Functional dystonias

Abstract

Dystonia is a movement disorder characterized by involuntary muscle contractions resulting in twisting movements and abnormal postures. This movement disorder can cause significant impairments during functional tasks including gait, mobility, and reaching. Dystonia must be distinguished from other hypertonic movement disorders, spasticity, and rigidity, to guide treatment and management options. Several clinical measurement scales have been developed to identify dystonia and rate its severity; these can be easily adapted for use in motion analysis labs. Additionally, the use of motion analysis kinetics, kinematics, and surface EMG has increased in use for monitoring dystonia. This chapter will discuss the common etiologies of dystonia, clinical scales used for diagnosis and efficacy of treatments, and the role of instrumented gait analysis, kinetics, and kinematics in the evaluation of dystonia.