By: Michael Falk, ATC-L, CSCS, SPT
This is my final blog in a 3 part series about the use of ice to treat soft tissue injuries (read Part 1 and Part 2 here). This subject has been the hardest post to both research and write. Frankly, there is a lack of high quality studies on the benefits of using ice following injury. Systematic reviews since as early as 2004 have been calling for studies with improved methodology in order to gain concrete evidence on how we should be using cryotherapy in our practice. In many of the systematic reviews I read, the average PEDro score was around 2 to 3 out of 10 (a scale used to rate the quality of evidence; the closer to a 10, the better the quality of evidence in the paper).
I believe the challenges with the research are multi-fold. First, it is difficult (nearly impossible) to blind a study participant as to whether they are receiving ice or not. Second, it is a difficult study to design, as I mentioned in previous posts. Very few researchers want to be on call 24 hours a day, 7 days a week in order to enroll participants in an acute injury study. Third, the use of ice has become so common, it would be very hard to maintain a control group (most people immediately start icing on their own after injury). Finally, there is no well-established protocol for the application of cryotherapy. Some authors perform ice with compression, some use ice packs, some use a cold-water immersion, and the list goes on. In the literature, there appears to be no set time period or dosage for cryotherapy; some clinicians apply ice for ten minutes and I saw one study that applied it for 6 hours. This much variability makes it very difficult to draw true conclusions from the research.
This lack of a standard for cryotherapy should raise serious questions about the efficacy of its use. If you go to a physician, do they say take this medicine, somewhere between 1-6 pills, maybe as often as 4-5 times a day, but it just depends on how you’re feeling? No. They prescribe a set dosage that has been researched and is appropriate for different body weights, age, medical conditions, etc.
Furthermore, what do we measure with cryotherapy research? Is it all about return to play? Ice is not the only factor that contributes to return to play. Do we measure swelling? Treatments outside of ice such as exercise, compression, elevation, etc. can also affect recovery. Do we measure pain? Do we measure inflammatory mediators? (As I mentioned in the first blog, I don’t think we want to decrease these processes, as they are an important first step in the healing cycle).
Finally, the rationale behind using ice can change as the injury develops. Within the first several hours after injury, we justify the use of ice for reducing secondary cell death. Then we justify its use by helping control the inflammation and swelling (again, I am not sure this goal is worthy). Then we talk about using ice after rehab exercises to control pain or damage that may have occurred while exercising that day. With the wide array of potential applications for ice, designing a study is very difficult. So, with that uplifting preamble, I offer you some of the articles that I found most interesting and provide you with some ways that these articles could be applied to your clinical practice.
A Couple of Systematic Reviews
Essentially, the research on using ice is inconclusive and of poor quality to the extent that drawing conclusions from it is difficult. For example, in 2004 Hubbard et al. reported four different studies on cryotherapy following ankle sprains and the effect on return to play. The authors found two studies that showed no difference and two studies that did show an improvement in the cryotherapy treatment group. So, score 2 for ice and 2 for no ice – a perfect tie. However, one of these studies compared using ice to using heat, so it was not a true control. And I don’t think any current practitioner would recommend heating an acute injury.
In 2012, van den Bekerem et al. performed a systematic review of the R.I.C.E. principle (rest, ice, compression, elevation) in ankle sprains. They attempted to look at each of these different variables in the literature. To stay on topic, I will only discuss the findings about ice.
Again, the results were mixed. Multiple studies found no difference between the ice group and the control group on swelling, ROM, pain, or ability to weight bear. Two studies found that cryotherapy resulted in faster return to play or decreased swelling compared to using heat (again, not a true control). One study also found that using a cooling gel under an ace wrap caused faster reduction in edema and increased return of ROM compared to compression alone. The authors’ conclusion was there is insufficient evidence to support the use of ice, but we need higher quality studies to truly make a judgment.
Things That Are Definitely True
If you have an ankle sprain, early controlled mobilization and exercise is better than ice alone. Bleakly et al. showed that early exercise increased the patient’s ability to walk and the number of steps that they took at 1 and 2 weeks after injury compared to a group who only used ice. No effect was noted on pain or swelling.
Ice does temporarily control pain. This doesn’t require fancy research. If something hurts and you ice it, that body part will become numb and you won’t feel it as much. However, we have other modalities that can be used to control pain temporarily that will not negatively impact the important inflammatory process and potentially affect the overall healing cycle. Additionally, research has found that exercise has been shown to have an analgesic effect.
What About In Rats?
While animal studies have their limitations (namely, humans are different then rats), good quality animal studies may at least be able to lead us in a direction and help guide further human studies on the use of cryotherapy. Schaser et al. had an interesting article (although it involved way more vascular physiology than I understand). The authors induced muscle damage in rats and studied what happened with prolonged (6 hour) treatment with ice. They found that ice significantly reduced macrophages, adhering leukocytes and granulocytes. I found it interesting that, despite the decrease in inflammatory cells, they found no differences in edema in the rats’ muscles. So, there were equal amounts of swelling, but less of the inflammatory cells necessary for normal healing.
Now, the authors felt that cryotherapy was still helpful because the cryotherapy group was able to maintain the capillary network and venule cross sectional area. This effect would, in theory, help maintain oxygenation and delivery of nutrients to the injured area. So, in rat studies, looking at the detailed vascular physiology, there may be some evidence that ice could be helpful.
If You Still Want to Use Ice
If reading these posts or doing your own research has led you to still use ice following injuries, then let me direct you to another article by Bleakly et al. He compared two different icing protocols: prolonged continuous application (20 minutes every 2 hours) and intermittent application (10 minutes of ice, 10 minute break, and 10 more minutes of ice repeated every 2 hours). The intermittent ice group showed decreased pain with activity compared to the continuous application. There was no difference in swelling, function or pain at rest.
However, I will note that even with the decreased pain, participants of both groups had difficulty running and cutting at 6 weeks.
The evidence is not clear at this point about what ice does do and what ice does not do to help recover from injury. Is the use of ice neutral (does no harm), does it offer some benefits that are just hard to measure or does it actually inhibit recovery? I am surprised that cryotherapy has become such a common treatment without any clinical support. The use of ice is commonplace and is often prescribed without a second thought. Your athlete gets hurt – you give them a bag of ice – we’ve all done it. I have routinely prescribed cryotherapy of 20 minutes on every two hours with no consideration of the body size of the person or the subcutaneous fat thickness that may affect the cooling delivered.
I would love to see a high quality study get funded to look at the effect of ice in treating acute injuries and help clinicians to develop better guidelines on whether ice should be used or not, and, if it should be used, what the best treatment parameters are.
Until then, in my practice, I plan to limit the use of ice and decide whether to use it on a case-by-case basis. I believe that controlled exercise and early mobilization (where appropriate) are alternates to using ice that will be more effective. The main indication I would use ice for is to control pain. However, there are other electrophysical agents to control pain that do not have the potential drawbacks of ice. If I do use ice for pain, I would no longer prescribe it for 20 minutes every two hours. I would use ice until the pain decreases (go for the numb) and only as needed.
I hope this series of posts was thought provoking about a commonly used practice. I would love to hear your thoughts on this post or on the series of posts.
I also hope if you work in a facility that has the ability to research, or if you know someone in academia, that you would try to convince them to look into this area of research and get some answers that are clinically applicable.
- Bleakley, Chris M., Suzanne M. McDonough, and Domhnall C. MacAuley. “Cryotherapy for acute ankle sprains: a randomised controlled study of two different icing protocols.” British journal of sports medicine8 (2006): 700-705.
- Bleakley, Chris M., et al. “Effect of accelerated rehabilitation on function after ankle sprain: randomised controlled trial.” BMJ 340 (2010).
- Bleakley, Chris, Suzanne McDonough, and Domhnall MacAuley. “The use of ice in the treatment of acute soft-tissue injury a systematic review of randomized controlled trials.” The American journal of sports medicine1 (2004): 251-261.
- Hubbard, Tricia J., and Craig R. Denegar. “Does cryotherapy improve outcomes with soft tissue injury?.” Journal of athletic training3 (2004): 278.
- Hubbard, Tricia J., Stephanie L. Aronson, and Craig R. Denegar. “Does cryotherapy hasten return to participation? A systematic review.” Journal of athletic training1 (2004): 88.
- Schaser, Klaus-Dieter, et al. “Prolonged superficial local cryotherapy attenuates microcirculatory impairment, regional inflammation, and muscle necrosis after closed soft tissue injury in rats.” The American journal of sports medicine1 (2007): 93-102.
- van den Bekerom, Michel PJ, et al. “What is the evidence for rest, ice, compression, and elevation therapy in the treatment of ankle sprains in adults?.” Journal of athletic training4 (2012): 435-443.