Coin Rubbing Part 2 (Addition)

The first post addressing studies showing possible physiological benefits/pathways of coin rubbing was getting too long so I did not include the following. Nevertheless, the content is important enough that I felt I needed to create an addendum.

A website associated with Vanderbilt University, written by a student in 2006, gives a brief overview of Cao Gio  (coin rubbing). At that time the student mentioned that no papers were written on the efficacy of the practice but that there were a variety of sources addressing the balms and oils that are used. It is entirely possible that any perceived benefits of the practice do not come from the rubbing at all but rather the tiger balm or menthol used. It is also possible that the oil and the rubbing activate different pathways. I am not going to summarize these articles like I did the others because it has already been done, but if you are interested here is the link. Scroll down to Other Perspectives. 


Among possible benefits perceived are reducing circulatory disorders and relieving tension headaches. The website mentions my favorite blanket explanation, the placebo effect and also points out that efficacy is hard to evaluate because coin rubbing is often used in tandem with bio-medical remedies.  

Coin Rubbing Part 3: Adverse Complications

My wife lives by the idea that medicine is a double sided sword and I have generally found that to be true more often than not. It was a shock to me when I learned that medicines I had considered benign as a child could actually have some pretty nasty side effects (ibuprofen, aspirin, etc...). Additionally, I am aware that traditional or alternative therapies that claim to have few side effects can often have disastrous ramifications. While I was volunteering with Operation Smile Cambodia I saw a horde of Cambodians that came through screening with extensive scars resulting from serious burns associated with "cupping".

Coming from this experience and perspective I expected to find at least some adverse side effects of coin rubbing. Surely there should be some physiological ramifications. Long term dermatological issues? Problems in pregnant women? Permanent damage to infants? Blood poisoning? I have not been able to find reports of any of these problems. Indeed it seems that the psychological ramifications of the "child abuse" label in the U.S. may be the most serious side effect (Besides, of course, the pain, discomfort and bleeding that accompanies the process). To some extent I am disappointed. While it would be wonderful to have a healing method that treats a variety of symptoms with absolutely no long term drawbacks, the absence of any complications tempts me to doubt its authenticity. If a procedure does something physiologically significant, the pathways should be able to cause harm as well as heal. I understand that many alternative healing methods follow the mantra that we need to open pathways to "allow the body to heal itself". Even the body's healing mechanisms have the potential to cause serious harm however (autoimmune disease, prolonged fever, clotting or lack thereof). On the other hand maybe the visible temporary side effects, which could cause nerve desensitization and increased circulation, are more than adequate and I am making something out of nothing.  

The only reports that I was able to find that relate at all to dangerous coin rubbing side effects addressed camphor intoxication and burns (associated with some practitioners who heat the oil they use).

Camphor Intoxication After Cao Gio (Coin Rubbing)

Cutaneous Side Effects of Alternative Therapy


 

Coin Rubbing Part 2: Studies on Physiological Benefits

To preface, I was very disappointed with the available literature on coin rubbing, and traditional medicine in general. This is both because of the dearth of scientific studies and the general quality of those that have been conducted. Traditional medicine is traditionally avoided by the western scientific community because it is not based on current world view/understanding of physiology and biology. There has been an increase in recent years of studies that have sought to identify a scientific basis behind traditional medicine but they are still few and far between. The studies that have been done are primarily relegated to journals with questionable underpinnings (journals dedicated to Chinese integrative medicine that are attached to schools of integrative medicine, for instance). Traditional/holistic/integrative/experimental medical techniques, perhaps because of the common ground of bio-medical rejection, are generally grouped together. As a result it is often difficult to pick and choose which healing techniques may have seeds of legitimacy and which ones have little benefit at all. In bio-medical journals the peer review process is cannibalistic. Scientists and physicians work hard to disprove, replicate and authenticate studies before they are published. I realize that this is not always the case but relative to alternative healing journals biomedical science is exclusive. I get the feeling that alternative healers are often willing to include any validation for any alternative healing theory because they are on the same side of the battle. Obviously this is not the case across the board but I do think that there is a significant difference in atmosphere. Regardless, some progress, however little, has been made.

Here are some of the studies that I have been able to find on the physiological benefits of coin rubbing. I think it is important to group them into two separate categories, studies which attempt to aid understanding of a biological mechanism and studies which try to show if coin rubbing actually does anything at all.

Randomized controlled pilot study: Quantitative sensory testing in patients with back pain before and after Gua Sha massage (Source)
Published in European Journal of Integrative Medicine, 2009

Experiment Design: 30 patients with back pain were put into a treatment group (TG) or waiting list control group (WLC). Patients were asked to rate their pain and then coin rubbing was started in the TG group after getting a baseline sensory data. After 7 days more sensory data was taken and the WLC received the treatment. Sensory data included mechanical detection threshold (MDT), pressure pain threshold (PPD) and vibration detection threshold (VDT). It was take at the site of pain, 10 cm next to the pain and two control areas.
Results: Decrease in pain ratings when comparing TG vs. WLC. There was no difference in VDT anywhere. While there were also no differences at site of maximum pain, the 10 cm mark showed increased MDT and PPD.
Conclusions: TG received a 35% decrease in self reported pain intensity, the control did not. It appears through the changes in thresholds that there were functional changes in the sensitized areas.
Analysis: This study sets out to show both that there is significant pain reduction and tries to probe where this might be taking place. I really wish that the control group was handled differently. Having the control group wait to receive the treatment does not counteract any psychological factors. Would having someone lightly massage your back, or talk to you about your problems or use a heat pack have given the same decrease in pain intensity? This is something that I feel that many of the people studying these traditional treatments are afraid to explore. Understandable it is difficult to find a good experimental procedure that finds its way around some of these problems but to be convinced I really need something more elegant. The only reason I like this study is because I think that if coin rubbing is doing anything physiologically, the most likely mechanism is through a change in the nervous system. The threshold information is interesting but we ultimately need experiments that can both confirm and explain this finding.    

Changes of bilirubin,SOD,IL-1,IL-6 and WBC count before and after Guasha treatment in rats (Source)

Published in Journal of Beijing University of Traditional Chinese Medicine, 2009

Experiment Design: Blood was taken from individuals with no coin rubbing, after a half hour of coin rubbing, after 6 hours of coin rubbing and after twelve hours of coin rubbing. They were then tested for the following compounds: bilirubin, superoxide dismutase (SOD), interlukin-1 (IL-1) and IL-6.
Results: Compared to the normal group, the 6 hour group had a lower white blood cell (WBC) count and a high level of bilirubin and the 12 hour group had very low levels of SOD.
Conclusion: From the data they concluded that the inflammatory reaction of WBC was inhibited and bilirubin was increased. They suggested this may be how fever is decreased and diseases cured. 

Analysis: This study fits into the category trying to find a mechanism. They do not specify which SOD enzyme but from what little I have been able to learn you don’t really want low levels. It is an important antioxidant and its mutation or absence is linked to a wide variety of diseases. Bilirubin is also an antioxidant but with different functions as well. It is a breakdown product in the catabolism of heme (the yellow color on your bruise). I do not have the necessary background to really make a valid argument or assessment but it seems to me that the differing blood levels of these compounds would be the natural product of widespread scraping and bruising. There is no explanation or hypothesis as to the mechanism by which fever would be abated or other healing would be initiated. While this study may or may not be perfectly legitimate as a building block (I really don’t know) there is not enough data to claim any conclusion as to the usefulness of coin rubbing and the publication source may present enough bias as to make it unacceptable.

Effects of Gua-Sha Therapy on Breast Engorgement: A Randomized  Controlled Trial (Source)

Journal of Nursing Research, 2010

Experimental Design: Randomized trial on 54 postpartum women in a teaching hospital. These women had both uncomplicated delivery and breast engorgement problems. Positions were identified and scraped consistently. A control group received hot packs and massage 20 minutes which was an instruction in a obstetrics textbook. 

Results: While there was no statistical difference between the groups at baseline, the coin rubbing group had "significant" (p < .0001) differences in body temperature, pain levels and discomfort levels after intervention.

Conclusions: Coin rubbing is an effective procedure that should be used by nurses to help alleviate breast engorgement.

Analysis: This study does not address mechanism at all but overall results on patients’ health. As far as I can tell the study proves that coin rubbing is an effective treatment for this particular ailment. I would like to see the study repeated. I would also like to see a study that addresses exactly why coin rubbing is producing these results but I guess that I am going to have to wait patiently. I really like that the control not only used heat pads but also massage. It is very possible that the personal attention and touch is part of the healing process and using heat pads exclusively would serve to diminish the power of the control.

The Effect of Gua Sha Treatment on the Microcirculation of Surface Tissue: A Pilot Study in Healthy Subjects (Source)

The Journal of Science and Healing, 2007

Experimental Design: Used Laser Doppler imaging to measure micro-circulation of surface tissue. Pictures were taken before and after for 11 patients. There was no control but rather a comparison to the baseline.

Results: Fourfold increase in circulation for the first 7.5 minutes, and significant increase throughout the entire 25 minutes following treatment (p < .001). Pain relief was also noted, and some even during follow up visits. 

Conclusions: Coin rubbing increases microcirculation in a localized area and may be the pathway by which pain is reduced. There is reduced pain in distal areas as well that do not experience microcirculation so there must be an "unidentified pain-relieving biomechanism".

Analysis: Another mechanism study. My favorite part of the article is when they describe coin rubbing as "therapeutic frictioning that intentionally raises transitory petechiae and ecchymosis". Petechiae and ecchymosis is an awesome way to say scraping and bruising. I doubt any traditional practice will be accepted into biomedical practice unless it is described in terms equally impressive. This study shows quite well that local areas increase microcirculation but falls short of identifying any kind of beneficial mechanism that leads toward healing. Regardless, the observations here are an important step in creating a more complete understanding of the process.

Effectiveness of Traditional Chinese "Gua Sha" Therapy in Patients with Chronic Neck Pain: A Randomized Controlled Trial (Source)

Pain Medicine, 2011

Experimental Design: 48 outpatients with chronic neck pain were randomly selected. 24 received coin rubbing, 24 (control) were treated with heat pads. Pain severity was assessed 1 week later. Pain at motion, neck disability index and quality-of-life were also assessed.

Results: Significantly better improvement among coin rubbing patients after 1 week (95% confidence interval). Pain at motion, neck disability index and quality-of-life also showed significant changes.

Conclusions: Coin rubbing has beneficial short-term effects on pain. Long-term management is undetermined.

Analysis: Like the breast engorgement study, this paper addresses whether or not coin rubbing has overall health benefits as opposed to understanding how it works. The lack of a hands-on interactive control, like massage, makes it difficult to isolate whether or not the coin rubbing is important or the attention of the provider is sufficient. This is a pretty straightforward and simple study. We are going to need a slew of these, conducted under different conditions, to really convince the bio-medical community that the procedure is beneficial.

There are a few studies which I have not been able to find in any language but Chinese or German:

Gua Sha Treatment used in the headache after the operations with spinal anaesthesia (Source)

Published in Journal of Clinical Medicine in Practice, 2011

Claims: Coin rubbing significantly decreases headaches in these conditions.

Gua Sha for migraine in inpatient withdrawal therapy of headache due to medication overuse (Source)

Forsch Komplementmed, 2007

Claims: Case study of a single patient shows that coin rubbing may be beneficial in treating headaches.

Perhaps my skepticism is unfounded, but I have a tendency to be suspicious of journals' motivation and incentives. My hope is that there will be an increasing interest in holistic and traditional medical traditions that will lead to more rigorous and thorough studies of these practices. While I have great respect for bio-medicine, I do not believe it to be unassailable and I feel/hope/think that the study of cultural and holistic medicine can compliment what we have learned of healing.

Coin Rubbing Part 1: Introduction

Known in Khmer as កោស​ ខ្យល់ (koah kshal - scraping the wind), in Vietnamese as Coa Gio (catch the wind), in Chinese as Gua Sha (scraping away fever), and in Indonesian as Kerokan (scraping technique), coin rubbing is a healing technique practiced in most of southeast Asia as well as some prominent east Asian countries. In Cambodia it is practiced by virtually everybody. The people I have talked to about the practice have never met another Cambodian who didn’t “believe” in coin rubbing. It is practiced both in families and professionally. Going down most roads in Phnom Penh you should eventually run into signs that advertise for 5000r massages.

While the practice and its explanation differ according to region, there are some important commonalities. The procedure always involves a type of oil or ointment and a hard circular disk, usually a coin. My experience has been almost exclusively with tiger balm but any oil containing combinations of camphor, methanol, winter green oil, eucalyptus oil, peppermint oil or cinnamon oil (taken from here citing Sullivan, 2005). My wife claims that before the magical introduction of tiger balm her family used machine oil. The oil is applied and a coin is rubbed until red marks, blood under the skin, becomes visible. In my experience, the lines are rubbed on either side of the spine (or directly down the middle) and then in horizontal lines down the back. If pain is serious enough it can also be done on the whole body (head, neck, chest, arm, legs). Sometimes it is only done in the local area of the pain or soreness. It is supposed to be able to cure insomnia, migraines, headaches, cramps, muscle soreness, respiratory problems, chronic pain, chronic cough, carpal tunnel, joint problems, whiplash, diarrhea, other stomach related problems, fevers, urinary disorders and probably a whole range of other symptoms.

Different hues and boldness of color can often be used as a diagnostic tool. I have heard different interpretations but my wife’s family generally follows a simple pattern. If the red of the blood is light, it is a light illness. As the red increases in intensity, so does the illness. Some people’s skin however, don’t show these fluctuations.

The lay explanations I have heard justifying the procedure generally rely on the idea of bad wind or miasma being the root of illness. The rubbing and breaking of blood vessels allows this miasma to leave from the body. Sometimes this is framed as an imbalance. As the practice probably comes from China some have linked it to yin and yang. Balance is an important part of all medical systems, and was even was the dominant paradigm of the western medical system before the 1900’s. It is an explanation that is intuitive and can be understood quite easily. Other explanations involve increasing blood circulation and breaking down toxic blood clots.

In the United States, Southeast Asian communities still practice coin rubbing but have run into problems with schools and medical professionals mistaking the marks for abuse. Proponents claim that it causes no long term harmful effects and is an attempt to heal a child from a loving parent. There is currently increased awareness of the cultural practice and the instances of these accusations have decreased. Despite this awareness however there is no actual acceptance of the practice as a legitimate healing method among western health professionals. In Cambodia the dissonance between what educated professionals are taught and what their families and patients practice is ignored but I can see it developing into a problem in the future. The scientific community cannot accept coin rubbing as legitimate practice for two reasons. The first is that it’s premise, that illness is caused by miasmas, has not been proven in a repeatable way in a laboratory. The second reason is that there are no studies showing that it effects pathways in the western physiological model of the body.       

I have heard a variety of lay explanations of how coin rubbing may be able to fit into a western model of medicine. They include the distraction of pain, a release of endorphin, muscle relaxation, bringing blood to the surface to cool down fevers, increasing white blood cells counts and, of course, the placebo effect. I'm not a huge fan of the placebo effect as a blanket explanation for anything and I may write more about the later. I think it is used too often to explain away results that we do not fully understand. Some or all of these may have an effect but unless someone forms a quality repeatable experiment it will all be guesswork. Coin rubbing may not have any real physiological benefit or it may use pathways that we have not yet begun to understand. Personally I think that there is a lot to learn from traditional medicine and that until it is fully understood, it needs to be taken with a degree of seriousness. I am also aware that popular use does not necessarily mean it is a positive procedure, as blood letting was at one point quite popular and has since been shown to be a negative experience.

For my next two posts I want to explore recent literature which may or may not show physiological benefits and physiological damage cause by the practice.

As always, feel free to comment with your own experiences and thoughts about coin rubbing.