Biofeedback

Definition[edit | edit source]

Biofeedback therapy is an instrument-based learning process that is based on “operant conditioning” techniques. It is an evidence-based approach to improve the ability to modify involuntary processes consciously. The basic biofeedback paradigm suggests that whenever we provide a human being with feedback about a biological process, that feedback enables the individual to increase awareness of the process and gain conscious control. The governing principle is that any behaviour-be it a complex maneuver such as eating or a simple task such as muscle contraction-when reinforced its likelihood of being repeated and perfected increases several fold.[1]

Physical therapists use biofeedback to help refine a movement sequence or activation pattern to assist patients to achieve a goal. This technique involves using visual, physical and/or auditory feedback to guide the patient to give their optimal performance.[2] The ultimate purpose is that the patient gets to know his own body signs and that he can control them consciously in the first place using biofeedback equipment, afterwards even without.[3]

Biofeedback usually involves the measurement of a target biomedical variable and relaying it to the user using one of two strategies;

1. Direct feedback regarding the measured variable, as in the case of heart rate or heart rate variability, where a numerical value is displayed on a wearable device, such as a watch.

2. Transformed feedback regarding the measured variable, where the measurements are used to control an adaptive auditory signal, visual display or tactile feedback method. [4]

Categories of biofeedback used in physical rehabilitation[edit | edit source]

The biofeedback measurements which are frequently used in physical rehabilitation can be categorised as being either physiological or biomechanical based on the parameter of interest. The physiological systems of the body which can be measured to provide biofeedback are the neuromuscular system, the respiratory system and the cardiovascular system, while biomechanical biofeedback involves measurements of movement, postural control and force. [5]

https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3687555/bin/1743-0003-10-60-1.jpg

Indications[edit | edit source]

Clinicians can incorporate biofeedback techniques into the overall treatment plan for a wide variety of conditions. It is frequently used to manage stress and anxiety, either if they are the primary illness or due to another cause. There is specific evidence that exists to support the use of biofeedback for specific ailments, including the following;

  • Constipation
  • Fecal incontinence
  • Urinary incontinence
  • Chronic pain - includes chronic low back pain, chronic pelvic pain, and other pain syndromes
  • Chronic insomnia
  • Migraine headaches
  • Chronic fatigue
  • Fibromyalgia
  • Epilepsy
  • Motion sickness
  • Depression
  • Anxiety
  • Raynaud phenomenon


Other indications for biofeedback are:

  • CVA
  • CVS/Fibromyalgia
  • Chronic pain
  • Neck pain
  • Post-traumatic stress syndrome
  • Hypertension
  • Headache – migraine – tension headache
  • Balance disorders
  • Attention Deficit Hyperactivity Disorder
  • Epilepsy

Different types of biofeedback[edit | edit source]

Many different forms of biofeedback are currently used in the clinical setting including:

  • Electromyography (EMG) - measures muscle tension
  • Thermal biofeedback - measures skin temperature
  • Neurofeedback/ electroencephalography (EEG) - measures brain wave activity
  • Electrodermography (EDG) - measures skin electrical activity
  • Heat Flux - measures the rate at which heat is being dissipated from the body
  • Pneumography - measures abdominal/chest movement when breathing
  • Capnometry - measures end-tidal carbon dioxide
  • Hemoencephalography - measures the differences in the colour of light reflected back through the scalp based on the relative amount of oxygenated and unoxygenated blood in the brain
  • Photoplethysmography (PPG) - measures peripheral blood flow, heart rate, and heart rate variability[6][7]

The limitations to biofeedback applications lay largely with the therapist. Given a solid understanding of the basic principles of the therapy in combination with a clinical understanding of the patient's problem, there are many novel applications for the therapy.

This page will focus exclusively on EMG Biofeedback.

Mechanism of Action[edit | edit source]

The autonomic nervous system regulates the functioning of the organs and functions of the body like breathing and beating of the heart. It isn’t dominated by our will, but it reacts to our mood. There are two major components of the autonomic nervous system, the sympathetic and the parasympathetic systems. The parasympathetic works in particular at rest and recuperation while the sympathetic works at efforts. Due to chronic stress, the autonomic nervous system can function worse, consequently, the regulation of the body may get disrupted and an imbalance between the two systems may arise.[8]

Biofeedback as a Component of Treatment[edit | edit source]

It is important at the outset to emphasize that biofeedback is not at its most effective when used as a treatment in its own right, but should be integrated with other therapeutic interventions. It acts as an enhancer of the therapy, enabling the patient (and the therapist) to make more effective and rapid progress towards the rehabilitation goal. Furthermore, it is useful in that it helps the patient to reduce their reliance on the therapist and become more reliant on their own performance. Clearly, this is not fully achieved if the patient becomes reliant on the machine instead of the therapist! It can be used effectively to enable the patient to take some control or ownership over their rehabilitation - empowerment is an often used phrase in this context. The key to the success of biofeedback in rehabilitation is to use the device as an adjunct to therapy, to enable the patient to gain control without reliance on the therapist, and once gained, to maintain control without either the therapist or the machine. This approach is entirely in keeping with the general aim of modern physiotherapy, and the technology is an aid to the outcome, not a magical solution.

Complications[edit | edit source]

Biofeedback is a very safe and well-tolerated procedure that has minimal complications. If biofeedback is used at all times during therapy, there may be a drop in the performance following its discontinuation. It is, therefore, beneficial to practice the same techniques without the biofeedback equipment as part of the overall treatment for sustained improvement. If the patient does not practice the techniques often, then the treatment can have less than intended results over time and may require retraining.[9]

Devices to receive in therapy[edit | edit source]

Electromyography[edit | edit source]

The principles of EMG biofeedback (EMGBF) are usefully reviewed, as a reasonable understanding of what the machine is doing will assist the therapist in determining the most appropriate machine settings and applications.

Read more about the Physiological principles

Indications[edit | edit source]

There are many indications for biofeedback. Stress urinary incontinence is an indication for biofeedback. We found in the literature that the addition of biofeedback to the training of the pelvic floor muscles for the treatment of stress urinary incontinence improved pelvic floor muscle function, reduced urinary symptoms, and improved the quality of life.[10][11]

Pelvic floor muscle exercises and biofeedback are also effective treatments for men with erectile dysfunction.[12]

Further, we found that EMG therapy is useful in enhancing knee extension after an ACL reconstruction but only in the early phase of rehabilitation after the reconstruction.[13]

If we search for evidence for biofeedback as the treatment for headaches we found that biofeedback-related approaches to headache therapy fall into two broad categories: general biofeedback techniques (often augmented by relaxation-based strategies) and methods linked more directly to the pathophysiology underlying headache. [14]

The use of general biofeedback-assisted relaxation techniques for headaches has been evaluated extensively. We can conclude that:

  • Various forms of biofeedback are effective for migraine and tension-type headache;
  • Outcomes with biofeedback rival outcomes with medication therapy;
  • Combining biofeedback with medication can enhance outcomes;
  • Despite efficacy in many patients, biofeedback fails to bring significant relief to a sizeable number of headache patients. [14]

Biofeedback methods that more directly target headache pathophysiology have focused chiefly on migraine and tension-type headaches. These headache-specific approaches include blood volume pulse biofeedback, which has considerable supportive evidence, and electroencephalographic feedback.[14] For tension-type headaches we found that biofeedback was more effective than headache monitoring, placebo, and relaxation therapies. The strongest improvements were found for the frequency of headache episodes. Further significant effects were observed for muscle tension. [15][16] Biofeedback is also used for patients with migraine. This treatment is found effective to reduce the number of headaches per week but there were no changes in intensity, disability or length of headache. [17]

Other indications for biofeedback are:

Stabilizer[edit | edit source]

Stabilizer

A stabilizer has come into general use for stabilization exercises for all parts of the body. A stabilizer is a pressure biofeedback unit and consists of an inelastic, three-section air-filled bag, which is inflated to fill the space between the target body area, a firm surface and a pressure dial for monitoring the pressure in the bag for feedback on position. The bag is inflated to an appropriate level for the purpose and the pressure is recorded. Movement of the body part off the bag results in a decrease in pressure while movement of the body part into the bag results in an increase in pressure. Its use in assessing the abdominal drawing-in action has become its most important use in relation to the treatment of problems for the local muscle system in patients with low back pain. [19]

[19]

The patient is positioned in hook-lying. The feet remain flat and the arms are held alongside the body. The stabilizer is positioned under the lumbar lordosis. During exercises, the spine cannot make any movements. The transversus abdominis is contracted while doing the exercises to maintain an appropriate position. Below the woman is holding the feedback unit to monitor the amplitude of her spinal movement (based on the pressure change on the dial). [20], [21]

[20]

Computer-supported test and training systems[edit | edit source]

Computer-supported test and training systems Centaur (left) and Pegasus (right)

Centaur[edit | edit source]

With this device, the global torso musculature can be specifically strengthened and its coordination trained. Furthermore, for the first time, it is possible to directly train the local, deeper-lying muscles (stabilizer). CTT CENTAUR works based on the following active principles:

  • By a coordinated tilt of the body, the torso needs to be stabilized against gravity.
  • By tilting and rotating the body is put into an unstable position so that the balance analyser sends impulses to the deeper-lying muscles.
  • Due to the upright posture during the training, the muscles are strengthened in the position in which they have to do the most supporting work.
  • The precisely reproducible application of strain allows for targeted and exactly documentable therapy and training. [22][23]

Pegasus[edit | edit source]

Computer-supported test and training system PEGASUS measure the range of motion and the strength profiles of the spine-stabilizing musculature in all anatomical planes. Thus mobility and strength deficits and imbalances are identified. Based on these results, specific training (maximum strength, strength endurance, strength coordination and mobility training) of the sensorimotor systems of the lumbar spine can be realized. Thereby, existing muscular imbalances and performance deficits are tackled and resilience of the spine is reestablished.[22]

Clinical Significance[edit | edit source]

Biofeedback techniques can potentially provide symptom relief and improve quality of life while also being safe and free of significant side effects. The methods allow patients to have some control over their disease, which is valuable in maintaining patient self-efficacy and overall well-being. With enough training sessions, patients can make changes that will last without the use of these instruments. Biofeedback can potentially also reduce the amount of medication a patient is taking, which can help patients avoid the problem of polypharmacy and limit side effects from other drugs. Clinicians may use biofeedback to control global physiologic reactions or specific muscle actions. Frequently targeted muscle groups are in the upper and lower limbs and the muscles used in gait. Muscles controlled by the autonomic nervous system, such as digestion, defecation, and urination, are also commonly selected. For urinary incontinence, pelvic floor muscles are the target, while in faecal incontinence, it focuses on the external anal sphincter. Biofeedback also has non-musculoskeletal targets such as anxiety and stress reduction. Biofeedback has also seen use in controlling the vasculature to reduce vasoconstriction, as well.[5][9]

References[edit | edit source]

  1. Rao SS. Dyssynergic defecation and biofeedback therapy. Gastroenterology Clinics of North America. 2008 Sep 1;37(3):569-86.
  2. Basmajian JV. Biofeedback: Principles and Practices for Clinicians. Williams & Wilkins; 1989.
  3. Biofeedback Vereniging Nederland. What is biofeedback? Available from: http://www.biofeedbackvereniging.nl/index.html (accessed 1/05/2013)
  4. Giggins OM, Persson UM, Caulfield B. Biofeedback in rehabilitation. Journal of neuroengineering and rehabilitation. 2013 Dec;10:1-1.
  5. 5.0 5.1 Giggins OM, Persson UM, Caulfield B. Biofeedback in rehabilitation. Journal of neuroengineering and rehabilitation. 2013 Dec;10:1-1.
  6. University of Maryland Medical Center. Biofeedback 2011. Available from: http://www.umm.edu/altmed/articles/biofeedback-000349.htm (accessed 1/05/2013)
  7. Lockheed M. Biofeedback research report 2010. Available from: http://www.etc.cmu.edu/projects/lm-motion/Research/biofeedbackResearch.pdf (accessed 1/05/2013)
  8. Van Ark A. Biofeedback 2010. Available from: http://www.vabs.nl/biofeedback/wat-is-biofeedback (accessed 1/05/2013)
  9. 9.0 9.1 Malik K, Dua A. Biofeedback. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553075/
  10. Fitz FF, Resende AP, Stüpp L, Costa TF, Sartori MG, Girão MJ, Castro RA. Effect the adding of biofeedback to the training of the pelvic floor muscles to the treatment of stress urinary incontinence. Revista Brasileira de Ginecologia e Obstetrícia. 2012;34:505-10.
  11. Norton C, Kamm MA. Anal sphincter biofeedback and pelvic floor exercises for faecal incontinence in adults—a systematic review. Alimentary pharmacology & therapeutics. 2001 Aug 22;15(8):1147-54.
  12. Dorey G, Speakman M, Feneley R, Swinkels A, Dunn C, Ewings P. Randomised controlled trial of pelvic floor muscle exercises and manometric biofeedback for erectile dysfunction. British Journal of General Practice. 2004 Nov 1;54(508):819-25.
  13. Christanell F, Hoser C, Huber R, Fink C, Luomajoki H. The influence of electromyographic biofeedback therapy on knee extension following anterior cruciate ligament reconstruction: a randomized controlled trial. Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology. 2012 Dec;4:1-0.
  14. 14.0 14.1 14.2 Andrasik F. Biofeedback in headache: an overview of approaches and evidence. Cleve Clin J Med. 2010 Jul 3;77(Suppl 3):S72-6.
  15. Nestoriuc Y, Rief W, Martin A. Meta-analysis of biofeedback for tension-type headache: efficacy, specificity, and treatment moderators. Journal of consulting and clinical psychology. 2008 Jun;76(3):379.
  16. Budzynski TH, Stoyva JM, Adler CS, Mullaney DJ. EMG biofeedback and tension headache: A controlled outcome study. Psychosomatic medicine. 1973 Nov 1;35(6):484-96.
  17. Cohen MJ, Mcarthur DL, Rickles WH. Comparison of four biofeedback treatments for migraine headache: physiological and headache variables. Psychosomatic Medicine. 1980 Sep 1;42(5):463-80.
  18. Calomeni MR, Rocha JA, Silva AP, Ribeiro LH, Marques L, Siza MA, Silva VF. Brain stimulation used as biofeedback training for recovery of motor functions deteriorated by stroke. Arquivos de neuro-psiquiatria. 2013;71:159-64.
  19. 19.0 19.1 Richardson C, Hodges P, Hides J. Therapeutic exercise for lumbopelvic stabilization. Edinburgh: Churchill Livingstone; 2004 May.
  20. 20.0 20.1 http://protherapysupplies.blogspot.be/2010/11/pro-therapy-supplies-carries.html
  21. Norris CM. Back stability: integrating science and therapy. Human Kinetics; 2008.
  22. 22.0 22.1 Physiomed. Biomechanical therapy systems. Available from: https://www.physiomed.de/en/therapy-solutions/show/Productgroup/computer-supported-test-and-training-sys/ (accessed 29 November 2020).
  23. Pfeifle C, Edel M, Schleifenbaum S, Kühnapfel A, Heyde CE. The reliability of a restraint sensor system for the computer-supported detection of spinal stabilizing muscle deficiencies. BMC Musculoskelet Disord. 2020 Sep 7;21(1):597.