Figure 2
From: The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion
Definitions of start angle and end angle. (A) The start angle is the angle between the line which connects the initial hand-rim contact point of the propulsion phase to the wheel center and the vertical line. (B) The end angle is the angle between the line which connects the final hand-rim contact point of the propulsion phase to the wheel center and the vertical line.