Obstacle Crossing With Lower Visual Field Restriction: Shifts in Strategy

ABSTRACT

In this study, the authors investigated how restriction of the vertical viewing angle influences obstacle-crossing behavior. Twelve participants stepped over obstacles of different dimensions while wearing visual-field-restricting goggles. Using full-body motion capture, several kinematic measures were extracted and analyzed. Results indicate that both a 40° and 90° vertical viewing angle yielded increased step length and toe clearance as compared to an unrestricted view (i.e., 135°), whereas speed remained unaltered. A further decrease (to 25°) caused participants to slow down in addition to a further increase of step length and toe clearance. These results are discussed in terms of a change in priorities, from conservation of energy and time to safety.

Keywords:

• lower visual field restriction
• motion capture
• obstacle crossing
• strategy shifts

ACKNOWLEDGMENTS

The authors wish to thank Koen Tan for his suggestions and assistance with MATLAB analyses and Annemarie Levert for supervision during the experimental sessions. This research has been supported by the GATE project, funded by The Netherlands Organization for Scientific Research (NWO) and The Netherlands ICT Research and Innovation Authority (ICTRegie).