The addition of stripes (a version of the ‘horizontal-vertical illusion’) increases foot clearance when crossing low-height obstacles

Foster, Richard J.; Buckley, John; Whitaker, David; Elliott, David B.

doi:10.1080/00140139.2015.1105304

Cited by 12 publications

(20 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous findings show that superimposing a stair horizontal-vertical (HV) illusion ( Fig 1A ) on to steps, stairs or obstacles can lead to subsequent increases in foot clearance of ~1cm [ 10 , 12 , 16 , 22 ]. This visuomotor interaction is thought to represent a perception-action link [ 23 ], and the illusion was developed on the basis of the original HV illusion ( Fig 1B ).…”

Section: Introductionmentioning

confidence: 99%

Using a stair horizontal-vertical illusion to increase foot clearance over an inconsistently taller stair-riser

et al. 2021

Self Cite

View full text Add to dashboard Cite

Introduction Stair falls can be caused by inconsistent stair dimensions. During ascent, inconsistently taller stair risers lead to reduced foot clearances as the inconsistency goes unnoticed. A stair horizontal-vertical illusion increases perceived riser heights and foot clearance and could offset reduced foot clearances over inconsistently taller risers, though this might impact other stair safety measures. Method Twelve participants (age: 22 (3) years) ascended a seven-step staircase under three conditions: i) all steps consistent in riser height (consistent), ii) a 1cm increase in step 5 riser height (inconsistent) and iii) a 1cm increase in step 5 riser height, superimposed with a stair horizontal-vertical illusion (illusion). Vertical foot clearance, foot overhang, and margins of stability were assessed over step 4, 5 and 6. Perceived riser height due to the illusion was determined through a computer perception test. A One-Way Repeated Measures ANOVA compared biomechanical variables between conditions. A One Sample t test compared perceived riser height to the true height. Results Over the inconsistent step 5, foot clearance reduced by 0.8cm compared to consistent. Illusion increased foot clearance by 1.1cm and decreased foot overhang by 4% compared to inconsistent. On step 4 the illusion led to more anterior instability compared to inconsistent. Illusion and inconsistent led to more mediolateral stability compared to consistent. The illusion increased perceived riser height by 12%. Discussion Foot clearance reductions over inconsistently taller risers can be offset by a stair horizontal-vertical illusion. Additional benefits included a safer foot overhang and unaffected stability over the inconsistent riser. Changes to step 4 stability might have resulted from leaning forward to look at the step 5 illusion. The stair horizontal-vertical illusion could be a practical solution for inconsistently taller stair risers, where a rebuild is usually the only solution.

show abstract

Section: Introductionmentioning

confidence: 99%

Using a stair horizontal-vertical illusion to increase foot clearance over an inconsistently taller stair-riser

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…Regardless of perceptual grouping, our results showed that additional visual information was used to control leaping kinematics even though it was not required for obstacle traversal and imposed no new constraints. Similar observations have been made for walking over other types of obstacles in other contexts, but in each case, the additional information provided had been intended to modify the mechanical outcome of obstacle contact [22,23] or had physically intersected with the top boundary of the obstacle in a manner intended or concluded to have altered the accuracy and/or precision of its perceived location [24][25][26][27][28][29][30][31]. Our findings suggest that integration of geometric information can occur without altered sensing of either the top edge or of the mechanical requirements of the traversal.…”

Section: Discussionmentioning

confidence: 76%

Visuomotor control of leaping over a raised obstacle is sensitive to small baseline displacements

Daniels

Burn

2021

R. Soc. open sci.

View full text Add to dashboard Cite

The limb kinematics used for stepping or leaping over an obstacle are determined primarily by visual sensing of obstacle position and geometry. In this study, we demonstrate that changes are induced in limb kinematics even when obstacle geometry is manipulated in a way that does not introduce a mechanical requirement for a change of limb trajectory nor increase risk of collision. Human participants performed a running leap over a single raised obstacle bar. Kinematic changes were measured when an identical second bar was introduced at a ground level underneath the obstacle and displaced by a functionally insignificant distance along the axis of travel. The presence or absence of a baseline directly beneath the highest extremity had no significant effect on limb kinematics. However, displacing the baseline horizontally induced a horizontal translation of limb trajectory in the direction of the displacement. These results show that systematic changes to limb trajectories can occur in the absence of a change in sensed mechanical constraints or optimization. The nature of visuomotor control of human leaping may involve a continuous mapping of sensory input to kinematic output rather than one responsive only to information perceived to be mechanically relevant.

show abstract

“…Elliott et al, 2015; David B. Elliott et al, 2009; Foster et al, 2016; Foster et al, 2015; Skervin et al, 2021), with 1.0 cm, a 17.5% improvement, in toe clearance observed in older adults. Importantly, introducing the vertical monochrome striping intervention to both the top and bottom steps maximized the vertical toe clearance effect, compared to no vertical striping, striping only the bottom step, or striping only the top step (D. B.…”

Section: Introductionmentioning

confidence: 90%

“…Elliott, Foster, Whitaker, Scally, & Buckley, 2015; David B. Elliott, Vale, Whitaker, & Buckley, 2009; Foster, Buckley, Whitaker, & Elliott, 2016; Foster et al, 2014; Foster, Whitaker, Scally, Buckley, & Elliott, 2015; Jacobs, 2016; Schofield, Curzon-Jones, & Hollands, 2017; Shaheen et al, 2018; Skervin et al, 2021; Thomas et al, 2021; Zietz, Johannsen, & Hollands, 2011). In fact, Elliott, Foster and colleagues have demonstrated that vertical, monochrome striping on the face of the bottom and top steps can increase vertical foot clearance 0.8 cm for young adults and up to 2.1 cm for older adults (D. B.…”

Section: Introductionmentioning

confidence: 99%

Stairway visual contrast enhancement to reduce fall-related events

Harper

Long

Corbridge

et al. 2022

Preprint

View full text Add to dashboard Cite

Falls on stairs occur frequently and pose a significant health and financial risk. Laboratory research has found that fall frequency can be reduced through contrast enhancement of the stairs by applying vinyl striping to the first and last steps' faces, and all the steps' top edges. Here we sought to determine if such step contrast enhancement can reduce the probability of fall-related events such as loss of balance, slips, trips, and falls in public university staircases. Cameras were used to capture stair users' ascent and descent on contrast enhanced (striped) and control stairways. Observed age group, observed gender, traverse direction (ascent, descent), fall-related events, and walking speed (m/s) were recorded. Fall-related events were reduced for the striped stairway compared to the control stairway (odds ratio = 2.87, average marginal effect = 0.002, p = .023) when controlling for observed gender, age category, and traverse direction. These results suggest contrast enhancement of first and last steps' face and all steps' edges may reduce fall-related events in public settings. Adding contrast enhancement to public stairways is a simple and cost-effective way to reduce the loss of balance, slips, and trips that could lead to catastrophic falls on stairs as well as the health and financial burden associated with such falls.

show abstract

The addition of stripes (a version of the ‘horizontal-vertical illusion’) increases foot clearance when crossing low-height obstacles

Cited by 12 publications

References 25 publications

Using a stair horizontal-vertical illusion to increase foot clearance over an inconsistently taller stair-riser

Using a stair horizontal-vertical illusion to increase foot clearance over an inconsistently taller stair-riser

Visuomotor control of leaping over a raised obstacle is sensitive to small baseline displacements

Stairway visual contrast enhancement to reduce fall-related events

Contact Info

Product

Resources

About