A comparison of the recognition distance of several types of pedestrial signals with low-vision pedestrians.

Although approximately 80-85% of the legally blind population has some residual vision, little research has examined the relative conspicuity of various types of visual pedestrian signals currently used by cities with this group of pedestrians. This research compared the relative conspicuity of an incandescent WALK sign, a white LED WALK sign, a blue LED WALK sign, and white and blue LED WALK signs that included an animated "eyes" display with legally blind participants who had some vision. All WALK signals were equated for brightness with the use of a N.I.S.T.-certified illuminance meter. Participants had to discriminate whether the test stimulus was a blue/white WALK sign or a blue/white DON'T WALK sign. Test stimuli were presented in randomized blocks of trials, and recognition distances were determined by having participants approach the test stimuli until they could identify them. Results indicated that there were no significant differences between the incandescent and LED signals without the animated eyes or between the blue and white LED signals. However, Tukey's method showed a significant contrast between the signals with the animated eyes display and signals without this display (F=149.88, P value<0.0001). Participants could identify the Walk signal 62% further away when it also contained the animated "eyes" display. These results show that the addition of an animated "eyes" display to the WALK sign significantly improves recognition distance for a large segment of persons with visual impairment.

A biomechanical evaluation of visually impaired persons' gait and long-cane mechanics.

This study was designed to compare selected kinematic components of gait and long cane mechanics between groups of visually impaired travelers. Twenty subjects were placed in Traditional or Modified technique groups according to their long cane traveling technique. Subjects were measured during the following conditions; 1) normal walking (NW), 2) walking while anticipating a simulated drop-off (AD), 3) walking while responding to an audible task (ST) and, 4) walking while anticipating a simulated drop-off and responding to an audible task (STAD). Data were analyzed using a repeated measures analysis of variance (ANOVA) and Pearson's r correlation coefficient. Analyses revealed no differences between groups of travelers. However, significant differences were noted between trials for components of gait velocity, stride length, and hip flexion velocity. These findings may indicate a potentially dangerous alteration in the normal gait cycle of visually impaired travelers when faced with additional attention-demanding tasks while walking.

Gait and long cane kinematics: a comparison of sighted and visually impaired subjects.

Although visually impaired individuals have used the long cane to increase mobility for many years, few empirical studies have examined the effectiveness of this tool. The purposes of this research were to determine if these cane procedures provide adequate protection for visually impaired individuals and to compare sighted and visually impaired gait mechanics. Seven sighted (four females, three males) and five visually impaired subjects (two females, three males) were videotaped at 60 Hz by two cameras situated at opposite 45 degrees angles to the subjects' frontal plane so that three-dimensional coordinates could be calculated via direct linear transformation. One-way analyses of variance were calculated on 17 variables to determine if there was a significant biomechanical difference between sighted and visually impaired gait at an adjusted alpha = .003. The results showed that for both groups the cane tip touched outside where the foot landed and that the only variable significantly different between the two groups was resultant cane velocity. The major conclusion of this research was that present cane techniques may not provide adequate protection for visually impaired individuals since the purpose of mobility training is to have the person touch the ground with the cane tip at the foot contact positions.

Travel behavior of nursing home residents perceived as wanderers and nonwanderers.

A video-based observational methodology was used to assess the travel behaviors of 40 nursing home residents, 24 of whom were identified by nursing staff as wanderers. Travel was monitored continuously for 30 days, resulting in the recording of over 5,000 unassisted travel events. Four basic travel patterns were observed: direct travel (86.8%), lapping (11.6%), random travel (.9%), and pacing (.7%). Travel efficiency (percentage of direct travel) was significantly related to cognitive status (r = .56), with inefficient travel most prevalent in severely demented participants.