Ice or Heat following Injury?

September 24, 2015

Using ice or heat following an injury and on painful areas of the body has been the topic of much discussion for years. We see various acronyms being awarded to injury management such as P.R.I.C.E (protection, rest, ice compressions and elevation, however, I have not found any stable evidence-based guidelines that have enabled an accurate, single way of responding to soft tissue injuries and joint traumas that every individual can use effectively.
Working in Professional Rugby League, I am continually treating players with acute injuries/trauma. In the past I have had people swear by taking a warm bath after an injury whereas others reach for the ice bags straight away. Even Physiotherapists offer mixed advice, so how do you decide what’s the best thing to do after an injury? Heat or ice?

Recent studies show that managing an acute injury with ice/cold therapy is likely to inhibit the healing process. So, after reading this blog I hope you will have a better understanding as to how to effectively manage your injuries, aches and pains…

So what’s happening physiologically post injury?

When a tissue is injured or traumatised be it following a sprain, a fall, post-surgery or blunt trauma we more often than not experience pain, swelling, an increase in local tissue temperature, movement of the tissue feels stiffer, and weight-bearing through that limb can be reduced as a result of the pain. These symptoms are caused by the following changes to that tissue, occurring as part of your body’s normal cellular response to trauma;

Local blood vessels are disrupted causing the injured tissue to bleed and a mixture of inflammatory chemicals then flood into the area producing swelling. This inflammatory ‘exudate’ contains numerous substances that serve to mop up any bacteria, stimulate the nerve endings to produce pain and begin laying down material to start the healing process. This acute phase of the injury is the body’s natural response to trauma – without this process, our tissues are not delivered the correct substances to repair and normal healing cannot occur.
The traditional rule of thumb has been that ice should be applied to an injured area within the first 24-72 hours following injury. Why do we want to immediately freeze the area? Well basically, because that’s what everyone has always done and what we’ve been told to do! Inflammation and swelling have been considered as ‘bad’ and as icing an injury causes the tissue to cool down and decreases our pain sensation, we assume that this is handling the inflammation in the right way and encouraging our recovery.

After applying ice a person will usually feel an intense cold within that tissue followed by an aching sensation, but then the area will start to go numb. Ice also decreases the temperature and brings about vasoconstriction of the blood vessels, limiting the bleeding and fluid release into the tissue, reducing swelling and suppressing the inflammatory response…after all, isn’t that what we want…to dampen down the inflammation?

If the body’s natural response to injury is to provide the tissues with the necessary chemicals and substances to carry out an effective healing process, why would preventing this from happening be sensible? By applying ice, we are really therefore getting in the way of our body’s normal physiological response to injury.

Some folk love nothing more that to soak into a warm bath after a bruising rugby match or following an exhausting 10K run. So if we choose heat over ice, what is heat therapy bringing to the injury table?
Applying heat can help to reduce the pain experienced, thought to occur by affecting the speed of the nerve conduction in the fibres that produce that pain. Often there is a feeling of relaxation associated with warmth, and therefore a person’s mind may tell them that they feel better with the heat. Physiologically heat does help to relax tissues by lengthening the collagen, enabling a person to stretch and move more effectively. Muscle spasm can be considerably reduced by applying heat to that muscle. However heat causes blood vessels to dilate, increasing the blood flow to that area and consequently more bleeding and swelling within that injured area, resulting in more pain. More inflammatory chemicals being produced can result in more scar tissue, and although scar tissue is important to replace injured tissues, too much of this can cause reduced function of that body part with a poorer blood supply, altered sensation and abnormal responses to stimuli. As heat effectively increases the inflammatory response, it’s therefore wise to wait until the swelling has begun to subside before applying hot packs or hot baths to the injured area, generally as one enters the subacute phase (3-7 days), or for prolonged symptoms lasting beyond a week. Bear in mind that this is a general timescale so best practice is to get professional advice.

So, if applying ice or heat to tissue immediately following an injury is disruptive to the healing process, what is advised to be the best solution?

We definitely want to limit excessive inflammation, but we also need our body to effectively remove debris, bacteria and inflammatory by-products whilst supporting an efficient and appropriate healing and repair process. Both Hot and Cold therapy have their advantages and disadvantages. Finding the correct balance is important for optimal healing process. It is suggested that cold therapy works best for those who have been suffering with joint and soft tissue pain for more than 2 weeks (i.e. when it is no longer acutely injured or inflamed), whereas heat therapy may work better in the earlier stages of muscular spasm, so long as there is no acute inflammatory process / swelling occurring at that time.
The most effective duration of cold therapy is currently debated. Traditionally, health professionals have advised individuals to apply a cold pack to the injured area for about 20-30 minutes at a time, but recent studies suggest that after around 10 minutes of cold therapy the decrease in the permeability of the lymphatic vessels hinders the fluid drainage from the damaged tissue.

When is contrast bathing useful?

Contrast bathing is an example of convection treatment and involves alternate hot and cold being applied to the tissue, in turn causing alternating periods of vasodilatation and vasoconstriction. This brings about an effective pumping of blood flow and fluid into and out of the area which helps to manage the swelling, flush out debris and injury by-products and stimulates the circulation to promote healing. This kind of therapy is deemed most useful for sprains and strains in the sub-acute injury stage. An individual can apply a hot pack followed by a cold pack, or submerge their affected body-part in alternating hot and cold baths for around 20 – 30 minutes, applying heat first then cold e.g. 2 minutes hot, 2 minutes cold.

Current thoughts on appropriate injury management…

Recent studies and debates have concluded that icing an injury in the early stages delays recovery, whilst applying heat immediately post-trauma will elevate the inflammatory response, therefore neither is advocated in the initial post-injury period. What is becoming increasingly endorsed by those researching injury management, is the consideration of elevation, compression, massage, gentle movement and appropriate loading versus rest. Experts suggest that rather than resting the injured area completely, gentle activity and careful loading of the tissue, appropriate to that injury, helps to stimulate tissue repair. Whilst resting and protecting an injury is important in order to prevent further trauma and an elevated inflammatory response, complete rest should be limited to immediately after the trauma only and of restricted duration. Resting for long periods following injury can produce adverse changes to the tissue, effectively slow the healing process and may risk muscle and tissue wastage through lack of use and reduced stimulus. Have you ever seen someone’s leg or wrist following a lengthy stint in a pot? Exactly! Gentle, progressive loading of the injured part can help to maintain strength and provides tensile stimulus to the repairing tissue which helps it to lay down scar tissue in its optimal alignment. ‘Optimal loading’ is recommended as a balanced way of allowing an injury to both rest and move / load appropriately to stimulate and support healing. As all injuries are individual, this optimal loading of the body area post-injury must consider the specific nature and severity of the injury, the tissue involved, and a person’s physiology, age and general health. Braces, crutches and strapping / taping can assist appropriate tissue loading in early rehabilitation and recovery in order to provide the body with the optimal stimulus vs rest.

If you have any questions about rehabilitation, or indeed if you are in need of some help in returning to sport after an injury, don’t hesitate to get in touch!