Co-presented with D. Peters, P. Robinson and M. Hollands
Introduction: Accidental falls are a leading cause of injury and
death in the growing elderly population (Pocinki, 1990). Falls
in this population are commonly reported as occurring during
walking (Berg et al, 1997). Control of the motion of the centre
of mass (COM) and its coordination with the centre of pressure (COP) of the stance foot are important for the maintenance of the whole body’s dynamic stability. Differences between young and older adults (Hahn and Chou, 2004) and between older adults with and without balance problems (Chou et al, 2003) have previously been identified in the relative motion of the COM and COP during obstacle walking. The aim of the present study was to determine if there are identifiable differences in the gait kinematics and COM-COP relationships between older adults with and without a history of falling (hereafter called fallers and
non-fallers respectively).
Methods: The gait patterns of six elderly non-fallers (mean age
69 ± 5 years) and six elderly fallers (72 ± 5 years) were analysed during level walking at self-selected pace. All participants were community-dwelling, and the faller group had all experienced at least 1 fall in the 12 months prior to testing.A 14-camera Vicon (624) system was used to collect full body kinematic trajectories (60Hz sampling frequency), which were used to calculate COM and temporospatial gait characteristics. Two AMTI force plates were used to measure ground reaction forces used to calculate COP data. Group differences were tested using t-tests. A mixed model ANOVA was used for testing group and left or right side interactions. A significance level of 0.05 was used for all statistical tests.
Results:No significant differences were found between the faller and non-faller groups for any temporospatial gait parameters or for COM-COP separation in the medio-lateral (ML). However, a significant difference was observed between groups in the COM-COP separation in the anterior-posterior (AP) direction at foot strike (F = 22.61, P < 0.01).
Conclusions: These preliminary results show significant differences between fallers and non-fallers in the relationship
between COM and COP (a measure associated with postural
stability) during specific points in time during the gait cycle.
These differences cannot be explained by differences in temporospatial aspects of gait (e.g. walking speed, stride lengths etc). The observed differences in the relationship between COM and COP motion could be interpreted as an indicator that older adult fallers have lower dynamic stability in the sagittal plane than non-fallers.
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