People with a transtibial amputation worldwide rely on their prosthetic socket to regain their mobility. Patient comfort is largely affected by the weight and strength of these prosthetic sockets. The use of additive manufacturing could give the prosthetist a range of new design possibilities when designing a prosthetic socket. These new design possibilities can in turn lead to improved socket designs and more comfortable prosthetic sockets. This new way of designing and producing prosthetic sockets radically differs from the manual traditional production process. This makes it difficult for prosthetists to understand how all these new design possibilities influence the mechanical properties of the additive manufactured prosthetic socket. Therefore there is a growing need for a method to evaluate the strength and stiffness of newly developed socket designs.We propose a method to evaluate the strength and stiffness of prosthetic sockets. A robotic gait simulator is used to apply realistic kinetics of amputee gait to the tested socket. A Digital Image Correlation (DIC) system is then used to measure the deformation of a prosthetic socket under different loading conditions. This way it is possible to check if plastic deformation will occur in the designed transtibial socket. Furthermore it is possible to assess the effect of cyclic loading on the 3D printed socket.To illustrate the proposed method, a transtibial prosthetic socket was designed using CAD software and produced with laser sintering PA12. DIC measurements were performed on this transtibial socket both before and after it was subjected to a cyclic load of 1 million cycles (mimicking realistic amputee gait).

An innovative tool to optimise the configuration and alignment of lower leg prostheses based on individual comfort needs of the patient will be developed in this project.

condition compared to all others except for the other footwear condition ( p 5 0.001). While peak AJC eversion angle was greater for both footwear conditions, TIR was less when running in footwear ( p 5 0.001). The peak eversion findings may be related to rearfoot motion being over estimated due to tracking the heel counter and not the foot for footwear conditions (Stacoff et al. 1992). The thigh segment angle at TD and peak TIR supported adjustments being made due to mode of cushioning. ConclusionBoth magnitude of cushioning and mode of cushioning affected kinematics while running. Kinematic adaptations while running barefoot versus running shod are not solely due to cushioning differences.

The registration of plantar pressure images is a widely used technique to support human gait analysis. In plantar pressure images, most of the time conventionally derived features are used for further processing. Recently, automatic feature extraction based on PCA and kPCA is being used, to increase the information that can be extracted from this data. In this paper, we describe our work flow and a case study on the application of predicting two pressure features and a non-pressure feature out of the automatically derived PCA features. This includes the normalization of the pressure images, the PCA based feature extraction, and building and testing the regression model based on a linear and kernel SVM.

Background and aim: Foot orthoses alter the kinematics and kinetics in gait. With the increasing importance of evidence based practice and with the permanent development of subtractive manufacturing and introduction of additive manufacturing, there is a growing need for quantification of orthoses parameters. We describe a measurement method and protocol to quantify different parameters of a foot orthosis.Technique: A texture analyser is used to impose a displacement of the surface of the orthosis, while the applied force is measured. The measured points are determined based on the location of anatomical landmarks on the foot. Out of the measured data, parameters are calculated representing the stiffness, compression set and shape.Discussion: To illustrate the proposed technique, five different parameters are extracted from three example orthoses. Results show the added value of the proposed technique as the parameters are not only defined by the material but also by the shape.