As Osteopath, we are frequently asked about the application of heat or ice to treat an injury. Heat (thermotherapy) and ice (cyrotherapy) are very popular, convenient and inexpensive ways to help treat pain and injuries. However, there is some controversy on which is more suitable to particular injuries how to optimize the benefits of each. Here is a quick overview on how you can get the most out of using heat and ice, for not only treating injuries, but also enhancing recovery and performance.
Ice is considered to be an analgesic (acting to relieve pain), which makes it useful in reducing local pain. It is also a vasoconstrictor, and this means it constricts the blood vessels at the site of
application. This can have both a positive and negative effect on the injured site. While reducing the blood flow to the area can reduce pain and swelling, it also decreases the amount of inflammatory mediators and cells that play an important role in the inflammatory response and tissue healing. Which asks the question, when should ice be applied? While there is still a lot of conflicting research on the best application for ice, current studies suggest that acute injuries (such as sprained ankle or torn muscle) have shown to respond best when using ice.
When applied, research has shown that ice can affect this tissues approx 2-4cm beneath the surface of the skin and a neurological and vascular effect at the spinal cord. This is done by reducing the pain signals that are sent to the brain, reducing the brain and the body’s perception of the pain, resulting in decreased pain.
A delay in applying ice to acute injuries has been demonstrated in the research to prolong the recovery. The research also suggests an increased therapeutic benefit when applied intermittently, opposed to having the ice on for long periods of time.
Precautions should be taken for anyone suffering from circulatory insufficiency and advanced
Heat therapy has been more closely associated with chronic pain (pain which is persistent or ongoing), and recurrent injuries.
The use of heat on tight muscles allows blood vessels to vasodilate (become wider) allowing increased blood to the area. Increasing the temperature of a chronically injured/tight muscle can
reduce cramping, spasms and tightness felt in the area. The dilation of the arteries and other blood vessels also allows for increased oxygen and nutrients delivered to the area, with the removal of muscle waste by-products, which can be toxic for a muscle and delay tissue healing. Increasing the temperature of a muscle by 1 degree, is associated with a 10-15% increase is local tissue metabolism. This increase in metabolism facilitates the healing process at a cellular level within the muscle.
Research has been done on the application of heat on the knees of asymptomatic (pain free) patients to measure the changes in blood flow. After 35 minutes of treatment there was a 29%
increase in blood flow when using heat at 38 degrees, a 94% increase with 40 degrees and 200% increase in 43 degrees.
Precautions should be taken for those suffering from diabetes, multiple sclerosis, peripheral vascular disease, spinal cord injuries and rheumatoid arthritis. There should also be come caution taken for pregnant women, growth plates, joint prosthesis and total hip replacements.
Thermotherapy and Cyrotherapy modalities have long been used to complement manual therapy in the treatment of acute and chronic injuries. The long term use of both heat and ice have been proven in research to have a more superior benefit, opposed to intermittent treatment. Having the knowledge of when heat or ice is more appropriate for your specific injury will enable better management of injuries, and will enhance the effect of manual therapy treatment.