Following on from my earlier blog on the use of Cold Therapy in the treatment of Acute Injuries, it is important to examine Heat Therapy. It is generally used in the treatment of Chronic Injuries. A chronic injury may be defined as physical injury, illness, or disease that is persistent, long-lasting and can develop slowly. In general, Chronic injuries have a constantly recurring pattern. Many chronic injuries have mild symptoms and low-grade pain, and can slowly worsen over months or even years which is why they are often ignored by the patient until a critical pain threshold is reached. Examples of Chronic injuries are repetitive strain injuries such rotator cuff tendinopathy, tennis elbow (lateral epicondylitis), golfers’ elbow (medial epicondylitis), plantar fasciitis, severs disease, patella tendinopathy and sub-occipital strain.
While the time frame for chronic injuries is subjective, and debatable, in general it is pain that last for longer than 12 weeks and match the pattern previously discussed. Early diagnosis by a qualified medical professional is imperative as best treatment outcomes are achieved by an individual approach to the condition. The longer the tissue is affected by the chronic injury the longer it takes the tissue to recover. The tissue is generally exposed to significate stress over a period that tends to be repetitive in nature, from which the tissue cannot recover before it gets exposed to the significant stress again. Whilst the reasons the tissue doesn’t recover in time can be multifactorial, commonly it is due to a lack of rest between repeated stress, lack of appropriate nutrition and the level of stress is beyond physical limits of tissue. There may even be an underlying disease process.
It is important to note that chronic injuries have acute and chronic aspects resulting in inflammatory flares and chronically hypertonic tissue. A good example of this is tennis elbow (lateral epicondylitis). This involves the chronic overuse of the muscles that extend the wrist and fingers and results in fibrotic changes to the muscles and tendons, especially where they attach at the lateral epicondyle. It is important to know when to use Heat and when to use Cold Therapy in Chronic Injuries, because if you apply heat to an inflammatory process, you will vasodilate blood vessels and contribute much more blood flow and greatly increase the level of inflammation. However, you will not feel this due to the pain numbing effect of Heat to the pain sensors in the area, and once the heat is removed and the pain sensors begin to fire again, the level of pain will increase in the area.
The ECRB muscle and tendon is usually involved in tennis elbow.
Reproduced and modified from The Body Almanac. © American Academy of Orthopaedic Surgeons, 2003.
Heat Therapy in a Nutshell:
- Used in the treatment of Chronic injuries.
- Vasodilates the blood vessels in the area of application, which supplies greater oxygen and nourishment to the affected tissue and improves the fluid dynamics of the area.
- Influences the sensory receptors of the tissue in the area, which competes with the pain receptor pathways to the brain, resulting in less pain (Gate control theory).
- Reduces pain very quickly, much faster than Cold Therapy.
- Decreases stiffness and improves flexibility of affected tissues.
- Stimulates microcirculation to chronically shortened tissue which can improve healing process and flushes waste products from the tissues.