The use of a cognitively demanding dual task while evaluating simultaneous movement performance has become an increasingly popular research tool. Clinically, dual tasking can provide an important glimpse into mechanisms that may underlie and even exacerbate movement impairments in Parkinson’s disease (PD) and other movement disorder populations.

One particularly interesting area addressed by dual tasking research is the potential influence of attention demand on aspects of gait and dynamic balance. Plotnik and colleagues1 attempt to determine whether temporal characteristics of gait are impacted by cognitive demand (see page 347). Much of their research suggests that coordination deficits observed during gait in PD may be identified by evaluating gait rhythmicity asymmetries. Most recently, they have employed a timing based gait cycle measure (PCI) to …