This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
Dull pain in the affected part, resembling that from a bruise; pain increased by motion, often of a cramp-like character, and sometimes excruciating; tenderness on slight pressure; pain relieved by firm pressure.
It is probable that this disease is often neuralgic in character, though it is likely that in many cases it is a manifestation in the muscles of the same disease which more often shows itself in the joints. It may affect any part of the muscular system, as the muscle of the scalp, muscles of the face and jaw, muscles of the eye and all other external, as well as internal, muscles. What is termed pleurisy of the diaphragm is probably in the majority of cases really rheumatism or neuralgia of that muscle. The most common forms of muscular rheumatism are pleurodynia, in which the disease affects the muscles of the chest, and lumbago, in which it is confined to the muscles of the back. Pleurodynia is often mistaken for pleurisy and intercostal neuralgia, as it occasions pain upon drawing a long breath as well as from coughing or sneezing. Persons suffering with it often imagine themselves to have some serious lung disease. When it affects the back, producing "crick in the back," the patient can neither bend over nor straighten up, but is obliged to hold the trunk in a stooping position.
The causes of muscular rheumatism are the same as those of other forms of rheumatism. Patients suffering with it generally have dark colored urine which contains large quantities of urates, or uric acid, indicating an inactive condition of the liver. It most frequently occurs in persons who make free use of meat, condiments, salt, and alcoholic drinks. It is, perhaps, frequently excited by taking cold through exposure to drafts.
The pains of muscular rheumatism are undoubtedly simulated, in many cases, by infection of the muscles with trichinae. As the capsules in which the parasites are inclosed become chalky from age, they are sources of irritation, as foreign bodies.