A comparison of knee kinematic characteristics of stroke patients and age-matched healthy volunteers

Objective: To investigate which knee kinematic characteristics show the greatest differences between stroke patients with minimal residual disability and age-matched healthy volunteers as a first step towards the development of a sensitive, objective measure of performance of movement for use in the clinical setting. Design: A comparative study. Setting: A movement analysis laboratory. Subjects: Ten patients between 6 and 12 months post stroke aged between 65 and 74 years and 10 age-matched healthy volunteers. All patients had made a good recovery and were able to complete all of the functional tasks. Interventions: Each subject had reflective markers placed on anatomical landmarks and was filmed performing three movement tasks: sit-to-stand, walking, and step on block. Main outcome measures: Knee kinematic characteristics involving timing, joint angle and angular velocity at key points during each task. Results: Significant differences were found between patients and volunteers for only some of the timing and joint angle characteristics but for all angular velocity characteristics for which the mean differences ranged from 31.85 degrees/s for sit-to-stand ( p = 0.013) to 82.5 degrees/s ( p = 0.014) for the swing phase of gait. Conclusions: These preliminary findings suggest that angular velocity of the knee during functional tasks might have potential as a sensitive, objective measure of performance of movement after stroke for patients with minimal residual disability.