Heat Therapy for Relieving Lower Back Pain

Heat therapy is one of the most ancient and common treatments used for relieving lower back pain. When someone comes to see me with back pain I always ask them if they have tried anything yet for pain relief. The most common answer is back pain medication, but the second most common answer is heat.

Heat comes in all sorts of shapes and sizes ranging from the humble hot water bottle, right through to heated pads and infra red lamps.

How does heat therapy work for back pain relief?

Heat therapy increases the blood supply to an area.

It does this by causing the blood vessels to widen or dilate. You can see this by the pinkness of an area exposed to heat. This may have several effects.

1. Increasing the blood supply may reduce muscle spasm and trigger points. Pain from muscle spasm may be caused by ischaemia or reduction in circulation so increasing the blood supply to the area may immediately help.

2. An increase in circulation may help to sweep away any pain producing chemicals that are there as a result of inflammation.

3. Possibly by reducing swelling in the area.

Heat therapy activates the pain gate.

As with TENS, acupuncture, acupressure and massage, stimulation of a sore area effectively reduces the volume of the pain signals being ‘heard’ by the brain. This is the same mechanism that is in play when we instinctively rub something when we have hurt it i.e. knocking an elbow.

Heat therapy causes the release of endorphins

Endorphins are the bodies own natural pain killers. As we know from stories of people in pain, the body can modulate pain by releasing opiates which diminish the sensation of pain (the brain can also increase pain but that’s another story – if you are interested read more here)

Does it really help lower back pain?

There is not much good evidence to draw on but the last review of heat therapy (1) found some evidence that it  reduces back pain in patients that have had pain for less than three months (acute pain). However, the effect only lasts for a short time. There is nothing to show it works if you have had pain for longer than three months (chronic pain).

Interestingly this review also found that combining heat with exercise is better again.

If you use heat make sure you do not burn. Patients with poor skin sensation or temperature awareness should not use it. Remove the heat if it becomes uncomfortable, do not press down on heat i.e. lie on a heat pad and do not fall asleep while using it. Discuss the use of heat with your health care professional.

References

1. French, S. D., Cameron, M., Walker, B. F., Reggars, J. W., & Esterman, A. J. 2006, "A cochrane review of superficial heat or cold for low back pain", Spine, vol. 31, no. 9, pp. 998-1006.

RESEARCH UPDATE

This systematic review was updated in 2010 and the authors found no further evidence either way so the original conclusions are still valid.

Lower Back Pain Toolkit Home Page

26-Sep-2011