Heat treatment relaxes and soothes the muscles, increases circulation, reduces stiffness and relieves pain. The warmth generated dilates the blood vessels of the chronic areas. This increases blood flow and helps to re-oxygenate and relax the muscles and ligaments.

In the treatment of muscle and ligament injuries, heat is normally applied during the repair stage of the injury. Also, when applied to tight muscles, heat helps to relax the muscle which prevents injury.