Student Projects - The Center-Mounted Footrest Redesign

Mid-drive power wheel chairs (PWC) have become more popular in recent years. However, due to the placement of the front casters, the traditional side-mounted footrests have been replaced by a single center-mounted footrest. Unfortunately, center-mounted footrests do not have a lift/lower mechanism that is easily operable by certain PWC users who transfer independently. Many PWC users have limited trunk strength and range of motion, decreased sensitivity in their lower body, and lack of fine motor function. This causes difficulty reaching the footrest to raise it. There is a need for a design solution that allows PWC users to independently lift and lower the footrest.

In order to implement a design solution to address the problem at hand, the students looked to gather more information about all facets of the problem and create, first a set of functional considerations of the target clientele and base functions, and then a set of design specifications and criterion for the design concepts. The students spoke with physical therapists and the PWC users themselves about the issues of stowing the center-mounted footrest. The students came up with four design solutions. The Track Slide Design uses a vertical slide which allows the use of a mobile, rigid moment arm that is attached to the footrest at one end to pull the footrest up and down. The Crank Design solution uses a four bar linkage attached to the footrest that lifts or lowers the footrest when side bar is pulled up. The Motorized Pulley System has a motorized drive shaft that is attached to the hinge on the footrest. The motor uses a belt and gear ratio to allow a slow and safe raising and lowering of the footrest.

Designers/Engineers: Katie Bell, Randy Han, Kimberly Holland, and Taylor Wells

Front view of the track slide design. Side view of the track slide design. Track Slide Design in use. Front view of the motorized pulley design. Side view of the motorized pulley design. Motorized pulley design in use.

For more information on this project, contact Summer Ienuso at ccn@coa.gatech.edu