as medical or professional ultrasound units.
The difference between a chiropractor or doctor’s ultrasound machine and a home ultrasound machine is the doctor’s ultrasound device utilizes continuous waves while a home version uses pulsed ultrasonic waves. This makes the home units safe for the general public, as continuous wave ultrasound can be dangerous if used in the wrong hands.
When using a home ultrasound therapy massage machine, you will treat more frequently than if you were have ultrasound treatments at a physical therapist’s office, but the results will be the same and in the long run, you will save money by doing treatments in the comfort of your own home.
Ultrasound Machine Specifications
17. What kind of technical specifications should I be looking for in a therapeutic ultrasound machine?
Ultrasound energy is transferred into the body based on 2 factors: frequency and power output. The frequency of an ultrasound machine is opposite to how deep the ultrasonic waves will penetrate.
A 1Mhz ultrasound unit’s waves will penetrate about 4 cm below the skin, while a 2 Mhz device will only penetrate about 2 cm. A low frequency means the sound waves will penetrate deeper, but using too low a frequency means the waves are too wide to effectively move any molecules. The 1MHz frequency is ideal, as it provides the best penetration and therapeutic effect.
This factor is measured in watts per square centimeter. More energy can be transferred into the body when the power is higher. However, too high a power output can cause burns on the epidermis and/ or to the tissue below the skin. Even medical practitioners using professional ultrasound machines, capable of higher powers, will typically use a low power setting below 1 watt / per cm2. So, more power is not necessarily better. In fact, it is more effective to use a lower power setting for a longer period of time.
The power output specification is often broken down further into peak intensity and average intensity.
The average intensity indicates the total amount of energy transferred into the body over a span of vibrate-rest cycles, while the peak intensity measures the height of the waves being sent into the body. The ultrasonic waves need to be large enough to have the desired massage effect on bodily tissues but there also needs to be adequate breaks between wave groups for tissue cool down. This vibrate-rest-vibrate-rest pattern is why a pulsed ultrasound machine is extremely effective.
Remember, the most important measurement is the watts per square centimeter, not the Total Power Output.
And again, it is more effective to treat the affected area more frequently and for longer periods with lower power.