Temporal Characteristics of High-Frequency Lower-Limb Oscillation during Freezing of Gait in Parkinson’s Disease

Figure 1

Typical FOG event. (a) Clinicians rating of FOG from video generated a binary trace, with “1” indicating a freeze event. (b) Left shank pitch velocity. (c) Left shank vertical acceleration. (d) Back vertical acceleration. (e) 4 s of shank acceleration, centered on the clinical onset of FOG. (f) Freeze band power of the shank was calculated at each point in time within a 0.64 s window by summation of power in the 3–8 Hz band. (g) 4 s of back acceleration, centered on the clinical onset of FOG. (h) Freeze band power of the back was calculated at each point in time within a 0.64 s window by summation of power in the 3–8 Hz band. In this instance, the onset of freeze band power (>3 SD above baseline) occurred initially in the shank, approximately 300 ms prior to onset at the back.