An Olympic sprinter tears a hamstring. An AFL footballer suffers an ACL injury. A junior gymnast sprains her ankle. A toddler bumps his head. Our instinctive response in each of these cases is to apply an ice pack. But why? What sort of ice is best? How long should we apply it? How often should we apply it?

Let’s explore the current evidence and throw in some common sense in an attempt to provide some logical guidelines.

Inflammatory Response

Before we discuss the efficacy of ice, we must understand the inflammatory response that occurs immediately proceeding an acute injury.

• Inflammation is a normal response by the body in the first few days post injury to remove dead and dying tissue and initiate healing.
• Our blood vessels can increase (vasodilation) and decrease (vasoconstriction) in diameter and they also have tiny holes like a sieve to allow different cells and fluid to perfuse in and out. When an injury occurs, the blood vessels dilate and the holes increase in size, allowing the special inflammatory cells to enter the damaged tissue and initiate healing.
• Inflammation results in swelling which increases pressure and pain sensitivity in the injured tissue, preventing further activity and damage.
• An excessive inflammatory response results in slower healing and a delayed return to sport/work/function.

How does ice help to reduce inflammation?

Heat is conducted away from a warm object towards a cooler object. Therefore icing an injured body part should result in decreased tissue temperature.

The effectiveness of ice in reducing tissue temperature depends on:

• The temperature difference between the source and the body part (frozen peas, crushed ice, gel ice pack)
• The size of the area (finger, thigh, buttock)
• The volume of blood flow through the area (blood is warm)
• The barriers to cooling (tea towel, clothing, etc.)
• The amount of overlying adipose (fat) tissue (insulator)

So why should we reduce tissue temperature?

• Vasoconstriction (decreased blood flow = decreased swelling)
• Decreased nerve conduction (decreased pain)

So there you have it… applying ice to an injured body part immediately post injury should result in a reduction in pain and swelling and a faster return to sport. That’s why we all do it but let me question this concept a little further…

• Who decided that the inflammatory response is excessive?
• If inflammation is a normal part of healing, why should we reduce it simply to return to sport faster? Does this affect the quality of healing?
• After all these years, why don’t we have a single high quality study to support the use of ice in enhancing tissue healing and hastening recovery?
• Why are their no clear guidelines for the use of ice following an injury?

Are you confused? You’re not the only one! Let’s explain a few things and throw in some common sense.

• Scientific research is hard!! For research to shape our clinical practice it must be high powered, high quality and show a clear and meaningful result. It is impossible to perform such a study on the efficacy of ice on humans. That is why there are no studies that prove ice helps. There are also no studies to prove it does harm!
• It feels good to ice an injury. Can you imagine sitting on the sideline after injuring yourself and saying no to an ice pack? Would you be worrying that you’re not doing everything you can to improve your injury. Our psychological state has an important effect on tissue healing.
• Have you heard the acronym NO HARM? It stands for no heat, alcohol, running or massage. These all create vasodilation, therefore increased swelling post injury and we conclusively agree that this is detrimental to healing. Doesn’t it make sense to do the opposite?
• Ice only forms one component of injury management.

My advice in managing an acute injury (in order of importance): Note that these don’t prevent the important inflammatory stage from occurring, they will simply prevent excessive swelling.

• Protect the injured area to avoid more tissue damage.
• Compress the affected area as quickly as possible with an elastic bandage/tape to reduce excessive swelling. Ensure you loosen the compression if discolouration, throbbing or pain occurs.
• Elevate the injured area if possible to reduce excessive swelling.
• Ice the affected area immediately following injury. Crushed ice with a wet fabric barrier or an ice bath are probably the most effective but anything cold should help. Apply for at least 15-20 minutes and repeat every hour or two, especially in the first day post injury. If the injured area is small and close to the surface you don’t need to apply the ice for as long. If the area is large and deep, like a corked thigh, apply the ice for longer. Don’t stress if you are unable to ice your injury!! Don’t set your alarm and wake up during the night to ice as rest is more important.
• Commence gentle movement as pain allows.

Ensure you consult your physiotherapist at My Physio Perth as every injury is different. We will use our wealth of academic knowledge and clinical experience to ensure you receive the optimal management.