RESUMO
Purpose. Motor freezing, the inability to produce effective movement, is associated with decreasing amplitude, hastening of movement, and poor coordination. We investigated how manipulations of movement amplitude and cadence affect upper extremity (UE) coordination as measured by the phase coordination index (PCI)-only previously measured in gait-and freezing of the upper extremity (FO-UE) in people with Parkinson's disease (PD) who experience freezing of gait (PD + FOG), do not experience FOG (PD-FOG), and healthy controls. Methods. Twenty-seven participants with PD and 18 healthy older adults made alternating bimanual movements between targets under four conditions: Baseline; Fast; Small; SmallFast. Kinematic data were recorded and analyzed for PCI and FO-UE events. PCI and FO-UE were compared across groups and conditions. Correlations between UE PCI, gait PCI, FO-UE, and Freezing of Gait Questionnaire (FOG-Q) were determined. Results. PD + FOG had poorer coordination than healthy old during SmallFast. UE coordination correlated with number of FO-UE episodes in two conditions and FOG-Q score in one. No differences existed between PD-/+FOG in coordination or number of FO-UE episodes. Conclusions. Dyscoordination and FO-UE can be elicited by manipulating cadence and amplitude of an alternating bimanual task. It remains unclear whether FO-UE and FOG share common mechanisms.
RESUMO
BACKGROUND: Gait impairments are well documented in those with PD. Prior studies suggest that gait impairments may be worse and ongoing in those with PD who demonstrate FOG compared to those with PD who do not. PURPOSE: Our aim was to determine the effects of manipulating step length and cadence individually, and together, on gait coordination in those with PD who experience FOG, those with PD who do not experience FOG, healthy older adults, and healthy young adults. METHODS: Eleven participants with PD and FOG, 16 with PD and no FOG, 18 healthy older, and 19 healthy young adults walked across a GAITRite walkway under four conditions: Natural, Fast (+50% of preferred cadence), Small (-50% of preferred step length), and SmallFast (+50% cadence and -50% step length). Coordination (i.e. phase coordination index) was measured for each participant during each condition and analyzed using mixed model repeated measure ANOVAs. RESULTS: FOG was not elicited. Decreasing step length alone or decreasing step length and increasing cadence together affected coordination. Small steps combined with fast cadence resulted in poorer coordination in both groups with PD compared to healthy young adults and in those with PD and FOG compared to healthy older adults. CONCLUSIONS: Coordination deficits can be identified in those with PD by having them walk with small steps combined with fast cadence. Short steps produced at high rate elicit worse coordination than short steps or fast steps alone.
