Analysis of gait abnormalities in Huntington disease

Objective: To evaluate patterns of successful gait strategy in Huntington d isease (HD) at various stages of illness to improve fall avoidance and main tenance of independence. Design: Repeated measurements of gait kinematic parameters and joint perfor mance during gait cycles of six HID patients compared to 30 age-matched con trols. Setting: A standard gait laboratory. Subjects: Six HD patients, rank-ordered for disease severity from minimal c horea to generalized dystonia, selected because they were ambulatory despit e 3 to 17 years' disease duration. One patient was from a nursing home (wal ked with assistance) and five were living independently, either alone or wi th a working spouse who was the caregiver. Main Outcome Measures: Standardized gait evaluations (retroreflective marke rs on standard bony landmarks) from five video angles, fed into digitizer t o computer-generate joint angles and standard gait kinematic parameters. Results: Wide variability in gait kinematic parameters and joint interactio n plots (phase plane and angle-angle plots) was observed between individual s and successive trials of the same limb, tending to increase with disease severity. Joint interaction plots show that random, highly variable distrac tions from planned trajectories are more apparent distally. Conclusions: Chorea in HD does not appreciably affect the center of gravity during ambulation, and the consistency of gait profiles at heel strike sho ws that the ultimate target is achieved in each step despite random and fre quent variability during the gait cycle. (C) 1999 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine an d Rehabilitation.