Monthly Archives: April 2020

What’s the Scoop on Cupping?

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My first exposure to cupping was seeing the perfectly circular bruises on Michel Phelp’s during the 2016 Summer Olympics. Since then, I have come across it many times in the University of Delaware athletic training room seeing athletes performing exercises with cups suctioned to their back. I have even tried it myself a couple of times to see what the hype was about and if I felt a difference using this type of recovery method. 

Figure 1. Michael Phelps swimming with visible cupping markers (bruises) on his shoulders. 

Now if you haven’t heard about cupping you may be wondering: what is cupping? Cupping is the application of plastic, glass, bamboo, or ceramics cups [1] to the skin via suction. The suction can either be created naturally by heating up the inside of the cup using a flame and allowing it to cool on the skin creating negative pressure and lifting/stretching the skin up. The other way to get this pressure is to use a suction device.[1] There are also two types of cupping, similar to needling; there are both wet and dry methods. Dry cupping is exactly the procedure I described above while wet cupping is when small cuts are made on the skin before the cup is applied and blood is drawn out. [1] The original idea behind this technique was that it was regulating Qi in the body. More recently, people claim that it promotes blood flow and therefore has a positive effect on the healing process, reducing soreness and pain. There are still many who find cupping bizarre and disgusting due to the often dark bruising and the odd look of the skin suctioned into cups. In particular, a Forbes article by Steven Salzberg goes as describes it as “someone giving you a massive hickey, and then doing another dozen or so all over your back, or legs, or wherever ” [2]. So by now, you should have a pretty clear image that while there are many advocates and cupping has been gaining interest (especially if professional athletes on the world stage have used it), there are still many skeptics and people who say it is harmful. Let’s see exactly what the research says about cupping. Is it beneficial? Harmful?

 

An article published in The Journal of Alternative and Complementary Medicine by a group of Australian and German researchers performed a systematic meta-analysis of clinical trials evaluating the effects of cupping on athletes. [3] They found 11 valid (according to their criteria) trials with a combined total of 498 participants from China, the United States, Greece, Iran, and the United Arab Emirates. Participants received cupping 1 to 20 times in daily or weekly intervals either alone or in combination with another procedure, like acupuncture.[3] The study found no conclusive results however. Even though there were improvements to the participant’s perception of pain, an increased range of motion, and lower levels of creatine kinase, there were large variations between symptom intensity and recovery measures, and other metrics.[3] There are also some limitations to this study. One of the main concerns is the reliability of the data. The researchers report an unclear or high risk of bias in many of the trials and they also mention that none of the trials reported safety. 

 

Another study published in 2016 in the Journal of Novel Physiotherapies evaluated the effects of various soft tissue mobilization techniques, including cupping, on active myofascial trigger-points in 20 amateur soccer players.[4] Athletes received cupping once a week for three weeks. They found that all techniques used, including cupping, improved pain pressure threshold and pain sensitivity significantly. [4] The researchers concluded that more research must be done to fully be able to draw a conclusion. Some limitations of the study were the small sample size (n = 20) and that the study was limited to only amateur soccer players. Other studies, including the previously mentioned study viewed multiple different sports instead of one. This also provided a much larger sample size compared to this study.  

 

Overall, there appears to be no definite answer, at least at this time, on if cupping helps promote healing and reduce pain and muscle soreness. For some, it appears to be beneficial in relieving pain but due to a limited number of studies and the questionable accuracy of others, there is no conclusive data for or against cupping. As the first-mentioned study by Bridgett et. al stated, “ No explicit recommendation for or against the use of cupping for athletes can be made. More studies are necessary for conclusive judgment on the efficacy and safety of cupping in athletes.” [3].

 

 

References:

[1] NCCIH. “Cupping.” November 2018. Retrieved from: https://www.nccih.nih.gov/health/cupping

[2] Steven Salzberg. “ The Ridiculous and Possibly Harmful Practice of Cupping”.  May 2019. Retrieved from: https://www.forbes.com/sites/stevensalzberg/2019/05/13/the-ridiculous-and-possibly-harmful-practice-of-cupping/#57ce2d2331f3

[3] Rhianna Bridgett, Petra Klose, Rob Duffield, Suni Mydock, and Romy Lauche.The Journal of Alternative and Complementary Medicine.Mar 2018. 208-219.http://doi.org/10.1089/acm.2017.0191

[4] Fousekis, Konstantinos et al. “The Effectiveness of Instrument-assisted Soft Tissue Mobilization Technique(Ergoné Technique), Cupping and Ischaemic Pressure Techniques in the Treatment of Amateur AthletesàMyofascial Trigger Points.” (2016).

 

Questions to Consider:

  1. Have you ever gotten cupping done? If yes, what are your thoughts? Did you find it beneficial? If no, was there a reason why?
  2. How do you think studies looking at cupping should compare its effects for the most accurate evaluation? Should they compare across different sports because the benefits should not be sport dependent or within one sport to get a better comparison?

To Stretch or Not To Stretch

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Stretching is regularly included in exercise regimes by athletic trainers and coaches and is often recommended to novice athletes. The chronic effects of stretching result from consistent practice and are thought to be a preventative measure to reduce risk of injury by increasing flexibility to increase overall range of motion. [1] This increased range of motion is thought to increase overall performance. However, those against stretching argue the long-term effects could lower performance by decreasing muscle strength.

Types of Stretching

Three common types of stretching include static, dynamic, and proprioceptive neuromuscular facilitation (PNF). [2] Static stretching involves lengthening a specific muscle group for a period of time without movement. This method is arguably the safest form of stretching, especially for beginners, as it minimizes the risk of tearing or straining the muscle by overstretching. [3] PNF incorporates static stretching in addition to isometric contraction and relaxation of the muscle. Unlike static and PNF methods, dynamic stretching involves active movements to increase the range of motion while raising the heart rate before an exercise.

Mechanisms to Increasing Flexibility

Several mechanisms describe how stretching can increase flexibility over time including increasing compliance and increasing stretch tolerance. Compliance relates to the elasticity of the muscle-tendon unit and is useful in generating forces as elastic energy is stored by eccentric contractions during the stretch-shortening cycle (SSC). [4] Stretching can increase the compliance of the muscle-tendon, increasing the energy potential. Increasing the stretch tolerance of a muscle is a second mechanism to increase flexibility. Long-term stretching can alter how the central nervous system receives signals from structures aiding in proprioception and regulation of muscle stiffness including nociceptors, Golgi tendon organs, and muscle spindles. [5] Altering these signals may result in greater ranges of motion with decreased resistance by the nervous system.

Stretching Reduces Injury in Some Sports

Research has shown that stretching can reduce injury by increasing flexibility, but only in some sports. For sports requiring jumping motions that involve high intensity SSCs, like soccer and football, stretching has been shown to reduce injury. [4] In these sports, the muscle-tendon system works as an elastic spring. With a compliant unit, potential injury is reduced as greater energy can be absorbed by the tendon, sparing the muscle fibers potential damage. However, if the tendon has low compliance greater forces can be transferred to the muscle, resulting in injury if the muscle is unable to support high amounts of energy.

A prospective study published in 2003 from Ghent University measured initial muscle flexibility for 146 male professional soccer players and analyzed how flexibility related to the development of muscle injuries throughout the season. Goniometers were used to measure the flexibility of the hamstring, quadriceps, adductor, and gastrocnemius muscles on both sides of the athletes. The study reported no statistical significance between players height and weight, but did not analyze other factors like age. Throughout the season, 67 players were diagnosed with a lower extremity injury. For the hamstring and quadriceps muscle, the injured group had a significantly lower initial mean flexibility. No significant difference for flexibility was found for injuries involving the adductor or gastrocnemius muscles which could be due to the low power of this analysis. Thus, this study recommends implementing a stretching program to prevent muscle injuries, although there are many limitations. This study only analyzed intrinsic muscle flexibility when muscle injury can be caused by many intrinsic and extrinsic risk factors. Also, the specific circumstances of the injuries were not incorporated in analysis. [6]

Unlike sports involving high intensity SSCs, there is insufficient evidence that stretching is effective in preventing injury in sports with lower intensity SSCs, including cycling and swimming, as well as jogging (which utilizes high intensity SSCs, but not at maximum exertion). [4,7] Rather than utilizing the ability to absorb energy, these sports utilize the conversion of metabolic energy into mechanical work by concentric contractions. [4]

Can Stretching Increase Performance?

Although long-term stretching can increase range of motion, this does not always mean an increase in performance.  A 2007 study investigated the long-term effects of PNF and static stretching on range of motion and jump performance. Twenty-three healthy male volunteers were randomly divided into 3 groups to follow a static stretching program, PNF stretching program, or a control group with no stretching. Range of motion was recorded by a goniometer. Jump performance was measured by timing a subject dropping from a box onto a contact mat and jumping as high as possible to then calculate jump height. Measurements were recorded at the beginning and end of the study. While no group had any significant change in jump performance, both stretching groups had a significant increase in joint range of motion. The authors believe measuring muscle hypertrophy could have been a better measure of performance. [8]

Does Stretching Decrease Performance?

Stretching is not always recommended for sports involving lower intensity SSCs because a muscle-tendon system that is too compliant could reduce performance. For these sports, decreased flexibility with greater stiffness can contribute to more rapid tension changes for faster responses. [4] A 2001 study investigated the effects of stretching on 16 male and 16 female college aged runners. At the beginning and end of the study VO2peak, running economy, and flexibility, measured by a sit and reach test, was evaluated. Running economy is used to evaluate running performance as a measure of VO2 and the respiratory exchange ratio. [9] The participants were randomly assigned to a stretching or non-stretching group and followed these programs for 10 weeks. The stretching group performed 15 static stretches in a 40 minute session for 3 days a week for the 10 weeks of the study. This study found an increase in flexibility in the stretching group, but no significant change in running economy for both the stretching or the non-stretching group. Stretching does not appear to increase or decrease running performance, and thus may not be harmful to incorporate in these sports. However, limitations to this study include the limited measurements of flexibility provided by the sit and reach test, as well as potential confounding factors that can affect running economy. [10]

Although acute stretching often results in decreased muscle strength, longer-term effects of stretching may actually promote muscle hypertrophy. A 2013 study analyzed the effect of stretching before a strength training workout and found that strength levels increased for both the stretching and non-stretching groups, although the group without stretching had a greater increase. [11]

To Stretch or Not To Stretch?

Overall, the long-term effects of stretching include increased flexibility which can reduce injury in sports with high intensity SSCs. Although stretching has not been found to decrease the risk of injury in sports with low intensity SSCs, it does not lower performance. The studies discussed did not find that stretching enhanced or reduced performance, but this may be due to influences to muscle hypertrophy that were not included in these studies. As long as stretching is performed utilizing proper techniques to prevent overstretching, incorporating stretching into your workout can be beneficial and help increase flexibility overtime.

Questions to Consider

  1. Do you regularly stretch? If so, do you prefer stretching before, after, or before and after your workout? In your own experiences have you noticed any effects from stretching versus not stretching?
  2. What do you think about the different methods to measure flexibility (goniometry, sit and reach test)? How might the limitations of each of these methods influence results and conclusions made by studies? If you are unfamiliar with sit and reach tests, check out this video. Is there a better way to measure flexibility?
  3. Do you think the duration of stretching for the stretching protocols in these studies is important to consider? Do you think these protocols should be standardized across studies (such as types of stretches performed or muscles that are targeted by stretching for certain sports)?

References

[1] Stone M, Ramsey MW, Kinser AM, O’Bryant HS, Ayers C, Sands WA. Stretching: acute and chronic? the potential consequences. Strength and conditioning journal. 2006;28(6):66-66. doi:10.1519/1533-4295(2006)28[66:SAACTP]2.0.CO;2.

[2] Mann D, Whedon C. Functional stretching: implementing a dynamic stretching program. Athletic therapy today. 2001;6(3):10-13. doi:10.1123/att.6.3.10

[3] Muniz Medeiros D, Martini T. Does Stretching Have Long-Term Effects on Muscle Performance? A Clinical Commentary. J Yoga Phys Ther. 2017;7(2). doi:10.4172/2157-7595.1000269

[4] Witvrouw E, Mahieu N, Danneels L, McNair P. Stretching and injury prevention : an obscure relationship. Sports Med. 2004;34(7):443-449. doi:10.2165/00007256-200434070-00003

[5] LaRoche D, Connolly D. Effects of stretching on passive muscle tension and response to eccentric exercise. The American Journal of Sports Medicine. 2006;34(6):1000-1007. doi:10.1177/0363546505284238

[6] Witvrouw E, Danneels L, Asselman P, D’Have T, Cambier D. Muscle flexibility as a risk factor for developing muscle injuries in male professional soccer players. a prospective study. The American Journal of Sports Medicine. 2003;31(1):41-46. doi:10.1177/03635465030310011801

[7] Yeung EW, Yeung SS. A systematic review of interventions to prevent lower limb soft tissue running injuries. Br J Sports Med. 2001; 25: 383-9. doi:10.1136/bjsm.35.6.383

[8] Yuktasir B, Kaya F. Investigation into the long-term effects of static and pnf stretching exercises on range of motion and jump performance. Journal of Bodywork & Movement Therapies. 2009;13(1):11-21. doi:10.1016/j.jbmt.2007.10.001

[9]Nelson AG, Kokkonen J, Eldredge C, Cornwell A, Glickman-Weiss E. Chronic stretching and running economy. Scandinavian Journal of Medicine & Science in Sports. 2001;11(5):260-265. doi:10.1034/j.1600-0838.2001.110502.x

[10] Saunders PU, Pyne DB, Telford RD, Hawley JA. Factors affecting running economy in trained distance runners. Sports Med. 2004;34(7):465–485. doi:10.2165/00007256-200434070-00005

[11] Borges Bastos CL, Miranda H, Vale RG, et al. Chronic effect of static stretching on strength performance and basal serum igf-1 levels. Journal of Strength and Conditioning Research. 2013;27(9):2465-2472. doi:10.1519/JSC.0b013e31828054b7