Fig. 6

Analysis of propulsion power during the adapted Illinois Agility Test course that included straight, tilted, slalom, and 180°-turning sections. Accumulated positive (green) and negative (red) power output during conventional wheelchair usage is shown on the left, and the steering-by-leaning mode on the right, while the AB group is shown at the top and the WU group below. Respective mean values are provided in the charts. Braking for directional control is central to conventional wheelchair propulsion and especially prevalent on the curve-inner side when turning and on the uphill side when moving along tilted surfaces. Steering-by-leaning reduced the propulsion power required to complete the course by an average 33% and braking by 61%. For visual representation, we interpolated the data from both wheels to a standardised length of 821 datapoints (based on relative section lengths). The power heatmaps were created by overlaying all trials as scatterplots at opacity of 1.5% whereby absolute power was mapped to circle size along the theoretical IAT course