Thesis (M.P.H.)--University of Wisconsin--La Crosse, 2009. / Includes bibliographical references (leaves 68-71).

Thesis (M.P.H.)--University of Wisconsin -- La Crosse, 2009. / Includes bibliographical references (leaves 68-71)

Background. Tripping is a common factor in falls and a typical safety strategy to avoid tripping on steps or stairs is to increase foot clearance over the step edge. In the present study we asked whether the perceived height of a step could be increased using a visual illusion and whether this would lead to the adoption of a safer stepping strategy, in terms of greater foot clearance over the step edge. The study also addressed the controversial question of whether motor actions are dissociated from visual perception. Methodology/Principal Findings. 21 young, healthy subjects perceived the step to be higher in a configuration of the horizontal-vertical illusion compared to a reverse configuration (p = 0.01). During a simple stepping task, maximum toe elevation changed by an amount corresponding to the size of the visual illusion (p<0.001). Linear regression analyses showed highly significant associations between perceived step height and maximum toe elevation for all conditions. Conclusions/Significance. The perceived height of a step can be manipulated using a simple visual illusion, leading to the adoption of a safer stepping strategy in terms of greater foot clearance over a step edge. In addition, the strong link found between perception of a visual illusion and visuomotor action provides additional support to the view that the original, controversial proposal by Goodale and Milner (1992) of two separate and distinct visual streams for perception and visuomotor action should be re-evaluated. / College of Optometrists

No description available.

The majority of stroke survivors return to living in the community; however, muscle weakness and cardiovascular deconditioning can restrict mobility, limit community access and independence, particularly when challenging activities like stair negotiation are involved. A “step-by-step” (SBS) strategy (both feet per step) may be adopted in lieu of a “step-over-step” (SOS) method (one foot per step) to increase stability and off-load the paretic limb though the physical demands of the two methods are unknown. The main objective of this thesis was to investigate the strength and energy demands of the two stair-stepping strategies in chronic stroke compared to healthy adults. The first study identified the relative strength and aerobic demands of both strategies. The results showed that the stroke group produced similar peak joint moments compared to controls, despite their slower cadence suggesting that the stroke group exerts comparable ‘effort’ to move more slowly. The SBS method was associated with lower strength costs (relative to individuals’ maximum strength output) than SOS, however aerobic cost was significantly higher. The second study identified the mechanical energy expenditures (MEEs) and transfers related to both strategies. The MEEs were found to be lower when the SBS strategy was used. Though expenditures were similar between groups, the stroke group had higher expenditures associated with the work of the less affected knee extensors (lead limb) during ascent and descent and controls exhibited higher expenditures for the plantarflexors during ascent. The reduced output of the trail (affected) limb plantarflexors likely resulted in the increased workload of the knee extensors. Overall, the aerobic cost per step was higher in stroke, particularly during descent, suggesting that in addition to reducing cadence, persons with stroke may be co-contracting to increase stabilization during descent, thus increasing oxygen demands. This thesis provides novel information on the physical demands associated with two methods of stair negotiation demonstrating that the SBS strategy might be better suited to persons with chronic stroke by minimizing the strength demands on the paretic side, but the benefit comes at an elevated aerobic cost. This information is valuable to rehabilitation professionals engaged in retraining mobility to facilitate community reintegration. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2013-09-30 13:42:08.209

The aim of this finishing work is carry out ergonomical analysis of stairs and ramps in the buildings outside. Performing analysis it was taken measurements of these elements similarly comparing them with measurements given in the Standard documents. The aim of this work is to evaluate as buildings admissions are fitted for people comfortable using them and offer conclusions and suggestions. In this work is analyzing material giving in the standards furthermore stairs and ramps fitting for peoples with wheelchairs.

Over the last decade it has become increasingly popular to provide large public areas with gracefully designed 'flexible' staircases. One inherent characteristic of this type of construction is a low stiffness to mass ratio and hence a low natural frequency when compared to more traditional designs. A number of staircases have been found to be dynamically responsive to pedestrian traffic resulting in costly repairs. The objective of this thesis was to investigate the differences between human induced loading on floors with that on stairs. Experimental work carried out on a purpose built staircase showed that forces up to 3 times the static body weight were generated during fast descents while forces up to 2.5 times the static body weight were generated during fast ascents. The work also showed that first harmonic values generated while ascending were slightly higher than for descending whilst second harmonic values were up to 3 times greater for fast descents than for fast ascents. When compared with floor testing, stair testing produced first harmonic values nearly 2.5 times greater with second, third and fourth harmonic values nearly 3 times greater. The harmonic results for the flat testing were also incorporated into a new mathematical expression to predict peak accelerations on simply supported floors and footbridges. The experimental results were duplicated analytically by developing a computer program to calculate the vertical ground reaction forces from body segment positional data. Following a Newtonian approach, the predicted first harmonic values were 20% to 30% lower than actual while the second harmonic values were approximately the same. Monte Carlo simulation techniques were also used to model the effects of group loading on stairs. The simulations predicted enhancement factors (a multiplier on single subject loading) of 3 to 6 for smaller groups(< 9 people) and 4 for larger groups(> 25 people). If the experimental/analytical results are combined with the group loading predictions, the harmonic values for groups ascending or descending flexible staircase could be substantially increased. These results demonstrate that loading data from floors is highly inappropriate for staircase design.

Thesis (M.S.)--Ohio University, March, 1993. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, November, 2006. / Title from PDF t.p. Includes bibliographical references.

Thesis (M.S.)--Georgia Southern University, 2005. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science" ETD. Includes bibliographical references (p. 36-39) and appendices.