Comparison of Quantitative Evaluation Methods for Pathological Gait Abnormalities in Stroke Survivors

Background/Objectives: The Gait Variable Score (GVS) and Gait Abnormality Score (GAS) have been proposed as methods for quantitatively evaluating deviations from normal gait patterns. This study aimed to investigate whether the GVS or GAS is more useful for evaluating gait in stroke survivors. Methods: We used open-access motion capture datasets from 43 stroke survivors and 82 healthy individuals. Nine kinematics and seven muscle activities were extracted. The GVS was calculated as the root mean square difference between the pathological and healthy gait patterns. The modified GAS (mGAS) newly defined in this study was calculated as the mean value of the absolute differences between the pathological and healthy gait patterns divided by the standard deviation of healthy gait patterns. The amplitudes of kinematics and muscle activities were calculated. Results: Both the GVS and mGAS were significantly higher in stroke survivors than in healthy individuals. A significant strong correlation for 16 variables (nine kinematics and seven muscle activities) was observed between the GVS and amplitude (r = 0.921), but no significant correlation was found between the mGAS and amplitude (r = 0.167). Conclusions: As the mGAS is not affected by the amplitude of kinematics and muscle activities, it allows for a comprehensive comparison of abnormalities in both kinematics and muscle activities. The mGAS may be more useful than the GVS for evaluating gait abnormalities in stroke survivors.