Patients in whom tests of neuromuscular transmission and acetylcholine receptors antibody measurements, single-fiber electromyography is used to detect myasthenia gravis. The jitter value is increased in all patients of myasthenia gravis. The muscle that is most commonly abnormal in myasthenia gravis is extensor digitorum communis although more muscles may be involved. Another group of muscles that are examined in diagnosis of myasthenia gravis is orbicularis ocular muscles. Increasing the temperature can increase the value of jitter further in patients of myasthenia gravis. Other tests should be performed to exclude other myopathies or neuromuscular disorders as jitter is increased in these disorders as well.