The best rule which applies with all injuries, but particularly an acute injury is, when in doubt use ice.
On a sprain, strain or contusion (bruise), icing should be performed for 15-20min every hour.
The time varies according to the depth and the severity of the injury, but generally you should continue icing until all the swelling has resolved and you are feeling much better. Not for only the first 72 hours.
NEVER use heat in the acute phase of injury (which is approx the first 72 hours from the time of the injury) as it will exacerbate inflammation and possibly increase bleeding into the area.
In the sub-acute situation (4 days – 7 weeks after injury) it is best to follow the advice of your physiotherapist, again when in doubt use ice, ice will be helpful at this stage of the injury to help reduce inflammation and particularly reduce muscle spasm. In the sub-acute phase ice can also be combined with exercise for example: lying on your back with the ice under the lower back while performing some gentle abdominal or lumber mobility exercises. Ice can also be combined with a stretch. For example; calf or hamstring so that the ice and stretch are done con-currently (together).
Heat may be used in this situation particularly in the clinical setting by a physiotherapist prior to mobilizing a stiff joint or before massaging tight muscles; this is when heat is being used for relaxation.
In the sub-acute phase, ice is not needed as frequently as in the acute phase but may still be done 2-3 times per day, especially at the end of the day or after exercise or activity.
It is in this stage of the injury (when the injury has prolonged over the amount of time it should of healed) where client preference and therapist preference creates more of an option to use heat or ice, although heat and ice are opposite modalities they have some functions in common such as pain relief, relaxation and increase blood flow. Some people find much better pain relief and relaxation with heat than ice and in the chronic situation it is normally fine to use heat, such as a microwave heat bag, hot shower etc. In some chronic conditions it is helpful to heat prior to exercise or stretching and to use ice post exercise. This is utilizing the benefits of both heat and ice.
• Both ice and heat can burn, always cover ice or heat pack adequately.
• If in doubt consult your therapist
REMEMBER IF IN DOUBT USE ICE!