A Reason for Cupping. What do we know? What now?

Jen Xu
15 min readAug 11, 2018

Cupping is an ancient type of “Eastern medicine”. Perhaps it’s easier to say it’s that thing Michael Phelps does with the perfectly round purple spots. There are plenty of theories about why it works, and while it’s still up to speculation of the exact mechanism(s), cupping can be extremely beneficial to athletes if used correctly. I suppose it’s the same for any sort of tool — graston, massage, dry needling. What is your intent? What is your goal, and can it be achieved? As well, what is safe and beneficial for the athlete, but can also help their performance — where is the line drawn?

I want to talk specifically about dry cupping with the vacuum mechanism. Cupping is thought to create negative pressure — there is compression around the rim of the cup, but there is distraction in the interior of the cup of the skin and the layers below of fascia and muscle. Cupping is also thought to increase local microcirculation — which is supposed to increase metabolite clearance. But some think that it’s more shown to interrupt the circulation because it cuts off the oxygen supply for a small period of time (1). That temporary hypoxia may result in metabolic acidosis, sure, but the belief is that it will lead to vasodilation and more blood supply. So whether directly or indirectly, there is thought to be some change in microcirculation in the area.

Unfortunately, there is not amazing research on the mechanisms behind cupping. Finding the mechanism is usually much harder than “proving” it’s effectiveness, but at some point I believe the effect is more important than the real, deep rooted cause when we are looking at CLINICAL significance/effectiveness.

Evidence-based medicine is an absolutely essential part of healthcare, but the issue is that it’s not so black and white. There are a lot of different components that need to come together. While evidence from clinical research studies is extremely important — anecdotal evidence and our own experiences need to also make an appearance. One of the most important clinical lessons I’ve learned is to always have a reason for why you do something. Be able to back up your actions — not just as an athletic trainer, but as a researcher. I hope to do that here.

Cupping would be a great addition to our toolboxes, with a lot of safety measures in place, and only being used for very specific issues (with the idea that we do NOT want to bruise). We don’t use it for the placebo effect. We aren’t here to say it’s a quick fix. So let’s get into the evidence.

Effects of Cupping Therapy in Amateur and Professional Athletes: Systematic Review of Randomized Controlled Trials.

In March 2018, a Systematic Review of RCTs was published for amateur and professional athletes (1). They measured a variety of outcomes: VAS pain scale, disability, pain pressure threshold, ROM changes in the lumbar spine, ITB and shoulder, muscular endurance. They also measured inflammation, stress and damage using creatine kinase and lactase markers (among other metabolites). Many studies the reviewers found reported improved pain/symptoms, increased range of motion, and changes in the physiological markers of damage.

ROM improves after cupping (specifically SLR and lumbar flexion) — it might be just due to muscle relaxation (neurological inhibition no longer!) or myofascial release effects, but truly, it’s fine…it occurs. However, think — does the improved ROM benefit athletic performance? No, unless it is LOADED! A passively increased ROM (aka flexibility) does not improve performance of functional movements, but an active one may (aka mobility). This is from a study by Moreside + McGill, one of the earlier ones about this phenomenom (Improvements in Hip Flexibility Do Not Transfer to Mobility in Functional Movement Patterns). Specifically for athletes, we can begin with loading muscles…and then progress to loading movements. However, to get to that active increased ROM, some more passive increased ROM through cupping, for example, could help — and not necessarily just physically, perhaps mentally or comfort-wise. AKA your brain giving your body permission to feel less painful in a specific position.

Cupping also seemed to be beneficial for perceptions of pain and disability. People’s perception of pain can shape their reactions to pain so that’s extremely important. There were also reductions in creatine kinase, a supposed marker of muscle damage — at least when compared to untreated or control groups. The creatine kinase assesses training-induced muscle damage — decreased amounts are assumed to show improved muscle “readiness” or recovery. Also, there were benefits specifically for soccer athletes in back and hip pain, as well as heel pain in other athletes.

Limitations of the studies mostly included small sample sizes. There was also the issue of — how do we create a control for cupping? Is simply “not cupping” enough? As well, there was either a high or unclear risk of bias in a lot of the studies. Most studies are single-group RCTs, which does not make for a quality study. Cupping also seems to show some more adverse events because of the marks it could leave (visually, it is shocking at times), yet there didn’t seem to be any assessments of adverse side-effects.

Consider also the cultural aspects of cupping. It is used and trusted highly in Arabic and Asian countries, so they have high expectations of its effects. Could that then skew the results of the studies? Or, even if there is not a cultural “reliance” on cupping, perhaps Westerners/Americans are simply fascinated by the process and that could skew the results as well. The mind is a very tricky thing.

This is the latest systematic review. There is no explicit recommendation for or against the use of cupping for athletes. More studies are necessary for conclusive judgment on the efficacy and safety of cupping in athletes. Some might say that there is no point in doing more studies if they keep saying more studies are necessary, but you also have to consider the quality of the studies. Because many cupping studies have issues with quality and standardization, I do agree with the idea that more studies need to be done. What if it were combined with other treatments? Again, myofascial release should not work on it’s own. In fact, it will not work on it’s own.

A pilot study analyzing the effects of Chinese cupping as an adjunct treatment for patients with subacute low back pain on relieving pain, improving range of motion, and improving function.

Cupping was studied as an adjunct treatment for LBP regarding relieving pain and improving range of motion and function. They wanted to assess if it could decrease tenderness to palpation and reduce acute pain. For baseline and post-treatment results, they assessed outcomes using: The Oswestry Disability Index (ODI) questionnaire, a pain scale using VAS from 0–100mm, straight leg raise and lumbar spine motion, and the pain-pressure threshold (aka tender to palpation?).

There was a significant post-treatment improvement in the pain VAS scale (p = 0.0001). However, I don’t currently have full access to the article (working on it), so one limitation is that we don’t know how soon after the post-treatment measurements were taken. This is an issue because we need to understand how long the results last and what happens at different times after treatments. However, we saw that there was increased SLR and lumbar flexion range of motion — we know myofascial release only lasts about 10–15 minutes so perhaps that can give us some indication on when the ratings were taken.

The authors state that Chinese cupping may be a low-risk therapeutic treatment for the prompt reduction of symptoms. We know that pain reduction as well as increased range of motion are two components that can lead to less painful and better rehabilitation exercises — as long as it happens soon after the treatment!

Long-term effect of cupping for chronic neck pain

In a study on the long-term effect of cupping for chronic neck pain (3), one group had 5 sessions over 2 weeks, and the other had “delayed treatment”, meaning they waited the 2 weeks. It took 15 minutes and the sessions were done every 3–4 days. The measured the VAS pain scale, the neck disability index (NDI) questionnaire, and a quality of life questionnaire using the Short Form-36 survey.

There were no changes in the VAS pain scales. Again, it depends when the results were measured and I believe that is a huge issue when it comes to studies of cupping, or even any studies of manual therapies. That aside, the NDI increased significantly by 3.15 points (a moderate effect size), and in the quality of life survey, there was an increased “quality” for the bodily pain and physical component summaries. One might also wonder if the quality of life changes are skewed because the second group had to wait 2 weeks for their therapeutic intervention…hmm.

Authors concluded that cupping is not effective on long-term pain intensity. However, when has any myofascial release study shown a long-term type of effect? (Also, this does not mean we shouldn’t do them as clinicians. There is nothing wrong with attacking the symptoms and root causes simultaneously…or even rarely, one at a time). I believe the goal of cupping should not be pain reduction, rather it is improved functionality. Limitations include small sample sizes, a rather high dropout rate, and a single-group design because, I mean, how are you supposed to find a control? This was an issue in nearly every study. I also believe one of the most important limitations was that we don’t know the time of measurements post-treatment, which seem to have a large effect especially with manual therapies.

The medical perspective of cupping therapy: Effects and mechanisms of action

In another study finally accepted in March 2018 (4), they examined the effects and mechanisms of cupping. The placebo effect is not a valid reason to perform interventions. I bring this up because plenty of clinicians have fear that the placebo effect is the only mechanism that explains cupping. There is not a specifically reliable and valid mechanism for cupping yet…so maybe this will have to do for now, which explains why it can be quite controversial.

There may be many effects — neurological, hematological, and immunological effects. For example, a metabolic hypothesis seems to say that it can decrease increased muscle activity (perhaps from the temporary hypoxia?), which then can result in pain reduction. We know that pain is related to nerves…so perhaps there is some decreased neurological sensation/signaling.

Another hypothesis includes a comfort/relaxation type of intervention. Perhaps that comfortable feeling from cupping results in an endogenous opioid production in the body, and that may result in improved pain control. As well, there are theories that it may enhance blood circulation could result in a healing effect — the idea being that it eliminates trapped toxins in the body.

We have talked about whether or not cupping is a placebo effect…meaning, does the mind play more of a role in its therapeutic effects? Progressive muscle relaxation is a tool used by sport psychologists to achieve relaxation mentally and physically, a great tool for anxiety and sometimes even recovery, I suppose. So if cupping could be considered a PMR, although it would be passive — could that help?

I believe I took this from the text, but it’s an important piece of information. “It has been claimed that cupping therapy tends to drain excess fluids and toxins, loosen adhesions and revitalize connective tissue, increase blood flow to skin and muscles, stimulate the peripheral nervous system, reduce pain, controls high blood pressure and modulates the immune system”.

Truly, I was unable to understand most of the mechanisms of cupping…I’m able to admit that I’m not necessarily at that place in my life/career, but I’ll definitely be asking questions when I begin school and find people who might be able to help me. However, one of the mechanisms that stuck with me is the Pain Gate Theory. I’ve seen two things in my clinical experiences that may relate (both at the same place) I watched dry needling — during and after the insertion of the needle, there is some light movement of the finger across the patient’s skin, a slight distance from the insertion point. I asked why that was necessary, and it was to activate nocioceptors and “distract” from the sharper pain of the needle. Some other times, I saw that heat packs were applied but with multiple layers of towels after acute injuries. Something you learn in school is that heat should not be applied to acute injuries, but I learned here about the different fibers — Alpha, delta, C fibers. Some specific fibers react more to temperature changes, so the slight increase in temperature (as opposed to a “steeper” increase if heat packs were applied with less extra towel layers) may actually decrease the pain sensation as the body reacts to the changes in temperature.

So the pain gate theory appeals to me because in the cupped areas, pain receptors are stimulated more (due to the intense pressure — the “pinching” feeling patients have reported to me), and as those impulses become more frequent…there’s an eventual closure of the pain gates.

This paper also expressed the conclusion that more RCTs, systematic reviews, and meta-analyses need to be done, but there are some theories so far that might need to be “proved” more.

What do they say about myofascial release + manual therapies in general? Why is this important?

The effects of foam rolling, for example, last only about 10–15 minutes afterwards. We know there is no physical tissue lengthening, rather it is a neurological adjustment and “relaxation” to the stimulus. However, that doesn’t mean it’s pointless. It’s important after that neurological change (however temporary it is) to load the movement and let the body understand the new range of motion they’ve achieved. It would only be pointless if the myofascial release/manual therapy were performed…but then nothing else at all occurred after. Stretching would be the bare minimum, but loading and rehab exercises would be highly preferred.

This is important to understand — we need to explain to our athletes and patients that cupping is not the fix. There’s no magical cure for injuries and soreness and weakness (for the most part). They need to put their own work in but we want to help them any way we can, and perhaps cupping can do just that.

Ok…so what do we do with the evidence?

Most importantly, we can see more studies are needed. Although there is not statistically significant data in some of these studies, there are still clinically significant points of interest we can look at and use to back up our actions in the clinic. A few of the studies have also seen that it should be used as part of a multidisciplinary approach. So, might we be able to study therapeutic exercises with cupping vs. no cupping? Just a thought, although I suppose studying the mechanism on it’s own with quality studies should come first.

The unfortunate truth is that adverse effects exist with cupping. There are times when bruising can occur (but it’s generally not as painful as a regular contusion). There are times you can be more sore afterwards, but you just have to make sure not to do it too long. However, it could also be true that the adverse effects of cupping look a lot worse than they actually are. Although the marks appear to be serious contusions, they don’t usually feel like bruising, it is supposedly stagnant blood that occurs after the blood circulation changes.

I believe that the increased ROM is one of the most key components of cupping. Studies did not seem to say how long the ROM improvement would last, but as stated earlier most myofascial releases have lasting effects of 10–15 minutes. That window of ROM improvement could be used to do some really great rehab exercises to lock in that new motion for the brain to understand. The term “loading” sounds a lot more…interesting, though.

The pain scale may not always improve, and this is because cupping’s main intent is not for pain relief. As I said earlier, changes in ROM and blood circulation seem to be the most important parts. However, we can see that self-rated functionality and disability indexes actually seem to improve quite often, which may relate indirectly to pain. Some even apparently felt that their quality of life improved after cupping sessions.

Finally, we know that it must be part of a multidisciplinary plan for pain. It will never be a quick fix. Especially because the evidence is not necessarily strong (it is moderate levels of evidence at most), we have to understand that it cannot be our only tool. Our athletes must know that as well because we can use it to increase self-efficacy in a sense. For example, in order to use it, we must do exercises after or else it is absolutely, completely pointless.

My personal experience:

I would like to share my own experience with this, not as any reason to back up my evidence, but I think it would be important. Cupping definitely needs to happen every few days for an extended period of time to feel like it does anything. It definitely must be loaded — train movements (good mornings, RDLs, reverse lunges, etc.).

I’ve had moments of soreness over the marks. Although they aren’t terrible, it’s not always fun so we have to be really careful of that. I’ve overly marked myself before and I definitely would not suggest doing that.

Moving cup is pretty painful to do on yourself, but it’s quite similar to graston and works really well on the low back, calves for shin splints, hamstrings, and scapula area.

The darkest spots I’ve found: low back, shoulders, neck. I tend to be more careful with the neck area. And actually, the chest is worse than even the neck — the spots stay for…a very long time.

Yes, pain reduction soon after the treatment happens. However, it does not necessarily last.

I’ve had lazy days where I cup and then go straight to bed, for example. It hasn’t felt as good as the days where I cup and then actually MOVE to help my muscles feel better.

Rules + Requirements that I would make for my ATR:

If I were to have my own team or be more “in charge” (neither of which are occurring right now but that’s okay!) — I would make quite a few rules for the use of cupping.

  1. People who truly need a myofascial release will get this — ex. Issues with tightening muscles with disc injuries, issues with spinal rotation (much more important than we think it is). It’s hard to categorize athletes in such a black-and-white “cupping” or “no cupping”, but I’d definitely try my best. Plus, this process does take some time and attention, and you can’t spend your entire day cupping everyone.
  2. You must load the tissues after the cupping — rehab, therapeutic exercises, you name it.
  3. You can only do it every other day MAX…every 3–4 days is pretty good, though.
  4. Moving cup may be better suited for most musculoskeletal issues. It can be done with those squishy ones or the plastic ones, you might just have to pump them more often.
  5. The aim is not to bruise heavily. It’s not cool. I’ve made this mistake before.
  6. The aim is not to “look cool” or feel good…especially if you already feel pretty good. Sure, it often ends up just being a feel-good tool…but it really shouldn’t be.
  7. General soreness is not a pre-req. Of course, I can’t stop you from buying your own cupping kit… but that’s an entire other issue.
  8. We need to tell them our INTENT: it’s part of a multi-disciplinary approach. It’s not a quick fix. You need to do more than just let these cups sit on you. Push yourself. Do things. Move.

I have been back and forth many times on this topic. For a time, I was obsessed with it. I was confused why more people didn’t do it. I suppose there was some sort of cultural component there for me — this is getting intense, but I guess I put high emphasis on the fact that I have Chinese heritage. I want to get more of it and I’m scared to lose what I already have, so I held onto this.

Then I began to say — hey, there is not very conclusive evidence on cupping — and I meant the hard evidence you really have to obey. I rejected using it for my athletes and became okay with the fact that I could just use it on my own and on my friends.

Finally, I began to think…wait, is there really no evidence? Or have I just believed people who may not really know what they’re saying? So that’s why I’ve wrote this, I guess. I definitely have a better understanding and I’d be more confident in explaining it to someone.

Now I know — okay, the evidence is not necessarily strong and no one has made any conclusive claims on it’s effects or it’s actual effectiveness. But that doesn’t mean you should not use it. EBM is not always black and white no matter how badly you want it to be. Scientific evidence is important but so is clinically significant and anecdotal evidence!

So we’ll see what happens in the future, but here are my thoughts as of August 2018!

1. Effects of Cupping Therapy in Amateur and Professional Athletes: Systematic Review of Randomized Controlled Trials.

2. A pilot study analyzing the effects of Chinese cupping as an adjunct treatment for patients with subacute low back pain on relieving pain, improving range of motion, and improving function.

3. Long-term effect of cupping for chronic neck pain

4. The medical perspective of cupping therapy: Effects and mechanisms of action (accepted Mar 2018)

5. Cupping therapy: An analysis of the effects of suction on skin and the possible influence on human health (2017)

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Jen Xu

Athletic trainer, PhD student, coffee lover. I write about fitness, mental health, being Asian-American, and personal growth.