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

Figure 3

Development of high frequency lower limb oscillation prior to and during FOG. (a) Four to six strides prior to freezing, stride (peak swing phase velocity) was consistent and little power was observed in the 3–8 Hz band. (b) In the three strides prior to FOG, peak swing phase velocity (and therefore stride length) successively decreased and high frequency oscillations developed at heel strike, reflected in growing power in the 3–8 Hz band. (c) During FOG, forward progression had ceased and high frequency oscillations dominated the frequency spectrum.