Variability among Practitioners in Dynamic Observational Alignment of a Transfemoral Prosthesis

The most innovative technology in prosthetic components cannot fulfill its objective without a proper patient interface and a proper alignment. Alignment, the orientation of components with respect to one another, is an area of prosthetic practice in which quantification and repeatability are not clearly defined. Researchers have sought an optimum standard and methods for automated alignment. Before automation is sought, variability among practitioners using current methods should be assessed. This investigation determined the outcomes of the alignment of five different prosthetic practitioners given the same subject and components using kinematic and kinetic gait analysis. Differences in static alignment were quantified through instrumented gait analysis; however, these differences were relatively small. Similar small differences were noted in gait velocity and ground reaction force, and bilateral joint angles during walking were very similar. This consistency among practitioners with varying levels of experience suggests that automated alignment is probably feasible but may not be necessary.