Orthopedics - Oleksa A.P. 2006

Occupational musculoskeletal disorders
Occupational myositis

Muscle diseases are a fairly common group of occupational pathologies. Two clinical syndromes are distinguished: myalgia and myositis. The forearm Muscles, particularly the posterior group, are most frequently affected, while the shoulder and shoulder girdle muscles are involved less often. Ballet and circus artists may experience pathological Changes in the Muscles of the lower legs and thighs.

Myalgia is characterized by a dull, aching, or nagging pain during work, a feeling of awkwardness, heaviness, and a decrease in work pace. The pain increases with muscle tension and Palpation.

Myositis (myofascitis) involves increased pain and paresthesias that trouble the patient at rest (especially at night). There are sensations of heaviness, tightness in the arms, and fatigue. The pain is typically dull and localized in the specific muscle group that bore the heaviest occupational load.

The extensor-supinator muscle group of the forearm is most commonly affected. Sometimes the trapezius and deltoid muscles are involved. The pain can be constant. Upon palpation, the muscles feel indurated, with nodules ranging from 3-4 mm to 2-3 cm in diameter. As the condition progresses, the muscles lose elasticity and become atrophic (myosclerosis).

An important diagnostic criterion is decreased endurance against static loads in the hand muscles. Deep palpation reveals a uniform thickening of the entire muscle. Occasionally, isolated, variously shaped thickenings ranging from the size of a pea to a walnut—known as myogenoses—can be felt within the Muscle tissue.

Due to the loosening of the intermuscular tissue in the forearm, rounded, granular-lobular formations known cellulites appear, arranged in separate chain-like groups. They are most frequently detected along the crest of the radius and may be tender upon palpation.

As the disease progresses, fibromyofascitis develops, characterized by a more pronounced pain syndrome and a sharper decrease in muscle strength.

Thus, the following Stages of the pathological process can be identified: myalgia — myositis — fibromyofascitis.

Treatment consists of physiotherapy Procedures (paraffin and ozokerite Applications, UHF therapy, Electrophoresis, ultrasound, diathermy), medications (intramuscular administration of a 2 % novocaine solution, 5 ml every other day for ten days; Vitamin B1, 30 mg daily for 15 days), and therapeutic exercise (physiotherapy).