July 6, 2020

Yetsa Tuakli-Wosornu, MD, MPH, has been working with her team on creating a more accessible wheelchair training roller for those who are seated. In the following interview, she details more of the inspiration behind this project, where it is now, and where she hopes it will go.

For more information about the Go Get Dem Wheelchair Racing Club Dr. Tuakli-Wosornu works with, visit https://www.gogetdem.com/

For a video showing Raphael Botsyo Nkegbe, founder of Go Get Dem, wheelchair racing, visit https://vimeo.com/395564024/3daa17f1f0

Q: What is this project that you are working on?

A: It’s a stationary training roller for those who use wheelchairs, those who are seated, which actually constitutes a very large part of the population (one in seven has some kind of an impairment that impacts activities of daily living in some way). For those who are physically impacted, sometimes they have to use wheelchairs in order to navigate the world. Thus, for those who are seated, there tends to be a little bit of a disparity in access to opportunities for health through fitness and physical activity. And developing a stationary training roller is kind of like developing a treadmill for those who ambulate, but it’s for those who are seated instead. Wheelchair training rollers tend to be very bulky, that’s the first thing. They also tend to be very expensive, that’s the second thing. And finally, whether they’re bulky or expensive, they tend to be difficult to assemble and to maintain.

So, our goal, along with some brilliant mechanical and biomedical engineers at the University of Delaware, was to develop an accessible, low cost, high quality wheelchair training roller for use around the globe. It’s important to note that 80% of the world’s disabled population lives in a developing country. So, the fact that a lot of these devices, whether it’s for fitness or for rehabilitation or for sports, are not very accessible to persons who may not have a great degree of resources is highly problematic and doesn’t track with the epidemiology of impairment globally.

That was the goal of the project. We didn’t name the first iteration, but the second iteration we named “Easy Roller.” We developed the first prototype over the course of one year along with a cohort of athletes from Ghana, who are going to be Paralympians (most of them compete either in wheelchair tennis, wheelchair basketball, or wheelchair racing). They were our experts. We developed prototype number one, iterated on that, and now we have prototype number two, which we call the “Easy Roller” because it contains stock products like devices that are used in airport conveyer belts in order to achieve the training experience. I don’t know if that name will change; hopefully it will.

Q: Can you give some technical details to describe how this training roller works?

A: So, there are a couple of aspects to every training roller no matter where you are in the world. The first and most important thing is some sort of drum, whether it’s four drums, two drums, or just one drum. The drum is the cylindrically shaped component that rotates. So typically, the wheelchair will be placed on top of the drum, whether it’s one, two, or four. A lot of sports chairs work well with just a single drum system, but that again tends to be made of steel and it’s quite large and laborious, and not exactly portable. Two-drum and four-drum training roller models tend to be a little bit more light weight and more portable. The drum is going to have to sit on some kind of an axis. The axis is again made of some type of durable metal, and the axis will be designed in such a way that it fits the drum system.

So, if the drum system is just one drum, then it’s just one major axis down the middle. Imagine a toilet paper roll on its holder or a paper towel roll on its holder. The drum would be the paper towel and the axis would be the holder. If it’s a four-drum model, then you’ll have more of an “H” shaped axis, onto which the drums are fixed, and then the wheels of the wheelchair sit somehow on the drums, whether it’s with two on each side of the chair or on the single drum. It also depends on whether you’re using a racing chair, a sports chair, or a daily-use wheelchair. Racing chairs are wheelchairs that typically have some kind of camber associated with their back wheels and then a long axis that extends forward ahead of the main wheels where there’s a third wheel at the front. You have to have something that can stabilize that third extended wheel. If you’re using a daily-use wheelchair, the wheels tend to be perpendicular to the ground; so, they’re not cambered in any way (meaning they’re not tilted). Then the drum or drums have to be angled in such a way that this can be accommodated. So, in summary, the drums are fixed to an axis, the axis is affixed to some sort of stationary frame that’s weighted so that as you’re pushing, you don’t push yourself off. Then the stationary frame is affixed to the ground in some way such that it provides the needed stability.

Figure 1. Computer Aided Design (CAD) rendering of The EasyRoller in use with a racing wheelchair. Note that the front wheel stabilizer (wedge recommended) is not shown in this image.  Source: A novel portable and cost-efficient wheelchair training roller for persons with disabilities in economically disadvantaged settings: The EasyRoller by Scheffers, Marjelle, et al.

Q: So how many drums are you using for your roller?

A: It’s a four-drum system this time around. We have two on each side; they contact the wheels of a daily-use or sports chair. There are some small casters in front of most daily-use and sports chairs. It’s an anti-tip mechanism, and we designed it so these casters sit in a stationary component of the roller. We just used a stock clamp that you might find at a mechanics shop or a Home Depot. This is just a point of contact for the casters in the front. So, we have four drums that are fixed to this small axis, but in order to simulate the feel of a road, you actually need a larger diameter. The large diameter drums are preferred by athletes and wheelchair fitness enthusiasts because they feel very similar to being on a road. If you’re pushing a wheelchair on a road, obviously your strokes are going to be much wider. To simulate that feel, we’ve actually just used stock weights, like weight plates, that you can find in any gym (like 5 pounds, 10 pounds, etc.). We affix those to the outside of the device on either side to increase the rotation moment such that it feels like a large-diameter drum even though the diameter of the conveyer belt rollers is small.

Q: Can you discuss some of the initial inspiration behind this project besides what we’ve already discussed?

A: So, the Go Get Dem Wheelchair Racing Club is a non-profit organization in Ghana, with whom I’ve worked for years. The group of athletes that constitute the club’s membership are all good friends of mine because we were teammates when I was competing for Ghana. And this group of athletes is probably the winningest group of athletes in our country. Raphael Botsyo Nkegbe, he’s the president of the organization and also the founder, will be participating in his fourth Paralympic Games in Tokyo 2021, and he’s therefore the most elite and accomplished athlete in our country, with or without a disability. He founded the club, and we asked him point blank, “What would be useful for you training-wise?” and the first thing out of his mouth was “A training roller that can one, travel with us, and two, we can easily maintain here at home.” So, that inspired us to start thinking carefully about how to design an accessible, portable, high quality, low cost training roller for athletes with impairments. Then we decided, well, why not make it not just for athletes but also for the average everyday man, who may not be an athlete but may still be seated and seek fitness.

Figure 2. First generation prototype of The EasyRoller. Shown here is one of the two free-standing roller frames with (1) the aluminium frame with (2) raised feet, (3) conveyor rollers, (4) friction disc brake, and (5) inertial weight (5 lb Olympic weight shown). Source: A novel portable and cost-efficient wheelchair training roller for persons with disabilities in economically disadvantaged settings: The EasyRoller by Scheffers, Marjelle, et al.

Q: Where do you hope this project goes and what implications do you hope it has in the future?

A: Access to fitness equipment is something we may take for granted here in the West but also as members of the mainstream population in terms of us not having physical impairments. So, when you think about the capacity to maintain health, really it has to do with a healthy lifestyle, whether you’re eating well or exercising on a regular basis or just being non-sedentary. We’re hoping by widening the market and diversifying what’s available to people who might be seated, that we encourage increased access and increased attainment of equipment that can help promote health through exercise. It’s really important to recognize that persons with disabilities are monumentally more sedentary that persons who don’t have disabilities; so, this really is a public health crisis in that community. Being able to diversify the market or add to it in any kind of way is important as a primary prevention mechanism for all kind of lifestyle related diseases, whether they’re mental or physical. So, providing access, increasing the access points, is critically important especially since, again, 80% of people with disabilities live in lower resource settings.

Q: Any new tech specs that you want to work on for your next prototype?

A: We want to be able to capture and feed back data related to the athlete’s or the participant’s physiology, whether it’s heart rate or heart rate variability; that would be great to capture and then feed back. Also, power output. Data related to the participant’s physical performance, and athletes mention that this would be great for them as well. It’s very similar to an erg machine where you have a read out that gives you the sense of power that you’re putting out or like a treadmill where you have a sense of how fast you’re going based on the data that’s provided to you from the machine. So, combining mobile tech or tech more generally with the basic prototype would be a huge win.