The primary function of heat in an injury setting is to cause an increase in blood flow and relax tight musculature.
We discussed how ice is used in an acute setting (1st 48 hrs after an injury) -thus reducing the inflammatory response, avoiding a backup of red blood cells.
Heat will then be used in the phases to follow: a sub-acute and chronic phase once the acute phase has passed (after 48hrs) to encourage blood to the area to deliver O2 and nutrients and therefore promote healing.
Heat will also relax the muscles which will further take pressure or tension off the injured area, thus allowing for a faster recovery. We have found that applying heat for no longer than twenty minutes and then allowing twenty to pass before re-applying and repeating 3 to 4 times a day.
Why do we use to heat and cold in combination?
This is when we want to create creates a pumping action to increase the amount of blood that moves through an area or region of the body, for example, chronic tendon injury to the Achilles tendon (tendinosis). A tendon has an extremely poor natural blood supply, therefore we need to encourage the blood flow to the injured tendon to encourage healing. Thus, we use the combination of both to be more aggressive in this situation.
Another great use for heat is keeping warm in winter and remembering movement is LIFE.
Tarnia and Joshua