Acupressure: The Evidence Presses On

By Nancy Selfridge, MD, Associate Professor, Department of Integrated Medical Education, Ross University School of Medicine, Commonwealth of Dominica, West Indies. Dr. Selfridge reports no financial relationships relevant to this field of study.

Acupressure is a therapeutic intervention that has its roots in Traditional Chinese Medicine (TCM) and is based on the same meridian theory used in acupuncture. However, rather than using needles, acupoints are typically stimulated using pressure from fingers, hands, elbows or, in some cases, by devices. The basis of meridian theory is that illness and symptoms result from alterations in the normal flow of qi in the body, defined as a life-supporting bioenergy that moves along a predictable network of pathways. Symptoms and illness can be improved by accessing these pathways through acupoints on the surface of the body and stimulating them in a prescriptive fashion, normalizing the flow of qi. Mechanism of action hypotheses based on Western concepts of human physiology include release of endorphins, functional peripheral and central nervous system changes, and changes in circulating and local bioactive substances such as cytokines and neurotransmitters.1

Acupressure has innumerable therapeutic applications in TCM. In conventional Western medicine, it is an attractive complementary and alternative medicine (CAM) intervention because of its low risk and cost, and the fact that it can often be self-administered. Over the last decade, research methodology on acupressure has improved, prompting several systematic reviews. Recent evidence of efficacy for the use of acupressure in a variety of clinical conditions is the focus of this review.

Clinical Trials

Nausea and Vomiting. Postoperative nausea and vomiting (PONV) has been a focus of acupuncture and acupressure studies as anesthesiologists continue to search for interventions that improve patient outcomes without the costs and risks of side effects associated with antiemetic drugs. The majority of studies have evaluated the effectiveness of stimulation of a single acupoint: the Pericardium (P6) acupoint at the wrist, 4 cm proximal to the wrist crease between the palmaris longus and flexor carpi radialis tendons. A 2011 Cochrane review identified 40 trials of P6 acupoint stimulation for PONV, 17 of which used acupressure.2 Of these 17 trials of acupressure, eight were determined by the reviewers to contain high risk of bias because of selective reporting. Most of these acupressure trials used a wrist band device (Sea-Bands©). There was no difference in the effect of acupressure compared to more invasive techniques, such as acupuncture or electrical stimulation, in this review. Stimulation of the P6 acupoint compared to sham treatment significantly reduced the risk of PONV and the need for antiemetic rescue (relative risk [RR] 0.71, 95% confidence interval [CI] 0.61-0.83; RR 0.70, 95% CI 0.59-0.83; RR 0.69, 95% CI 0.57-0.83, respectively). Risks of PONV were similar with acupoint stimulation and antiemetic drugs. Reviewers concluded that patients with a high risk of PONV would likely benefit from P6 acupoint stimulation.

A systematic review of acupressure for symptom management by Lee et al included six trials for nausea and vomiting related to pregnancy, four trials for nausea and vomiting related to chemotherapy or radiation, 11 trials for PONV, one trial for motion sickness, and one trial for nausea and vomiting due to myocardial infarction. Again, nearly all of the reviewed trials employed wrist bands for the acupressure intervention. These authors concluded that evidence of efficacy for acupressure compared to sham or control for nausea and vomiting prevention and treatment in general was equivocal, primarily due to small samples or methodological flaws.3

However, in a systematic review of 71 studies of acupressure intervention for a variety of clinical problems, Robinson et al concluded that the intervention was actually supported by strong evidence for reducing PONV risk, thanks to the analyses in the Cochrane review mentioned above, and moderate evidence for pregnancy-related nausea and vomiting. These authors conclude that there is some quality evidence from systematic reviews for chemotherapy-induced nausea and vomiting supporting acupressure, but only a small number of the reviewed interventions was true acupressure.4

Pain. Robinson et al reported in their review that pain was the most common issue addressed by acupressure. They included a systematic review, six randomized controlled trials (RCTs), and several studies with various methodological flaws including non-randomization of treatment or control groups, or lack of a control group. The review concluded that there was consistent evidence showing that acupressure is more effective than control for reducing dysmenorrhea, lower back pain, and labor pain. Less conclusive evidence is available for minor trauma and injection pain; evidence for headache is insufficient.4 A small (n = 33) RCT compared local and distal acupressure with a control group that did not receive any stimuli for the treatment of chronic neck pain. In this study, acupressure at both locations improved pain outcomes compared to the no-treatment control group (P < 0.05). Interestingly, autonomic function changed only in the group receiving local acupressure (P < 0.05).5 A systematic review of acupuncture and similar techniques for dysmenorrhea concluded from two RCTs that auricular acupressure (application of pressure over acupoints on the auricle) was beneficial for improving menstrual pain.6

Insomnia. Five RCTs of acupressure for insomnia and fatigue were included in the systematic review by Lee et al, who noted that all investigators concluded that acupressure was useful for reducing insomnia and fatigue; however, studies were of low quality.3 Robinson et al, in their review of the same and five additional studies, reported that acupressure for insomnia, fatigue, and depression due to renal disease has moderate evidence of efficacy similar to placebo, while evidence for improving sleep quality in institutionalized elderly is strong, though again failing to consistently support specific effects of acupressure compared to sham.4 A review of insomnia and the use of CAM by Sarris et al included two RCTs on acupressure; the authors concluded that there was evidence to support the treatment of chronic insomnia with acupressure (d = 1.42-2.12).7

Other Conditions. Lee et al reviewed four trials of acupressure for dyspnea related to chronic lung disease, including chronic obstructive pulmonary disease (COPD), bronchiectasis, and asthma. These studies included subjective and objective parameters (pulmonary function tests, oxygen saturation, and exercise capacity) as outcomes. In all four studies, acupressure improved outcomes compared to either placebo or standard care controls.3 Again, all of the studies were of low quality. Chang et al reported that acupressure improved symptoms of urodynamic stress incontinence and pelvic floor strength (P < 0.05) compared to both sham treatment and usual care (pelvic floor training).8 Pelvic floor muscle strength was the primary outcome measure in this study, evaluated by perineometry, measuring vaginal squeeze pressure. Unfortunately, the study was only single-blinded, as the investigator was the intervention provider. However, this is one of very few clinical trials that have included an objective outcome measure.8 Another well-designed, single-blind crossover study noted decreased heart rate in stroke patients treated with acupressure compared to sham acupressure.9 A recent small pilot study compared acupressure to standard treatment for atopic dermatitis and noted improvement in lichenification (P < 0.03) and decreased pruritis (P < 0.05) in the acupressure group compared to usual care control.10 A systematic review of acupressure for treating neurological disorders included a total of six controlled trials. The authors concluded from one RCT and three controlled clinical trials that there is some evidence that acupressure improves function and symptoms in patients with stroke but that all trials were limited by methodological flaws and high risk of bias.11 A randomized, single-blind, crossover trial by Harris et al concluded that self-administered acupressure can modify alertness in students in a classroom setting.12 Based on the results of this study, Zick et al studied the effects of self-administered stimulatory or relaxation acupressure in patients with cancer-related fatigue, hypothesizing that both low- and high-dose stimulatory acupressure would reduce fatigue symptoms and relaxation acupressure would help control for the placebo effect. Surprisingly, their results showed that relaxation acupressure significantly reduced fatigue compared to stimulatory acupressure.13 Jin et al reported that acupressure as an adjunct to usual care inhibited the development of diabetic complications in patients with type 2 diabetes.14 Their trial included a control group receiving only usual care, but no sham treatment group. Of interest is that the acupressure treatments were 90 minutes each and delivered by a practitioner 4-6 times per week for 3 years, a rather intensive intervention. Multiple objective outcome measures showed improvement in the acupressure treatment group compared to controls: total cholesterol, triglycerides, LDL, HDL, and nerve conduction velocities. Kidney function also was stable in the treatment group compared to controls.14 Still, without a sham intervention of similar practitioner-patient intensity, it is hard to ascertain the specific effects of acupressure.

Adverse Effects

Acupressure is considered safe and non-invasive. Local skin reactions, blistering, and swelling with wrist band acupressure devices have been reported in some studies. It is considered normal to feel a temporary heaviness, aching, or tingling at the point of the acupressure administration. These symptoms were mentioned in a few of the articles reviewed. In TCM, these sensations are an indication that qi has entered the area, a desired treatment effect.

Conclusion

Clinical trials of acupressure appear to be steadily improving with respect to methodology over the last several years. Current research evidence supports that acupressure is effective for reducing the risk of nausea and vomiting in high-risk, postoperative patients, in pregnant patients, and possibly in cancer patients. There is consistent evidence of efficacy for reducing dysmenorrhea, low back pain, and labor pain. Acupressure appears to improve sleep quality in elderly institutionalized patients, and reduces fatigue in patients with chronic renal failure. Limited data supports acupuncture for stress incontinence and prevention of diabetic complications. Still, nearly all of the evidence is compromised by methodological flaws and bias. For example, sample sizes are characteristically small; acupressure doses for various conditions vary widely from a few minutes to a few days; and acupressure regimens also vary widely in technique and number and choice of acupressure sites, even when applied for the same condition. In many studies, there is a lack of information about practitioner-patient interaction for control and treatment groups, creating a potentially serious confounding variable. The Cochrane review on nausea and vomiting reports several common serious sources of bias in the acupressure studies: selective reporting, lack of allocation concealment, and no blinding of outcome assessor. Wide confidence intervals in most studies suggest that we still know very little about the effect sizes of acupressure interventions. More high-quality acupressure studies are needed, addressing the methodological flaws and bias that exist in the current body of work. Future studies including objective outcomes may add insight into the mechanisms of action of acupressure and meridian therapies in general.

Recommendations

Acupressure is a low-risk intervention that has an additional advantage in that it can be self-administered for some conditions, increasing its potential cost-effectiveness. Acupressure can be recommended as first-line therapy and adjunctive therapy for prevention of nausea and vomiting postoperatively, during pregnancy, and during cancer treatment. Acupressure may help low back pain patients, women in labor, and patients suffering from dysmenorrhea, and it can be offered to patients as an alternative or adjunct to medication. Elderly in nursing homes may benefit from acupressure to improve sleep quality, avoiding the pitfalls of sleep medication and providing an intervention that could be administered, after training, by local staff.

Acupressure therapists are not consistently regulated in the United States; acupressure therapy often falls outside the regulatory legislation and certification mandates that apply to massage therapy and other forms of bodywork. However, many massage and acupuncture schools in the United States offer acupressure courses and a certifying examination in Asian Bodywork Therapy is available through the National Certification Commission for Acupuncture and Oriental Medicine. Online tutorials and courses are also available for acupressure training. Patients can and do access these tutorials to learn about acupressure self-administration and it is also likely that the training and experience of acupressure providers in communities varies widely. Thus, physicians and other professionals recommending acupressure as an intervention for their patients and clients are wise to investigate the services available in their area thoroughly, seeking and recommending practitioners who are formally trained and certified.

References

1. Michelfelder AJ. Acupuncture for headaches. In: Rakel DP, ed. Integrative Medicine Philadelphia, PA: Saunders; 2007.

2. Lee A, et al. Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting. Cochrane Database Syst Rev 2011;(2):CD003281.

3. Lee EJ, et al. The efficacy of acupressure for symptom management: A systematic review. J Pain Symptom Manage 2011;42:589-603.

4. Robinson N, et al. The evidence for Shiatsu; a systematic review of Shiatsu and acupressure. BMC Complement Altern Med 2011;11:88.

5. Matsubara T, et al. Comparative effects of acupressure at local and distal acupuncture points on pain conditions and autonomic function in females with chronic neck pain. Evid Based Complement Altern Med 2011;2011.pii:543291.

6. Cho SH, et al. Acupuncture for primary dysmenorrhea: A systematic review. BJOG 2010;117:509-521.

7. Sarris J, Byrne GJ. A systematic review of insomnia and complementary medicine. Sleep Med Rev 2011;15:99-106.

8. Chang KK, et al. Effect of acupressure in treating urodynamic stress incontinence: A randomized controlled trial. Am J Chin Med 2011;39:1139-1159.

9. McFadden KL, et al. Cardiovascular benefits of acupressure (Jin Shin) following stroke. Complement Ther Med 2010;18:42-48.

10. Lee KC, et al. Effectiveness of acupressure on pruritus and lichenification associated with atopic dermatitis: A pilot trial. Acupunct Med 2012;30:8-11.

11. Lee JS, et al. Acupressure for treating neurological disorders: A systematic review. Int J Neurosci 2011;121:409-414.

12. Harris RE, et al. Using acupressure to modify alertness in the classroom: A single-blinded, randomized, cross-over trial. J Altern Complement Med 2005;11:673-679.

13. Zick SM, et al. Relaxation acupressure reduces persistent cancer-related fatigue. Evid Based Complement Altern Med 2011;2011.pii:142913.

14. Jin KK, et al. Acupressure therapy inhibits the development of diabetic complications in Chinese patients with type 2 diabetes. J Altern Complement Med 2009;15:1027-1032.