#Contusion of Muscle.#—­Contusion of muscle, which consists in bruising of its fibres and blood vessels, may be due to violence acting from without, as in a blow, a kick, or a fall; or from within, as by the displacement of bone in a fracture or dislocation.

The symptoms are those common to all contusions, and the patient complains of severe pain on attempting to use the muscle, and maintains an attitude which relaxes it.  If the sheath of the muscle also is torn, there is subcutaneous ecchymosis, and the accumulation of blood may result in the formation of a haematoma.

Restoration of function is usually complete; but when the nerve supplying the muscle is bruised at the same time, as may occur in the deltoid, wasting and loss of function may be persistent.  In exceptional cases the process of repair may be attended with the formation of bone in the substance of the muscle, and this may likewise impair its function.

A contused muscle should be placed at rest and supported by cotton wool and a bandage; after an interval, massage and appropriate exercises are employed.

#Sprain and Partial Rupture of Muscle.#—­This lesion consists in overstretching and partial rupture of the fibres of a muscle or its aponeurosis.  It is of common occurrence in athletes and in those who follow laborious occupations.  It may follow upon a single or repeated effort—­especially in those who are out of training.  Familiar examples of muscular sprain are the “labourer’s” or “golfer’s back,” affecting the latissimus dorsi or the sacrospinalis (erector spinae); the “tennis-player’s elbow,” and the “sculler’s sprain,” affecting the muscles and ligaments about the elbow; the “angler’s elbow,” affecting the common origin of the extensors and supinators; the “sprinter’s sprain,” affecting the flexors of the hip; and the “jumper’s and dancer’s sprain,” affecting the muscles of the calf.  The patient complains of pain, often sudden in onset, of tenderness on pressure, and of inability to carry out the particular movement by which the sprain was produced.  The disability varies in different cases, and it may incapacitate the patient from following his occupation or sport for weeks or, if imperfectly treated, even for months.

The treatment consists in resting the muscle from the particular effort concerned in the production of the sprain, in gently exercising it in other directions, in the use of massage, and the induction of hyperaemia by means of heat.  In neglected cases, that is, where the muscle has not been exercised, the patient shrinks from using it and the disablement threatens to be permanent; it is sometimes said that adhesions have formed and that these interfere with the recovery of function.  The condition may be overcome by graduated movements or by a sudden forcible movement under an anaesthetic.  These cases afford a fruitful field for the bone-setter.