We spend a lot of time reviewing and discussing ways to use mTrigger biofeedback to increase muscle activation, improve muscle timing, and in turn increase strength output. However, numerous randomized controlled trials have suggested the use of EMG biofeedback for reducing muscular guarding and lessening movement compensation patterns.(1–4) One of the lesser known but equally effective uses of sEMG biofeedback is for relaxation training or reducing compensation.
Increased muscle activation or guarding is frequently seen after surgery, when in pain, or with compensatory movement patterns, and is usually disadvantageous. Sometimes a muscle is overactive and needs to be down regulated or inhibited. In this instance, mTrigger surface EMG biofeedback allows patients to receive information on the level of resting muscle activation they have. The real-time visual biofeedback allows for neuromuscular adaptations and learning to occur that will balance out muscle tension, promote relaxation, and indicate proper recruitment. On top of that, in one study, results indicated that EMG activity was reduced and maintained even once feedback was removed.(5)
mTrigger biofeedback also yields very effective results with reducing compensation patterns. Following pain, injury, as a result of muscle weakness, or for a handful of other reasons, the body will start to move in the “path of least resistance.” Initially this is fine and doesn’t cause major issues. However, flawed movements and compensation patterns can become problematic when repeated over time. The farther out from injury or surgery one gets, the more difficult working out of these motor habits becomes. The use of mTrigger biofeedback can greatly help to ease this process.
Click here to hear Dr. Kaysha Bates talk through the clinical applications for relaxation and inhibition outlined below.
For example, with shoulder issues, poor scapular mechanics and muscle activation patterns are common. By using surface EMG biofeedback on the upper traps, Dellve et al. was able to demonstrate a decrease in upper trapezius muscle over activation, a decrease in pain, and an increase in function.(1)
- Upper Trap and Lower Trap
- Using dual channels, place one set of electrodes on the upper trap and the other set of electrodes on the lower traps of the effected shoulder.
- The patient is instructed to perform shoulder elevation / scaption exercises.
- As the patient performs the exercise, they are instructed to keep upper trap activation low. The muscle activation meter should stay relatively the same during the exercise. Contrary, they are instructed to simultaneously increase activation of the lower traps. As a result, the muscle activation meter for this channel should increase.
Another example relates to relaxation of an overactive muscle. After knee surgery, regaining knee extension can be limited by hamstring guarding. In which case, biofeedback can be an excellent tool to decrease resting activation levels.
- Prone Hang
- Position the patient in prone doing a prone hang
- Place one set of electrodes on the most “active” part of the hamstring. You will only need one channel.
- In “Train” mode note the level of hamstring muscle “guarding” or “activation” that is present. Let’s say it was 200V
- Set the goal roughly between 180-200uV
- Allow the patient time to work on deactivating or relaxing their hamstring muscles with the assistance of mTrigger biofeedback
So why does it work?
Muscle guarding is linked to the autonomic nervous system.(6) Increased muscle tension occurs when a muscle is kept too tense for too long, often unknowingly.(7) Visual biofeedback allows you to make subtle changes to your muscles in order to control your body’s muscle function.(8) The biofeedback sensors help you to receive information about the muscle tension in your body and give you the ability to practice new ways to control that tension.(8) This direct input allows the patient to associate tension levels with muscle sensations and learn to balance the two out.(7)
To set up relaxation or compensation training using mTrigger there will be two major differences from the strength training setup.
First, the exercise activation goal (MVC) must be much lower, as now we are trying to achieve relaxation or reduced muscular activation. The goal will be based on the level of resting activation the client has. Select a goal that is at or just slightly lower than their resting activation. If you are not dealing with activation during full rest, set the goal according to the level of activation that occurs during the target exercise. Then, indicate to the patient that their goal is to perform the exercise while keeping the feedback meter as low as possible.
Second, when using the audio feature with relaxation training, the goal is to turn or keep the tone OFF. This happens when the client successfully reduces their target muscle activation level during exercise.
Here are some additional examples involving relaxation and compensation to try:
- Standing Lumbar Flexion
- Using dual channel mode, place one set of electrodes on the right lumbar paraspinals and one set on the left lumbar paraspinals.
- Instruct the patient to perform lumbar flexion – slowly bending forward then relaxing once they get as far as they can.
- During the motion, lumbar paraspinal activity will be high, however during the transition from forward flexion to relaxation, the patient is instructed to decrease the muscle activation meters on both paraspinals almost completely
*Those who struggle with back pain often have a difficult time turning on/off their spine muscles.
- Quad Set or TKE
- Using dual mode, place one set of electrodes on the quad and one set on the hamstring.
- Instruct the patient to perform a quad set or standing TKE
- As the patient performs the exercise, they are instructed to hamstring activation low as they simultaneously increase activation of the quad. As a result, the muscle activation meter for this channel should increase
Being able to down regulate an overly active muscle is sometimes just as important as being able to activate it. Compensation patterns and muscle over activation (protection) are common after injury but they should not last long. Utilizing visual biofeedback during this stage can create a turning point towards better movement, less pain, and improved outcomes.
Biofeedback for addressing compensation patterns with low back pain
More ways to use biofeedback
1. Dellve L, Ahlstrom L, Jonsson A, et al. Myofeedback training and intensive muscular strength training to decrease pain and improve work ability among female workers on long-term sick leave with neck pain: a randomized controlled trial. doi:10.1007/s00420-010-0568-5
2. Voerman GE, Sandsjö L, Vollenbroek-Hutten MMR, Larsman P, Kadefors R, Hermens HJ. Effects of ambulant myofeedback training and ergonomic counselling in female computer workers with work-related neck-shoulder complaints: a randomized controlled trial. J Occup Rehabil. 2007;17(1):137-152. doi:10.1007/S10926-007-9066-3
3. Giggins OM, Persson UM, Caulfield B. Biofeedback in rehabilitation. J NeuroEngineering Rehabil 2013 101. 2013;10(1):1-11. doi:10.1186/1743-0003-10-60
4. Ma C, Szeto GP, Yan T, Wu S, Lin C, Li L. Comparing biofeedback with active exercise and passive treatment for the management of work-related neck and shoulder pain: a randomized controlled trial. Arch Phys Med Rehabil. 2011;92(6):849-858. doi:10.1016/J.APMR.2010.12.037
5. Morasky RL, Reynolds C, Clarke G. Using biofeedback to reduce left arm extensor EMG of string players during musical performance. Biofeedback Self Regul. 1981;6(4):565-572. doi:10.1007/BF00998740
6. What Is Biofeedback Therapy? Uses Of Biofeedback Training | Drake Institute. https://www.drakeinstitute.com/what-is-biofeedback-treatment
7. Biofeedback therapy: A natural cure for tension and migraine headaches. https://www.saybrook.edu/unbound/biofeedback-therapy-natural-cure-tension-migraine-headaches/
8. Biofeedback – Mayo Clinic. https://www.mayoclinic.org/tests-procedures/biofeedback/about/pac-20384664