This study is meant to see if there is improvement in gait or freezing of gait are seen after changes in the stimulation parameters. Subjects will be randomly assigned to four different stimulation parameters: both stimulators on (BL ON), both stimulators off (BL OFF), right stimulator on (R ON), left stimulator on (L ON). The investigators will assess your gait using a clinical scales as well as wearable sensors attached to your body. Assessments will be done one hour after each change in the stimulation parameters.