Vibration As A Modality In Occupational Therapy

By David F. Garner OTR/L

Nancy was a 74-year-old female who had a total left hip replacement. During the first few sessions of occupational therapy at the skilled nursing facility, her participation in therapy was greatly limited by 8-9 out of 10 pain. She refused sessions because of pain. She was taking the maximum doses of pain medicine and due to other issues, was unable to take muscle relaxers. After an assessment, I determined much of her pain was due to muscle tightness and cramps in her thigh and low back secondary to post-surgical guarding reaction. 

In our third session, I tried our vibrating massager to see if that would relieve her pain. After 10 minutes of vibration set to 60 Hz, her pain decreased from 9/10 to 4/10. She then participated more easily in dressing tasks. For each subsequent session when her pain was high, she was brought to the gym a few minutes early and used the vibrating massager on herself. Sometimes, she would stay after and continue treating herself. Vibration also has many other benefits. It is a modality missing from many clinicians’ bag of tricks.

Vibration has uses across the lifespan for a variety of ailments. (see this article) The body responds positively to biomechanical stimuli. It is believed vibration provides similar stimuli which promote beneficial responses in the body. Before the prevalence of modern electric vibrating massagers, tuning forks were used for decades to relax muscle trigger points and increase stimulation. In fact, vibration as a medical treatment is over 200 years old. Jean-Martin Charcot noted that whole body vibration reduced Parkinson’s symptoms and invented a chair to treat patients. Vibration is useful when other modalities such as heat and e-stim are contraindicated. Additionally, some facilities are unwilling to provide heat or electrical modalities. Vibration is a safe, cheap, and highly portable alternative, but should be considered a secondary substitute to other modalities for some conditions. 

Vibration is a modality any client or caregiver can easily purchase and be taught to apply without a therapist present. There are virtually no negative side effects except for those who are sensitive to vibration (such as vibratory urticaria), yet many numerous benefits. Quality units can be purchased for around $100. 

Now, let’s address terminology. I avoid the term vibrator because of the connotation of sex toys. I prefer the phrase vibrating massager or simply massager. I often use the vibrating massager in the gym where others may overhear conversations. So, I like to avoid language that might sound like I’m discussing a private topic in public. 

Vibration frequency measurements vary between models. Some models list their frequency settings in hertz (Hz), a measure of pulses per second, while others list them in revolutions per minute (RPM). Some list them as vibrations per minute (VPM) which is the same as revolutions per minute. Either is fine so long as you know the purpose of each setting. Muscle relaxation takes place around the 20-60 Hz or 1200-3600 RPM range. Higher ranges can also induce some relaxation however this lower range is often more comfortable. Muscle contraction is stimulated best by the 90-130 Hz or 5400-7800 RPM range or higher.

There is research going back decades on the benefits of vibration therapy. Several studies and articles are linked below. Further research is certainly needed, however. The body of research on this topic leaves a lot to be desired. The dearth of available studies means it is difficulty to provide robust evidenced-based guidelines for frequency of vibration, duration of treatment or number of treatment sessions for most conditions. The guidelines provided below are often based off of one to two studies and some clinical judgement. Clinical experience will aid the therapist in finding best practices.

Uses for Vibration as a Modality

·       Myofascial pain due to soreness/tightness: Begin by applying in the relax range to the muscle belly. Apply for 10-20 minutes. Use can reduce pain by up to half and last up to 72 hours. It may be less effective for chronic pain or large muscle groups. However, since it is a easily accessed and cheap therapy, patients may be willing to try and see if it offers any relief. Medication alternatives are usually worth trying. 

·       Hypertonia and spasticity: Vibration reduces tone when applied to muscle belly of high tone/spastic muscles. Apply in the relax range to agonist muscles and in the contract range to antagonist muscles to stimulate reciprocal inhibition. Effectiveness can be improved by applying sustained stretch lasting 5-10 minutes during vibration treatment. Some research has shown that vibration alone is no better than stretching alone. However, no studies have been found yet looking at both applied simultaneously verses applied individually. In my clinical experience, applying both can have a synergistic effect, or at minimum, the vibration may help reduce the pain of stretching. 

·       Hypotonia/Flaccidity: Applying vibration in the contract range to the muscle belly excites muscle tissue causing contraction. It can be applied for at least 5 minutes and has similar effects to electrical stimulation. The effects including promoting neurogenesis and strengthening muscles. It may take a few sessions to see results. For clients who have also lost sensation, the vibration stimulates flaccid muscles and promotes the activation of sensory receptors. Here is a video from the physical therapists Bob & Brad on the technique. Here is another. 

·       Scar tissue mitigation: Use of a percussion massager has similar effects to traditional manual scar massage techniques. It can break down scar tissue, increase blood flow, alleviate pain, reduce itching, and improve healing including minimizing scar tissue formation. Some may be more likely to use a massager at home than traditional manual massage techniques. It may be contraindicated for scars over bony prominences. 

·       Hyperesthesia: Use of low frequency ranges have been shown to reduce tactile defensiveness and hyperesthesia. Begin at 1-2 seconds and increase per client tolerance. If a client struggles to tolerate it at the lowest frequency, try placing a sponge or folded towel between the massager head and skin to reduce transmitted vibrations. A sonic toothbrush may be less intense than a full-size massager. Apply in addition to texture desensitization exercises.

·       Neuropathy: Use of vibration provides increased circulation, reduced pain, and high stimulation to the nervous system promoting regeneration. Whole-body vibration for neuropathy is effective. But this is not practical for many patients. A vibrating ball or massager can provide similar benefits when held in the hand or against the foot. Portable vibrating foot plates are also available for use while seated. A sonic toothbrush may be more appropriate for the facial region for this condition. Vibration can be applied in the relax range for 10-12 minutes per day or every other day.

·       Low arousal/unilateral neglect: Vibrations in the low-frequency range can provide an excellent alerting stimulus. It can provide high sensory input to hands/arms/chin to increase alertness and attention to specific regions. Explain what you will be doing before contact. Introduce for 2-3 seconds, then slowly increase the time of contact to determine client response. Application up to 5 minutes to neck muscles at the start of the session can improve attention to the neglected side.

·       Tremors: There is some evidence that vibration can reduce the severity of all tremor types. Product reviews on Amazon.com for vibrating tools corroborate this, but results vary. Either high or low frequencies can be effective with results lasting several hours. However, one may not see results for a few weeks initially. It seems to be most successful if applied to the hands or arms affected for 10-20 minutes three or more times a day. The best results are seen immediately after, so completing a treatment session before meals is useful. Reasonably priced balls like this can be purchased as well as more expensive devices.

• Freezing of movement: difficulty initiating movements common with Parkinson’s and other conditions can be a major barrier to life. It can affect gait but also upper extremity movement. Vibration stimulation can reduce freezing symptoms in some people at least partially. Vibration should be applied similarly to use for tremors.

·       Tissue healing: Vibration applied around healing tissues (but never on top of open wounds) has been shown to speed recovery. One study even found it to be more effective than electrical stimulation. It can be applied at 35-45 Hz for 10-30 minutes per day for best results. 

      Insomnia/sleep hygiene: There is evidence that vibration applied in the relax range before sleep can improve the quality of sleep and reduce insomnia. It has similar relaxation effects to massage including reduced stress and anxiety and more relaxed muscles by stimulating the parasympathetic nervous system. Apply to feet or high muscle tension areas for ~10 min as close to bedtime as possible. 

There are some precautions and contraindications for the use of vibration per manufacturers. Some recommend avoiding use of massagers on or next to a healing fracture that has not been reinforced with implanted hardware. However, many studies have shown benefits with no major adverse effects at 35-50 Hz and there are vibration devices prescribed to promote bone healing. Avoid using massagers near an electrical implant like a pacemaker. Never use on a limb with a suspected DVT (usually indicated by swelling, pain, and warmth) or with a patient at risk for blood clots. Patients who have been on blood thinners and do not currently have a clot are likely safe. Consult with the patient's physician. Never use on open or sutured wounds/incisions, bruises, burns, tumors. Also avoid areas of unexplained swelling and swelling related to infection. Do not use with patients who have a history of adverse reactions to vibration such as swelling or vibratory urticaria (indicated by itching, swelling and redness). It is quite rare and less than 1000 people have been diagnoses with it in the United States. Check your model's instruction manual for specific warnings.

Some patients may experience side effects including minor to moderate itching following treatment. This is a common side effect and not necessarily indicative of an adverse reaction. If the patient can tolerate the side effects, it is generally safe to continue treatment. Stop the session early if irritation or pain occurs. Consult with the patient's physician as needed. Note, some doctors discourage use of vibration during post-surgical recovery, however, recent research finds it is beneficial rather than harmful. It has similar benefits to post surgical massage. The decision to use it should be considered by the treatment team.

Overall, vibration is one of the safest modalities so long as the above contraindications are heeded. Nearly all patients will enjoy the relaxing sensation and wish for it to continue longer than time allows. Redness can appear on the skin after use due to friction of the head on skin. A bit of lotion or massage oil applied to the skin before treatment will minimize this. When documenting I typically record the location of application, purpose, frequency, and duration as well as patient response. It can be charged under therapeutic activity or neuromuscular re-education.

Selecting A Tool

There are numerous electric massagers available.  Some have a percussive action with a reciprocating head (sometimes called massage guns). Others simply vibrate at a given frequency, typically higher than the percussion type. Percussive massagers have gained a lot of popularity in recent years in the world of sports. Both have many benefits. The percussive action of a massage gun can be too harsh for many applications. There are some additional considerations with percussive massagers. Many models have a plunger head that travels back and forth 1-1.5 cm or more. For those with plenty of muscle mass, that is beneficial. It may be counterproductive for the geriatric population who often have low muscle mass meaning the massage gun could be painful. Additionally, they are contraindicated for people with low bone density. Some models combine vibration with mild percussion. The head only travels a few millimeters. These models may be appropriate for patients with low tissue mass. The vibrating massager (without percussion) is the most versatile for therapy purposes. 

Vibrating tools come in many designs, some with two or more heads. Massagers with a single large head tend to have the most versatility. The head diameter should be at least 3.8 cm (1.5 inches) at its widest. Smaller heads are useful for targeting muscle knots but can be painful for other purposes. Thus, a larger head is more adaptable. Many models have an angled form factor while some are straight. An angled head enables one to easily reach their own back. The straight design can be more ergonomic if being used by a therapist, but either design is useful. See Figure 1 for an example.

Many models are battery powered which offers portability and convenience. Corded designs are usually cheaper, and you never have to worry about the battery dying mid treatment. Power supply depends on the therapist's preference.

Lastly, look for a model that has at least two modes for more versatility. Look at the instruction manual to find the frequencies of each mode. On some cheap models, the lowest frequency can be close to 100 Hz. This is not ideal for relaxing muscles. Others (like this) may have multiple settings but the highest is still in the relax range. Check that the lowest frequency is in the 20-60 Hz or 1200-3600 RPM range and highest frequency is approximately 90-130 Hz or 5400-7800 RPM for the most versatility. Also beware of any models labeled percussion massager. Percussion massagers' are only useful for pain relief and are not versatile. 

 

Versatile models: 

Magic Wand Plus HV-265 (settings between 2700-6300 RPM)

Prosepra PL021 (settings between 3000-6000 RPM)

Wahl 4120 (settings between 60-120 Hz) 

TOLOCO EM26 (seven settings up to 3200 RPM). Model is a massage gun offering percussion massage only. Useful for sore/tight muscles only.

ARK Z-Vibe (one setting at 7000 RPM). Model is most useful for increasing arousal or attention to specific body regions.

Phillips Sonicare 1100 (one setting at 400+ Hz). Model is a sonic toothbrush. Intensity is much lower than massagers.