Energy cost of propulsion in standard and ultralight wheelchairs in people with spinal cord injuries

Background and Purpose. Wheelchair- and subject-related factors influence the efficiency of wheelchair propulsion. The purpose of this study was to compare wheelchair propulsion in ultralight and standard wheelchairs in people with different levels of spinal cord injury. Subjects. Seventy-four subjects (mean age=26.2 years, SD=7.14, range=17-50) with spinal cord injury resulting in motor loss (30 with tetraplegia and 44 with paraplegia) were studied. Method. Each subject propelled standard and ultralight wheelchairs around an outdoor track at self-selected speeds, while data were collected at 4 predetermined intervals. Speed, distance traveled, and oxygen cost ((V) over dot (O2) mL/kg/m) were compared by wheelchair, group, and over time, using a Bonferroni correction. Results. In the ultralight wheelchair, speed and distance traveled were greater for both subjects with paraplegia and subjects with tetraplegia, whereas (V) over dot (O2) was less only for subjects with paraplegia. Subjects with paraplegia propelled faster and farther than did subjects with tetraplegia. Conclusion and Discussion. The ultralight wheelchair improved the efficiency of propulsion in the tested subjects. Subjects with tetraplegia, especially at the C6 level, are limited in their ability to propel a wheelchair.