Citation

Aberg AC, Frykberg GE, Halvorsen K. Gait Posture 2010; 31(4): 438-443.

Affiliation

The Swedish School of Sport and Health Sciences, Box 5626, SE-114 86 Stockholm, Sweden; Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala Science Park, SE-751 85 Uppsala, Sweden.

Copyright

(Copyright © 2010, Elsevier Publishing)

DOI

10.1016/j.gaitpost.2010.01.018

PMID

20189390

Abstract

Most falls in older people are due to loss of balance during everyday locomotion, e.g., when initiating walking from sitting; sit-to-walk (STW). It has been considered that the broader stride width in walking that is seen in many people with fear of falling (FoF) does not increase stability, but could be predictive of future falls because of increased medio-lateral (ML) velocity of the body centre of mass (CoM). This study was aimed to examine step-, velocity- and stability-related parameters, focusing on ML stability, in STW performance of people with and without FoF. Ten subjects with FoF and 10 matched controls, aged >/=70 years, were included. Kinematic and kinetic data were collected in a laboratory. Stability parameters were calculated from a formula implying that the vertical projection of the CoM extrapolated by adding its velocity times a factor radicall/g (height of inverted pendulum divided by gravity) should fall within the base of support (BoS). A related spatial margin of stability (SMoS), defined as the minimum distance from the extrapolated CoM (XCoM) to the boundaries of the BoS, was also calculated. In the phase 'seat-off-second-toe-off', the FoF group had significantly (p<0.05) shorter and broader steps, lower forward but similar ML CoM velocity, and broader CoM and XCoM widths. The FoF group therefore exhibited a disproportionately large sideways velocity compared to the controls. This indicates that STW may be a hazardous transfer for older people with FoF, which should be relevant in assessment and training aimed at preventing falls.

Language: en