Enhancing Rigidity in Folding Wheelchairs The Clinical Corner article, Manual Mobility: The Basics, describes the different categories of manual wheelchairs, known generically as transport, standard, folding, rigid and tilt-in-space. It was noted that the more rigid the wheelchair, the easier it is to propel the chair as rigidity decreases flex in the frame of the chair. The ideal is that all of the energy of propulsion is translated into movement as any frame flex is lost movement. The more rigid the wheelchair, the more efficient the propulsion can be. 2017-04-25 Keep Reading