We have all seen the pictures. Athletes looking to get an edge have turned to cupping, an ancient healing modality, and have shown up to many sporting events covered in the characteristic circular bruises of a cupping treatment. In physical therapy circles, cupping has had a bit of a revival, and is often incorporated as part of a treatment to help relieve pain and get patients better. It is not hard to find reports of the beneficial effects of cupping; just look for the Twitter and Instagram posts, the Facebook discussions, and the course advertisements targeted towards you.
Despite the enthusiasm, cupping is not without its critics. Many suggest cupping should not be a part of physical therapy practice, or medical practice in general, and should remain in antiquity along with bloodletting, acupuncture, and reflexology. In this article, we will take a critical look at the scientific research on cupping and I will help you decide whether or not it should become a part of your practice.
What Is Cupping Therapy?
Cupping refers to using cups made of glass, bamboo, or plastic to create suction on the skin for therapeutic purposes. There is evidence that cupping has been performed since 3300 BC, and is practiced widely in the eastern world (4). There are many types of cupping, each with their own protocols and techniques, and it can be paired with other treatments like acupuncture. Two broad categories of cupping can be distinguished; wet cupping involves scarification or cutting of the skin prior to the application of the cups, which will allow blood to be drawn into the cup, and dry cupping, which involves the application of the cups to the affected area only.
Cupping is purported to have various health benefits, but trying to list them all is an exercise in futility. As practiced in the eastern world, the claims tend to be broad and non-specific. In the physical therapy world however, it is used more narrowly and is focused on pain management, among a few other uses. As physical therapists interested in helping our patients with pain, cupping may be of interest to us.
The State Of The Research
If we want to establish ourselves as allied health team members and evidence-based professionals it is essential that we critically evaluate the scientific evidence on a given treatment and adjust our beliefs and practice accordingly.
Reading through the available literature revealed two broad trends. First, cupping simply hasn’t been studied that much. While it is hard to precisely quantify how many studies have been performed on any given treatment, a student can read through a representative majority of cupping trials and reviews in an afternoon. Second, the overwhelming majority of trials were of relatively low quality and had a high risk of bias. This was characterized by low numbers of participants, failures to control for researcher bias, lack of blinding of any kind, comparisons to an inactive control group, only short-term follow ups, and lack of placebo-controlled study designs.
While having insufficient high-quality research is not a problem unique to cupping, it is still something we need to consider when we adopt new treatments. Given the caveats listed above, what does the research actually say?
A paper from 2016 was the only available trial that attempted to control for non-specific effects cupping might have. The researchers recruited 141 patients with fibromyalgia and randomized them into one of three groups. One group received a true cupping treatment to various body parts. A second group received an identical treatment but the researchers utilized sham cups, which had tiny holes in them that prevented any negative pressure from developing. Lastly, a control group was advised to just continue normal activities and refrain from trying any new treatments. The cupping groups underwent five treatments over the course of two weeks. They found that while both cupping groups reported better outcomes on a visual analog scale and a functional measure compared to usual care, there was no differences between true cupping and sham cupping (15).
A similar study was performed in 2018 on 110 patients with chronic low back pain. They were divided into a normal cupping group, a “minimal” cupping group that utilized a lower negative pressure, and a control group that did nothing. All three groups were allowed to take pain medication as needed. After eight cupping sessions over four weeks, both cupping groups had similar decreases in pain (20).
Many other smaller preliminary trials have been performed comparing cupping to a waitlist control or usual care for different populations and have shown that dry or wet cupping can reduce pain by varying amounts. These populations include people with headaches (1), low back pain (2, 9, 12), neck pain (7, 8, 14 16, 19) and knee osteoarthritis (21). Throughout each of these trials, the amount of sessions, techniques, and outcome measures varied, but all reported beneficial effects. Cupping also edged out hot packs for neck pain (13) and carpal tunnel syndrome (18), and beat e-stim for plantar fasciitis (10). We need to be careful interpreting this group of studies however, because we expect an active group receiving an intervention to do better than an inactive control, especially when it comes to subjective outcomes like pain.
Systematic Reviews And Meta-Analyses
The systematic reviews and meta-analyses thus far reinforce the broader trend seen in the trials we examined above.
One review from 2017 focused on the effects of cupping on athletes and found 13 papers on 11 different trials. On the majority of the outcomes each study looked at, cupping provided beneficial effects. However, most of the time, cupping was compared to an inactive control or no intervention at all, there were no placebo controls, there was significant variability in technique, it was unclear if the studies found were adequately peer-reviewed, there was no blinding, and there was no information about safety or side-effects (4). The authors go on to say they cannot make any recommendations for or against cupping in clinical practice.
Three other reviews for low back pain, knee osteoarthritis and in pain in general came to similar conclusions. Cupping may be helpful for reducing pain, but the quality of the research, statistical heterogeneity, and high risk of bias present in the research limits the strength of the evidence (11, 17, 22). Three other more broad reviews that did not limit their literature search to a specific condition or type of cupping found that results were mixed overall, and we need better quality research to make any definitive conclusions (2, 5, 6).
The Clearest Picture
Taking a look at the totality of the evidence, what can we say with certainty in regards to cupping? Is something of clinical value actually happening during a cupping treatment? Anecdotal evidence and very weak scientific evidence suggests that in isolation, cupping may help reduce pain by small amounts for various conditions, but the literature is not strong enough to give us a definitive answer. We have no studies looking at how cupping would fair in addition to a traditional physical therapy treatment program. The one study we have that was designed to differentiate between specific and non-specific effects failed to show cupping has any additional benefits over a credible sham procedure. In regards to the potential placebo effects, one author writes:
As of today, there are no strong studies we can be confident in that suggest cupping adds anything of value beyond nonspecific pain relief, which almost all of our other treatments can provide. This may change, but cupping has only faced one hard test of effectiveness and it failed.
The Role Of Cupping In Physical Therapy Practice
So where does that leave us? How should we view treatments that have anecdotal support, yet weak or absent scientific evidence? Many online discussions and public debates break down at this point but reasonable people can disagree. The arguments in favor of cupping typically point out that patients report benefits after cupping sessions, the research isn’t absolutely negative (even though it is weak), and in the therapist’s experience, they have seen benefits. These seem to fit Sackett’s classic definition of evidence-based practice we all learned in school, and is therefore okay to include as part of a multi-modal treatment.
My opinion diverges here because of a fundamentally different philosophy on what physical therapists do and why they should do it. It is not enough to merely show a treatment can reduce pain by a few points in a handful of poorly-designed trials and to have anecdotal success stories from patients and other therapists. Any treatment can be justified with this type of reasoning, including homeopathy, craniosacral therapy, acupuncture, reiki, or magnet therapy. If we are going to be a respected part of the medical community, we need to embrace science-based medicine, and seek strong scientific ground and biological plausibility for the things we do. Cupping has not met that threshold.
We already provide many of these types of treatments, and we don’t have robust evidence to suggest that cupping offers something significantly different or better. Why would we need more of the same? If you chose to incorporate cupping into your treatments, it is important to emphasize that cupping is largely unstudied and has only been shown to reduce pain by small amounts. It should be a minor part of treatment, if at all. As far as the science is concerned, cupping has not yet passed any fair tests, and as such, we should all be very skeptical of the inclusion of it in physical therapy practice.
- Ahmadi, Alireza, et al. “The Efficacy of Wet-Cupping in the Treatment of Tension and Migraine Headache.” The American Journal of Chinese Medicine, vol. 36, no. 01, 2008, pp. 37–44., doi:10.1142/s0192415x08005564.
- Albedah, Abdullah, et al. “The Use of Wet Cupping for Persistent Nonspecific Low Back Pain: Randomized Controlled Clinical Trial.” The Journal of Alternative and Complementary Medicine, vol. 21, no. 8, 2015, pp. 504–508., doi:10.1089/acm.2015.0065.
- Bedah, Abdullah M.n. Al, et al. “Evaluation of Wet Cupping Therapy: Systematic Review of Randomized Clinical Trials.” The Journal of Alternative and Complementary Medicine, vol. 22, no. 10, 2016, pp. 768–777., doi:10.1089/acm.2016.0193.
- Bridgett, Rhianna, et al. “Effects of Cupping Therapy in Amateur and Professional Athletes: Systematic Review of Randomized Controlled Trials.” The Journal of Alternative and Complementary Medicine, vol. 24, no. 3, 2018, pp. 208–219., doi:10.1089/acm.2017.0191.
- Cao, Huijuan, et al. “Clinical Research Evidence of Cupping Therapy in China: a Systematic Literature Review.” BMC Complementary and Alternative Medicine, vol. 10, no. 1, 2010, doi:10.1186/1472-6882-10-70.
- Cao, Huijuan, et al. “An Updated Review of the Efficacy of Cupping Therapy.” PLoS ONE, vol. 7, no. 2, 2012, doi:10.1371/journal.pone.0031793.
- Chi, Lee-Mei, et al. “The Effectiveness of Cupping Therapy on Relieving Chronic Neck and Shoulder Pain: A Randomized Controlled Trial.” Evidence-Based Complementary and Alternative Medicine, vol. 2016, 2016, pp. 1–7., doi:10.1155/2016/7358918.
- Cramer, Holger, et al. “Randomized Controlled Trial of Pulsating Cupping (Pneumatic Pulsation Therapy) for Chronic Neck Pain.” Forschende Komplementärmedizin / Research in Complementary Medicine, vol. 18, no. 6, 2011, pp. 327–334., doi:10.1159/000335294.
- Farhadi, Khosro, et al. “The Effectiveness of Wet-Cupping for Nonspecific Low Back Pain in Iran: A Randomized Controlled Trial.” Complementary Therapies in Medicine, vol. 17, no. 1, 2009, pp. 9–15., doi:10.1016/j.ctim.2008.05.003.
- Ge, Weiqing, et al. “Dry Cupping for Plantar Fasciitis: a Randomized Controlled Trial.” Journal of Physical Therapy Science, vol. 29, no. 5, 2017, pp. 859–862., doi:10.1589/jpts.29.859.
- Kim, Jong-In, et al. “Cupping for Treating Pain: A Systematic Review.” Evidence-Based Complementary and Alternative Medicine, vol. 2011, 2011, pp. 1–7., doi:10.1093/ecam/nep035.
- Kim, Jong-In, et al. “Evaluation of Wet-Cupping Therapy for Persistent Non-Specific Low Back Pain: a Randomised, Waiting-List Controlled, Open-Label, Parallel-Group Pilot Trial.” Trials, vol. 12, no. 1, Oct. 2011, doi:10.1186/1745-6215-12-146.
- Kim, Tae-Hun, et al. “Cupping for Treating Neck Pain in Video Display Terminal (VDT) Users: A Randomized Controlled Pilot Trial.” Journal of Occupational Health, vol. 54, no. 6, 2012, pp. 416–426., doi:10.1539/joh.12-0133-oa.
- Lauche, Romy, et al. “The Effect of Traditional Cupping on Pain and Mechanical Thresholds in Patients with Chronic Nonspecific Neck Pain: A Randomised Controlled Pilot Study.” Evidence-Based Complementary and Alternative Medicine, vol. 2012, 2012, pp. 1–10., doi:10.1155/2012/429718.
- Lauche, Romy, et al. “Efficacy of Cupping Therapy in Patients with the Fibromyalgia Syndrome-a Randomised Placebo Controlled Trial.” Scientific Reports, vol. 6, no. 1, 2016, doi:10.1038/srep37316.
- Lauche, Romy, et al. “The Influence of a Series of Five Dry Cupping Treatments on Pain and Mechanical Thresholds in Patients with Chronic Non-Specific Neck Pain - a Randomised Controlled Pilot Study.” BMC Complementary and Alternative Medicine, vol. 11, no. 1, 2011, doi:10.1186/1472-6882-11-63.
- Li, Jin-Quan, et al. “Cupping Therapy for Treating Knee Osteoarthritis: The Evidence from Systematic Review and Meta-Analysis.” Complementary Therapies in Clinical Practice, vol. 28, 2017, pp. 152–160., doi:10.1016/j.ctcp.2017.06.003.
- Michalsen, Andreas, et al. “Effects of Traditional Cupping Therapy in Patients With Carpal Tunnel Syndrome: A Randomized Controlled Trial.” The Journal of Pain, vol. 10, no. 6, 2009, pp. 601–608., doi:10.1016/j.jpain.2008.12.013.
- Saha, Felix J., et al. “The Effects of Cupping Massage in Patients with Chronic Neck Pain - A Randomised Controlled Trial.” Complementary Medicine Research, vol. 24, no. 1, 2017, pp. 26–32., doi:10.1159/000454872.
- Teut, M., et al. “Pulsatile Dry Cupping in Chronic Low Back Pain – a Randomized Three-Armed Controlled Clinical Trial.” BMC Complementary and Alternative Medicine, vol. 18, no. 1, Feb. 2018, doi:10.1186/s12906-018-2187-8.
- Teut, Michael, et al. “Pulsatile Dry Cupping in Patients with Osteoarthritis of the Knee – a Randomized Controlled Exploratory Trial.” BMC Complementary and Alternative Medicine, vol. 12, no. 1, Dec. 2012, doi:10.1186/1472-6882-12-184.
- Wang, Yun-Ting, et al. “The Effect of Cupping Therapy for Low Back Pain: A Meta-Analysis Based on Existing Randomized Controlled Trials.” Journal of Back and Musculoskeletal Rehabilitation, vol. 30, no. 6, June 2017, pp. 1187–1195., doi:10.3233/bmr-169736.