October 13, 2014
Have you ever hurt yourself or had a dull ache and wondered “should I use heat or ice?”…
Often, the first questions people ask when they come into the physical therapy clinic deals with pain control. The questions are always similar: “Should I heat or ice at home?” and “What is the difference or benefit of each?” People are concerned if one should be used over the other, and which will have a better effect on improvement of their injury. Which will allow for a quicker recovery, and what will help with the pain?
The application of “cold” to an injured area has various physiological effects on the body. First, cryotherapy (or therapeutic use of cold) should be used for inflammation (swelling) control IMMEDIATELY after an injury, otherwise known as an “acute injury”. The sooner the application, the greater and more immediate the benefit. Acute inflammation typically subsides within 48-72 hours after the “incident” occurred. The best judge if inflammation is present is to one, feel the area to see if the skin temperature is elevated at the suspected injured area, and two, look and inspect the area for increased swelling (does it look like a hot air balloon?). If so, RICE. The combination of rest, ice, compression and elevation (RICE) has been shown to be the best way to control for acute inflammation.
So how does this work? When cryotherapy is applied to the skin, it causes an immediate constriction (closure) of cutaneous (close to the body’s surface) blood vessels. This causes a decrease in blood flow to the area where cold is applied. This “phenomenon” continues for 15-20 minutes, and ice should be applied in time increments no greater than this. Ice can be reapplied once an hour. Cryotherapy also increases the blood “thickness” in the area of application, slowing the rate of blood “rushing” to the injury. These two concepts combined allow for less fluid loss and decreased swelling in and around the injured area. This is important, as an injured area typically has increased blood flow. Increased blood flow is the body’s natural response to allow healing to occur. Fresh blood to an injured area is healthy. Too much blood flow to an area, however, causes significant swelling.
An example of when to use ice might be to help prevent every girls worst nightmare: injuring that ankle last evening when performing that dance move at that wedding you attended, only to see it swell up; you would not be able to get your Uggs on; winter would be fashionably ruined, basketball season is toast. Putting ice on the ankle immediately after the incident is going to help “save the day”.
Cold will also decrease how fast a nerve transmits a signal from the brain to the body, and vise versa. Ironically, the designated pain nerve fibers we have in our body are one of the most affected. We can take advantage of this by “tricking” the pain fibers in our body, allowing for an increase in pain tolerance as well as a decrease in pain sensation IF pain is present. This idea can last for up to 1-2 hours after application of cold. This “tricking” effect would come into play on that ankle you rolled at that wedding, decreasing the pain sensation. DISCLAIMER: It will NOT “trick” the mind in “forgetting” the dance move that landed you straight on the floor with everyone watching. That unfortunately is your own problem to address.
Finally, cold therapy can also be used for delayed-onset muscle soreness (DOMS). DOMS is simply the inflammation of muscle and/or tissues in the body that is caused by exercise. Research has also found that cold and light exercise to an area previously having inflammation can assist in decreasing the “DOMS” effect. Whether its exercises with your therapist following a rotator cuff repair, that agonizing golfer’s elbow after shooting par (preferably not putt-putt), or simply hitting the gym and doing “curls for the girls”, a little cold therapy to that area of soreness can help you in the long run. Your body will thank you later.
So what about the HEAT (and no, not Miami or Lebron leaving, or your 99mph fastball)…
Heat, like cold, has a unique physiological effects on the body as well. Heat causes blood vessels to “open” and increase blood flow to muscles. Heat, like ice also alters how fast a nerve “fires”. Nerve firing rate is decreased in a particular nerve in our body that cause muscle “spasms” (Charlie horses/knots) to occur. By applying heat to this area, it therefore, “theoretically”, will allow for relaxation of a muscle spasm. Heat also increases pain threshold by causing fresh blood supply to enter an area lacking blood supply. When little fresh blood supply is in a particular area of our body, this can cause what the body perceives as “pain”. By applying heat, this can assist in blood flow and increased oxygen to the area. Where there is fresh blood and oxygen, there is healing occurring! However, remember everything in moderation. Too much blood flow causes inflammation and swelling. A typical guideline is 10-15 minutes at any given time.
Finally, heat increases tissue extensibility or “stretchiness”. This concept is used when further motion wants to be achieved. “Most” of the newly acquired range of motion is maintained when the tissue then cools down. Because of this, it is recommended that stretching be performed during or immediately after the heat is applied if this is the outcome wanted.
So, in quick review, ice will help with immediate injury to tissue as well as helping with “soreness” or DOMS after using muscles. Heat should be applied if muscle spasms are present or if increased range of motion is wanted. However, remember that these two pain alleviators are just ONE optional piece of the puzzle to a full and healthy recovery. It’s never a bad idea to ask your physical therapist if you are concerned with applying either of these to an injury site. They are always more than willing to assist you!
Colton Aman PT, DPT