Heat therapy
Encyclopedia
Heat therapy, also called thermotherapy, is the application of heat to the body for pain relief and health. It can take the form of a hot cloth, hot water, ultrasound
, heating pad
, hydrocollator
packs, whirlpool baths, cordless FIR heat therapy wrap, and many others. It can be beneficial to those with arthritis
and stiff muscle
s and injuries to the deep tissue of the skin. Heat may be an effective self-care treatment for conditions like rheumatoid arthritis
.
Heat therapy is most commonly used for rehabilitation purposes. The therapeutic effects of heat include increasing the extensibility of collagen tissues; decreasing joint stiffness; reducing pain; relieving muscle spasms; reducing inflammation, edema
, and aids in the post acute phase of healing; and increasing blood flow. The increased blood flow to the affected area provides proteins, nutrients, and oxygen for better healing.
Moist heat is more effective at warming tissues than dry heat because water transfers heat more quickly than air. This results in the perception that the tissue is heated more deeply, which increases the effect on muscles, joints, and soft tissue. Heat is typically applied by placing very warm, wet towels on the relevant body part.
The newest breed of heat therapy device combines a carbon fiber heater with a cordless rechargeable Lithium battery and is built into the specific body wrap (i.e. shoulder wrap or back wrap) for targeted heat therapy, and can be used as an alternative to chemical or plugged-in heating pads that are also used for menstrual cramping relief.
Infrared radiation
Infrared radiation is a convenient system to heat parts of our body. It has the advantage over direct contact in that radiation can heat directly the area where the blood capillaries and neuron terminals are. When heat comes from a direct contact source it has to heat the external layer of the skin, and heat is transferred to the deeper layer by conduction. Since heat conduction needs a temperature gradient to proceed, and there is a maximum temperature that can be safely used (around 42°C), this means lower temperature where warming is needed.
Infrared
(IR for short) is the part of the electromagnetic radiation
spectrum comprised between 0,78 μm and 1 mm wavelength
. It is usually divided into three sections:
IR-A, from 0,78 to 1,4 μm.
IR-B, from 1,4 to 3 μm.
IR-C, from 3 μm to 1 mm.
IR radiation is more useful than the visible radiation for heating our body because we absorb most of it, compared to a strong reflection of visible light. Penetration depth of infrared radiation in our skin is dependent of wavelength. IR-A is the most penetrating, and reaches some millimeters, IR-B penetrates into the dermis (about 1 mm), and IR-C is mostly absorbed in the external layer of the epidermis(estratum corneum). For this reason the lamps
used for therapeutic purposes produce mainly IR-A radiation.
that increases the supply of oxygen, and nutrients and the elimination of carbon dioxide and metabolic waste.
Heat therapy is useful for muscle spasms, myalgia
, fibromyalgia
, contracture
, bursitis
.
Because heat is a vasodilator, it should be avoided in tissues with inadequate vascular
supply, in case of acute injury, in bleeding disorders (because heat would increase bleeding), in tissues with a severe lack of sensitivity
, in scars.
Another use is the treatment of infection and cancers by the use of heat. Cancer cells and many bacteria have poor mechanisms for adapting to and resisting the physiological stresses of heat, and are more vulnerable to heat-induced death than normal cells.
s and migraine
s. Many people who suffer from chronic headaches also suffer from tight muscles in their neck and upper back. The application of constant heat to the back/upper back area can help to release the tension associated with headache pain. In order to achieve heat therapy for headaches, many use microwaveable pads which can often overheat, potentially leading to injury, and lose their heat after a few minutes. Some new products use heated water, running through pads, to maintain a constant temperature, allowing headache sufferers to use hands-free heat therapy in the treatment of their headache pain.
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
, heating pad
Heating pad
A heating pad is a pad used for warming of parts of the body in order to manage pain. Localized application of heat causes the blood vessels in that area to dilate, enhancing perfusion to the targeted tissue...
, hydrocollator
Hydrocollator
A hydrocollator is a liquid heating device primarily used in physical therapy clinics to heat and store hot packs for therapeutic use. Hydrocollators are often made out of stainless steel and some can heat up to such as the E-1 and E-2 series....
packs, whirlpool baths, cordless FIR heat therapy wrap, and many others. It can be beneficial to those with arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
and stiff muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s and injuries to the deep tissue of the skin. Heat may be an effective self-care treatment for conditions like rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
.
Heat therapy is most commonly used for rehabilitation purposes. The therapeutic effects of heat include increasing the extensibility of collagen tissues; decreasing joint stiffness; reducing pain; relieving muscle spasms; reducing inflammation, edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
, and aids in the post acute phase of healing; and increasing blood flow. The increased blood flow to the affected area provides proteins, nutrients, and oxygen for better healing.
Application
Direct contactMoist heat is more effective at warming tissues than dry heat because water transfers heat more quickly than air. This results in the perception that the tissue is heated more deeply, which increases the effect on muscles, joints, and soft tissue. Heat is typically applied by placing very warm, wet towels on the relevant body part.
The newest breed of heat therapy device combines a carbon fiber heater with a cordless rechargeable Lithium battery and is built into the specific body wrap (i.e. shoulder wrap or back wrap) for targeted heat therapy, and can be used as an alternative to chemical or plugged-in heating pads that are also used for menstrual cramping relief.
Infrared radiation
Infrared radiation is a convenient system to heat parts of our body. It has the advantage over direct contact in that radiation can heat directly the area where the blood capillaries and neuron terminals are. When heat comes from a direct contact source it has to heat the external layer of the skin, and heat is transferred to the deeper layer by conduction. Since heat conduction needs a temperature gradient to proceed, and there is a maximum temperature that can be safely used (around 42°C), this means lower temperature where warming is needed.
Infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
(IR for short) is the part of the electromagnetic radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
spectrum comprised between 0,78 μm and 1 mm wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
. It is usually divided into three sections:
IR-A, from 0,78 to 1,4 μm.
IR-B, from 1,4 to 3 μm.
IR-C, from 3 μm to 1 mm.
IR radiation is more useful than the visible radiation for heating our body because we absorb most of it, compared to a strong reflection of visible light. Penetration depth of infrared radiation in our skin is dependent of wavelength. IR-A is the most penetrating, and reaches some millimeters, IR-B penetrates into the dermis (about 1 mm), and IR-C is mostly absorbed in the external layer of the epidermis(estratum corneum). For this reason the lamps
Infrared lamp
Infrared lamps are electrical devices which emit infrared radiation. Infrared lamps have many uses, but are most commonly used in communication and heating. Less common uses include illumination for use with night vision devices.-Heating:...
used for therapeutic purposes produce mainly IR-A radiation.
Mechanism of action, and indications
Heat creates higher tissue temperatures, which produces vasodilationVasodilation
Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
that increases the supply of oxygen, and nutrients and the elimination of carbon dioxide and metabolic waste.
Heat therapy is useful for muscle spasms, myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, fibromyalgia
Fibromyalgia
Fibromyalgia is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion...
, contracture
Contracture
A muscle contracture is a permanent shortening of a muscle or joint.. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy....
, bursitis
Bursitis
Bursitis is the inflammation of one or more bursae of synovial fluid in the body. The bursae rest at the points where internal functionaries, such as muscles and tendons, slide across bone. Healthy bursae create a smooth, almost frictionless functional gliding surface making normal movement painless...
.
Because heat is a vasodilator, it should be avoided in tissues with inadequate vascular
Vascular
Vascular in zoology and medicine means "related to blood vessels", which are part of the circulatory system. An organ or tissue that is vascularized is heavily endowed with blood vessels and thus richly supplied with blood....
supply, in case of acute injury, in bleeding disorders (because heat would increase bleeding), in tissues with a severe lack of sensitivity
Stimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
, in scars.
Another use is the treatment of infection and cancers by the use of heat. Cancer cells and many bacteria have poor mechanisms for adapting to and resisting the physiological stresses of heat, and are more vulnerable to heat-induced death than normal cells.
For headaches
Heat therapy can be used for the treatment of headacheHeadache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
s and migraine
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
s. Many people who suffer from chronic headaches also suffer from tight muscles in their neck and upper back. The application of constant heat to the back/upper back area can help to release the tension associated with headache pain. In order to achieve heat therapy for headaches, many use microwaveable pads which can often overheat, potentially leading to injury, and lose their heat after a few minutes. Some new products use heated water, running through pads, to maintain a constant temperature, allowing headache sufferers to use hands-free heat therapy in the treatment of their headache pain.
In plants
Thermotherapy may also be used in vine propagation to get rid of viroids (particles smaller than viruses) which may affect the new vine.See also
- Infrared radiation, one means for delivering heat
- MoxibustionMoxibustionMoxibustion is a traditional Chinese medicine therapy using moxa, or mugwort herb. It plays an important role in the traditional medical systems of China, Japan, Korea, Vietnam, Tibet, and Mongolia. Suppliers usually age the mugwort and grind it up to a fluff; practitioners burn the fluff or...
- Migraine#Cryotherapy and Thermotherapy