The word myopathy means “disease of muscle.” More specifically, myopathies are diseases that cause problems with the tone and contraction of skeletal muscles (muscles that control voluntary movements.) These problems range from stiffness (called myotonia) to weakness, with different degrees of severity
There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even paralysis.
Causes of muscle disorders include
Injury or overuse, such as sprains or strains, cramps or tendinitis
A genetic disorder, such as muscular dystrophy
Inflammation, such as myositis
Diseases of nerves that affect muscles
Sometimes the cause of muscle disorders is unknown.