Centre of mass motion during stair negotiation in young and older men.

The aim of this study was to compare centre of mass (COM) motion and its separation from centre of pressure (COP) as 13 young men (aged 23-36 years) and 15 healthy, community dwelling older men (aged 73-84 years) ascended and descended a three step staircase at a controlled cadence of approximately 90 steps/min. Centre of mass was obtained from whole body motion analysis, and simultaneously, COP was obtained using force plates built into the steps. The following variables were investigated: medio-lateral COM range of motion; peak antero-posterior and medio-lateral COM-COP separation; and peak antero-posterior, medio-lateral, and vertical COM velocities. No significant differences in these variables between young men and older men were present during ascent or descent. It was concluded that frontal plane dynamic stability during stair negotiation is well maintained in healthy older men, and that healthy older men do not exhibit an altered strategy in traversing the COM in the plane of progression during stair negotiation.