The NIH Taskforce on Childhood Motor Disorders has produced three papers defining movement disorder terminology:

• Sanger TD et al. (2003) Classification and Definition of Disorders Causing Hypertonia in Childhood. Pediatrics 111: e89-e97 (open access)
• Sanger TD et al. (2006) Definition and Classification of Negative Motor Signs in Childhood.  Pediatrics 118:2159-67 (open access)
• Sanger TD et al. (2010) Definition and classification of hyperkinetic movements in childhood.  Mov. Disord. 25:1538-49 (access for subscribers)