PhD Defense by Jui-Te (Ray) Lin
In partial fulfillment of the Requirements for the Degree of
Doctor of Philosophy in Applied Physiology
Jui-Te (Ray) Lin
Will defend his thesis
"The influence of wheelchair mechanical parameters and human physiological fitness on propulsion effort"
Friday, October 28
555 14th Street, Room 1253
Dr. Stephen H. Sprigle
Dr. Minoru "Shino" Shinohara
Dr. Mindy L. Millard-Stafford
Dr. Teresa K. Snow
Dr. Randy Trumbower
For wheelchair users, the ease of maneuvering a wheelchair is crucial for their mobility and participation in their communities, thus improving their quality of the life. From a mechanical design standpoint, the major factors influencing propulsion efforts are inertia and frictional energy loss. On a wheelchair with greater inertia and/or greater frictional loss, a user needs to exert greater instantaneous forces and metabolic costs while completing a maneuver. Greater propulsion effort can lead to difficulty in achieving the desired speed and a higher probability of fatigue over long bouts of mobility. The majority of wheelchair studies that attempt to evaluate propulsion efforts across wheelchair configurations examines long and steady propulsion. However, the results of these studies cannot represent performance during daily maneuvers, which include changes in speed and direction. Physiological fitness was proved to be related to health status and exercise performance. In addition, the biomechanical characteristics of the user were widely studied in the impact of wheelchair maneuvers. However, it is still unknown how these operator factors would influence daily wheelchair propulsions. Therefore, the overall objective of the study is to define the relative influence of mechanical wheelchair parameters as well as individual physiological and biomechanical variables on propulsion efforts during over-ground maneuvers.
To meet the overall objective, we define three specific aims. The first is to develop and validate a test that quantifies the impact of wheelchair configurations on frictional energy loss, particularly loss related to turning trajectories. The second is to develop and validate a testing protocol designed to measure maximum propulsion strength, which will test subjects in a realistic condition – while seated in their wheelchairs. The third is to identify the impact of the mechanical parameters of wheelchairs as well as the physiological and biomechanical variables of operators on propulsion efforts during over-ground maneuvers. Mechanical parameters include both inertial and frictional measurements. Operator factors include shoulder position, propulsion strength, and aerobic capacity. Biomechanics studies commonly control for these operator factors, which this study will analyze to evaluate the physiological fitness of wheelchair users. To evaluate the performance of daily maneuvering, we designed a repeatable maneuver consisting of several momentum changes. Because of the breadth of wheelchair configurations and variance in user physical capacity, it is necessary to define the effects of wheelchair configurations and user fitness on propulsion. Clinicians can use such information to select equipment and prescribe exercise to wheelchair users, and manufacturers can use it to improve wheelchair design.
- Workflow Status: Published
- Created By: Tatianna Richardson
- Created: 10/17/2016
- Modified By: Tatianna Richardson
- Modified: 10/17/2016