A pilot study to characterize racing wheelchair propulsion biomechanics in virtual reality and the real-world for a 1500-meter indoor track

• Author / Creator

  Hampshire, Sydney Maria Turai

• Many of the 65 million wheelchair users in the world rely on their upper extremity to propel themselves in a manual wheelchair. Unfortunately, the human shoulder is not designed for the imbalanced and extreme forces required to propel a manual wheelchair in our built environments. Upper extremity pain and pathologies associated with manual wheelchair propulsion arise quickly after confinement to a manual wheelchair. Understanding propulsion styles and remedial training of manual wheelchair users is vital, something that may be done effectively in a virtual reality simulation.
  The purpose of this pilot study was to develop a research protocol, identify issues with the virtual reality simulation, and examine dynamics measurements taken in the real-world and compare them to dynamics measurements taken in virtual reality. The long-term goal of this research is to optimize a wheelchair track athlete’s performance and enable them to propel themselves with a more efficient propulsion technique that also minimizes their risk of injury. Doing so should assist all manual wheelchair users by creating balance in the muscles of the upper extremities and reduce what are currently inevitable injuries.
  This was a confirmatory research, longitudinal study. It explored the hypotheses that there was no difference between in dynamics measures and reported perceived experience in the real-world and in a virtual world.
  Ten healthy and physically active non-disabled individuals were observed as they propelled a racing wheelchair for 1500-meters around a track in the real-world and a representation of the track in a virtual environment. Participants were 20 – 24 years old. The virtual world incorporated an instrumented wheelchair ergometer capable of simulating the inertia of the participants and wheelchair. Dynamic (ergometer and wearable dynamic device) and qualitative data on perceived presence and exertion as well as upper extremity pain in the virtual environment (questionnaires) were gathered. Participants propelled at their own set pace in both environments and were not full-time manual wheelchair users.
  Steady state cadence, acceleration, steady state and ramp up phase power, ramp up phase force, and the time interval were not different between the two test environments, implying that overall power and the rolling resistance were also not different. Whole test cadence, ramp up and average velocity, distance traveled, time taken to complete the test, ramp up energy, and ramp up push number were all different between the two test environments. Presence and immersion in VR can still be improved, supported by a relatively low average reported presence. Visually induced motion sickness was not experienced by study participants. Shoulder pain in daily living was reported as zeroes or “not performed” and did not differ between the two test environments. The shoulder and overall test areas had different levels of reported exertion between the two test environments. The 1500-meters time point was the most similar test time point between the two test environments. No significant differences between the RW pretest and post-test shoulder pain, but there were significant differences between the VR pretest and post-test shoulder pain.
  The study failed to reject the null hypothesis that there was no significant differences between the dynamics measurements and perceived experiences of the study participants in the two environments. This was likely due to a high variance in the mechanical parameters of the virtual simulation. Participants reported a moderate visual representation of the real-world in the virtual world, no motion sickness, a relatively low level of exertion, and no shoulder pain. However, the virtual world did not fully represent the real-world in a physical way. The dynamics settings of the wheelchair ergometer need to be further adjusted, specifically the inertia weight settings.
  This pilot study shows significant differences in dynamic and self-reported measures between the two environments. Improvements to the design of the virtual reality system were identified and procedures for collecting training session data and calibrating the ergometer system were developed.

• Subjects / Keywords

  • percieved presence
  • wheelchair
  • virtual reality
  • ergometer
  • indoor track
  • propulsion
  • shoulder pain
  • real-world
  • racing wheelchair
  • real world
  • dynamics
  • percieved exertion

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-cbwh-g007

• License

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