WHEELCHAIR FIT SETUP EFFECTS ON PATIENT-REPORTED OUTCOMES AND BIOMECHANICS: AN INTERDISCIPLINARY ANALYSIS ON USER-CENTERED APPROACH OF WHEELCHAIR USE

Abstract

This project investigates the impact of wheelchair fit metrics on propulsion mechanics and functional outcomes in manual wheelchair users with spinal cord injury (SCI) and spina bifida (SB). Ensuring proper wheelchair fit is crucial for optimizing propulsion, comfort, and reducing the risk of injury, especially overuse injuries in patients with spinal cord injury and dysfunction (SCI/D). This project sought to explore and add to literature surrounding the associations between wheelchair fit, patient-reported outcomes (PROs), and propulsion dynamics. This was done by correlating wheelchair fit measures with patient-reported outcomes, elbow angles at top dead center (TDC) and propulsion dynamics. Several group comparisons were also made between adult- and pediatric-onset groups to determine the effect of onset in wheelchair fit, PROs, and propulsion dynamics.Participants completed patient-reported outcomes questionnaires on pain, pain interference, and independence. Using three-dimensional motion capture, quantitative measurements of their wheelchairs were recorded, and propulsion biomechanics were analyzed. The participants were all adults with SCI/D and were separated into adult-onset and pediatricnset groups to explore the differences between the two groups. The project focused on several wheelchair fit measures, including horizontal axle position (HAP), vertical axle position (VAP), backrest height (BH), seat width (SW), and seat dump angle (SDA). The PROs assessed were Wheelchair User’s Shoulder Pain Index (WUSPI), Spinal Cord Independence Measure Version III (SCIM-III), and the Patient-Reported Outcomes Measurement Information System (PROMIS) Adult Pain Interference Short Form 8a. Conservative, non-parametric statistical analysis was used due to the lack of normality in the data set and the small sample size. Spearman’s methods were used for correlation analysis and Wilcoxon rank sum methods were used for group comparisons. One of the key findings of the project was that vertical axle position had a significant positive correlation with PC-WUSPI and PROMIS pain interference scores. It was also determined that the 3D flexion-extension elbow angle had a significant negative correlation with VAP. There was also a significant difference in PROMIS pain interference scores between onset groups, with the adult-onset group having more pain interference than the pediatric-onset group.