Analysis of impairments influencing gait velocity and asymmetry of hemiplegic patients after mild to moderate stroke

Objective: To identify the most important impairments determining gait velocity and asymmetry in patients with mild to moderate stroke. Design: Descriptive analysis of convenience sample. Setting: Outpatient rehabilitation clinic of a hospital in Taiwan. Participants: Twenty-six subjects with mild to moderate spastic hemiparesis after a single onset of stroke, all able to walk independently without any assistance or device. Interventions: Not applicable. Main Outcome Measures: Subjects' maximal muscle strength (isokinetic peak torque, total work), motor and sensation function, and ankle plantarflexor spasticity of the affected lower extremity were examined using the Cybex 6000 dynamometry, Fugl-Meyer Assessment, and Modified Ashworth Scale, respectively. Gait velocity, as well as temporal and spatial asymmetry, were evaluated when subjects walked at their comfortable and fast speeds by using the GailMatII. Results: Regression analyses revealed that the total work isokinetic measures of the affected hip flexors and knee extensors were the most important independent determinants of the comfortable and fast gait velocities, respectively (R-2=.57, R-2=.72). Spasticity of the affected plantarflexors was the most important independent determinant of temporal and spatial gait asymmetry during comfortable-speed (R-2=.76 for temporal asymmetry; R-2=.46 for spatial asymmetry) and fast-speed (R-2=.75 for temporal asymmetry; R-2=.45 for spatial asymmetry) walking. Conclusions: Gait velocity and asymmetry of patients with mild to moderate stroke were affected by different physical impairments. Whereas gait velocity was mainly affected by weakness of the affected hip flexors and knee extensors, gait asymmetry was influenced primarily by the degree of the spasticity of the affected ankle plantarflexors. Therapeutic interventions aiming to improve different aspects of gait performance of these patients may emphasize treatment of different impairments. (C) 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.