Systems design methodology for personalised design customisation of sports wheelchairs
Creators: name: Usma Alvarez, Clara Cristina
Publisher: name: RMIT University
Year: 2024

description: The state of the art in current wheelchair sports equipment design, demonstrates a steady progression in the process of wheelchair design improvement and adaptation to purpose in order to suit different sporting disciplines and game roles. However, the process of tuning the design of the wheelchair to suit the particular needs of elite athletes in terms of performance and ergonomic requirements, currently requires a research and evidence-based design methodology. This investigation aims to: i) characterise the sports wheelchair activity, including performance variables and design parameters in relation to the three main classification groups of wheelchair rugby athletes (high, mid and low pointers); ii) investigate the rugby wheelchair performance indicators both under game and laboratory conditions and establish critical relationships between wheelchair design parameters and the performance requirements for elite wheelchair rugby athletes; iii) identify the relevant design space for design customisation of rugby wheelchairs for individual wheelchair rugby athletes and the contribution of each design parameter to athlete’s mobility performance; iv) formulate a systems design methodology for design customisation of rugby wheelchairs that can be used to determine a high performance wheelchair design that best matches the requirements of the individual athlete.<br><br>In order to effectively refine the user interphase design of the wheelchair, it is essential to narrow down the key dimensions within the design space, that are likely to have an effect on the performance of an individual athlete. The methods developed and used throughout this thesis are grounded on a number of case studies built on analysis of the test data obtained from elite wheelchair rugby athletes who volunteer for this research project. Initially, the Qualitative Function Deployment (QFD) method is used to systematically analyse data collected through international online surveys, focus groups and questionnaires from elite level wheelchair rugby players. Subsequently, experimental studies conducted on court and in the laboratory yield significant relationships between wheelchair design parameters and task-specific performance functions. Four key design factors (wheel diameter, camber angle, seat height and camber bar depth) are then iterated at incremental dimensional levels to the athlete’s current chair configuration; and tests are performed and analysed through an new extension to the Taguchi method. Subsequent analyses of acceleration, velocity, and time in the push phase of the propulsion cycle, as well as recovery time for each of the participating athletes performing a linear sprint task are correlated to the positive/negative contribution of each of the four design factors to the outlined performance variables as well as their combined effect in a specific wheelchair configuration model. Performance rankings and magnitude-based inferences on the true value of the effect statistic are then used to define a high performance design space for athlete’s wheelchair selection. This process has led to the formulation of a systems design methodology for design customisation of sports wheelchairs, which can be used across the various sporting disciplines to customize wheelchairs that best meet the athlete's needs in terms of performance and ergonomic requirements.