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| -Thanks for pic, WebMD.com |
Hating on cryotherapy or “icing” musculoskeletal injuries
seems to be the flavor of the month thing to do. Decades of conventional wisdom
has told us that everything should be iced immediately after injury. RICE &
PRICE were so-so nice we thought. However, when held under the light of
scientific inquiry the evidence for cryotherapy was found to be on thin ice.
This blog post today isn’t going to be a rehash of previous
arguments against cryotherapy. Here is a recent post by Josh Stone, MA, ATC where
he gave his top 10 reasons to cease the cryotherapy craze. Instead, today I
am going to discuss a recently published study on cryotherapy. This study by
Selkow et al1 was just published early online by the Journal of
Athletic Training.
What did they investigate?
The authors wanted to investigate the effect of repeated
cryotherapy treatments on microvascular perfusion after a bout of eccentric
exercise. Why eccentric exercise? They did this because it has been previously
shown in the literature that eccentric exercise results in increased blood flow
just like the vasodilation associated with musculoskeletal injury. Therefore,
this study would look directly at a very common clinical scenario (using cryotherapy
on an acute episode of local inflammation.).
In this article the authors used a single-blind randomized
controlled trial study design. They recruited 18 healthy subjects for this
study and divided them into three separate groups (intervention, sham, and
control.). If you are looking to find a good level of evidence when it comes to
studies this is grade A stuff. The investigators were the ones blinded to the
intervention not the subjects. I can imagine it would be difficult to blind a
subject from whether or not they were receiving cryotherapy and that is why the
authors didn’t use a double-blinded study design.
How did they investigate it?
The authors used microbubble infusion via an intravenous
catheter that was measured using ultrasound imaging. This allowed the
investigators to determine blood flow/local perfusion. After establishing a
baseline, the subjects performed an eccentric exercise protocol. Within 1
minute of finishing the eccentrics the subjects were provided with the
intervention (ice, sham, or control) depending on their random group
allocation.
After applying the intervention, perfusion was once again measured
using the microbubbles and ultrasound. This began within 30seconds of
completing the intervention. After this the participants returned 10, 24, and
48 hours after the initial intervention to reassess pain using a visual analog
scale (VAS) before undergoing another intervention session (the same as the
first, depending on their group placement). This closely mimicked what may be
seen in an athletic training or by a person following traditional RICE advice
at home.
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| Kind of like this...but not quite. |
So What Did They Find Out?
The authors found out that there was NO difference in the
amount of microvascular perfusion between the different intervention groups.
This means a sham ice modality, doing nothing at all, and a bag of ice all had
the exact same influence when it came to perfusion levels. In other words, the
cryotherapy treatment was useless in terms of influencing perfusion. However,
there was a difference between pain levels as assessed using the VAS. This was
not much of a surprise considering cryotherapy has previously been noted for
its ability to influence pain levels.
What does this all mean?
It is just another piece of evidence to support the idea
that icing may not be doing what we thought it was doing. Specifically,
cryotherapy does not seem to make a big difference in local blood flow after
injury. Especially when considered in the light of an eccentric exercise model
in this case. However, cryotherapy still remains a viable modality to alter
pain perception within patients. While cryotherapy may not fix anything it may
still be an option to modulate pain or suffering associated with experiencing a
musculoskeletal injury.
Update:
I want people to realize that ice does currently have a time and a place. However, that place may not be where we once thought it was. Despite cryotherapy not changing bloodflow it does a great job of modulating pain. Additionally, cryotherapy has recently been found to be a great modality for treating arthrogenic muscle inhibition...Specifically in the quadriceps after knee injury. So ice is still cool for some mechanisms! Remember that!
Update:
I want people to realize that ice does currently have a time and a place. However, that place may not be where we once thought it was. Despite cryotherapy not changing bloodflow it does a great job of modulating pain. Additionally, cryotherapy has recently been found to be a great modality for treating arthrogenic muscle inhibition...Specifically in the quadriceps after knee injury. So ice is still cool for some mechanisms! Remember that!
References:
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