Relationships between muscular torque and gait speed in chronic hemiparetic subjects

Purpose. To identify which paretic and non-paretic muscular groups of the lower limbs were the best predictors of gait speed in chronic hemiparetic subjects. Method. Twelve hemiparetic subjects with ages ranging from 65 to 75 years (70.67±3.31 years) were included in this cross-sectional study. All participants had time since onset of stroke of at least six months and the ability to walk independently. Main outcome measures included self-selected gait speed and maximum isometric torques of both the paretic and non-paretic lower limbs. Pearson's correlation coefficients and stepwise regression analysis were employed to investigate the level of associations between the outcome variables. Results. Mean gait speed was 0.65±0.33 ms^-1. There were significant differences (p>0.01) in torques values between paretic and non-paretic lower limbs for all assessed muscular groups. Stepwise regression analysis revealed that the most important independent variable for predicting gait speed was the isometric torque of paretic knee flexors (R_ajust²). No significant associations were found between any torque values of the non-paretic side and gait speed. Conclusions. The paretic knee flexors were shown to play an important role in predicting gait speed after stroke, but no influences were found for the muscular groups of the non-paretic side. Therefore, findings of the present study suggest that paretic knee flexors torque should be addressed in rehabilitation programmes aiming to improve gait speed after stroke.