Wheelchair axle position effect on start-up propulsion performance of persons with tetraplegia

Abstract

Abstract-This repeated measures study assessed the changes in speed, acceleration, stroke frequency, and shoulder range of motion (ROM) associated with different wheelchair axle positions in people with chronic cervical (C) 6 tetraplegia. Our main hypothesis is that the up and forward axle position is the most conducive to wheelchair propulsion, increasing speed and acceleration with a lower stroke frequency. In a chronic spinal cord injury (SCI) unit, we measured the speed, acceleration, stroke frequency, and shoulder ROM in four different axle positions in eight subjects with C6 SCI. We analyzed two startup strokes over a smooth, level vinyl floor in the Motion Analysis Laboratory (Fleni Institute; Escobar, Argentina). We analyzed data for significant statistical differences using the Wilcoxon signed rank test and the Friedman test. Our study showed that the up and forward axle position results in an increase of speed and acceleration, with a higher stroke frequency and a decreased shoulder ROM. In addition, the down and backward axle position results in the lowest speed and acceleration, with a lower stroke frequency and an increased shoulder ROM. The up and forward axle position was the most conducive to stroke compared with other positions we analyzed.

Evaluation of wheelchair resistive forces during straight and turning trajectories across different wheelchair configurations using free-wheeling coast-down test

“…Current clinical practice advocates for a forward axle position based on its advantage from a biomechanical perspective [34][35]. Pitch stability is rightly identified as an important consideration when determining how anterior the axle should be positioned.…”

Impact of rear wheel axle position on upper limb kinematics and electromyography during manual wheelchair use

“…However, in their study they did not find any difference between the two wheel positions with respect to mechanical efficiency, estimated exertion, breathlessness, seating comfort, estimated propulsion qualities, pelvic position or activity performance (Samuelsson et al 2004). Freixes et al (2010) also assessed the changes in speed, acceleration, stroke frequency and shoulder ROM in…”

“…The axle position of down and backward axle position resulted in a lower speed and acceleration with a lower stroke frequency and an increased shoulder ROM. Freixes et al (2010) indicated that these were clinically important findings for wheelchair propulsion in their homes. The improvement of manual wheelchair propulsion has become increasingly important as the population of individuals using wheelchairs is growing and requires efficient mobility to maintain the user's independence and quality of life.…”

Changes in wheelchair biomechanics within the first 120 minutes of practice: spatiotemporal parameters, handrim forces, motor force, rolling resistance and fore-aft stability

“…Highly constraining tasks, such as startup or kerb mounting, can require up to three times more energy expenditure than propulsion [13]. However, in spite of its recurrence in daily life, few studies in the literature focused on propulsion and startup [14,15].…”