Use of harmonic ratios to examine the effect of cueing strategies on gait stability in persons with Parkinson's disease.

Objective: To determine if gait stability, as measured by harmonic ratios (HRs) derived from trunk accelerations, is improved during 3 amplitude-based cueing strategies (visual cues, lines on the floor 20% longer than preferred step length; verbal cues, experimenter saying "big step" every third; cognitive cues, participants think "big step") in people with Parkinson's disease.

Design: Gait analysis with a triaxial accelerometer.

Setting: University research laboratory.