Cold Therapy or Heat Therapy?
Physiotherapy clients are often uncertain whether it is appropriate to use cold therapy or heat therapy for the treatment of their injury or pain, and there is in fact a lot of conflicting advice as well as half-truths offered as gospel.
In essence the choice is dependent upon whether there is a likely benefit from slowing down or speeding up the biological activity in that region of your body, although as with most aspects of biology it isn’t necessarily a simple case of one or the other.
The most common opinion about cold therapy seems to be its suitability for the treatment of an acute injury such as a sprained ankle, a muscle strain, or a bone fracture, but there are certain chronic conditions that also often respond favourably to cold therapy.
Cold Therapy for Acute Injuries
First Aid guidelines for many years have emphasised the R.I.C.E protocol – Rest, Ice, Compression, Elevation – for the initial treatment of acute injuries. All four aspects of this protocol aim to reduce the activity of the injured area so that swelling and pain can be minimised, especially in the first 48-72 hours after the injury.
The initial swelling and internal bleeding associated with these injuries can be just as debilitating as the injury itself, and can cause a lot of pain due to compression of nerve endings in the area. Cold therapy can help to minimise swelling and bruising by reducing the regional blood flow and can help to alleviate the pain by numbing the irritated pain receptors.
For the first few days after an acute injury cold therapy such as ice packs can be applied as often as every 2 hours during waking hours. The ideal duration of application varies for every individual due to many factors, including body composition, age, and the area being treated, but one useful guideline for effectiveness and safety is to maintain the contact for up to 5 minutes after the area has become numb. Any longer than this duration introduces the possibility of further injury due to frostbite – this is one scenario where you can definitely have too much of a good thing.
It is also important to note that in the first 3 days after an acute injury it is advisable to avoid anti-inflammatory medications as they tend to inhibit blood clotting, which can increase bruising and swelling in the area and potentially hinder the recovery. If cold therapy is not providing sufficient pain relief it is advisable during this period to simply use an analgesic such as paracetamol.
Cold Therapy for Chronic Injuries
One type of chronic injury that often benefits from cold therapy, and that physiotherapists frequently encounter, is tendinopathy. This type of injury used to be called tendonitis but since recent research has concluded that there is rarely any inflammation associated with tendon injuries they are now called tendinopathies.
A common feature of tendinopathies is persistent pain which obviously impacts on your tolerance of activity but can also potentially reduce your willingness to persist with treatment and rehabilitation.
Cold therapy can therefore be beneficial for tendinopathies, and other injuries or conditions causing persistent pain, by providing localised pain relief so that effective treatment and rehabilitation can proceed and it may also help to reduce the development of central sensitisation that can occur as a result of chronic pain.
Most people innately use heat therapy – a bath, a shower, a spa – for relaxation and it is true that heat will generally relax your muscles and provide some relief from aches and pains due to posture, activity or stress.
The benefits of heat therapy are due to stimulatory effects – increased blood flow, increased lymphatic flow, increased cellular activity, and increased muscular elasticity. The body is constantly repairing and replacing our cells, and heat therapy simply increases the rate at which your body can repair and heal itself.
As outlined above the First Aid guidelines initially recommend cold therapy after an acute injury but after that period it is reasonable to start using heat therapy provided this does not result in a recurrence of swelling.
Many chronic issues such as postural tension, arthritis and joint stiffness also tend to respond well to heat therapy and enable people to maintain their participation in rehabilitation programs and to enjoy an active lifestyle.
When to Use Both Cold and Heat Therapy
The concept of repeatedly and rapidly alternating between heat and cold therapies has been embraced in sports medicine as a way of improving the rate of recovery from strenuous training or competition, and the same principles are likely to apply to recovery from any chronic or repetitive overload of the muscular or skeletal systems, such as intense athletic pursuits and manual labour.
The effectiveness of this strategy is presumed to be due to the contrasting stimulation and suppression of metabolic functions in the body and which seems to assist the body to heal itself more rapidly.
It is essential that anyone with impaired circulation or sensation, such as diabetics, remain aware that they may be less tolerant of heat and cold therapies, and they will often need to reduce the duration and frequency of application to avoid a thermal injury such as frostbite or burns.