Is Freezing of Gait in Parkinson's Disease a Result of Multiple Gait Impairments? Implications for Treatment

Figure 1

Freezing of gait and gait features deterioration. (a) Quality of performance of gait features associated with FOG (thin lines in top 5 traces) may vary over time (hypothetical data). Similarly the level of interaction between these gait features may vary with time and in response to different circumstances or provocations (see text). BCG—Bilateral coordination of gait. (b) The combination of the performances of the individual gait features dictates whether FOG will occur or whether functional walking will be maintained. If the overall performance deteriorates below a certain threshold (horizontal line), then gait freezes (FOG zone). Deterioration in the overall gait performance can be an expression of malfunction of single gait feature associated with FOG (see text). In some cases, the deterioration of one gait feature can cause the deterioration of one or more gait features as portrayed in (a). FOG—Freezing of gait, a.u.—arbitrary units