One of the golden rules of first aid is that when you injure yourself, you must use ice to reduce the swelling. But is this really the case?
Over the last few years the medical and Allied Health community have become incredibly self critical, subjecting all of our “gospel truths” and common interventions to rigorous scientific scrutiny. This means that even every day interventions that do help people have to be tested against a sham or placebo intervention to see if they have any specific benefit above convincing a patient that they are having a “treatment event” which has been well established to generally help someone even if it is a sham (read any of the literature about Homeopathy, for instance).
This has resulted in some quite shocking truths, causing doctors and physiotherapists to become very uncomfortable. For instance, it is now widely accepted that
- stretching before exercise doesn’t reduce the risk of injury, and in fact will reduce athletic performance.
- Codeine is not an effective pain killer
- Echinacea doesn’t help colds
- Cough syrups don’t work (other than codeine, funny enough)
- Trigger points don’t exist (see this blog)
- Core exercises to strengthen inner abdominals don’t reduce persistent back pain
- Knee arthroscope is no more effective than sham for arthritis
…….. and the list goes on.
So what can we rely on? In the world of acute sports injury management, surely the gold standard of first aid is to Rest, Ice, Compress, and Elevate?
While the research has been around for a little while, there has been social media storm recently among health care practitioners about strong evidence to doubt the accepted effects of using ice to reduce swelling post injury (see here for BJSM article). But how can this be so? Everyone knows that ice reduces swelling!
In fact, it doesn’t. The lymphatic system is what reduces swelling, by absorbing oedema from the interstitial space (in your tissues) and then transporting it back to your circulation, via the lymph nodes where all the rubbish is filtered out. When you apply ice you actually impair this in two ways;
- By increasing the viscosity of the fluid you reduce its ability to flow through the lymphatic vessels (compare trying to suck an ice cold thick shake through a straw, vs when it melts)
- Reducing the temperature makes the lymphatic vessels become more permeable, allowing the oedema to leak back into the tissues, promoting swelling
Not only this but you reduce the activity of the macrophages (cells that consume damaged tissues and chemical debris near the injury), reduce production of growth factors etc. Swelling contains lots of really necessary stuff to heal your injuries, and the goal of reducing it in the first place is questionable. If the swelling is so severe that it is impeding movement and reducing your ability to stay active, which does promote recovery, then elevating the injured body part above the level of the heart (not just up on a chair) and applying external compression do actually help reduce swelling. These two methods have a plausible basis in physics, elevating the limb promoted lymphatic drainage via the effects of gravity, and compression produces a pressure gradient limiting swelling in the tissues, and promoting uptake into the lymphatic vessels.
If the swelling is less severe than this, then rest assured that is your body’s amazing self-healing system at work, and get on with life. Movement and gentle exercise promote healing, lymphatic drainage, and reduce psychological aversion to loading the injured part (being too precious).
So what about Rest then? Well, this is fine advice for serious injuries, at least for the first day or two. Traditionally this has been mistakenly taken as “Rest until it doesn’t hurt any more”. Prolonged rest causes muscle and tendon wasting, reduction of bone mineral density, reduced strength of the healing scar, and kinesiophobia (conscious or subconscious fear of movement).
Part of the healing process is inflammation, and as discussed before, it is wonderfully helpful stuff – however, it does make your alarm bell nerves (nociceptors) more sensitive, meaning they will send danger messages to your brain about tissue damage WAAAAAYYYYYY before you’re actually likely to cause any real damage. Anyone who has sprained an ankle or broken a bone will tell you that within a few minutes, even light touch on their skin some distance away from the injury will elicit pain when there is no plausible way this could cause further damage. This increase in sensitivity is natures way of making you rest and recover, but it is too successful in most cases. Starting movement and exercises early, even with mild to moderate pain, is much more beneficial than prolonged rest.
To sum it up – don’t ice, rest very little, compress if you must, elevate if you feel it is necessary to keep active. Remember that swelling is your body’s natural way of healing – why get rid of it?
What to do instead? This infographic has been flying around on twitter between physios and health professionals for the last couple of months, but has certainly ramped up since the BJSM article referenced above (which the image comes from).
The new emphasis is on understanding your injury – knowing that mild to moderate pain is not likely to be a sign of further damage, and that moving and staying active, even exercising, is likely to result in faster healing, stronger tissues, and more confident return to life – even while you’re swollen and sore.
Peace and Love, I’m out.
written by Ben Kewish, Physiotherapist