F. Ito,T. Mori,K. Kikkawa, H. Okada

This study seeks to propose a method to assess the walking motion of elderly males using criterial kinetic parameters for young males during walking and to suggest how to maintain their walking capabilities at the same level as those of young males. For this purpose, we used the coefficient of variation (= SD / MEAN * 100, CV), z-score and weighted z-score (= z-score /CV) to clarify parameters that differentiate the walking of elderly males from that of young males. The subjects were 13 healthy young Japanese males and 104 healthy elderly Japanese males. They were instructed to walk about 10m at two selected speeds (Normal Walk (NW) and Maximum-speed Walk (MW)). We videotaped them during walking with a digital VTR camera at 60fps in order to analyze their motion in the sagittal plane. The ground reaction forces on the right foot were also measured by a force platform installed below the walkway. After synchronizing the video data and ground reaction forces, we calculated various kinetic data (joint torques, joint torque powers and joint work at the ankle, knee, and hip), step length, and walking velocity using a link-segment model based on the inverse-dynamics method. The CV, weighted z-score, and correlation coefficient between age and weighted z-score of each parameter were then calculated. Finally, we composed a regression equation for estimating “gait age” from several weighted z-scores that had statistically significant and high correlation coefficients with age (p

Keywords (Optional): 
motion analysis
aging assessment
inverse dynamics