Written by Helen Cooke and the CAM-Cancer Consortium.
Updated April 29, 2016

Biofeedback

Abstract and key points

  • Biofeedback involves the use of instrumentation to monitor, amplify, and feed back information on physiological responses so that a patient can learn to regulate these responses.
  • There is presently a lack of good quality, single-intervention trials, so it is not possible to draw clear conclusions about the role of biofeedback for people with cancer.
  • Biofeedback has a good safety record.

Biofeedback involves the use of instrumentation to monitor, amplify, and feed back information on physiological responses so that a patient can learn to regulate these responses. Although some of the studies included in this summary indicate an improvement in pain relief and chemotherapy-related nausea and anxiety, these studies have not been reproduced and have considerable methodological limitations. Four of the five trials included have 12 participants or fewer per group. The only larger, well-conducted study reported no benefits when compared with relaxation and no intervention. Evidence is therefore insufficient to document the benefits of biofeedback for people with cancer.

Biofeedback is considered to have few adverse effects.

What is it ?

Description

Biofeedback is a process that is used to enable an individual to learn how to change physiological activity for the purposes of improving health and performance1. A variety of different biofeedback techniques are available. The two most commonly used techniques by people with cancer are electromyography (EMG), which measures the electric activity in muscles, and skin temperature (ST) biofeedback. These instruments rapidly and accurately 'feed back' information to the user. The presentation of this information — often in conjunction with changes in thinking, emotions, and behaviour — supports desired physiological changes. Over time, these changes can endure without continued use of an instrument.

Application and dosage

Biofeedback is most commonly taught by health care professionals including clinical psychologists and nurses, as well as hypnotherapists and complementary practitioners. Training is either conducted in groups or one-on-one sessions, lasting twenty to thirty minutes. Patients are informed about the purpose of the training; i.e. to help them become relaxed and comfortable. The therapist then attaches electrodes or skin temperature thermistors and demonstrates how to use the equipment2.

Participants are subsequently given suggestions about how to influence physiological responses and any symptoms they are experiencing. For example EMG-biofeedback users are told they may find it helpful to imagine relaxing and letting go of any muscle tension and see how this alters the biofeedback reading and tone. ST-biofeedback users are told they may find it helpful to imagine that their fingers and hands are warm and comfortable. A small band indicates changes in finger temperature.

Patients are recommended to use the equipment once or twice a day, in order for them to master the skill3.

History/providers

Scientists began to make the link between electrical responses in nerve and muscle activity in the early 1900s. Edmund Jacobson who worked as a physiologist/physician in the 1930s and John Basmajian, a Canadian academic and scientist were early pioneers in the field of biofeedback4.

Claims of efficacy/mechanism of action/alleged indications

Biofeedback is aimed at allowing people to monitor and influence specific physiological responses the individual would likely to be otherwise unaware of by providing information about moment-to-moment physiological responses such as muscle tension and skin temperature3.

 EMG feedback is most commonly used by people with cancer as a technique to initiate a deep state of muscle relaxation, with the aim of inducing a generalised relaxation response and relief in cancer-related symptoms.

Adverse effects, including gastro-intestinal upsets such as nausea and vomiting that are caused by high levels of anxiety also appear to be reduced through this muscle relaxation mechanism. It is thought that muscular relaxation may directly inhibit the characteristic sequence of muscular activity that generally precedes nausea and vomiting. It has been suggested that the 'relaxation response' may help break the pain-anxiety-muscle-tension cycle5. ST biofeedback aims to help people control peripheral blood flow to their peripheries and has been shown to improve circulatory and vascular disorders such as Raynaud’s disease3. Skin temperature drops just before vomiting, it has therefore been proposed that by teaching patients to adapt their skin temperature biofeedback may also benefit chemotherapy-related nausea and vomiting3.

It has been proposed that learning biofeedback and relaxation skills can contribute to improved feelings of self-efficacy, by helping people with cancer feel more in control of any side-effects including chronic pain5.

Prevalence of use

The exact prevalence of the use of biofeedback for cancer patients is unknown.

Legal issues

The Biofeedback Certification International Alliance10 certifies individuals who meet education and training standards in biofeedback. It is the certification body for the clinical practice of biofeedback by the Biofeedback Foundation of Europe11, the Biofeedback Certification Institute of America1 and the International Society for Feedback Research12.

Costs and expenditures

Biofeedback can be administered or taught fairly easily and is therefore a relatively inexpensive therapy depending on the context within in which it is administered.

Does it work ?

Although some of the studies included in this summary indicate an improvement in pain relief and chemotherapy-related nausea and anxiety, these studies have not been independently replicated and have very small sample sizes. Evidence is therefore insufficient to document the benefits of biofeedback for people with cancer. Due to the difficulty in creating appropriate and credible placebo conditions double-blind studies are difficult to complete for this intervention.

Different types of biofeedback have been widely used in a variety of health care and rehabilitation settings. Reported effects from randomised controlled trials include a reduction in chronic pain2. Other reported benefits from case reports and uncontrolled trials include relief of stress and tension5.

Controlled clinical trials

Four controlled3,5,6,7 and one uncontrolled clinical trial9 have assessed the benefits of biofeedback for cancer patients.

A well-performed randomised clinical trial (RCT) assessed the effectiveness of electromyography (EMG) biofeedback, skin-temperature (ST) biofeedback and relaxation training in reducing the aversiveness of cancer chemotherapy (n=81)3. Results showed that patients who undertook relaxation training experienced a reduction in nausea and anxiety during their chemotherapy, when compared to the no-intervention group. Although the EMG and skin temperature biofeedback reduced levels of physiological arousal in participants, this did not alter the chemotherapy side-effects. Results suggest that relaxation training, but not biofeedback is effective in reducing adverse effects of chemotherapy.

A small RCT investigating the effectiveness of relaxation training supplemented with visual and auditory electromyography (EMG) biofeedback signals found a reduction in pain intensity in people with advanced cancer (n=12) compared to the control group (n=12)5. This study is limited by its small sample size.

Another small RCT explored changes in the immune system and psychological profile of women with breast cancer who had recently undergone radical mastectomy (n=13). Patients were randomised to either an intervention group who were trained in relaxation, guided imagery and biofeedback over a 24 week period or a waiting list control. Results indicate that relaxation, guided imagery and biofeedback interventions can be correlated with immune system and anxiety measures6. Due to the small participant number and the use of a multi-modal intervention it is impossible to draw conclusions about the benefits of biofeedback.

Another small RCT investigating the effectiveness of electrodermal (skin conductance) and electromyographic (EMG) biofeedback for people with advanced cancer found reduced pain during the intervention  (n=12). However, only six of the 12 participants completed the trial. Five participants died and one moved away from the area. The study results are limited by the small sample size and lack of an adequate control group. The study utilised an ABA single-subject design, where subjects acted as their own controls.7

There is insufficient evidence from one small uncontrolled feasibility trial (n=12) that biofeedback (heart rate variability) or relaxation is beneficial as a coping strategy for children with cancer experiencing procedural distress.9 Although participants demonstrated an improvement in heart rate variability coherence scores in sessions 3 and 4 (p<0.05), the study is limited by its small sample size and lack of control group.

Is it safe ?

Biofeedback appears to have a good safety record8.

Adverse events

No adverse events were reported in the studies analysed for this summary.

Contraindications

Some concern has been raised on the use of this intervention in individuals who have a history of psychiatric illness8.

Interactions

None known.

Warnings

None known. Some participants found the technique a little cumbersome and inconvenient when they were attempting to use biofeedback equipment at the same time as undergoing chemotherapy3.

Citation

Helen Cooke, CAM-Cancer Consortium. Biofeedback [online document]. http://cam-cancer.org/The-Summaries/Mind-body-interventions/Biofeedback. April 29, 2016.

Document history

Most recent update and revision in November 2015 by Helen Cooke.
Summary fully updated and revised in November 2013 by Helen Cooke.
Summary fully updated and revised in September 2012 by Helen Cooke.
Summary first published in August 2011, authored by Helen Cooke.

References

  1. Association for Applied Psychophysiology and Biofeedback USA [website], accessed 16th September 2015.
  2. Sellick SM and Zaza C. Critical review of 5 nonpharmacologic strategies for managing cancer pain. Cancer Prev Control. 1998; 2(1):7-14.
  3. Burish TG and Jenkins RA. Effectiveness of biofeedback and relaxation training in reducing the side effects of cancer chemotherapy. SO: Health Psychology: Official journal of the Division of Health Psychology, American Psychological Association. 1992; (1): 17-23.
  4. Payne R and Donaghy M. 2010. 4th Edition. Payne’s Handbook of Relaxation Techniques: a practical guide for the health care professional. London: Churchill Livingstone, Elsevier.
  5. Tsai PS, Chen PL, Lai YL, Lee MB, Lin CC. Effects of electromyography biofeedback-assisted relaxation on pain in patients with advanced cancer in a palliative care unit. Cancer Nursing. 2007; 30(5):347-53.
  6. Gruber BL, Hersh SP et al. Immunological responses of breast cancer patients to behavioral interventions. SO: Biofeedback and self-regulation. 1993; (1): 1-22.
  7. Fotopoulos SS, Cook MR, Graham C, Cohen H, Gerkovich M, Bond SS, Knapp T: Cancer pain: evaluation of electromyographic and electrodermal feedback. Prog Clin Biol Res. 1983; 132D:33-53. Ref ID: 25675
  8. Ernst E, Pittler M, Wider B and Boddy K. Oxford Handbook of Complementary Medicine. Oxford: Oxford University Press, 2008.
  9. Shockey DP, Menzies V, Glick DF, Taylor AG, Boitnott A, Rovnyak V. Preprocedural distress in children with cancer: an intervention using biofeedback and relaxation. Journal of pediatric oncology nursing : official journal of the Association of Pediatric Oncology Nurses. 2013;30(3):129-38.
  10. The Biofeedback Certification International Alliance [website], accessed 16th September 2015
  11. The Biofeedback Federation of Europe [website], accessed 16th September 2015
  12. The International Society for Feedback Research [website], accessed 16th September 2015