Freezing of gait (FOG) is a halting of step-to-step production despite voluntary intention to walk, and is arguably the most debilitating motor symptom of Parkinson’s disease (PD), resulting in falls, injury, and potentially hospitalization. The cause of FOG is unclear, however, previous work has demonstrated that when individuals who experience FOG perform a secondary task while walking (dual tasking), episodes of FOG are provoked. These findings motivated investigations into training individuals who experience FOG to walk while completing a secondary attention task to improve dual tasking ability, thereby decreasing the severity of FOG, risk of injury and improving quality of life. To maximize both ecological validity and safety of patients, Killane and colleagues (2015) trained individuals who experience FOG to navigate through a virtual reality maze by “stepping-in-place” (since virtual reality was presented on a stationary monitor) on a balance board while completing a secondary attention task. While this experiment provided physical and cognitive training, “stepping-in-place” does not ecological replicate normal walking, and therefore, sub-optimal for assessing FOG in PD. To improve upon this protocol, a platform that allows stationary walking that is biomechanically similar to over ground walking (such as the Virtuix Omni™) would be ideal. Therefore, the purpose of the proposed study is to investigate whether walking in virtual reality on a Virtuix Omni™ platform may be an effective method to elicit and measure FOG so that future dual task training interventions may use this technique as a clinical tool for assessment and rehabilitation of FOG.
