Movement disorders cause a disruption in the normal flow of movement. Problems with the movement system can generate movements that are too weak, too forceful, or uncoordinated. Involuntary movements might happen at rest, or intentional movements might not happen. Neurological conditions can lead to either slower or absent movements (hypokinetic) or faster or involuntary (hyperkinetic) movements. Members of the Movement Disorder research focus group study how movement is coordinated by interacting brain centers.