Spatial Mobility of the Visually Handicapped Active Person: A Descriptive Study

Abstract

Specific aspects of mobility and spatial orientation of the visually handicapped have attracted the attention of researchers for a quarter of a century; generally speaking, their work can be placed in four fields of study. First, interest has been focused on the capacity of blind people to move unaided in various spatial settings and to mentally map an environment. A second preoccupation revealed by the literature has been the spatial information transmitted to the visually handicapped by tactile maps, by adapted sign system and by electronic guidance systems. Other projects have focused on the environment in which visually handicapped move and on the environmental aspects that affect their mobility. Finally, some researchers have investigated how the development of technical aids has facilitated the mobility of blind people.

Nonvisual judgment of the crossability of path gaps.

“…Acoustic stimulation is the basis for most of the major approaches to electronic mobility aids; moreover, vision-impaired individuals spontaneously use acoustic information when it is available (e.g., Passini, Dupré, & Langlois, 1986). Persons in that study reported being able to detect open doors by use of sound; whether they were finding the openings by a sort of echolocation or simply by the amplitude of the environmental noise on the other side of the doorway was not specified.…”

“…Moreover, even for cane-aided locomotion, settings quiet enough for cane-produced sounds to be audible are rare in the real world. As pointed out by Foulke (1969; see also Passini et al, 1986), the sound of traffic (pervasive in some of the most critical environments for caneaided locomotion) is likely to drown out any sounds of tapping, which led Foulke some years ago to suggest and develop a silent cane with a caster wheel at the tip. If it is nevertheless believed the sound of tapping is the information of choice in relatively quiet settings when a rigid probe is used, then it must also be held that this sort of perception is of an entirely different nature from the natural and practical examples of locomotion to which it is compared.…”

Stress Associated with Transportation: A Survey of Persons with Visual Impairments

“…Persons who are visually impaired find that open areas such as lobbies and parking lots are difficult to navigate (Passini et al, 1986), presumably because these areas lack spatial and directional information (Marston & Golledge, 2003). An increased stress response is associated with unfamiliarity with an area, lack of travel skills, and route complexity (Seki & Sato, 2011;Tanaka, Murakami, & Shimuzi, 1982).…”

Visual control of locomotion: Strategies for changing direction and for going over obstacles.

“…The 8-cm-high obstacle is approximately 10% of the average leg length and is meant to represent the average curb height or smaller obstacles found in the environment. Note that the small obstacles rather than larger ones pose problems when vision deteriorates (see Passini, Dupre, & Langlois, 1986), causing more falls because of trips (cf. Ashley, Gryfe, & Amies, 1977; Prudham & Evans, 1981).…”