ミオトニーMeanings1nounmyotoniamedicineMedical term for delayed muscle relaxation after contraction; see also 筋緊張 (muscle tone).See also: 筋緊張ミオトニーは、筋きん強きょう直ちょく性せいジストロフィーの症しょう状じょうの一ひとつです。Myotonia is one of the symptoms of myotonic dystrophy.