Article

This study assessed the effects of dim light and four experimentally induced
changes in vision on gait speed and footfall and trunk parameters in older
persons walking on level ground. Using a quasi-experimental design, gait
characteristics were assessed in full light, dim light, and in dim light combined
with manipulations resulting in reduced depth vision, double vision, blurred
vision, and tunnel vision, respectively. A convenience sample of 24 home-dwelling
older women and men (mean age 78.5 years, SD 3.4) with normal vision for their age and able to walk at least 10 m without assistance participated. Outcome
measures were gait speed and spatial and temporal parameters of footfall and
trunk acceleration, derived from an electronic gait mat and accelerometers. Dim
light alone had no effect.
Vision manipulations combined with dim light had
effect on most footfall parameters but few trunk parameters. The largest effects
were found regarding double and tunnel vision. Men increased and women decreased
gait speed following manipulations (p=0.017), with gender differences also in
stride velocity variability (p=0.017) and inter-stride medio-lateral trunk
acceleration variability (p=0.014). Gender effects were related to differences in
body height and physical functioning. Results indicate that visual problems lead
to a more cautious and unstable gait pattern even under relatively simple conditions. This points to the importance of assessing vision in older persons and correcting visual impairments where possible.

Langue : ANGLAIS