 Freezing of gait FOG is a common yet poorly understood motor symptom in persons with Parkinsons disease PD. Previous studies have shown that bilateral uncoordinated gait and gait asymmetry are related to FOG, and that intensive treadmill training in PD patients can improve gait. However, no group has yet studied the effect of robot-assisted gait training RAGT on FOG. The primary aim of this study is to collect pilot data on the effect of robot-assisted gait training in reducing episodes of freezing in PD. 