A system including a mobility-assistance apparatus and a bag. The apparatus includes one or more shafts. The shaft defines a lumen, has an open end in communication with the lumen, and defines a longitudinally-extending slot in communication with the lumen. An end cap is releasably engagable with the open end to enclose the lumen of the shaft. The bag includes a body and one or more attachment members coupled to the bag via flange portion(s). The attachment member is configured for receipt within the lumen of the shaft with the flange portion extending through the slot of the shaft. The attachment member is insertable into and removable from the lumen of the shaft when the end cap is disengaged from the open end of the shaft, and is retained within the lumen of the shaft when the end cap is engaged with the open end of the shaft.