Cold Compression is a combination of cryotherapy and static compression, commonly used for the treatment of pain and inflammation after acute injury or surgical procedures.
Cryotherapy, the use of ice or cold in a therapeutic setting, has become one of the most common treatments in orthopedic medicine. The primary reason for using cryotherapy in acute injury management is to lower the temperature of the injured tissue, which reduces the tissue’s metabolic rate and helps the tissue to survive the period following the injury. It is well documented that metabolic rate decreases by application of cryotherapy.
Static Compression is often used in conjunction with cryotherapy for the care of acute injuries. To date, the primary reason for using compression is to increase external pressure on the tissue to prevent edema formation (swelling). This occurs by hindering fluid loss from the vessels in the injured area, making it more difficult for fluids to accumulate. Ice with compression is significantly colder than ice alone due to improved skin contact and increased tissue density caused by extended static compression. Tissue reaches its lowest temperature faster and the tissue maintains its cool even after treatment ends.
Cold Compression Devices
Continuous Cold Therapy Devices (also called ice machines) which circulate ice water through a pad are currently the subject of class action lawsuits for skin and tissue damage caused by excessive cooling/icing time and lack of temperature control. Reported injuries range from frostbite to severe tissue damage resulting in amputation. Device Brand Names include: DonJoy Iceman, BREG Polar Care, CP2 Cold Compression and EBice cold therapy systems.
Studies have shown that the body activates the hunting response after only 10 minutes of cryotherapy, at temperatures less than 49F (9.5C). The hunting response is a cycle of vasoconstriction (decreased blood flow), then vasodilation (increased blood flow) that increases the delivery of oxygen and nutrient rich blood to the tissue. Increased blood flow can slow cell death, limit tissue damage and aid in the removal of cellular debris and waste products. Under normal circumstances the hunting response would be essential to tissue health but only serves to increase pain, inflammation and cell death as excess blood is forced into the area.
Cold Compression Wraps
Cold compression wraps using either re-freezable ice or gel are a much safer product, as such products do not exceed the cooling/icing time recommended by the established medical community. Many of the ice wraps available use adjustable elastic straps to aid in compression over the injured areas. More advanced single-use wraps have guidelines to indicate how the bandage should be applied in order to achieve optimum compression required for an acute injury. Most ice wraps that use ice, have a built-in protective layer, so ice is not applied directly to the skin, which can result in a burn to the area sometimes known as a “cryoburn”. Popular brands of ice wraps include: HyperIce Compression Wraps, BodyMed Cold Compression wraps, Torex roll on compression sleeves, Procep Hot & Cold Compression Wraps, Hyperice, NMS Cold Pack, CP2 Professional Inflatable Compression Cold Pack, Recoverice, Cold One, Cool Relief, Pro Ice, Trainers Pick, Icy Cools, Neo-ice (新冰) etc.
Heat therapy, also called thermotherapy, is the use of heat in therapy, such as for pain relief and health. It can take the form of a hot cloth, hot water bottle, ultrasound, heating pad, hydrocollator packs, whirlpool baths, cordless FIR heat therapy wraps, and others. It can be beneficial to those with arthritis and stiff muscles 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 therapy has been believed to be more effective at warming tissues than dry heat, because water transfers heat more quickly than air. Clinical studies do not support the popular belief that moist heat is more effective than dry heat. Moist heat results in the perception that the tissue is heated more deeply. In fact, recent studies indicate that vasodilation, the expansion of the blood capillaries (vessels) to allow more blood flow, is improved with dry heat therapy. Expansion of the blood capillaries is the primary objective of heat therapy. Heat therapy increases the effect on muscles, joints, and soft tissue. Heat is typically applied by placing a warming device on the relevant body part.
Newer breeds of heat therapy devices combine a carbon fiber heater with a cordless rechargeable lithium battery and are built into the specific body wrap (i.e., shoulder wrap or back wrap) for targeted heat therapy. Such devices can be used as alternatives to chemical or plugged-in heating pads, but have not been shown to improve the clinical benefit. All devices primarily provide heat to promote vasodilation.
- 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.
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 infrared lamps used for therapeutic purposes produce mainly IR-A radiation.
Mechanism of action, and indications
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.
The use of Heat Therapy for deep-seated tissue can be treated with shortwave, microwave, and ultrasonic waves. This produces a high temperature that penetrates deeper. Shortwave produces a 27MHz current, microwaves use 915 and 2456 MHz, and ultrasound is an acoustic vibration of 1MHz. The way ultrasonic waves work is they selectively superimpose the incoming wave and increase the energy for absorption, and the significant part of the longitudinal compression gets converted into shear waves. When they are rapidly absorbed, the interface between soft tissue and bone is selectively heated. 
Heat therapy can be used for the treatment of headaches and migraines. 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.
Thermotherapy increase the extensibility of collagen tissues. Using heat, it can relieve the stiffness in joints in different cases. Shortwave and Microwave heat application may reduce muscle spasms, and selective heating with microwaves can accelerate absorption of hematomas. This will, in turn, allow the stiff muscle to stretch. Ultrasounds are not absorbed significantly in homogenous muscle. Heat therapy using hyperthermia has been used to treat cancer in combination with ionizing radiation. 
Contrast bath therapy
Contrast bath therapy, also known as “hot/cold immersion therapy“, is a form of treatment where a limb or the entire body is immersed in warm water followed by the immediate immersion of the limb or body in ice water. This procedure is repeated several times, alternating hot and cold. Note that the treatment should always end in the ice water, as heat will induces the body’s inflammatory response, while cold helps to decrease inflammation.
The theory behind contrast bath therapy is that the warm water causes vasodilation of the blood flow in the limb or body followed by the cold water which causes vasoconstriction, increasing local blood circulation. Additionally, the lymph vessels contract when exposed to cold, and relax in response to heat. The lymph system, unlike the circulatory system, lacks a central pump. Alternating hot and cold, lymph vessels dilate and contract to essentially “pump” and move stagnant fluid out of the area. This positively affects the inflammation process, which is the body’s primary mechanism for healing damaged tissue. One study showed that fluctuations in intramuscular temperature were lower than those caused by a hot bath alone.
Contrast bathing can be used to reduce swelling around injuries or to aid recovery from exercise. It can also significantly improve muscle recovery following exercise by reducing the levels of blood lactate concentration. For any injury presenting with palpable swelling and heat, and visible redness – such as a strain/sprain – contrast baths are contraindicated during the acute inflammation stage. Acute inflammation begins at the time of injury and lasts for approximately 72 hours.
Effectiveness in athletic recovery
The current evidence base suggests that contrast water therapy (CWT) is superior to using passive recovery or rest after exercise; the magnitudes of these effects may be most relevant to an elite sporting population. There seems to be little difference in recovery outcome between CWT and other popular recovery interventions such as cold water immersion and active recovery.
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