Static strength of lower-limb prosthetic sockets for the activities of daily living

Despite the central role that a prosthetic socket plays as the link between the patient and their prosthesis, yet no common guidelines or standardized methods exist to test their mechanical strength. Consequently, the socket structural properties remain largely unknown. The absence of a method to quantify socket structural strength has negative consequences, such as: the tendency to over-fabricate the socket, a general limitation in the introduction of innovative materials and techniques, and a challenge in complying with the current European regulatory requirements. To overcome these limitations, the authors defined a five-step plan intended to serve as a groundwork in the prosthetic field for the definition of a standardized testing method for prosthetic sockets. This plan includes the systematic analysis and organization of the available literature into key domains, the proposal of recommendations to address the current gaps in knowledge, the design, implementation and application of a test bench system based on the available evidence and on a worst-case approach and, finally, the definition of manufacturing guidelines based on quantitative data to be included in the production process of the INAIL Prosthetic Center. The activities described in this manuscript should guide other researchers of the prosthetic community to take coordinate action in the definition of a standardized method for socket testing.