Three-dimensional foot shape analysis in children : a pilot analysis using three-dimensional shape descriptors

Existing clinical measures to describe foot morphology are limited in that they are commonly two-dimensional, low in resolution and accuracy, and do not accurately represent the multi-planar and complex changes during development across childhood. Using three-dimensional (3D) scanner technology provides the opportunity to understand more about morphological changes throughout childhood with higher resolution and potentially more relevant 3D shape measures. This is important to advance the prevailing arguments about the typical development of children's feet and inform the development of appropriate clinical measures. 3D shape descriptors derived from 3D scanning can be used to quantify changes in shape at each point of the 3D surface. The aim of this study was to determine whether 3D shape descriptors derived from 3D scanning data can identify differences in foot morphology between children of different ages. Fifteen children were recruited from three age groups (2, 5, and 7 years of age). Both feet were scanned in bipedal stance, using the Artec Eva (Artec Group, Luxembourg, Luxembourg) hand-held scanner. Three dimensional shape descriptors were extracted from the 3D scans of the right foot, to create histograms for each age group and heat maps of representative participants for comparison. There were changes to the dorsal, medial and lateral surfaces of the feet with age. The surfaces became less round along with an increase in indented areas. This is supported by the heat maps which demonstrated that the surfaces of the anatomical landmarks (e.g. the malleoli and navicular tuberosity) became more rounded and protruding, with indented surfaces appearing around these landmarks. On the plantar surface, the concavity of the midfoot was evident and this concavity extended into the midfoot from the medial aspect as age increased. The findings of this study indicated that with increasing age the foot becomes thinner in 3D, with bony architecture emerging, and the medial longitudinal arch (MLA) increases in area and concavity. Three-dimensional shape descriptors have shown good potential for locating and quantifying changes in foot structure across childhood. Three-dimensional shape descriptor data will be beneficial for understanding more about foot development and quantifying changes over time

Multimodal spatial mapping and visualisation of Dinaledi Chamber and Rising Star Cave

The Dinaledi Chamber of the Rising Star Cave has yielded 1550 identifiable fossil elements – representing the largest single collection of fossil hominin material found on the African continent to date. The fossil chamber in which Homo naledi was found was accessible only through a near-vertical chute that presented immense practical and methodological limitations on the excavation and recording methods that could be used within the Cave. In response to practical challenges, a multimodal set of recording and survey methods was thus developed and employed: (1) recording of fossils and the excavation process was achieved through the use of white-light photogrammetry and laser scanning; (2) mapping of the Dinaledi Chamber was accomplished by means of high-resolution laser scanning, with scans running from the excavation site to the ground surface and the cave entrance; (3) at ground surface, the integration of conventional surveying techniques as well as photogrammetry with the use of an unmanned aerial vehicle was applied. Point cloud data were used to provide a centralised and common data structure for conversion and to corroborate the influx of different data collection methods and input formats. Data collected with these methods were applied to the excavations, mapping and surveying of the Dinaledi Chamber and the Rising Star Cave. This multimodal approach provides a comprehensive spatial framework from individual bones to landscape level

Feature-Based Models for Three-Dimensional Data Fitting.

There are numerous techniques available for fitting a surface to any supplied data set. The feature-based modeling technique takes advantage of the known, geometric shape of the data by deforming a model having this generic shape to approximate the data. The model is constructed as a rational B-spline surface with characteristic features superimposed on its definition. The first step in the fitting process is to align the model with a data set using the center of mass, principal axes and/or landmarks. Using this initial orientation, the position, rotation and scale parameters are optimized using a Newton-type optimization of a least squares cost function. Once aligned, features embedded within the model, corresponding to pertinent characteristics of the shape, are used to improve the fit of the model to the data. Finally, the control vertex weights and positions of the rational B-spline model are optimized to approximate the data to within a specified tolerance. Since the characteristic features are defined within the model a creation, important measures are easily extracted from a data set, once fit. The feature-based modeling approach is demonstrated in two-dimensions by the fitting of five facial, silhouette profiles and in three-dimensions by the fitting of eleven human foot scans. The algorithm is tested for sensitivity to data distribution and structure and the extracted measures are tested for repeatability and accuracy. Limitations within the current implementation, future work and potential applications are also provided

ToScA North America (6 – 8 June 2017, The University of Texas, Austin, TX) Program

ToScA North America will address key areas of science, including Multi-modal Imaging, Geosciences, Forensics, Increasing Contrast, Educational Outreach, Data, Materials Science and Medical and Biological Science.University of Texas High-Resolution X-ray CT Facility (UTCT); Jackson School of Geosciences, The University of Texas at Austin; Natural History Museum (London); Royal Microscopical Society (Oxford, UK)Geological Science

Just find it: The Mymo approach to recommend running shoes

Wearing inappropriate running shoes may lead to unnecessary injury through continued strain upon the lower extremities; potentially damaging a runner’s performance. Many technologies have been developed for accurate shoe recommendation, which centre on running gait analysis. However, these often require supervised use in the laboratory/shop or exhibit too high a cost for personal use. This work addresses the need for a deployable, inexpensive product with the ability to accurately assess running shoe-type recommendation. This was achieved through quantitative analysis of the running gait from 203 individuals through use of a tri-axial accelerometer and tri-axial gyroscope-based wearable (Mymo). In combination with a custom neural network to provide the shoe-type classifications running within the cloud, we experience an accuracy of 94.6 in classifying the correct type of shoe across unseen test data

Six Degrees of Freedom: Kinematics of the Healthy Ankle Syndesmosis Joint

Syndesmotic injury, more commonly known as a high ankle sprain , accounts for over 12% of all ankle sprain incidents in the US; of which, over 25% occur during a sporting activity. Typically, harm to the syndesmosis occurs in sports such as football, soccer, lacrosse, and hockey where it is common for an athlete to experience rapid and extreme dorsiflexion-external rotations of the foot. Severe syndesmotic sprains have been noted by clinicians as the most difficult ankle injury to accurately diagnose and treat, require the most recuperation time, and often results in life-long dysfunction. Even more problematic, 40% of patients suffering from a high ankle sprain also report joint instability 6 months after the initial injury. The distal tibiofibular syndesmosis joint consists of a fibrous interosseous membrane and four stabilizing ligaments, allowing for only slight movements of the fibula about the tibia. These distal bone surfaces closely articulate with the talus to form a stable mortise joint, giving the ankle joint complex its hinge-like range of motion (ROM). In the case of severe ankle sprains, excessive external rotation, dorsiflexion, and eversion of the foot can cause tearing of these stabilizing ligaments, distraction of the bones, or even fracture. A rigid screw fixation method is the standard practice for repair in these severe cases, although new dynamic fixation techniques using sutures and buttons instead of a screw are thought to allow for a more natural motion of the joint during healing and better post-operative results. However, most research of the ankle joint complex has primarily been dedicated to the talocrural joint formed between the talus and tibia, where the fibula is treated as single segment with the tibia. Very little research has been dedicated towards understanding the unique role the fibula plays in dynamic weight-bearing tasks to overall ankle joint strength, stability, and mobility. This gap in knowledge of fibular articulation and load bearing, lends to the difficulty and inaccuracy in properly reducing the bones during syndesmotic fixation. There also lacks a clear and consistent method for syndesmotic fixation with minimal validation that dynamic fixation heeds superior post-operative results. Gaining insight on healthy syndesmosis joint motion could provide baseline measures for more realistic loading conditions of cadaveric testing various fixation devices, serve as design parameters for new device design, set a gold standard for normal range of motion (ROM) in rehabilitation, and ultimately improve diagnostic and treatment modalities for syndesmotic injury. The goals of the project were to establish a standard for the six degree of freedom (DOF) kinematics in the syndesmosis and talocrural joints in healthy active adults, as well as define the normal ROM. This was done using a high speed stereo radiography (HSSR) system to capture dual plane in-vivo motion of the bones with sub-millimeter and sub-degree accuracy. Changes in bone positioning during static and dynamic weight bearing activities were compared to a non-weight bearing neutral pose of the foot. The second scope of this work defines average values of medial and lateral clear space widening between the bones. Both are current clinical measures used to gauge the degree of ankle injury and instability present. Knowing the kinematics of the bones primarily responsible for stability of the ankle joint complex, along with their expected distraction between each other could help bridge the gap in the diagnosis and treatment of severe high ankle sprains, as well as reduce the risk of incorrect healing and chronic ankle instability