Abstract
[Purpose] As basic research on the analysis of the effect of use of a stick during standing, we investigated the changes of center of gravity (COG) sway of an apparatus simulating the physical experience of an elderly person. [Subjects] The subjects were 15 healthy persons: 10 males, 5 females, average age 40.4 ± 5.9 (ranging from 31 to 51 years of age). [Methods] The measurement of COG sway was performed with an Active Balancer (Sakai Medical Co.) under 3 conditions: with no stick and no apparatus, with the apparatus only, and with the apparatus and the stick. [Results] It was found that with use of the apparatus the total COG sway path length, COG sway speed (path length/sec), the area of the envelope of COG sway and the rectangular area increased, as well as the displacement of the antero-posterior sway center average and the lateral and antero-posterior sway standard deviations. Furthermore, when the stick was used, the locus of COG sway was anteriorly maintained resulting in a reduction in sway. [Conclusion] From these results, the COG sway, reflecting the knee, hip and trunk flexion, of elderly persons in the standing position, is shifted more forward than that of healthy non-elderly persons, and the sway is larger and more rapid. However when a stick is used, the results suggest the sway is reduced to the same level as that of healthy non-elderly persons.
