Reliability of lower limb kinematics, mechanics and energetics during gait in patients after stroke.

OBJECTIVE: To assess the reliability of kinematic, mechanical and energetic gait variables at short (1 day) and medium (1 month) intervals in adult patients after stroke. DESIGN: Prospective study. SUBJECTS: Ten patients with chronic post-stroke (mean age 53.5 years; age range 25-80 years). METHODS: Three-dimensional gait analysis was performed 3 times in these subjects: at baseline (T0), after 1 day (T1) and after 1 month (T2). The reliability of the gait analysis was tested by comparing gait variables measured at T1 and T0 (1 day interval), at T2 and T0 (1 month interval). The inter-session reliability of kinematic, mechanical and energetic variables was calculated by intra-class correlation coefficient (ICC). RESULTS: The reliability of kinematic variables ranged from excellent to moderate (ICC >or= 0.51), except for the ankle position at heel strike (ICC = 0.44). The reliability of mechanical and energetic variables ranged from excellent to good (ICC >or= 0.71). The most reliable variable was external mechanical work (ICC = 0.96). The kinematic, mechanical and energetic variables did not change significantly between T0, T1 and T2 (repeated-measures analysis of variance). CONCLUSION: Kinematic, mechanical and energetic gait variables present good reliability when measured at 1 day and 1 month intervals in adult patients after stroke