It has been widely known in the athletic community to ice an injury as soon as it occurs. Most of us have heard the term RICE thrown around the locker room like a sweaty jock strap. Even our mothers will tell us an old wives tale about how not icing could cause permanent vision loss or something to that degree. But where did this theory come from? And most importantly, is it as effective as people claim it to be?
I stumbled on an online video from 2014 posted by Kelley Starrett, creator of MobilityWOD, where he interviews Gary Reinl, known as the “Anti-Ice Man”.
In this interview Reinl explains how icing an injury is not the best method of treatment. Being the type of person that needs to know the why to everything (and I mean everything), I did some research to try to back up this unwritten rule.
The use of cold application for therapeutic treatment is known as Cryotherapy. It was first introduced by the Egyptians as early as 2500 BCE, and later Hippocrates, due to its analgesic and anti-inflammatory properties. By the early 1800’s the study of cryotherapy for surgical use was being studied in Europe. Doctors were starting to notice ice application destroyed tumor tissue and reduced pain. Since then, ice has become one of the most popular methods used to treat soft tissue injury. Over the years researchers have analyzed the physiological effects of ice therapy. It not only decreases muscle spindle fiber activity and nerve conduction, but it also causes vasoconstriction of the blood vessels, decreases local metabolism and enzymatic activity, and decreases the oxygen demand of the muscle.
So what does this mean for inflammation?
A systematic review conducted in December 2010 entitled, “Cryotherapy and inflammation: evidence beyond the cardinal signs” reviewed the rationale for cryotherapy intervention in the acute phases of soft tissue injury. It analyzed the physiological, cellular and molecular models of inflammation and the relevant outcomes associated with inflammation before the injury and up to one week post injury. The results found:
- White blood cells, the ones responsible for an important immune defense mechanism, were blocked from the site of injury up to 24 hours post injury and lowered the overall count in 48 hours.
- New muscle tissue growth was inhibited with temperatures below 5˚C
- Increased cell death of injured tissue due to oxidation by free radicals
- Decreased rate of circulatory blood flow but increased tissue perfusion
This basically translates to an injury that has no bacterial protection, very little healthy tissue regeneration, and a vascular block of debris build-up around the area.
Another study from February 2011 entitled, “Influence of icing on muscle regeneration after crush injury to skeletal muscles in rats” was done on the extensor digitorum longus of rats. It examined the difference between applying ice packs for 20 minutes at the time of injury versus not icing. The end result showed smaller sized regenerating muscle cells by day 4 and abnormal collagen formation with less overall regenerating muscle fibers by day 28. Re-injury time anyone?
The cycle of inflammation happens for a reason, to clear out damaged tissues and prepare for regrowth. It’s a natural process similar to breathing. Obviously the rules of icing may change dependent on the type of injury, as most of the studies done have been tested on a contusion (bruise). However, if we are slowing down the delivery of the good products and trapping the removal of the bad byproducts, it makes the healing process longer. Aside from alleviating pain, there doesn’t seem to be any scientific evidence to back up the theory of icing to speed recovery time.
So please, use those bag of peas for dinner and keep the joints around the injury moving instead.
Takagi, R, et al. Influence of Icing on Muscle Regeneration After Crush Injury to Skeletal Muscles in Rats. J of App Phys. February 1, 2011; vol. 110 no. 2 382-388
Bleakly, C. and Davidson, G. Cryotherapy and Inflammation: Evidence Beyond the Cardinal Signs. Physical Therapy Reviews, December 2010