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.