Disruptive influences of a cued voluntary shift on coordinated movement in Parkinson’s disease

A temporary and/or involuntary stoppage of movement is identifiable in the execution phase of writing, walking, and turning movements in individuals with Parkinson's disease (PD) and may be referred to as freezing. However, the unpredictability of such akinetic impairments has made it difficult to study experimentally. The present study compared PD and age-matched control groups in their ability to coordinate continuous and simultaneous upper …