This study investigated the importance of binocular vision to foot placement accuracy when stepping
onto a floor-based target during gait initiation. Starting
from stationary, participants placed alternate feet onto
targets sequentially positioned along a straight travel path
with the added constraint that the initial target (target 1)
could move in the medio-lateral (M-L) direction. Repeated
trials when target 1 remained stationary or moved laterally
at the instant of lead-limb toe-off (TO) or 200 ms after TO
(early swing) were undertaken under binocular and monocular viewing. Catch trials when target 1 shifted medially
were also undertaken. Foot-reach kinematics, foot trajectory corrections and foot placement accuracy for the step
onto target 1 were determined via 3D motion analyses.
Peak foot-reach velocity and initial foot-reach duration
were unaffected by vision condition but terminal foot-reach
duration was prolonged under monocular conditions
(p = 0.002). Foot trajectory alteration onsets were unaffected by vision condition, but onsets occurred sooner
when the target shifted in early swing compared to at TO
(p = 0.033). M-L foot placement accuracy decreased
(p = 0.025) and variability increased (p = 0.05) under monocular conditions, particularly when stepping onto the
moving target. There was no difference between vision
conditions in A-P foot placement accuracy. Results indicate that monocular vision provides sufficient information
to determine stepping distance and correctly transport the
foot towards the target but binocular vision is required to
attain a precise M-L foot placement; particularly so when
stepping onto a moving target. These findings are in
agreement with those found in the reaching and grasping
literature, indicating that binocular vision is important for
end-point precision. / The Health Foundation, UK. Grant (3991/3322)
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/6888 |
| Date | 29 October 2011 |
| Creators | Chapman, Graham J., Scally, Andy J., Buckley, John |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, No full-text in the repository |
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