Describe the characteristics of Myotonia Congenita

Muscle stiffness and delayed relaxation (generally painless) upon intitial activity  Unusual exertion asscoiated with muscle hypertrophy (increased muscle mass) Myotonia Congenita can be hereditary in an autosomal dominant (e.g. Thomsen Disease) OR recessive (e.g. Becker Disease). Myotonia Congenita can be caused by poisoning from certain weedkillers.