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by Danielle Clark-Fox, DPT

ice or heat for injury

This has to be one of the most frequently asked questions in our clinic, no matter which area of the body we are talking about. So I thought it would be a good idea to put together some good information about when to use which!

In general the best rule of thumb is ice when something just occurred (immediate- 72 hours) that’s causing any or all of the following symptoms: bruising, pain and swelling. After that initial time frame it may become more beneficial to use heat. Of course now we get to all the nuances and exceptions to what I just stated!

Ice’s modus of operation is to decrease blood flow to the area applied via blood vessel constriction. This will slow the area’s metabolism and decrease any inflammatory response. Ice will decrease your pain by interrupting the pain signals sent from the area to the brain, known as an analgesic effect. Ice is best for acute injuries described above, chronic issues such as back pain and overuse or repetitive injury conditions after activity. Ice should be used 10-15 minutes with some barrier between you and the ice such as a towel- you can frostbite yourself if you aren’t careful!

Heat’s modus of operation is the counterpoint of ice. Heat will increase blood flow to an area and relax surrounding muscles and tissues. Therefore, any area to which heat is applied should not be swollen. Heat can be useful to decrease tension through muscles and trigger points, decrease pain from a cervicogenic headache, loosen up an area irritated from overuse or repetitive motion before activity. Heat should be applied for 10-20 minutes only, with too high a temperature and/or length of treatment you can irritate or burn your skin.

Many patients ask me why I start a treatment with heat and end with ice. My answer for each patient regardless of injury is based around the same principle- I want to relax the area to start with so I can get in there and perform manual therapy to improve tissue integrity or range of motion. This is common with IT band injury, shoulder injury/surgery or chronic back pain without inflammation. After a treatment the area may have become a bit irritated so I want to calm this down with ice. I think many patients ask me to clarify on this point because I’m telling them to use ice at home when the area is “kicked up and bothering” them as I like to say. This is because their daily activity or a specific task has irritated the area causing pain and inflammation even if they can’t see swelling and ice will be much more beneficial to decrease their pain and minimize any inflammation along the recovery process.

So in general each can be extremely beneficial with a few simple rules, and easy to implement at home with frozen peas or hot towels!

Dr. Fox is a physical therapist at Boston Sports Medicine.