Multiple parameters of gait were evaluated in 50 adult acquired hemiplegic patients and 30 control patients with no history of gait abnormality and no deviation from normal gait by observational analysis. Findings in the hemiplegic group include: 1) increase in the proportion of the gait cycle spent in stance and double-limb support phases in both the normal and affected limb; 2) consistent deviation from normal gait pattern by observation and objective pattern analysis; 3) abnormal phasic activity of specific muscles and muscle groups in the affected limb; and 4) a consistent electrogoniometric deviation from normal joint ankle progression in the affected hip, knee and ankle. These data lend credence to the hypothesis that gait deviation in adult acquired hemiplegia follows a consistent pattern varying with the severity of central nervous system involvement. These data also provide a baseline from which to measure therapeutic intervention in this complex patient population.