Cryotheraphy being the first line of defence against pain and bleeding through reducing blood flow does not necessarily facilitate healing but gives a temporary stability. Healing happens through the flow of blood hence thermotherapy is one of the main modalities used in this process. Thermotherapy is the application of heat on a human body to facilitate local circulation on an injured area to align with the rest of the body post acute phase
Thermotherapy facilitates healing in sub acute phase through vasodilations hence increasing blood flow across the affected/injured tissue.
Thermotherapy should not be used until active inflammatory process is over. It basically reverses the process of cryotherapy as it facilitates the healing process. There are a number of contradictions of this modality including but not limited to, application on special population (infants and elderly), application on sensitive tissues etc.
Physical principles of heat
There are a number of principles of heat transfer namely , conduction, convection, radiation and conversion.
Conduction occurs when heat is transferred from a warmer object to a cooler one. Heat should not exceed 116 degrees F. Examples are moist heat packs, paraffin baths, and electric heating pads.
This is a process whereby heat energy is transmitted through empty space. Heat is transferred from one object through space to another object for example infrared heating and ultraviolet therapies.
Refers to the generation of heat from another energy form such as sound, electricity and chemical agents for example, ultrasound therapy, and chemical agents balms.
Physiological effects of heat
Body”s response to heat depends on the type of heat energy, duration , intensity and tissue types are the effects are :decreased muscle spasm, decreased pain perception, increased blood flow, increased metabolic rate, decreased joint stiffness, increased range of motion, and increased general relaxation.
There are a number of thermotherapy methods namely, moist heat packs, whirlpool bath, contrast bath, ultrasound therapy and heat sprays. In this context we will focus on moist heat packs and contrast bath.
Moist heat packs
These are can be in form of commercial packs.-hydro collator packs or silicate gel in a cotton pad immersed in 170 degrees of hot water. Layers of towels are used between packs and skin to avoid burning, as packs cool remove towels.
Deep tissues are not significantly heated, it is inhibited by subcutaneus fat that acts as an insulator Patients should be in a comfortable position and should not lie on the heat pack because heat cannot be dissipate out.
Heat should be applied for 15 -20 minutes otherwise it will cause harm on tissues especially on special populations.
Contrast bath is a therapeutic method which uses heat and cold as a way of stabilizing the injured area to meet local circulation. There is a possibility that the heat pack might be having temperatures slightly higher than the injured area hence contrast comes in as a reliable solution.
One unit holding hot water at 105-110 degrees F, another unit holding cold water 50-65 degrees F. The goal of alternating hot and cold is to increase local circulation to the treated limb. The limb is first placed in warm water for 5minutes, then is alternated to the cold water for 1minute. Hot to cold is 1 cycle, after first cycle use 4 minutes in hot and 1 minute in cold. Repeat 4/1 cycle for up to ,30minutes