Heat vs Ice
This feature is going to be the first of many to discuss topics of conversation I frequently have with my patients. In this edition, I want to talk about the use of heat or ice following injury. In addition, when to use each and when to avoid.
The mnemonic RICE was created in 1978 by Gabe Mirkin, a Sports Medicine Physician, that describes the use of Rest, Ice, Compression, and Elevation to treat sport-specific injuries. Today, this mnemonic has become standard practice immediately following any injury. However, after many years of experience and practice, Dr. Mirkin began to notice that the site of injury reaches a point where it no longer requires the anti-inflammatory effects of ice. In fact, if used past the acute stage of injury, it can impede and interfere with the body’s natural healing response. Because of this, Dr. Mirkin recanted his mnemonic in 2014.
Before we talk about heat or ice, let’s discuss the stages of healing.
First, we have the Acute stage, a.k.a. the Inflammatory phase. This stage most commonly lasts between 24-72 hours following the injury. During this stage, the body is focusing white blood cells and inflammatory markers to the site of injury in order to protect it from further injury/infection and begin the healing process. This is what causes swelling.
Next, we have the Sub-Acute stage, a.k.a. the Proliferative phase. This stage can occur anywhere from 2 days to 6 weeks where the body transitions from the Acute to Chronic Stages. We typically see a reduction in swelling, though pain and loss of function persist. The body has sent the proper chemicals to the area signaling a need for repair and the healing process has begun by lying down new tissue. However, this new tissue is not mature enough to replace the original, damaged tissue.
Finally, the Chronic stage, a.k.a. the Remodeling phase. During this stage, the new tissue is being remodeled and strengthened in order to perform the function of the original, damaged tissue. This stage can last from weeks to months, even years, depending on the severity of the injury. Typically we see scar tissue first. But over time, can be replaced with viable, functioning tissue more similar to that of the original, damaged tissue.
What are the effects of Heat and Ice?
Ice reduces blood flow via vasoconstriction, or narrowing of the blood vessels. Ice also increases fluid viscosity (makes it thicker), makes the area numb to pain, and reduces the flexibility/mobility of the underlying tissue by reducing it’s elasticity.
On the other hand, Heat increases blood flow, decreases fluid viscosity (makes it thinner), and increases the flexibility/mobility of underlying tissue by increasing it’s elasticity.
So how does this relate to tissue injury?
Injuries with a specific Mechanism Of Injury (MOI), such as a traumatic event, sets off the 3 stages of healing. Ice can be useful during the acute stage in order to prevent excessive inflammation and swelling. Inflammation is necessary and helpful during this stage, but too much can be harmful. This is where the ice is important during the first 24-72 hours.
If ice is used after this stage of healing, it can inhibit the body’s natural healing response by reducing blood flow, reducing mobility/flexibility, and increasing the viscosity of the interstitial fluid or remaining swelling. These effects make it more difficult for the body to remove and flush the area of the swelling and slow down the laying of new, healthy tissue.
During the sub-acute and chronic stages, heat is more appropriate in order to continue bringing healthy blood, oxygen, and nutrients to the area and remove swelling and metabolic byproducts. Continued use of heat can facilitate this process. In addition, the heat will further improve the tissue’s flexibility and mobility as it matures and strengthens as to avoid a loss in any range of motion or elasticity during this time.
I see many people that come in and are still using ice weeks and months following the onset of injury or pain. At this point, the ice is simply slowing down the body’s natural healing response and likely contributing to a bigger problem!
What about Chronic pain without a specific MOI?
In this scenario, we need to conceptualize a different model of healing. Chronic pain can be due to many factors, from neurological, centrally-mediated pain sensitivity, muscle guarding/spasms, etc. Because of this, heat or ice recommendations should be on a case-by-case basis. However, what’s most important is achieving some form of relief. For this reason, I usually ask my patients to try both and go with whichever one feels better!
While this is a very generalized explanation of tissue healing and the effects of heat or ice, I hope this edition provides some clarity to the Heat vs Ice debate and helps you make a decision as to which is most appropriate for you.
If you’d like to discuss further, please feel free to reach out to grant@advancedmanualtherapies.com.
Thanks for reading!
-Dr. Grant