Rossi, Erica2026-05-062026-05-062026-05-062026-04-30https://hdl.handle.net/10012/23233The transtibial prosthetic socket is a key component in below-knee prostheses. While technology used to create and augment sockets have been evolving, testing methods have not kept pace. The criterion standard for the testing of transtibial prostheses, ISO 10328, does not specify testing for the socket as a stand-alone unit beyond static compression testing to simulate heel-strike and toe-off components of gait. Additionally, the limb dummies or Mock Residual Limbs (MRLs) used in these testing methods to interface with, and impart loading on, the socket are poorly defined and typically made of non-compliant plaster or polyurethane. This lack of standardization, specifically socket testing, has been identified by the American Orthotics and Prosthetics Association Socket Guidance Workgroup as a major limitation and motivated this thesis. This research aimed to develop a mechanical cyclic gait testing setup utilizing a novel compliant MRL. Ten (10) MRL variations were developed, comprising of an aluminum threaded rod to simulate the tibia and a single or dual-layer of silicone to simulate the skin and soft tissues of the residuum. EcoFlex 00-30 and VytaFlex 30A silicones were selected as the MRL materials to replicate skin and tissue material properties and mechanical behaviour. Three novel 3D printed Spider structures were also developed (50 mm, 70 mm diameter, and Equidistant) and integrated with the tibia rod to promote material adhesion between the rod and the silicone and support load transfer by creating a mechanical interlock with the silicone. Affixed to the VIVO™ Joint Simulator, MRLs were seated into a transtibial prosthetic socket for uniaxial and multiaxial mechanical testing. The VIVO™ enabled custom cyclic gait waveforms representing realistic amputee knee joint forces and moments. These loads were imparted on the socket and enabled the evaluation of MRL mechanical properties. Uniaxial and multiaxial cyclic gait testing of the MRLs and socket system highlighted the ability of the Spider to increase the MRLs response to loading. The 50 mm Spider saw an improved moment loading response, and the 70 mm Spider improved force loading response when integrated with the MRLs. Additionally, increased stiffness of the single layer VytaFlex 30A silicone (compared to the single layer EcoFlex 00-30) allowed for an improved moment loading response of the MRL. The dual-layer (60:40) MRL of VytaFlex 30A and EcoFlex 00-30 further improved MRL force loading response. The top two performing MRLs recommended for further research are the VytaFlex 30A Core, and EcoFlex 00-30 Outer Shell 50 mm Spider MRL and the VytaFlex 30A 50 mm Spider MRL. By leveraging the ability of dynamic mechanical testing this research can act as a bridge between rudimentary bench testing and resource intensive clinical trials – revolutionizing the way socket testing is viewed and promoting more efficient technology development.enprostheticsmultiaxial testingtranstibialprosthetic socketstandardizationgait simulationMaster Thesis