Human Movement Science · Jul 21, 2026

Effects of vertical edge presence on foot trajectory during obstacle crossing in younger and older adults

By Sakurai R, Suda Y, Miura Y et al.

Adjusting limb movements when stepping over obstacles is essential to avoid tripping, especially in older adults among whom age-related physical decline increases the risk of falls. This study aimed to determine whether older adults modify their foot movements according to obstacle shape, particularly the presence of a vertical edge, and whether their responses differ from those of younger adults. Data from 12 younger and 13 older adults were analyzed. Participants stepped over obstacles placed 5 m away under four conditions that varied in shape and dimensions. Raised rectangular obstacles with clearly defined vertical edges and raised arch-shaped obstacles without vertical edges were presented in small (2.5 cm high × 8 cm deep) and large (5 cm high × 16 cm deep) sizes. Foot trajectories during the swing phase from toe-off to heel contact were compared using Statistical Parametric Mapping (SPM). Compared with raised arch-shaped obstacles, younger adults raised their leading foot higher when crossing both small and large raised rectangular obstacles, beginning at approximately 30% of the swing phase and continuing until immediately before the obstacle was crossed. By contrast, SPM did not reveal significant differences in foot trajectory patterns between raised rectangular and arch-shaped obstacles in older adults. However, discrete foot-clearance measures at obstacle crossing showed significant shape-related differences in both groups. These findings suggest that trajectory-level adaptation to obstacle shape was less clearly expressed in older adults than in younger adults under the examined conditions and that obstacle-shape effects may be detected differently by full-trajectory and discrete analyses.

doi.org/10.1016/j.humov.2026.103519PubMed 42480241Mechanisms