Why is EMG muscle testing valuable to us?

As biokineticists, we need to evaluate our patients to see if we can find the reason for their pain, stiffness, weakness etc. Even if the patient already has a diagnosis, we need to evaluate the patient to identify the severity of the diagnosis. Surface EMG Muscle Testing helps us do just that. It gives us objective information that we can use to monitor improvement over time. EMG results also gives us a clearer picture of the direction of treatment we need to take. The prescribed exercise program can be more specific and detailed to the patient after an EMG test.

The surface EMG is a very versatile test and does not provide any pain to the patient while testing. We can test within the patient’s subjective pain limits, it can be placed on most muscle / body areas, in seated, standing or lying down postures and during various joint actions. The tests are easily reproduced in the future to compare test results. There is another reason to use EMG. It is called EMG triggered muscle stimualtion. This is specifically to assist very weak patients after testing them by providing additional assistance during exercise rehabilitation. Some EMG devices that biokineticist use have the EMG triggered muscle stimulation. This will be discussed in the following section.

What is EMG Muscle Testing?

EMG stands for Electromyography. Electro referring to electricity the nerve produces and myo referring to the muscle. We use a surface EMG Muscle Testing which allows us to assess the health of your muscles and the nerve cells that control them. In essence, how well does your muscle activate. how quick and for how long can it keep the activation. Good activation normally suggests good muscle strength.

EMG results can thus reveal muscle weakness or dysfucntion as well as nerve dysfunction. The EMG uses tiny devices called electrodes that we place on the surface of your skin. The electrodes translate electrical signals from your nerves into graphs and numerical values. This data allows us to understand what might be the problem and accordingly suggest specific treatment.

Different EMG Muscle Testing methods

It is important for patients to understand that there are 2 ways of completing an EMG test. The one used by biokineticists is a surface EMG (sEMG). sEMG inolves the graphic recording (electromyogram) of a muscle contraction. As well as the amount of electrical activity generated in a muscle. We place electrodes on the surface of your skin in the area of pain or over the muscle that requires evaluation.

There are specific preparations to clean the skin and mark the area of electrode placement. The EMG device then connects to the electrodes and the test can be completed in a non-invasive manner with no pain provided by the EMG. This method is used to get an indication of nerve-muscle health and activation rather than diagnosing a condition. The reports are useful when blended with other clinical findings.  And all these data give us a clearer picture for rehabilitation. Which can assist in decision making to guide patient treatment.

The second method of EMG is one most used by neurosurgeons, neurologists, nerve specialists and in hospitals. They use an intramuscular EMG. During the intramuscular EMG, a needle electrode is inserted through the skin, directly into the muscle and it records the electrical activity in that muscle. This is normally a very painful procedure and is used to accurately diagnose a neuromuscular condition.

Why complete a Surface Electric Muscle Generation (sEMG) Test

Any muscle weakness, joint injury or athlete can benefit from sEMG testing and rehabilitation. But your doctor may order a sEMG if you have signs or symptoms that may indicate a nerve or muscle disorder. Such symptoms may include:

• Tingling
• Numbness
• Muscle weakness
• Muscle pain or cramping
• Certain types of limb pain
• Rule out conditions such as muscle disorders, muscular dystrophy or myasthenia gravis. Carpal tunnel syndrome, peripheral neuropathies, amyotrophic lateral sclerosis or a herniated disk in the spine affecting muscles and their function

What does the test involve

First, you need to book an appointment with us, no referral letter needed. As all initial evaluations, we complete a medical history and the get to the sEMG testing if so indicated. You wear clothes that exposes the skin of the joint or muscle to be tested. We measure the muscle activation by placing electrodes on the skin after it is cleaned. Specific electrode selections are made for the size and area of the muscle. The Biokineticist also explains what you need to do during the test.

What you will know after your sEMG test

Your results of the sEMG will indicate the following:

1. Muscle health – activation relating to strength / weakness
2. Differences in muscles, right side compared to left side
3. Activation patterns, how fast, how much and for how long
4. Notes by biokineticist on any recommendations, guidelines regarding clinical exericse therapy

Advantages of sEMG

• sEMG is safe, easy, and non-invasive
• Provides objective quantification of the energy and health of a muscle
• Helps in decision making both before/after surgery
• Observe muscle energy in a resting state or during specific movement patterns
• Can determine early and late firing of muscles
• Can determine if a particular exercise actually activates a muscle as intended
• Determine the effectiveness of a rehabilitation program / exercise therapy
• Can suggest methods to improve treatment approaches
• Biofeedback tool for patients in rehabilitation setting: EMG Triggered stimulation / Neuromuscular electrical stimulation (NMES), re-education and self regulation

Click here to see how we use the sEMG as a treatment tool –

EMG Triggered muscle stimulation

Patients we test and treat with sEMG

• Nerve injuries i.e. foot drop, sciatica etc
• Post stroke weakness and spasticity
• Weakness in muscles due to chronic conditions
• Weakness in elderly, athletes etc.
• Chronic back pain
• Shoulder pathology / pain, rotator cuff injury, shoulder replacements / reverse shoulder replacements
• Neck, shoulder, back, hip, knee, ankle instability and immobility
• Hip replacements, knee replacments

Which patients cannot receive sEMG testing or treatment

Any person who has a cardiac pacemaker or implantable cardioverter-defibrillator (ICD). If you are not sure if this is safe for you, please feel free to contact us.

Please click here to read more about EMG vs TENS vs EMS