TURN-IT FOG: Improving Turning and Freezing of Gait in People With PD

Inclusion Criteria: * diagnosis of idiopathic PD from movement disorders neurologist with the United Kingdom Brain Bank criteria of bradykinesia with one or more of the following - rest tremor, rigidity, and balance problems not from visual, vestibular, cerebellar or proprioceptive conditions * reporting FOG in the New Freezing of Gait questionnaire (N-FOGQ) * Hoehn \& Yahr stages II-IV * ages 50-80 years old * cognitive ability sufficient to participate in testing procedures and exercise classes * be willing and able to participate in exercise intervention 3x/week for 6 weeks Exclusion Criteria: * Major musculoskeletal or neurological disorders, structural brain disease, epilepsy, acute illness or health history, other than PD, significantly affecting gait and turning (i.e., musculoskeletal disorder, vestibular problem, head injury, stroke, cardiac disease) * medical condition or medications that precludes moderate-intensity exercise * Montreal Cognitive Assessment (MoCA) ≤21 or inability to follow directions * excessive use of alcohol or recreational drugs * recent change in medication * inability to stand and walk for 2 minutes without an assistive device