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The Science of Superficial Heat Therapy

The early development of Heat Therapy was almost entirely in the form of hot water and hydrotherapy. The ancient Hindus, Persians, Hebrews and Egyptians all used water in the treatment of various diseases. In Greece and Rome its value reached a much greater recognition whereby Temples were often built at the site of natural hot springs.

In 1876 Winternitz published his studies on the influence of hydrotherapy upon metabolism, the blood, excretions and other functions of the body.  Today, we continue to employ the use of heat as our ancient healers did for the relief of pain and injury. The delivery system for thermal care is now more sophisticated, specific and convenient.

FlexEze Heat Wraps are the latest innovation in Thermotherapy and generate a continuous low level heat as a result of a simple non-toxic chemical reaction that is air-activated. Our Heat Wrap delivers a sustained temperature above 40 degrees for approximately 12-15 hours, which is around 20 times longer than wheat bags or hot water bottles.

This is ideally suited for prolonged application where maximum delivery of heat can be applied whilst movement is maintained throughout the day. The obvious benefit over wheat packs is the convenience and portability with minimal disruption to your daily routine. FlexEze Heat Wraps are long lasting, lightweight and comfortable.

How does Superficial Heat reduce pain?

Thermal signals are transmitted by small myelinated delta fibres with a diameter range of 2 to 5 microns. Upon entering the central nervous system, the thermal fibres travel to the lateral Spinothalamic tract. It is thought that thermal receptors are stimulated by changes in their metabolic rates, these changes resulting from the fact that temperature alters the rates of intracellular chemical reactions approximately 2.3 times for each 10 degrees Celsius change.

Muscle spasm is a frequent cause of pain, the reason for this is probably two-fold.  Firstly, the contracting muscle compresses the intramuscular blood vessels and either reduces or cuts off blood flow. Secondly, muscle contraction increases the rate of metabolism of the muscle. Muscle spasm causes relative ischemia (reduced blood flow) resulting in pain.

It is thought lactic acid build up in tissues, formed during ischemia, coupled with other chemical agents formed in tissue as a result of muscle cell damage stimulate pain nerve endings. The pain of ischemia is relieved by supplying oxygen to the tissues.

The physiological mechanism for the inhibition or modulation of pain is known as the “Gate Control Theory”. This was first postulated by ‘Melzack and Wall’ in 1965. The theory suggests that after the pain fibres enter the spinal cord they terminate in the Substantia Gelatinosa (SG), a cluster of neurons in the dorsal horn, the pain signals are then transmitted through one or additional neurons before travelling upwards to the brain, however there are other inputs to the SG in addition to pain fibres.  One of these are signals from thermo-receptors which terminate in the dorsal horn also and from here second-order neurons send short axons to terminate in the SG. Most of these terminate on the pain fibre axons before they synapse with the neurons of the SG, thus resulting in presynaptic inhibition. Thus signals from thermo-receptors can greatly depress the transmission of pain signals from the pain fibres to the brain.

Recent research has shown that sustained low grade heat is effective for pain relief. The use of FlexEze Heat Wraps delivers a continuous low level heat for prolonged hours, providing non-drug pain relief to back pain. The flexible nature of a FlexEze heat patch allows for easy movement and is discrete and convenient to wear, delivering all day pain relief whilst allowing you to maintain your normal daily routine.

When should Superficial Heat be used?

Heat has been used for thousands of years in the treatment of different types of pain. Injuries caused by trauma or overuse, such as ligament injuries, muscle strains or tears, are often treated during the acute stage by cooling and compression to limit bleeding. After 48 hours, heat treatment may be introduced to help the healing process by increasing blood flow to the injured area.

One of the most important effects of heat therapy is its influence upon collagen fibres which comprise 90% of the human body’s tendon structure. Heat increases elasticity of tendons promoting faster recovery from soft tissue injury.

Heat therapy decreases joint stiffness, muscle tightness and relieves spasm, further reducing the risk of injury. Heat may be used in both the prevention and rehabilitation of overuse injuries and to treat after-effects of injured muscles and tendons. It is invaluable during warmup training sessions and also during cold weather.

Heat therapy provides pain relief from back pain and muscular or joint pain. Heat improves collagen fibre elasticity and is assists both preventing and rehabilitating musculo-skeletal injuries.