Abnormalities of the First Three Steps of Gait Initiation in Patients with Parkinson's Disease with Freezing of Gait

Figure 2

Averaged COP trajectory and heel contact position between the onset of COP displacement and the 4th toe off. Circles indicate the average of the normalized COPs. Triangles indicate the average of the normalized heel contact positions. Data points indicate the mean, and error bars indicate standard errors of the mean.