Pain in a muscle or a group of muscles is known as muscular rheumatism, and wasting of muscular substance is the common effect of paralysis and of diseases attended with great exhaustion. Progressive muscular atrophy is the name given to a complaint characterised by much local wasting of muscular substance, associated with a peculiar condition of the spinal cord.
Hypertrophy of muscles, when confined to those of voluntary motion, can hardly be recognised as a disease, and is more the consequence of continuous exercise, as may be illustrated in the brawny arms of the blacksmiths; on the other hand, hypertrophy or enlargement of the heart, the most important of the involuntary muscles, is a most serious disease.
In muscle spasms and cramps, there is not only loss of voluntary movement and an excess of involuntary and irregular action, but as the sensory nerves remain intact, pain may be excessive to the extent that it has been likened to medieval torture.
Scrivener's palsy is the best known of a number of conditions connected with the over-use of muscles in various occupations.
Reflex spasm may be caused by some form of irritation, such as a bullet, a carious tooth, or enlarged glands. When affecting the facial muscles and causing great pain, it is known as histrionic spasm. Aches, stiffness and rigidity of muscles can occur in anaemia, in the legs when affected by varicose veins, and in some cases of arterial obstruction. If a bather becomes cold and exhausted, the resulting muscle stiffness and weakness may render the victim helpless.
Adapted from Surgery, its Theory and Practice, by William Johnson Walsham, FRCS (Eng) MB and CM (Aberdeen), published in 1887 by J & A Churchill of London.