Hello Everybody,
Things have been moving fast and I was very busy finishing up research methods and psychology of leadership. Both courses are complete and I now have more time to focus on my research project.
Since my last blog post I had a great conversations on the phone and on email with Dr. Colin Higgs. Dr. Higgs is one of the leading researchers in the para-sport world and did some amazing pioneer work in researching optimal racing chair design. We talked about some of the challenges and gaps that exist within Paralympic research. It was so interesting to hear about all the projects that Dr. Higgs was and still is involved in. He suggested to me to look at ideal tire pressure for racing wheelchairs. There has been research done on bicycles and every-day use wheelchairs but the fact that racing wheelchairs are propelled on a synthetic track changes the demands for tire pressure and it might be depending on weight and also the hardness of the track.
Dr. Higgs and I discussed the potential use of an accelerometer called raspberrypi. https://www.raspberrypi.org. This micro-processor that can act as a 3 axis accelerometer could detect acceleration and deceleration and give me data on the rolling friction on the racing chairs for different tire pressures. We also discussed the hypothesis of having different ideal tire pressures for different body weights. Instead of using the same athlete we could replace the subjects by sand bags and explore the relationship of different weights and tire pressures.
A study done by Barbosa et al. in 2019 looked at using a smart phone accelerometer app to collect acceleration and deceleration data for wheelchair racing. They concluded that the smart phone had a 16%-22% error margin and that the smart phone might not be a reliable instrument to assess wheelchair racing performance.
To be honest I’m a little bit intimated using a technology I have never used before. When I started this masters I did not think that I would be delving this much into using technology in order to collect the data. However this will be a great opportunity to learn more about accelerometers and data collection which is widely used in the field of exercise science and I’m looking forward to it.
Coach Ueli
Ueli, interesting topic and I am glad you are having discussions with Colin. I a curious to know how much tire pressure actually contributes to the different KPIs in WC racing. As a totally ignorant observer, I might think that there are 3 factors that impact any race. 1. Accelerating to speed. 2. Maintaining Speed (Resisting deceleration), and 3. Maintaining speed in corners. Therefore my questions would be to what extent does tire pressure contribute to these factors. Of course there is are other physiological, technical, mental elements that could equalling contribute to the 3 KPIs above, so it would be interesting to know the % contribution that equipment (tire pressure) can add to (or take away from) the performance in each of the 3 areas. The challenge will be identify your research methods. My initial thought is that any statistical model would have to be a within subject design as you will need to control for all of the extraneous factors above plus consistency of the testing environment (same heat, wind, moisture etc). I suppose that if all of these factors can be relatively well controlled (indoors) or measured, then you could simply look at adjusting tire pressure and see the effect on the different KPIs and overall time-trial performance. Anyway, as indicated these are only the thoughts of the ignorant and naive.
Oh yeah.. one more crazy thought. Is there any advantage to incrementally adjusting pressure between right and left wheels? For example can tire pressure be tuned to the athletes abilities to generate push if one arm is more dominant than the other, or does this really matter? Or is there an advantage in different tire pressures for cornering? ie. the right tire actually travels a longer distance in the race than the left tire and does this really matter?
Thanks Dave,
There are definitely many factors that will play in when it comes to wheelchair racing performance. I think the reason I believe the tire pressure is significant is due to my conversation with Dr. Colins but also perusal observation of athletes and their behaviour in choosing tire pressure. This easy to manipulate factor is often done in a very subjective matter and a lot of athletes don’t even monitor their tire pressure and go by feel. However I did find some studies on rolling resistance and tire pressure on day chairs. The pressure for those tires is a lot lower but there were significant differences especially for softer surfaces. This makes me believe it’s an important factor and something that can be so easy manipulated. As for the curves I could not find any studies at the moment but it would be interesting to investigate this as well. I have been talking to the biomechanics department at Dalhousie University and I’m looking at the best ways of measuring deceleration. It was mentioned to me that having the athletes in the chair would increase external validity as the forces apply more to real life. However the challenge will be for the athletes to remain in the same position and be fairly consistent in the their incoming speed. So many things at the moment. There is much more literature out there and I will investigate further into an ideal research proposal. I’m fortunate enough to have a lot of experts in my corner and also now having access to data collection instruments through Dalhousie University will really help me out.