A Comparison of the Center of Pressure during Stair Descent in Young and Healthy Elderly Adults

[Purpose] The purpose of this study was to investigate the center of pressure (COP) trajectory during stair descent in young and healthy elderly adults. [Subjects] Fifteen community-dwelling healthy elderly adults (mean age, 73.1 +/- 4.3 years) and 15 healthy young adults (mean age, 23.6 +/- 2.4 years) volunteered to participate in this study. [Methods] Subjects stood in a predetermined position oil the top of a staircase. Participants were then instructed to descend the staircase with three steps at a self-paced speed and continue for several strides after striking the force platform on the floor. Participants were required to place only one foot on each step (foot-over-foot) at a time. Performance was assessed by recording changes in the displacement of COP in the anteroposterior (A-P) and mediolateral (M-L) directions as well as recording the average velocity of COP by the use of two force platforms. [Results] The A-P and M-L displacements of COP as well as the average velocity of COP of the elderly were significantly lower than those of the young adults for both the right and the left feet (p<0.01). [Conclusion] The COP shift and velocity during stair descent might be appropriate parameters for identifying risk factors associated with stair-based accidents or falling.