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Edmonton Physio Intramuscular Stimulation

Intramuscular Stimulation (IMS)

Many people who suffer from chronic pain become frustrated when other treatments cannot help. Chronic pain can occur even when there is no injury or inflammation, IMS is a scientifically proven method for diagnosing and treating it.

What is Intramuscular Stimulation?

Intramuscular Stimulation (IMS) is an effective treatment for chronic pain of neuropathic origin. IMS was developed by Dr. Chan Gunn while he was a clinic physician at the Worker’s Compensation Board of British Columbia in the 1970s. He is presently President of iSTOP and clinical professor at the University of Washington’s Multidisciplinary Pain Center in Seattle. Dr. Gunn has been awarded The Order of British Columbia as well as The Order of Canada for his contribution towards solving chronic pain.


IMS uses implements adapted from traditional acupuncture however it is based on scientific neurophysiological principles. The acupuncture needles used are very thin (much thinner than the hollow needle used to inject medicine or to take blood samples). You may not even feel it penetrating the skin, and if your muscle is normal, the needle is painless. However, if your muscle is supersensitive and shortened, you’ll feel a peculiar sensation – like a muscle cramp or Charlie horse. This is a unique sensation caused by the muscle grasping the needle. Patients soon learn to recognize and welcome this sensation. They call it positive pain because it soon disappears and is followed by a wonderful feeling of relief.  The needle may still be in you, but because the muscle is no longer tight, you no longer feel it. What has happened is that the needling has caused your abnormal muscle shortening to intensify and then release. Normal muscle due to its lack of supersensitivity does not react to the presence of the needle and thus does not produce this sensation.

What is neuropathy?

Doctors and therapists usually have no difficulty in treating pain caused by injury (a sprain or fracture for example) or inflammation (such as rheumatoid arthritis). But they are perplexed by pain that shows no history or sign of tissue damage or inflammation, such as headaches, “whiplash”, backache, tennis elbow, or frozen shoulder. 


Dr. Gunn has introduced the term “neuropathic pain” to describe this type of pain. Typically this occurs when nerves malfunction following minor irritation. Nerves and nerve-endings become extremely sensitive and cause innocent, harmless signals to be exaggerated or misinterpreted by the body.  (This characteristic is known medically as supersensitivity). The result is pain, even when extensive medical tests show that there is “nothing wrong”. Until recently, supersensitivity has received little attention in medical circles.

Frequency of treatments

The effects of IMS are cumulative. Treatments are usually once a week (but can be spread out to two weeks) to allow time between treatments for the body to respond to the altered tissue tension. The number of treatments you require will depend on several factors such as the duration and extent of your condition. If the pain is of recent origin, one treatment may be all that is necessary. In published studies of patients with low back pain, the average number of IMS treatments required was 8.2.

Treating Neuropathic pain

Supersensitivity and muscle shortening cannot be operated on and “cut away”. “Pain killers” and other analgesic pills only mask the pain. The goal of treatments is to release muscle shortening which presses on and irritates the nerve as well as the muscle’s attachments. Supersensitive areas can be desensitized and the persistent pull of shortened muscles released. 

Shortened Muscle Syndrome

An important factor in neuropathic pain is muscle shortening, caused by muscle spasm and contracture. Muscle shortening produces pain by pulling on tendons creating a tendonitis type reaction as well as distressing the joints they move often restricting motion.  These conditions are customarily regarded as “local” conditions and may not receive the appropriate diagnosis or treatment as the “effect” is often treated rather than the cause. ​

Involvement of the Spine

The most common cause of nerve irritation and neuropathic pain is ultimately a dysfunction in the area of the spine whether it is restriction of joint motion, aggravation of the spinal disc, or degenerative changes. This dysfunction often sets up a pattern of supersensitivity throughout all the musculature that is supplied by the nerve that exits the level involved.  Often there is no acute neck or back pain related to this irritation as it has not reached the threshold necessary.  Your therapist will be able to identify subtle signs of this dysfunction as it relates to your condition during the examination.

How IMS Compares to Acupuncture

Traditional Acupuncture

  • Medical examination not applicable

  • Medical diagnosis not relevant

  • Needle insertions according to Chinese philosophy into non-scientific meridians

  • Knowledge of anatomy not applicable 

  • No immediate objective changes anticipated

  • Is an “energy flow” treatment utilizing systemic reaction to stimulus

IMS Treatment​​

  • Medical examination is imperative

  • Medical diagnosis is necessary 

  • Needle insertions indicated by physical signs

  • Knowledge of anatomy is essential

  • Prompt subjective and objective effects are usually experienced

  • Mechanical effect on tissues

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