Intramuscular temperature changes during and after
cryotherapy in healthy individuals.

Rupp KA, Herman DC,
Hertel J and Saliba SA. J Orthop Sports Phys Ther.2012 [Epub ahead of

The use of
cryotherapy in treating musculoskeletal injuries is common. When this treatment
is applied a number of physiologic changes occur such as decreasing skin and
muscle temperature, decreasing pain, and controlling edema. While cryotherapy
can be applied in many forms, two popular applications, crushed ice bags (CIB)
and cold-water immersion (CWI) exist but the efficacy of one other the other
has not been fully explored. Therefore, Rupp and colleagues performed a
crossover study to compare the length of time required to decrease patients’
intramuscular temperature 8°C below baseline.
Secondary aims of this study were to examine intramuscular temperature changes
90-minutes post-treatment, the relationship between adipose tissue depth and
cooling time, as well as perceived discomfort of the patient being treated.
Eighteen healthy adults (7 men, 11 women) volunteered for the study. All
patients underwent an ultrasound evaluation to determine each patient’s adipose
thickness at the patient’s medial, non-dominant calf. An 18-gauge microprobe
was then inserted just below the adipose tissue (determined through ultrasound
imagine) of the patient’s dominant calf to measure intramuscular temperature.
After taking a 5 minute baseline temperature reading, patients received a
randomly allocated treatment (either CIB: 1500mL of crushed ice in 38 cm x 51
cm plastic bag, wrapped with plastic wrap at 40-50 mm Hg; CWI: 10 gal tub
filled with crushed ice and cold water, approximately 12°C
with no unnecessary ankle movement). Each treatment was applied until the
intramuscular temperature reading decreased 8°C. Once the 8°C
decrease was reached, the treatment was removed and the patients were asked to
score their level of discomfort subjectively, as the patients were asked to
gauge their level of discomfort “at the most intense point of treatment” on a
visual analog scale. Rewarming was then measured as each patient was asked to
lay prone for 90 minutes post-treatment. Patients returned three to seven days
later to receive the other treatment. Overall, the time required to decrease
intramuscular temperature 8°C was not
significantly different between interventions and adipose tissue thickness was
not a factor in the rate of cooling. There were significant differences
however, regarding rewarming as tissues which underwent CWI remained
significantly colder than CIB. Also of interest, was that a majority of the
patients required more than 30 minutes of treatment to decrease 8°C.

This study presents
interesting data on one of sports medicine’s most widely used modalities. The
data presented suggests that both CWI and CIB are effective at decreasing
intramuscular temperatures but at different rates. While both treatments are
effective, perhaps it should be the goal of the therapy that dictates which
method is used. For example, if the goal of the therapy is to fluctuate between
temperatures to pull edema from the injured site, CIB may be more effective as
the temperature changes more rapidly after the CIB is removed. Also interesting
was the finding that a majority of patients needed longer than 30 minutes of
treatment to decrease the intramuscular temperature 8°C.
This finding must be interpreted cautiously though as the authors do point out
that there is no current optimal temperature change for the desired
physiological effects of cryotherapy. This would be useful information for the
clinician and should be a focus of future research. In the end, the method of
cryotherapy chosen by the clinician must be based on the body part being
treated and the means available to that clinician.  Tell us what you have found. Do you find your
athletes prefer CWI over CIB or vice versa? Which treatment do you find gives
the best results following an acute injury?

Written by: Kyle
Reviewed by: Stephen

Related Posts:

Rupp KA, Herman DC, Hertel J, & Saliba SA (2012). Intramuscular Temperature Changes During and After 2 Different Cryotherapy Interventions in Healthy Individuals. The Journal of Orthopaedic and Sports Physical Therapy PMID: 22446500