Travel in Adverse Winter Weather Conditions by Blind Pedestrians: Effect of Cane Tip Design on Travel on Snow.

"Winter weather creates many orientation and mobility challenges for people who are visually impaired (Couturier & Ratelle, 2010; Welsh & Wiener, 1976). Snow cover obscures familiar tactile clues, makes it more difficult to manipulate the long cane, and alters one's cane-based perception of the surroundings (Wall, 2001). Getting the cane tip stuck is one of the noticeable challenges when traveling in snow, particularly when the walking surface is covered in deep snow (Couturier & Ratelle, 2010; Welsh & Wiener, 1976). Having one's long cane get stuck may cause more frequent stops and starts, thereby increasing the time required to complete a given route. Such frequent stops and starts may also result in more steps being taken to cover a given distance which, in turn, may contribute to increased veering (Kallie, Schrater, & Legge, 2007). In addition, it appears that sticking can cause a traveler to veer from and can force the traveler's body to unintentionally turn from the intended line of travel (R. Savage, personal communication, April 2, 2015; M. Weessies, personal communication, April 2, 2015; S. Williams-Riseng, personal communication, December 10, 2014). Furthermore, cane sticking may cause frustration to the traveler by frequently disrupting a rhythmic cane swing (M. Ainsworth, personal communication, February 1, 2015; M. Jimenez, personal communication, February 1, 2015; N. Stanford, personal communication, January 31, 2015). Only a handful of studies have examined the effect of cane tip design on the frequency of sticking. La Grow, Kjeldstad, and Lewandowski (1988) found no significant difference in the frequency of sticking among the pencil, marshmallow, and curved tips when participants traveled on a sidewalk in a residential neighborhood. However, Pietrowicz (1987) and Robertson (1987) reported significantly fewer instances of sticking when using the marshmallow tip than when using the pencil tip on a rural road and residential sidewalk, respectively. In addition, Wang (1991) found the ball tip to be more effective than the marshmallow or metal glide tip in reducing the incidents of sticking in a rural area. However, we found no published studies that experimentally examined the effect of cane tip design on cane sticking when traveling on a snow-covered surface. The purpose of the present study is to examine how different cane tip designs affect the travel performance of blind pedestrians on a snow-covered surface. METHOD Study design and recruitment criteria A repeated-measures design with Latin Square counter-balancing was used for the study. Recruitment criteria included legal blindness with no other disabilities, familiarity with basic cane techniques, regular travel in winter (even when the ground is covered with snow), and enough stamina to walk a few blocks without resting. Apparatus Participants used identical canes of different lengths (Ambutech UltraLite Graphite Rigid Cane) with four different cane tips perceived to be advantageous in reducing the incident of sticking (at least on dry surfaces): (1) metal glide tip (Ambutech MT 4070), (2) marshmallow roller tip (Ambutech MT 4090), (3) roller ball tip (Ambutech MT 4061), and (4) bundu basher tip (Bevria ES 4274) (see Figure 1). A participant's cane length was assigned based on height: vertical distance from the ground to two inches above the participant's xiphoid process, as described in La Grow and Long (2011). [FIGURE 1 OMITTED] Research procedure Each participant signed the informed consent form approved by Western Michigan University's Human Subjects Institutional Review Board before participating in the study. Sleep shades (Mindfold Relaxation Mask) were worn by all participants during all trials (except for those with no light perception). A rectangular block in a residential neighborhood in Kalamazoo, Michigan, was selected for the study (see Figure 2). …