Structural testing of lower-limb prosthetic sockets: A systematic review

A lower-limb prosthetic socket is the custom-made structural element interfacing the residual limb of a person with an amputation to their prosthetic leg comprising off-the-shelf componentry. The socket can be subject to mechanical failure, especially when new fabrication methods and materials are introduced (e.g. 3D printing). Failures can have severe consequences for patients. A systematic review was conducted to collect information about available socket mechanical testing methods, to support the definition of widely accepted guidelines. To this aim the structural testing methods were reviewed, but not the results of the individual studies. 729 records were retrieved, of which 16 articles were included. No articles addressed transfemoral socket testing, as all focused on transtibial sockets. Thirteen articles used some sort of adaptation of ISO 10328, and all of them simulated the toe-off instant of gait, with load level acceptable for patients from 100 to 125 kg of weight. Ten considered a rigid limb dummy. Overall, ISO 10328 appears as a viable starting point for defining a testing guideline, but a considerable number of details has to be agreed upon, starting from clear definitions of anatomical landmarks and socket axes, which are required to implement a representative and repeatable test method.