To be able to get front casters and then rear wheels up a kerb or small step. To descend kerbs and single steps in one safe controlled action.
Back wheel balance (BWB). This skill can look flash on the dance floor but is in turn the start of kerb ascent and descent. BWB is also used to negotiate the chair over grass, shingle and other difficult terrain, and to control steep ramp descent.
Understanding ramp ascent and descent can help you use ramps in a controlled way and prevent you losing control.
Descend stairs or steps safely, and identify where this is and is not safe and practical to do so.