June 21, 2019
A question I get asked a lot is, “is ice or heat best for my injury?” So this sounds like a good place to start my series of blogs covering all things physio!
This question is not as simple as it sounds so I will go through the basics of the science of how ice and heat affect the bodies tissues. We will touch briefly on the controversy surrounding the use of ice in sports medicine and then I will walk you through how I use ice and heat to help my patients feel better and recover quicker.
What is it that ice does exactly to our body when we jump in the ice bath or wrap the frozen peas around an ankle?
The biggest effect icing or cooling has on the body is the reflex vasoconstriction of the blood vessels in the area being cooled. If the blood vessels constrict or narrow this means less blood flow to the effected area. Less blood flow equals less swelling but it also means less of the good stuff in the blood which promotes healing.
Ice effects the body in other ways too, it slows nerve conduction velocity, this may have effects on the cells that nerves effect for example it may play a role in increasing pain tolerance or reducing pain output, it can effect the motor neurons making muscles contractions less powerful and reduce spasticity in muscles.
Not surprisingly, heat has the opposite effect on the tissues of the body. It primarily causes vasodilatation. When blood vessel dilate blood flow increases which brings nutrients, oxygen and chemicals which assist in the healing process along with it.
Heat also improves the extensibility of the surrounding tissue making muscles easier to stretch and joints easier to move.
In the first few days immediately following an injury the increased blood flow caused by applying heat can increase swelling around the injured area potentially increasing pain and reducing movement.
WHY IS APPLYING ICE SUDDENLY CONTROVERSIAL?
Most people have heard the acronym RICER (or one of its many variations).
It stands for REST, ICE, COMPRESSION, ELEVATION and REFER and has been the most widely accepted protocol for managing soft tissue injuries since the 1970’s. Dr Gabe Mirkin who came up with this acronym did so based on theory (which was common in the 70’s) rather than on irrefutable scientific evidence. Now that our research methods and technologies have improved we are able to study the effectiveness of these theories much better. In fact Dr Mirkin is now one of many who question this protocol!
The main focus of the detractors is that by applying ice to the body you are limiting the blood flow to the injured area and thereby you are not getting the normal breakdown of damaged tissue and not getting the influx of nutrients and chemicals which stimulate the healing cascade. This line of thought definitely has merit as getting blood to an injured area is absolutely crucial for the injured structure to heal.
Others remain unconvinced that applying ice for 20 minutes every hour after the injury reduces blood flow to the point where healing is compromised (remember for the other 40 minutes of every hour normal blood flow is restored). It has been widely believed that there is an overcompensation by the body to an injury and the increase in blood flow is excessive as indicated by the amount of swelling that can form when left untreated.
With this issue I can definitely see both sides of the argument. However I don’t believe that replacing one theory with another is necessarily the best way to go about changing what we believe is best practice. At this point in time I am yet to be convinced that applying ice to injured soft tissue impedes the healing cascade. The articles I have read surrounding this issue are all based on opinion and theory. What we need is some robust studies that look at a large number of people with the same injury and split them into ice and no ice and see whether there is a significant difference between the groups. I read a recent study that attempted to look at this in rats. They looked at the amount of certain inflammatory mediators in the blood, collagen protein levels and looked at the muscle tissue under the microscope over a period of time after injury and found that the inflammatory mediator levels were decreased at day 3 and 7 post injury but the collagen protein and muscle tissue observations were the same as the non ice group. This showed there was a potential decrease in inflammation due to the ice but no effect on regeneration/tissue healing. Bear in mind this study was a one off study that has yet to be repeated and was done on rats, but at least it’s a start!
It’s also important to remember the impact ice has on pain and if it does nothing more than relieve someones pain without the need for medications then in my mind that makes it worth while.
Heat can still play in important role in the early phases of a soft tissue injury. In the back and neck for example, the joints or muscles that typically get injured are quite deep which makes them a lot harder to cool with ice. Also these structures tend to have quite small blood vessels meaning the effects of swelling are not as severe in these areas. With necks and backs muscle spasm tends to play a bigger role in the persons pain experience and these respond well to heat being applied.
Another important part of early injury management, that isn’t discussed in the RICE protocol, is loading the injured body part. As long as there is no fracture or major damage it is important for injured athletes/people to commence loading as soon as possible within their pain limits. Early mobilisation aids faster recovery, reduces
muscle wasting, maintains strength, maintains joint range of movement, removes excessive swelling and reduces fear avoidance behaviours. Some simple ways to load an injury safely include; simple range of motion exercises (moving the joint through its range), walking, cycling on stationary bike, swimming, walking in a pool, stretching, resistance band exercises and light weights etc. Remember with these exercises it is important that the patient feels comfortable doing them.It is also important that significant trauma such as fractures or ligament or tendon ruptures have been ruled out. If in doubt whether there is significant trauma or not seek the advice of a health professional such as a GP or physiotherapist as soon as practical.
- Ice reduces blood flow and swelling to an injured area and reduces pain
- Heat increases blood flow to an injured area an reduces muscle spasm
- Early movement promotes faster and more effective healing in absence of significant trauma
- The research on the effectiveness of ice and heat on recovery from injury is inconclusive
- I find heat works best for backs and necks
- I find ice works best for peripheral joints (shoulders, knees, ankles etc)
- Do what makes it feel better!
If you have had a recent soft tissue injury and you are unsure how severe it is, or want to get back to full function in as short a time as possible, book in for an appointment with our friendly physiotherapists.
Call: 0400 163 609
Book online: www.inspirephysiocentre.com.au
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Ramos GV, Pinheiro CM, Messa SP, Delfino GB, Marqueti RDC, Salvini TDF, Durrigon JLQ; Cryotherapy reduces inflammatory response without altering muscle regeneration process and extracellular matrix remodeling of rat muscle; Scientific Reports; 2016; 6; 18525, doi 10.1038
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