Influence of visual cues on gait in Parkinson's disease during treadmill walking at multiple velocities.

OBJECTIVE: To evaluate the interaction of different treadmill-induced gait velocities and visual cues on the gait performance in Parkinson's disease (PD).

BACKGROUND: External cuing has been reported to facilitate hypokinetic gait patterns in PD.

METHODS: 19 PD-patients and 17 controls volunteered for the study. Gait analyses were conducted using dynamic pressure sensors integrated in a treadmill at a given velocity of 1, 2, 3 or 4 km/h. For each velocity, measurements were performed under three conditions. The first condition was without visual cuing, the remaining two consisted of visual cuing e.g. white stripes put on the treadmill belt 25 or 50 cm apart.

RESULTS: Visual cuing lowered the cadence and increased stride length and stride time while maintaining gait velocity in both PD-patients and controls. A significant interaction between this effect of visual cuing and gait velocity was observed. Visual cuing demonstrated a clear velocity-dependency with less influence on cadence, stride length, stride time and coefficient of variation in stride time at higher velocities. At lower velocities visual cuing was more effective in reducing gait variability as assessed by the coefficient of variation in stride time in PD-patients than in controls.

CONCLUSION: The current experiment shows that the gait patterns of PD-patients are not rigidly coupled to gait velocity and can be manipulated with visual cuing techniques. Our results suggest that visual cuing can improve the efficacy of treadmill training. Due to an interaction between the effect of visual cuing and gait velocity, the application of visual cues could enhance the efficacy of treadmill training particularly at lower velocities.