The cerebellum plays an important role in generating well-coordinated locomotion, voluntary limb movements and eye movements (Morton et al. 2004). It is particularly important for balance and limb coordination needed to generate a stable gait pattern (Morton et al. 2006). Specific roles of the cerebellum for gait include coordinating the two legs to produce a stable rhythmic pattern, dynamic regulation of balance, and adaptation of the pattern through practice (Morton et al. 2004). Though the core deficits of PD patients are largely different than those of cerebellar patients, they do show decreased bilateral coordination (Plotnik et al. 2008) and a fundamental disturbance in stride length regulation (Morris et al. 1998) during walking.