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Posts Tagged ‘Journal of Athletic Training’

A little over a year ago, I wrote a blog post reviewing a study that compared crushed ice, cubed ice, and wetted ice and their effect on tissue cooling. The conclusion of the study was that wetted ice was the most effective in providing both surface temperature and tissue cooling.

So, if the goal was to produce the most tissue cooling – the choice would have been to use cubed ice and add about a cup of room temp water to get your wetted ice treatment.

Now, let’s fast forward to phase two that will help us even make better evidence-based decisions when we choose ice as a treatment modality.

The most recent edition of the Journal of Athletic Training published a study entitled: The Magnitude of Tissue Cooling During Cryotherapy With Varied Types of Compression.

This study compared the use of no compression, Flex-i-Wrap, and an elastic wrap as compression methods when applying ice. The study looked at both surface temperatures and intramuscular cooling. An interesting side note was that this study utilized crushed ice. (This is not a criticism – simply an observation that we can take into account at the end of the study when developing some take home points of note).

Going into the study we would probably surmise that an ice bag secured with any type of compression would produce greater tissue cooling than no compression. This was largely true but there were some additional interesting findings.

In respect to surface temperature cooling, there was a statistically significant difference with compression using an elastic wrap and no compression. However, there was no statistically significant difference between using Flex-i-Wrap and no compression or Flex-i-Wrap versus the elastic wrap. So, from this we can conclude that compression with an elastic wrap provides the greatest amount of surface temperature cooling. (Although we must also note that skin temperature is not necessarily a direct reflection of what is happening intramuscularly).

When comparing intramuscular tissue temperature at approximately 2 cm below the skin, again compression with an elastic wrap produced greater intramuscular tissue cooling than both the Flex-i-Wrap and no compression.

This to me was a bit of a surprise. I would not have expected much difference in means of compression. Many athletic trainers utilize Flex-i-Wrap or similar type product for several reasons. Apparently, the elastic wrap adds a level of insulation that is not necessarily provided with the Flex-i-Wrap.

Another point that was also driven home in the study I reviewed last year, was that tissue cooling continues after the ice is removed. Ice, in this study, was applied for 30 minutes and the coldest tissue temperatures were measured at 40 minutes post treatment. So the tissue cooling continues for approximately 10 to 15 minutes following ice treatment.

Please read the study in depth – it was well done and again helps us toward more evidence based practice.

So when we look at this study and compare it with the previous study, what sort of best practices can we establish when using ice as a treatment modality?

  • Cubed, wetted ice is the treatment of choice – crushed ice is probably the least “effective” in comparing the methods of cryotherapy using ice
  • Use compression over no compression – so instead of simply laying an ice bag on an ankle, calf, knee, etc – make sure to secure it with a compression wrap
  • Use an elastic wrap as the choice of compression – This method is more effective than using other plastic wrap methods
  • Both studies utilized treatment times of 30 minutes so this probably serves as a great reference point as well

Following these evidence-based parameters will help athletic trainers provide their athletes and patients with proven methodologies that will ultimately provide more effective treatment. If you have these elements at your disposal, the research shows these are more effective.

Thanks again to the authors of this study and to David Tomchuk, MS, LAT, ATC, CSCS who took extra time to answer questions that I had about this study.

What are your thoughts? Do this studies change the way you think about the application of ice?

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The 2010 Supplement to the Journal of Athletic Training has a vast number of abstracts contained within. Today I want to discuss the abstract entitled The Effects of Ultrasound Transducer Velocity on Intramuscular Tissue Temperature Across a Treatment Site.

Ultrasound is a commonly used, yet maligned modality. As a result, it is important to have studies that speak to it’s efficacy (or lack thereof for that matter) as a treatment and also help to determine parameters for use.

This study aimed to determine if transducer velocity (how quickly the soundhead is moved over the surface) affected intramuscular tissue temperature. Now the authors stated that the general recommendation for soundhead velocity is 4 cm/s and the recommended treatment area is twice the size of the soundhead. Whether the velocity recommendation or whether there was uniform heating within the treatment area were points of interest for this study.

The researchers had 12 subjects and performed continuous ultrasound treatment for 10 minutes at 1 MHz frequency and 1.5 w/cm2 intensity. Intermuscular temperature changes were assessed via sensor probes at 2.5 cm below skin surface. The researchers used velocities of 2 cm/s, 4 cm/s, and 6 cm/s and compared the results.

The study concluded that sound head velocity had no effect on temperature rise during treatment. The other finding in this study was that tissue heating was not uniform across the treatment area. The further away from the center of the treatment area, the less the increase in tissue heating.

Here is an alternate, yet very similar study from 2006 that yielded very similar results. The parameters of this study were very similar. The treatment area was twice the size of the soundhead. This study measured transducer velocities of 2-3 cm/s, 4-5 cm/s, and 7-8 cm/s. Muscle temperature for this study was measured at 3 cm below one-half of the skinfold thickness. Overall, this study showed very similar tissue temperatures between the three tested treatment velocities.

Overall, the one abstract reveals some compelling evidence regarding ultrasound as a treatment. Both studies when looked at together are even more convincing.

So here are some conclusions that we can come to about ultrasound as a treatment based upon both of these studies:

  • There were no significant changes in intermuscular temperature from transducer velocities of 2 cm/s to 8 cm/s.
  • The further away from the center of the treatment area, the less the intermuscular temperature increase
  • Continuous ultrasound at 1.5 cm/2 x 10 minutes in two separate studies produced tissue temperature increases of 4 to 5 degrees celsius
  • Intermuscular tissue temperature was shown to increase during treatment from 2.5cm to approximately 3cm below the skin.

So at the end of the day:

  • Transducer head velocity plays little role in the elevation of intermuscular tissue temperature
  • Treatment parameters of 1.5 cm/2 x 10 minutes of continuous ultrasound seem to be good starting points to deliver muscular tissue temperature increase
  • Using the above treatment parameters, you can expect approximately 4-5 degrees Celsius of temperature increase
  • The larger your treatment area is, the less the tissue temperature increase at the outer rims of the treatment area.

So as we try to become more evidence-based in our approach, these findings can help us to make more appropriate choices in the use of ultrasound as a treatment modality.

What are your thoughts? Did you find any other conclusions from these studies?

Photo Credit here

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iceWell…I got the latest issue of the Journal of Athletic Training recently and there is definitely some good reading in this issue.

One of the studies that really caught my eye regarded the fascinating topic of what else – the application of ice.

Which takes me back to my student trainer days. I gave a wrestler an ice pack and his comment to me went something like this – with all of the technology we have available to us nowadays, isn’t ice still kind of like from the stone ages. I didn’t really have a good argument for him. And that was probably almost 20 years ago.

However, in all seriousness, as we try to validate our practices with sound evidence and research, I found this study quite valuable.

The study is entitled: Comparisons of Cubed Ice, Crushed Ice, and Wetted Ice on Intramuscular and Surface Temperature Changes. The goal of this study was to determine if the different types of application of ice packs effected the cooling of surface and intramuscular temperatures. The authors specifically measured three applications of ice: cubed ice, crushed ice (my personal favorite – prior to this study that is), and wetted ice (crushed ice with water added in the bag). The authors noted that there have been different studies measuring different methods of cold application but there were no studies really differentiating between the three types of ice pack application. So as a result, this study delves into some interesting new ground.

The study group consisted of 6 healthy men and 6 healthy women. The area treated was the gatrocnemius and none of patients had known lower leg injuries, allergies to ice, etc. There was a template used so that each subject received treatment over the same amount of surface area. Here is some additional information directly from the study to describe temperature measurement:

We measured intramuscular temperature using a 26-gauge, 4-cm microprobe (MT-26/4; Physitemp Instruments
Inc, Clifton, NJ) and cutaneous temperature using a surface thermocouple (SST-1; Physitemp Instruments
Inc). The microprobe and thermocouple were sterilized with CIDEX OPA Solution (Advanced Sterilization
Products, Irvine, CA), as recommended by the manufacturer. We inserted the full 4-cm length of the microprobe
into the lateral aspect of the gastrocnemius, using the previously measured depth as the insertion point. Thus, the
tip of the microprobe was placed at a depth of 2 cm plus one-half of the skinfold measurement below the treatment
area on the posterior aspect of the gastrocnemius.

All ice applications used a 22×40-cm clear, 1-mil polyethylene bags. Each application for cubed and crushed ice respectively used 2000 mL of the ice application. As for the wetted ice, 2000mL of cubed ice was put into the bag and then 300mL of room temperature water was added to the bag. The surface of the bag was dry on the outside. Ice was applied in a freestanding fashion and was not secured with any type of elastic bandage. The ice was applied for 20 minutes. Temperatures were monitored and recorded every 30 seconds for 20 minutes and then also every 30 seconds for a 120 minute recovery period.

As far as the results are concerned, crushed ice produced the smallest mean temperature changes from 4.3 degrees Celsius intramuscularly and 15 degrees Celsius at the surface. Wetted ice produced the greatest mean temperature changes from 6.0 degrees Celsius intramuscularly and 17.0 degrees Celsius at the surface. Cubed ice produced greater temperature changes intramuscularly than crushed ice but less change than crushed ice at the surface.

So here are some additional key findings by the researchers regarding surface area temperature:

  • After 20 minutes of treatment, the mean surface temperature for wetted ice (13.3 degrees Celsius) was lower than both the cubed and crushed ice (16.3 and 15.9 degrees Celsius respectively)
  • As far as surface temperature was concerned, wetted ice produced a lower surface temperature than cubed ice through to the 30 minute mark in the recovery period and a lower surface temperature than crushed ice through the 60 minute mark in the recovery period. After these time periods respectively, the difference in surface temperature between the wetted, cubed and crushed ice was insignificant.
  • So regarding surface temperatures, wetted ice was most effective in lowering surface temperature during the treatment and recovery periods than cubed and crushed ice. (Interestingly, crushed ice lowered the surface temperature more than cubed ice but was unable to create sustained lower temperature throughout the recovery period.)

As for intramuscular temperature, here are the key findings:

  • After 20 minutes, wetted ice produced lower mean temperature (30.3 degrees Celsius) than both cubed and crushed ice (31.1 and 32.4 degrees Celsius)
  • After 30 minutes in the recovery period, wetted ice produced colder intramuscular temperature than cubed ice.
  • Throughout the entire 120 minute recovery period, wetted ice produced colder temperatures than crushed ice
  • Overall, wetted ice was the most effective ice treatment at lowering intramuscular temperatures

So of course the question is, why the differences?

Well, honestly if we get away from science one would probably logically say that the crushed ice would be best simply because it conforms best to the body and would probably cover the most surface area. Makes logical sense. However, when we return back to science we can see how the findings can actually be different.

When you look at it, the water that is added to wetted ice actually is able to contact a larger surface area than even the crushed ice. Secondly and most importantly, with ice you are dealing with thermal energy transfer. Water is a much better medium for conducting thermal energy than air. The water in the wetted ice provides a better energy transfer medium whereas with the crushed and cubed ice, there are pockets of air between the ice and the skin surface. To take this even further, the authors point out that crushed ice is less dense than cubed ice and relies even more heavily on air to transfer thermal energy than cubed ice. Thus, the results that crushed ice fared the worst across the board in lowering both surface and intramuscular temperature now make more sense.

Another point that I found very interesting is that while surface temperatures immediately began to increase once the ice pack was removed in all three applications, intramuscular temperatures continued to decline up to 15 minutes into the recovery period following the treatment.

Overall, I do find some great takeways from this study:

  1. The application of ice does clinically decrease not only surface temperature but also intramuscular tissue as well
  2. The most effective treatment for lowering the surface and intramuscular treatment of the area you are treating is wetted ice
  3. Those ice bags that we prepare before a contest and are a little sloppy come halftime or later on are actually more effective for treatment than say those “fresh” ice bags we make
  4. While the surface temperature will begin to rise immediately upon removing ice, the intramuscular tissue will continue to decrease for up to 15 additional minutes

If you haven’t read the study in its entirety, I’d recommend you do so following the link above. It is always great to revisit some pretty common practices in our profession as new research becomes available.

What did I miss? Any other takeaways that you found that I didn’t mention? Feel free to share your thoughts.

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