Myopathy- any of various neuromuscular disorders. Myopathies most often affect muscles connected to bones such as the biceps in the upper arm and the quadriceps in the thigh.
The primary symptom is muscle weakness, which is due to dysfunction of the muscle fiber. Other symptoms of myopathy can include muscle cramps, stiffness, and spasm. Myopathies can be inherited (such as the muscular dystrophies) or acquired (such as common muscle cramps).
For those with a myopathy the prognosis will vary.
Some individuals have a normal life span and little or no disability. For others, however, the disorder may be progressive, severely disabling, life threatening, or fatal.