Intended for healthcare professionals

Rapid response to:


Randomised controlled trial of physiotherapy compared with advice for low back pain

BMJ 2004; 329 doi: (Published 23 September 2004) Cite this as: BMJ 2004;329:708

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Magnesium deficiency as a cause of back pain

EDITOR- One of the main causes of chronic idiopathic back pain
appears to be magnesium deficiency which would not necessarily respond
quickly to either general advice or physiotherapy. Deficiency of this
essential bulk mineral can be related to impaired muscle function by the
use of a myothermogram. This test, first described by Dr John McLaren
Howard in 1989, uses sensitive temperature recording equipment in a
clinical test of muscle action.1

Dr Howard wrote that in the subcellular events responsible for muscle
contraction the biochemical energy utilized must equal the energy output
of the system and this is essentially the external work done plus the heat
energy produced. The external work can be limited so that a plot of the
heat produced during contraction and relaxation should reflect the
subcellular chemistry. The limiting factors are the difficulty of
detecting very small temperature changes and the efficient way in which
muscle heat is conducted away by the circulation.

The myothermogram demonstrates abnormalities of potential diagnostic
significance in deficiencies of magnesium, calcium, iron (in
children),manganese and folate. The test also detects reduced oxygenation
perfusion and abnormal results are seen in thyroid disorders. It shows
that muscle damage can result from exercise during magnesium
deficiency,which can also be diagnosed by analyses of magnesium levels in
sweat and
red blood cells. It is easy to imagine how mechanical back problems can
occur when muscle are contracting irregularly, as demonstrated by
irregular patterns on a myothermogram.

In some patients magnesium may be difficult to replete, especially if
the patient has absorption problems, hypochlorhydria or selenium
deficiency. However, verified successful repletion of magnesium is usually
accompanied by resolution of idiopathic back pain in my experience and
that of others.2

1.Howard J. Muscle Action, Trace Elements and Related Nutrients: The
Myothermogram. In: Chazot G, Abdulla M, Arnaud P, eds. Current Trends in
Trace Element Research: Proceedings of International Symposium on Trace
Elements. Paris, 1987, Smith-Gordon, London, 1989, pp79-85

2. Vormann J, Worlitschek M, Goedecke T, SilverB. Supplementation
with alkaline minerals reduces symptoms in patients with chronic low back
J Trace Elem Med Biol. 2001;15(2-3):179-83.

Competing interests:
None declared

Competing interests: No competing interests

28 September 2004
Ellen C G Grant
physician and medical gynaecologist
20 Coombe Ridings, Kingston-upon-Thames, KT2 7JU, UK