KINEMATICS AND DYNAMIC STABILITY OF THE LOCOMOTION OF POSTPOLIO PATIENTS

The study reported in this article was conducted to propose a set grap hical and analytical tools and assess their clinical utility by analyz ing gait kinematics and dynamics of polio survivors. Phase-plane portr aits and first return maps were used as graphical tools to detect abno rmal patterns in the sagittal kinematics of post-polio gait. Two new s calar measures were introduced to assess the bilateral kinematic symme try and dynamic stability of human locomotion. Nine healthy subjects a nd seventeen post-polio patients were involved in the project. Signifi cant increases in the knee extension and ankle plantar flexion of post -polio patients were observed during the weight acceptance phases of t heir gait. Polio patients also exhibited highly noticeable excessive h ip flexion during the swing phase of their ambulation. Using the propo sed symmetry measure, we concluded that post-polio patients walked les s symmetrically than normals. Our conclusion, however was based on the bilateral symmetry in the sagittal plane only. Finally, we observed t hat post-polio patients walked significantly less stably than normals. In addition, weaknesses in lower extremity muscles of polio patients were found to be an important factor that affected stable ambulation.