Heat Therapy - When to use it and how

Heat Therapy is a very useful self help technique for muscular pain.  As muscular pain accounts for a large proportion of chronic pain, including most cases of back and neck pain this makes heat therapy an invaluable technique.  Pain due to muscular spasm and “trigger points” can be intense but still respond well to heat.

When to use heat

Heat is great for relieving stress and muscle pain.  We therefore need to identify when we are experiencing muscle pain and when we are not.  Most muscle pain is caused by trigger points in muscles.  A trigger point is a small localised area of muscle spasm (intense muscle contraction) within a muscle.  It will feel hard, and knot like, be painful to the touch, aggravated by use of the muscle in which it is located.  Pain due to trigger points is usually worse at the end of the day and relieved by rest, movement and stretching.

When not to use heat

Heat should not be used on a recent injury.  In the 24-48 following an injury the body responds by becoming inflamed and swollen.  The correct approach is therefore to apply ice therapy to suppress circulation and reduce unnecessary swelling.  Heat increases circulation and therefore if applied too soon after an injury will exacerbate swelling and slow down the healing process.  A tear of a muscle or soft tissues (ligaments, tendons and joint capsules) will be inflamed and therefore be swollen, red, warm and dysfunctional (useless).  Do not apply heat in this situation.  Pain following trauma can sometimes be due to a more serious injury, e.g. disc injury, spinal joint (facet joint) strain, ligament us sprain, fracture etc.  If in doubt visit your doctor or make an appointment with us to rule out a more serious underlying cause of your pain.  If you have recently been physically injured do not use heat.  Contact adoctor or a osteopath in your area

If you perform a new type of exercise at a moderate to high intensity you will experience pain after about 24-48 hours that can then last for days.  This phenomena is known as DOMS (delayed-onset muscle soreness) and will not be relieved by heat therapy.

How heat therapy works

Trigger points are aggravated by stress.  Assuming you are not overheated in the first place, heat has a comforting and relaxing effect on the whole body.  As we relax, muscle tone decreases and trigger point activity decreases.

Trigger points physiology is not fully understood but the mechanism of pain has been identified.  Within a trigger point circulation stagnates, waste products accumulate and a cocktail of chemicals build up that irritate nerve endings and cause pain.  Heat promotes circulation helping to flush out this irritant cocktail of chemicals and supply fresh nutrients and oxygen into the trigger point.

Heat Therapy Method

Heat can be applied globally or locally.  Global heating, heating the entire body can be achieved using a bath, hot shower or sauna.  Local heating can be applied using a heating pad, heated gel pack or hot water bottle.  Heating pads are probably the best option for local/specific heating.  These pads retain moisture in the air that in turn conducts heat more efficiently than a conventional dry hot gel pack or hot water bottle.