Balance assessment and rehabilitation from home

Inclusion Criteria: 1. Diagnosis of idiopathic PD from movement disorders neurologist with the United Kingdom Brain Bank criteria of bradykinesia and one or more of the following - rest tremor, rigidity, and balance problems not from visual, vestibular, cerebellar or proprioceptive conditions 2. responsive to levodopa (self-reported) 3. Hoehn \& Yahr stages I-III; 4. ages 55-85 years old 5. ability to follow directions in order to participate in testing procedures and exercise classes 6. free of any medical conditions or medication that contraindicates participation in an exercise program 7. willing and able to participate in rehabilitation intervention approximately 3x/week for 4 weeks while also refraining from making changes to medications (as reasonable) or to other exercise programs during the study period. Exclusion Criteria: 1. Major musculoskeletal or neurological disorders, structural brain disease, epilepsy, acute illness or health history, other than PD, significantly affecting gait and balance (i.e., musculoskeletal disorder, vestibular problem, head injury, stroke, cardiac disease, etc.) 2. medical condition that precludes exercise 3. cognitive inability to participate in an exercise program, such as MoCA score less than or equal to 19, prior diagnosis of dementia or inability to follow directions 4. recurrent fallers, defined as those who fall more than 3 times a week (from patient and caregiver recollection) 5. excessive use of alcohol or recreational drugs 6. recent change in medication 7. inability to stand and walk for ISAW without an assistive device.