The purpose of this study is to determine whether a laser light beam, attached to a rolling walker and projected onto the floor, reduces freezing episodes in patients with Parkinson's disease.

Freezing of gait is a debilitating feature of Parkinson's disease. This study aims to determine whether a laser light beam, attached to a rolling walker and projected onto the floor, reduces freezing episodes. Patients will perform two trials of 3 timed walking tasks: once with the laser beam and once without. For each trial, the time to complete, number of steps, and number of freezing episodes will be recorded. Patients will be randomized to perform the first trial either with the light or without the light, to control for fatigue.

Inclusion Criteria:

• idiopathic PD confirmed by a movement disorders neurologist
• a Mini-Mental Status Examination (MMSE)[13] score ≥ 24 to ensure competence to participate in informed consent and an ability to learn procedurally the use of the rolling walker with laser beam
• functional visual acuity for recognizing the laser beam on the rolling walker
• FOG in both on and off medication states, as indicated by a score of ≥ 2 on Item 14 of the Unified Parkinson's Disease Rating Scale (UPDRS) and/or ≥1 on Item 3 of the Freezing of Gait Questionnaire (FOGQ)
• ability to ambulate for at least household distances with or without an assistive device as indicated by scoring 0, 1, or 2 on Items 15 and 29 of the UPDRS.

Exclusion Criteria:

• diagnosis of a gait disorder other than Parkinson's disease