Article

The objective of this study was to investigate the effects of age and speed on
body center of mass (COM) motion over a gait cycle. Whole body kinematics and
ground reactions were recorded for 21 healthy young (21-32 y) and 20 healthy
older adults (66-81 y) walking at 80%, 100% and 120% of preferred speed.
The limb-induced COM accelerations and the work done on the COM by the limbs were
computed. Despite walking with similar gait speeds, older adults did
significantly (p<0.05) less positive work on the COM during push-off but then
performed more positive work on the COM during midstance. As a result, older
adults induced lower tri-axial COM accelerations via the trailing limb and higher
vertical COM acceleration via the leading limb during double support. Older
adults also reduced the mediolateral COM acceleration induced by the leading limb
during the last third of double support. The forward and vertical components of
the limb-induced COM accelerations were highly correlated (p<0.005) but were not
correlated to the mediolateral component during double support, at any speed.
Together, these results suggest that older adults use the leading limb to
compensate for reduced vertical support and work done by the trailing limb.
Further, older adults seem to adapt their gait patterns to reduce mediolateral
COM accelerations. These findings are relevant for understanding the factors that underlie walking performance and lateral balance in old age.

Langue : ANGLAIS