A validated computational framework to evaluate the stiffness of 3D printed ankle foot orthoses

The purpose of this study was to create and validate a standardized framework for the evaluation of the ankle stiffness of two designs of 3D printed ankle foot orthoses (AFOs). The creation of four finite element (FE) models allowed patient-specific quantification of the stiffness and stress distribution over their specific range of motion during the second rocker of the gait. Validation was performed by comparing the model outputs with the results obtained from a dedicated experimental setup, which showed an overall good agreement with a maximum relative error of 10.38% in plantarflexion and 10.66% in dorsiflexion. The combination of advanced computer modelling algorithms and 3D printing techniques clearly shows potential to further improve the manufacturing process of AFOs

Development and clinical evaluation of laser-sintered ankle foot orthoses

Ankle foot orthoses (AFOs) are traditionally manufactured using vacuum thermoforming as shaping technology. Additive manufacturing has the potential to disruptively change the way these orthopaedic devices are produced. In this study, AFOs are developed which are virtually designed and produced with laser sintering as shaping technology. The mechanical and clinical performances of these laser-sintered AFOs are compared with traditionally manufactured AFO by asking seven patients (both children and adults) to walk with each type of AFO

A review of additive manufacturing studies for producing customized ankle-foot orthoses

Ankle-foot orthoses (AFO) are prescribed to improve the patient’s quality of life. Supporting weak muscles or restraining spastic muscles leads to smoother and more stable locomotion. Commonly, AFO are made using thermoplastic vacuum forming, which requires a long time for production and has limited design options. Additive manufacturing (AM) can solve this problem, leading to a faster and cheaper solution. This review aimed to investigate what is the state-of-art using AM for AFO. Evaluating the used manufacturing processes, customization steps, mechanical properties, and biomechanical features in humans would provide significant insights for further research. The database searches combined AM and AFO with no year or publication type restrictions. Studies must have examined outcomes on human participants with the orthoses built by AM. Other types of orthotic devices or different manufacturing techniques were excluded. Nineteen studies met the inclusion criteria. As stated by having all studies conducted in the last nine years, this is a very recent domain. Different AM processes have been used, with the majority relying on Fused Deposition Modeling. Overall, the manuscripts’ quality is deficient, which is critical to promoting further studies with higher samples. Except for one paper, AM-printed AFO was comparable or superior to the thermoplastic vacuum forming AFO in mechanical tests, kinematics, kinetics, and participant feedback.info:eu-repo/semantics/publishedVersio

Design and Additive Fabrication of Foot and Ankle-Foot Orthoses

Foot and ankle-foot orthoses are prescribed in order to promote mobility through supporting and/or realigning the lower leg and alleviating pain in the foot in different parts of the gait cycle. This paper will outline new approaches to the design and manufacture of personalised foot and ankle-foot orthoses (FO and AFO) using additive fabrication technology. The research is addressing the need for specific software design tools for orthosis design which enable their properties to be locally tailored within a mass customisation framework. Structure/material testing to support that activity is also being undertaken and will be described.Mechanical Engineerin

Patient specific ankle-foot orthoses using rapid prototyping

Background Prefabricated orthotic devices are currently designed to fit a range of patients and therefore they do not provide individualized comfort and function. Custom-fit orthoses are superior to prefabricated orthotic devices from both of the above-mentioned standpoints. However, creating a custom-fit orthosis is a laborious and time-intensive manual process performed by skilled orthotists. Besides, adjustments made to both prefabricated and custom-fit orthoses are carried out in a qualitative manner. So both comfort and function can potentially suffer considerably. A computerized technique for fabricating patient-specific orthotic devices has the potential to provide excellent comfort and allow for changes in the standard design to meet the specific needs of each patient. Methods In this paper, 3D laser scanning is combined with rapid prototyping to create patient-specific orthoses. A novel process was engineered to utilize patient-specific surface data of the patient anatomy as a digital input, manipulate the surface data to an optimal form using Computer Aided Design (CAD) software, and then download the digital output from the CAD software to a rapid prototyping machine for fabrication. Results Two AFOs were rapidly prototyped to demonstrate the proposed process. Gait analysis data of a subject wearing the AFOs indicated that the rapid prototyped AFOs performed comparably to the prefabricated polypropylene design. Conclusions The rapidly prototyped orthoses fabricated in this study provided good fit of the subject's anatomy compared to a prefabricated AFO while delivering comparable function (i.e. mechanical effect on the biomechanics of gait). The rapid fabrication capability is of interest because it has potential for decreasing fabrication time and cost especially when a replacement of the orthosis is required

Virtual design of modular 3D printed ankle foot orthoses

Enkel-voet-ortheses (EVOs) zijn externe medische hulpmiddelen die het natuurlijk looppatroon van patiënten met neurologische en/of musculoskeletale aandoeningen herstellen. Het ontwerp en de mechanische eigenschappen van het EVO zijn afhankelijk van de behoeftes van de patiënt. Het meest gebruikte productieproces is ‘thermoforming’, waarbij de vaardigheid van de vakman gereflecteerd wordt in de prestaties van de EVO. Dit proces laat niet toe om de mechanische eigenschappen aan te passen en te testen, wat eveneens nadelig is voor de efficiëntie en tijdslijn van het productieproces. Additieve productietechnieken kunnen hiervoor een oplossing bieden, waarbij de vorm en functionaliteit gegarandeerd wordt. Deze doctoraatsthesis onderzoekt het potentieel van 3D geprinte EVOs door hun mechanisch gedrag te analyseren met behulp van simulaties en experimenten. Hiervoor werd een experimentele opstelling ontworpen en patiënt-specifieke eindige elementenmodellen opgesteld, die gevalideerd werden met de experimentele resultaten. Deze modellen en experimenten lieten toe om het mechanisch gedrag van de EVOs beter te begrijpen, en geven relevante informatie voor hun toekomstige ontwikkeling om klinische implementatie te bevorderen

The specification and evaluation of personalised footwear for additive manufacturing

The personalisation of footwear offers advantages not only for runners, but to anyone who wishes to become more active. Additive manufacturing (AM) technology has the potential for making footwear personalisation economically feasible by allowing direct manufacture from CAD models and its tool-less capability. This thesis aims to develop and explore the process of footwear personalisation using AM and evaluates such footwear in terms of discomfort and biomechanics. To start to explore this process a repeated measures pilot study was conducted. Six recreational runners had anthropometric measurements of the foot taken and the plantar surface of both feet scanned. From the scans and measurements, personalised glove fit insoles were designed and manufactured using AM. Participants were then fitted with footwear under two experimental conditions (control and personalised), which were compared in terms of discomfort, performance and biomechanics. The findings of this pilot confirmed the feasibility of the personalisation process. A longitudinal study was then conducted to evaluate the short and medium term use of personalised footwear in terms of discomfort and biomechanics. A matched pairs study design was utilised and 38 recreational runners (19 pairs) were recruited. Control (generic shape) and personalised geometry insoles were designed and manufactured using AM. The participants wore the footwear each time they went running for a 3-month period. They also completed an Activity Diary after each training session and attended 4 laboratory sessions during this period. The results showed significantly lower discomfort ratings in the heel area and for overall fit with the personalised insoles. However, discomfort was reported under the arch region for both conditions (supported by the Activity Diary), indicating that the foot scanning position and material may need modifying. With regard to the biomechanics, the personalised insoles also led to significantly lower maximum ankle eversion and lower peak mean pressure under the heel, which are potentially positive effects in terms of reducing injury risk. A case study is then reported which explored foot capture using a dynamic scanner for the design and manufacture of insoles using AM. Through the development of four insoles, it was found that the selection and manipulation of the scan data from the series of frames generated during ground contact were the most demanding elements of the process. Finally, recommendations and guidance are given for the footwear personalisation process (foot scan position, anthropometry, insole design and AM), together with its potential benefits and limitations

The use of 3D surface scanning for the measurement and assessment of the human foot

<p>Abstract</p> <p>Background</p> <p>A number of surface scanning systems with the ability to quickly and easily obtain 3D digital representations of the foot are now commercially available. This review aims to present a summary of the reported use of these technologies in footwear development, the design of customised orthotics, and investigations for other ergonomic purposes related to the foot.</p> <p>Methods</p> <p>The PubMed and ScienceDirect databases were searched. Reference lists and experts in the field were also consulted to identify additional articles. Studies in English which had 3D surface scanning of the foot as an integral element of their protocol were included in the review.</p> <p>Results</p> <p>Thirty-eight articles meeting the search criteria were included. Advantages and disadvantages of using 3D surface scanning systems are highlighted. A meta-analysis of studies using scanners to investigate the changes in foot dimensions during varying levels of weight bearing was carried out.</p> <p>Conclusions</p> <p>Modern 3D surface scanning systems can obtain accurate and repeatable digital representations of the foot shape and have been successfully used in medical, ergonomic and footwear development applications. The increasing affordability of these systems presents opportunities for researchers investigating the foot and for manufacturers of foot related apparel and devices, particularly those interested in producing items that are customised to the individual. Suggestions are made for future areas of research and for the standardization of the protocols used to produce foot scans.</p

3-D printed smart orthotic insoles: Monitoring a person's gait step by step

© 2017 IEEE. This article reports a 3-D printing intelligent insole gait monitoring system based on an embedded fiber Bragg grating (FBG). The smart insole combines 3-D printing technology and FBG sensors providing high sensitivity and end-point low cost. Results using pressure points measured by four FBGs are sufficient to differentiate foot loads and gait types

Mobility in individuals with traumatic lower-limb injuries : implications for device design, surgical intervention and rehabilitation therapies

Traumatic injuries to the extremities are commonly observed in emergency room patients and military personnel in combat. Restoring high mobility and functionality is a primary goal post-injury, which may require the use of rehabilitative devices, surgical interventions, and rehabilitation therapies. The research detailed in this dissertation investigates specific elements of these approaches through the use of experimental study and modeling and simulation. In the first study, the influence of passive-dynamic ankle-foot orthosis bending axis on the gait performance of limb salvage subjects was investigated. Bending axis location was altered by fabricating customized orthosis components using additive manufacturing and was tested in a gait laboratory. Altering bending axis location did not result in large or consistent changes in gait measures, however subjects expressed strong preferences for bending axis condition and preference was strongly related to specific gait measures. This suggests that preference and comfort are important factors guiding the prescription of bending axis location. In the second study, musculoskeletal modeling was used to examine the influence of transfemoral amputation surgical techniques on muscle capacity to generate forces and moments about the hip. Muscle reattachment tension and stabilization were shown to be critical parameters for post-amputation capacity, which supports the use of myodesis stabilization (muscle is reattached directly to bone) in amputation procedures. In the third study, a forward dynamics simulation of transfemoral amputee gait was developed and used to examine individual muscle and prosthesis contributions to walking subtasks. The residual hip muscles, and intact ankle, knee, and hip muscles worked synergistically to provide body support, anteroposterior propulsion, mediolateral control, and leg swing. Increased contributions of contralateral muscles to ipsilateral subtasks as well as increased duration of specific muscle contributions were observed in comparison to non-amputee and transtibial amputee walking. These findings can be used to help develop targeted rehabilitation therapies and improve transfemoral amputee locomotion. Through elucidating the influence of PD-AFO bending axis on gait performance as well as the influence of transfemoral amputation surgical techniques on muscle capacity and function, this research provides a foundation for improved rehabilitation outcomes, and thus mobility for individuals who have experienced traumatic lower-limb injuries.Mechanical Engineerin