Safety is a prevalent issue related to wheelchair use, with one study highlighting that 55% of wheelchair users reported experiencing at least one collision, and 17% reported experiencing two or more collisions within a three year period. You can read our earlier blog article on the prevalence of wheelchair collisions for additional statistics. Here is a quick view of the consequences of wheelchair collisions and accidents.

So why is it that individuals who have demonstrated their abilities sufficiently enough to be prescribed a wheelchair experience these challenges? At the other end, is it really the case that individuals who are currently being excluded from powered (motorized/electric) mobility device use are too “unsafe” to drive? As a researcher mainly working with individuals with cognitive impairment, I knew there was little research that offered insights into the skills required to use a powered wheelchair. There is even less research to support the misconception that those with cognitive impairment cannot use or learn how to use a powered wheelchair. Despite this, individuals, specifically with cognitive impairment, are given few opportunities to trial and learn how to use a powered wheelchair.

How can we be sure that we are giving everyone a fair chance at independent mobility? In addition, are we viewing mobility as not just a way to get from point A to point B, but also as a necessary tool for learning and development in general.

7 years ago, when I had just started my company Braze Mobility, I walked into the home of a potential client, Wade Watts, and was taken aback by the amount of damage in his home. While I had seen safety often being the reason cited for long-term care residents being denied access to powered wheelchairs, I was not aware of the prevalence of accidents in the community. Despite the fact that Wade is skilled enough to be able to navigate even the most challenging environments, I noticed baseboards had been ripped off many of his walls. He even had to remove a couple of doors because of the damage to his doorways.

In fact the more wheelchair users I spoke to, the more I realized how commonplace property and wheelchair damage are. One of my clients, Herman Witlox, is another wheelchair user who is extremely skilled at using his device, and explains “I can turn [my wheelchair] through a few millimeters of clearance…I can [drive] up two 2 by 4s into the side of the vehicle – that’s a pretty narrow path to keep on course”. Despite this, he shared that

“2 or 3 dents in the wall a day [was] normal. I just [learned] to live with it”.

By Herman Witlox

Through my decade-plus-long research in the mobility space and more than 7 years of providing mobility solutions, I have witnessed a plethora of barriers in accessing and maintaining safe and independent mobility. Exploring these barriers in depth for each individual user can ensure that we identify solutions that address their specific needs.

When I get an inquiry from a therapist or a caregiver about a client who is “driving into things” and I ask the question “why?”, the reasons are often unclear or unknown. I have heard the phrase “they are just a terrible wheelchair driver”, many times from frustrated spouses or other family members who have had to pay for all the damage. However, in my experience, this reason is rarely true.

Most non-wheelchair users, including some therapists that prescribe the technology, don’t realize that operating a wheelchair, especially a powered one, can be extremely difficult. In this blog series, we break down the challenges in 3 areas: technology, environment, and client. By examining each of these individual areas, we aim to provide a more holistic view of safety-related pain points and barriers in wheelchair use. In this first article in the blog series, we highlight factors that are technology-specific.

Seating

Seating is of utmost importance in allowing the user to navigate effectively and comfortably. An individual can experience pain with wheelchair use, independent of their current diagnosis and functioning. When a comfortable, dynamic (movable) seating option is available and positioned correctly for the user, it can reduce the user’s pain by avoiding sliding, slipping, and sudden movements that can all cause injury. In addition, seating adjustments can improve safe and efficient operation of the wheelchair by ensuring that the drive control (the mechanism used to operate a powered wheelchair) is visible and within reach. A RESNA position paper provides insight on the seating-related challenges faced by wheelchair users and associated recommendations. Permobil provides a helpful seating and positioning guide. Additionally, Michelle Lange provides insight into some factors that come into play when considering seating in this Decision Making Tree. 

Even when an optimal seating configuration is selected, the backrest of the wheelchair typically creates a massive “blind spot”. If you have never used a wheelchair and don’t believe me, try sitting in a regular office chair and try to look at the floor behind you (without turning the chair or the seat if you’re in a swivel chair). This is challenging if not impossible for just about anyone, regardless of your upper body mobility. So, it is not surprising that most wheelchair users cannot easily see what’s behind them.

Braze Blind Spot Sensors can be used as a tool to enhance spatial awareness in these blind spots around the wheelchair, and have helped clients like Wade, Herman and hundreds of other wheelchair users. In a recently published 3rd-party peer-reviewed study where existing powered wheelchair users were asked to detect objects in the rear using their standard methods (such as shoulder-checking), the participants detected low stationary (static) obstacles with only 44% accuracy. When participants used the Braze Blind Spot Sensors, their accuracy in detecting these obstacles increased significantly to 96% and they were able to do so in significantly less time. The sensors significantly increased the users’ accuracy in other scenarios as well including detection of higher and moving (dynamic) obstacles in the rear.

Power Wheelchairs Programming and Configurations

Powered wheelchairs can reach relatively high speeds, and if users are not familiar with their speed and acceleration capabilities, they may lose control, leading to collisions or tipping over. Rapid acceleration or sudden stops can catch users off guard and result in accidents, as the user’s entire body or parts of their body can make a jerk-like movement because of this change in speed. Appropriate adjustments can be programmed by a wheelchair provider or manufacturer rep in collaboration with the therapist to ensure user needs are met. The wheelchairjunkie provides information on various programming aspects such as speed of acceleration, deceleration, and turning, and how they impact the powered wheelchair driving experience.

In addition, certain wheelchair configurations can compromise the user’s rear, peripheral, and even front visibility. For example, a user who needs to be in a tilted position while driving will typically have an altered field-of-view that limits their ability to see objects that are lower to the ground. Accessories like oxygen tanks, backpacks, custom leg and footrests, and communication devices that increase the space taken up by the wheelchair can also block the user’s view of obstacles in their environment, making them more likely to have accidents. Bariatric wheelchairs (engineered with a heavier weight capacity and broader seats than standard wheelchairs) can pose additional challenges due to wider wheelchair dimensions, making navigation in tight spaces particularly challenging. Wheel drive configurations (front-, mid- and rear-wheel) can also have an impact on maneuverability, as explained in this article by Permobil. For example, certain types of wheel drive configurations are better for textured pathways while others are better in navigating tighter spaces.

Braze Blind Spot Sensors have helped clients in all of the above scenarios by providing feedback regarding the location and proximity of objects in the environment, thereby increasing spatial awareness in areas that are not directly visible to the client. They can also help new wheelchair users learn the extremities of their wheelchair as they figure out how to maneuver in various spaces with their wheel drive configuration.

Drive Controls

Powered wheelchairs are typically driven using a joystick. However, some users might be unable to operate a wheelchair with a joystick and require the use of “alternative drive/access controls” or “specialty control interfaces”. Alternative drive controls allow a user to control and drive the wheelchair without a joystick, using other parts of the body such as the chin, tongue, mouth, for example. Numotion provides some details of these alternative drive controls. It might be necessary to trial various drive controls in order to find the best fit for the client that allows them to operate a powered wheelchair safely.  Michelle Lange provides decision-making trees for joystick and non-joystick driving methods. Here is another resource from mo-vis that sheds light on how to find a good fit between the user and drive controls. 

While alternative drive controls provide increased opportunities for independent mobility, devices such as head arrays, sip and puffs, and eye gaze require the user to face forward while driving, potentially limiting their spatial awareness. I once saw a client who is a skilled head array user, but certain environments required her to navigate doorways backwards. As she would try to back up through the door and shoulder-check to make sure she was centered, she would inadvertently activate her head array (which detected her head movements as designed) and zig zag through the doorway hitting the sides multiple times.

Braze Blind Spot Sensors can be used in conjunction with alternative drive controls to enhance spatial awareness of obstacles around the wheelchair. In addition, the multi-modal alerts (visual, audio, and vibration) can be used by clients to help center themselves in tight spaces like doorways and elevators to improve their navigation skills, even when moving backwards. This feature can greatly improve powered wheelchair usability, considering 40% of powered wheelchair users in a study reported difficulty with steering tasks, especially while navigating through doorways and elevators.

Take-Aways

Challenges related to seating, programming/configurations, and drive controls can be addressed in various ways, including some of the suggestions in the references provided. It can be helpful to discuss these with the wheelchair provider and therapist when getting a new wheelchair in order to facilitate a better fit between these factors and the user. Some useful considerations when purchasing a new powered wheelchair can be found in our earlier blog article.

Braze Blind Spot Sensors are helpful smart wheelchair technology to help mitigate some of the challenges related to spatial awareness that are often exacerbated by seating, wheelchair configurations/accessories and drive controls.

This blog is related to challenges in wheelchair operation that relate specifically to the wheelchair user’s technology. There are also factors related to the environment and the user that can present safety issues, but I will go over these in the next articles.

References/Citations:

The Prevalence of Wheelchair Collisions

Power Wheelchair Programming Basics

Things to Consider When Ordering a Power Wheelchair

Nilsson, L., & Kenyon, L. (2022). Assessment and Intervention for Tool-Use in Learning Powered Mobility Intervention: A Focus on Tyro Learners. Disabilities, 2(2), 304–316. MDPI AG. Retrieved from http://dx.doi.org/10.3390/disabilities2020022

https://0201.nccdn.net/1_2/000/000/184/61f/Dynamic-Seating-decision-making-tree.pdf

https://hub.permobil.com/wheelchair-seating-and-positioning-guide?hsCtaTracking=a441268d-99eb-45d7-9720-7773f158b694%7C79195703-8467-4542-b4ff-2cfbca0b8929

Lange, M. L., Crane, B., Diamond, F. J., Eason, S., Presperin Pedersen, J., & Peek, G. (2021). RESNA position on the application of dynamic seating. Assistive technology : the official journal of RESNA, 1–11. Advance online publication. https://doi.org/10.1080/10400435.2021.1979383

Pellichero, A., Best, K. L., Routhier, F., Viswanathan, P., Wang, R. H., & Miller, W. C. (2021). Blind spot sensor systems for power wheelchairs: obstacle detection accuracy, cognitive task load, and perceived usefulness among older adults. Disability and rehabilitation. Assistive technology, 1–9. Advance online publication. https://doi.org/10.1080/17483107.2021.1983654

Mortenson, W. B., Miller, W. C., & Hardy, T. (2009). Ready to roll? Wheelchair use in residential care. . Disability Health Research network: UBC Okanagan. http://www.dhrn.ca/page.php?pageID=181

https://hub.permobil.com/blog/power-wheelchairs-where-is-my-drive-wheel-why-does-it-matter#:~:text=The%20location%20of%20this%20drive,%2C%20and%20rear%2Dwheel%20drive.

https://www.numotion.com/products-services/adults/power/alternative-access-controls#:~:text=Alternative%20Access%20Controls%20include%20head,is%20attached%20to%20your%20wheelchair.

https://0201.nccdn.net/4_2/000/000/076/de9/joystick-decision-trees.pdf

https://0201.nccdn.net/1_2/000/000/0d7/f97/non-joystick-driving-methods-decision-making-tree-text-reference.pdf

https://www.mo-vis.com/news/blog-series-how-formalize-selection-process-drive-controls-electric-wheelchair-users

Fehr, L., Langbein, W. E., & Skaar, S. B. (2000). Adequacy of power wheelchairs

Read More