ABSTRACT
Objective To study the effect of age on the trajectory of the center of plantar pressure.Methods Twenty-five healthy young people constituted a youth group,while another 25 elderly counterparts formed an aged group.Descriptors of everyone's gait were collected using an AL-600 gait and balance training and evaluation apparatus.The length of the total trajectory of the center of plantar pressure (COPD) was recorded along with the average left and right deviation of the center of plantar pressure (COPD-X) and its average anterior-posterior deviation (COPD-Y) in the heel strike (LR),single plantar stance (SPS) and push-off (PS) phases of striding.Results The average COPD of the aged group was significantly longer than that of the youths.For both groups,the average COPD-X and COPD-Y deviations in SPS were significantly less than those in the LR and PS phases,with no significant difference between them.Compared with the youth group,the average COPD-X in the LR and PS phases and the average COPD-Y in the PS were significantly greater among the aged,but there was no significant difference between the two groups in the average COPD-X in SPS or in the average COPD-Y in the LR and SPS phases.Conclusions The average COPD,COPD-X and COPD-Y increase with age,indicating the higher risk of falling.The changes in each sub-phase of gait are different,but those in the LR and PS phases more reliably reflect stability.