Design Of Orthosis Research Articles

Designing Hand Orthoses: Advances and Challenges in Material Extrusion

The intricate structure of human hands requires personalized orthotic treatments, especially with the growing aging population’s demand for accessible care. While traditional orthoses are effective, they face challenges of cost, customization time, and accessibility. Additive manufacturing, particularly material extrusion (MEX) techniques, can effectively address challenges in orthotic device production by enabling automated, complex, and cost-effective solutions. This work aims to provide engineers with a comprehensive set of design considerations for developing hand orthoses using MEX technology, focusing on applying design for additive manufacturing principles, to enhance rehabilitation outcomes. This objective is achieved by establishing design requirements for hand orthoses, reviewing design choices and methodologies across conventional and state-of-the-art MEX-based devices, and proposing an innovative approach to orthotic design. Hand orthosis design requirements were gathered through workshops with occupational therapists and categorized into engineer-, medical-, and patient-specific needs. A review of 3D-printed hand orthoses using MEX analyzes various design approaches, providing insights into existing solutions. The study introduces a modular design concept aimed at improving rehabilitation by enhancing customizability and functionality. It highlights the potential of MEX for creating personalized, cost-effective orthoses and offers recommendations for future research, to optimize designs and improve patient outcomes.

Patient-specific design and fabrication of a trapeziometacarpal joint orthosis using a computed tomography image-based finite element model

Patient-specific design and fabrication of a trapeziometacarpal joint orthosis using a computed tomography image-based finite element model

Efficacy of a Modified Thoracolumbosacral Orthosis in Adult Idiopathic Scoliosis: A Case Study

Background and Objectives: Adult patients with late-onset idiopathic scoliosis (LIS) presents with cosmetic concerns, back pain, muscle fatigue and the psychological effects of living with a visible deformity. The purpose of this study was to evaluate the effectiveness of modified thoracolumbosacral orthosis on adult female patient with LIS who had been suffering from chronic back pain still refusing for spinal surgery. Case Report: A 27-year-old female patient clinically diagnosed with late onset left LIS with apex at T8 level reported to our institute for spinal rehabilitation with orthotic management. She was completely examined for radiographic findings and treated with physiotherapy and modified thoracolumbosacral orthosis with anterior corset and turn buckle device for gradual correction of deformity and spinal alignment. At a 12-month follow-up, the patient no longer suffered from daily low back pain (LBP) (with heavy lifting only) and was fully active. Additionally, her post intervention radiographs showed an improvement in left thoracic scoliosis and coronal balance. Conclusion: This study suggests that the new modified custom-made design of spinal orthosis may be effective in the management of adult LIS and it represents an acceptable alternative to surgery for patients who refused for surgery.

Anatomical-Based Customized Cervical Orthosis Design in Automation

Cervical orthoses, vital for neck immobilization in medical care and sports, often struggle to provide adequate support due to individual neck shape and size variations. This study addresses this issue by developing a specific computer-aided orthosis design software tailored for creating customized 3D-printed cervical orthoses. The self-developed software embedded anatomical and rehabilitation knowledge into the orthosis design process, ensuring consistency and reducing manual modification. Finite element analysis of cervical orthoses determined that a minimum thickness of 5 mm PLA (polylactic acid) material is necessary to meet safety requirements. This study highlights the automation potential of customized computer-aided orthosis design and underscores the potential to revolutionize orthopedic care. We also applied easy-to-access 3D printing technology to fabricate well-fitting and immobilized cervical orthoses. These customized cervical orthoses offer a promising future with the advantages of being cost-effective, lightweight, immobility, comfortable, easy to wear, and minimal accessories to meet clinical needs, enhancing patient comfort and compliance and providing reassurance about the economic benefits of the technology.

The suppression of lower leg electromyography when walking in textured foot orthoses.

Previous research exploring the effects of tactile feedback in standing balance protocols may have generated results that misrepresent the modulatory capabilities of cutaneous afference on generating motor output responses. The neurosensory mechanism of textured foot orthoses to maximize the activation of cutaneous mechanoreceptors is through repetitive foot sole skin indentation. Thus, the purpose of this experimental protocol was to investigate muscular activity amplitude changes during the stance phase of gait, specifically when walking on level ground and when stepping onto a raised wedge, and while wearing textured foot orthoses compared to orthoses without texture. Twenty-one healthy young adults were fit to a standardized neutral running shoe and completed five level and wedged walking trials wearing both orthoses. Kinematic, kinetic and electromyography (EMG) data were recorded from eight lower limb muscles. The results of this study revealed EMG suppression of lower leg musculature during stance when walking in textured foot orthoses,and this was most pronounced when lower leg musculature is typically most active. The addition of texture in foot orthoses design, spanning the entire length of the foot sole, appears to be a clear mechanism to modulate neurosensory feedback with intent to suppress EMG of shank musculature during gait.

A New Automatic Process Based on Generative Design for CAD Modeling and Manufacturing of Customized Orthosis

As is widely recognized, advancements in new design and rapid prototyping techniques such as CAD modeling and 3D printing are pioneering individualized medicine, facilitating the implementation of new methodologies for creating customized orthoses. The aim of this paper is to develop a new automatic technique for producing personalized orthoses in a straightforward manner, eliminating the necessity for doctors to collaborate directly with technicians. A novel design method for creating customized wrist orthoses has been implemented, notably featuring a generative algorithm for the parametric modeling of the orthosis. To assess the efficacy of the developed algorithm, a case study was conducted involving the design and rapid prototyping of a wrist orthosis using Fused Deposition Modeling (FDM) technology. Subsequently, the developed algorithm was tested by clinicians and patients. The results obtained indicate that the implemented algorithm is user-friendly and could potentially enable non-expert users to design customized orthoses. These results introduce innovative elements of originality within the CAD modeling, offering promising solutions to the challenges associated with the design and production of customized orthoses. Future developments could consist of a better investigation regarding the parameters that influence the accuracy of the scanning and of the printing processes.

Effectiveness of Custom-Made Designed and 3D-Printed Wrist-Driven Orthoses on Grasp Strength of Lost Hand Function

ABSTRACT Introduction Wrist-driven orthoses can be used in people who have lost their hand functions to a certain extent. The orthoses are designed to harness residual wrist power and convert it with a mechanism to move the fingers. We developed 3D-printed wrist-driven orthoses for spastic hands and improved three-point grasp between thumb and index-middle fingers’ function. Methods Three orthoses were designed and manufactured for two participants with and without extension assists according to children’s needs. This study presents 3D designing and printing of three orthoses and investigates the effectiveness on the pinch force and daily living activities for participants with loss of hand function. Results Custom-made 3D-printed wrist-driven orthoses that provide hand function and are functional, lightweight, and aesthetically pleasing were manufactured in a shorter duration than conventional orthoses. Discussion This technique is acceptable and improves function of spastic and different traumatically injured hands. A wrist-driven orthosis was used in the treatment of 2 patients. It was found that the pinch force and the performance in daily living activities had increased. Complete joint alignment was guaranteed, and the orthoses were aesthetically pleasing and light. Clinical Relevance This study is clinically relevant since it gives a suitable, easy to produce, modifiable, economic orthosis design while continuing to provide comfortable, durable, and lightweight design.

A systematic review of the explicit knowledge used and evidence base in the process of design and fabrication of orthopedic footwear

BACKGROUND: The design and manufacturing of effective foot orthoses is a complex multidisciplinary problem involving biomedical and gait pattern aspects, technical material and geometric design elements as well as psychological and social contexts. This complexity contributes to the current trial-and-error and experience-based orthopedic footwear practice in which a major part of the expertise is implicit. This hampers knowledge transfer, reproducibility and innovation. OBJECTIVE/METHODS: A systematic review of literature has been performed to find evidence of explicit knowledge, quantitative guidelines and design motivations of pedorthists. RESULTS: 17 studies have been included. No consensus is found on which measurable parameters ensure proper foot and ankle functioning. Parameters suggested are: neutral foot positioning and control of rearfoot motion, maximum arch, but also tibial internal/external rotation as well as a three point force system. Also studies evaluating foot orthoses centering on the diagnosis or orthosis type find no clear guidelines for treatment or for measuring the effectiveness. CONCLUSIONS: A gap in the translation from diagnosis to a specific, customized and quantified effective orthosis design is identified. Suggested solutions are both top-down, fitting of patient data in simulations, as well as bottom-up, quantifying current practices of pedorthists in order to develop new practical guidelines and evidence-based procedures.

Identification of excessive contact pressures under hand orthosis based on finite element analysis.

Implicit magnitudes and distribution of excessive contact pressures under hand orthoses hinder clinicians from precisely adjusting them to relieve the pressures. To address this, contact pressure under a hand orthosis were analysed using finite element method. This paper proposed a method to numerically predict the relatively high magnitudes and critical distribution of contact pressures under hand orthosis through finite element analysis, to identify excessive contact pressure locations. The finite element model was established consisting of the hand, orthosis and bones. The hand and bones were assumed to be homogeneous and elastic bodies, and the orthosis was considered as an isotropic and elastic shell. Two predictions were conducted by assigning either low (fat) or high (skin) material stiffness to the hand model to attain the range of pressure magnitudes. An experiment was conducted to measure contact pressures at the predicted pressure locations. Identical pressure distributions were obtained from both predictions with relatively high pressure values disseminated at 12 anatomical locations. The highest magnitude was found at the thumb metacarpophalangeal joint with the maximum pressure range from 13 to 78 KPa. The measured values were within the predicted range of pressure magnitudes. Moreover, 6 excessive contact pressure locations were identified. The proposed method was verified by the measurement results. It renders understanding of interface conditions underneath the orthosis to inform clinicians regarding orthosis design and adjustment. It could also guide the development of 3D printed or sensorised orthosis by indicating optimal locations for perforations or pressure sensors.

Design and optimization of lower limb exoskeleton based on multi-axis knee joint

PurposeThe purpose of this paper is to improve the problem of kinematics incompatibility of human–exoskeleton in the existing rigid lower-limb exoskeleton (LLE).Design/methodology/approachIn this paper, following an introduction, the motion characteristics of the human knee joint and the design method of the exoskeleton were introduced. A kinematics model of the LLE based on cross-four-bar linkage was obtained. The structural parameters of the LLE mechanism were optimized by the particle swarm optimization algorithm. The predefined trajectories used in the optimization process were derived from the ankle joint, not the instantaneous center of rotation of the knee joint. Finally, the motion deviation of the optimization result was simulated, and the human–exoskeleton coordination experiment was designed to compare with the traditional single-axis knee joint in terms of comfort and coordination.FindingsThe lower limb exoskeleton mechanism obtained in this paper has a good tracking effect on human movement and has been improved in terms of comfort and coordination compared with the traditional single-axis knee joint.Originality/valueThe customized exoskeleton design method introduced in this paper is relatively simple, and the obtained exoskeleton has better movement coordination than the traditional exoskeleton. It can provide a reference for the design of lower limb exoskeleton and lower limb orthosis.

Empowering Rehabilitation: Design and Structural Analysis of a Low-Cost 3D-Printed Smart Orthosis.

Three-dimensional (3D) printing of polymer materials encompasses a wide range of applications and innovations. Polymer-based 3D printing, also known as additive manufacturing, has gained significant attention due to its versatility, cost-effectiveness, and potential to revolutionize various industries. The current paper focuses on obtaining a durable low-cost rehabilitation knee orthosis. Researchers propose that the entire structure should be obtained using modern equipment within the additive manufacturing domain-3D printing. The researchers focus on determining, through a 3D analysis of the entire 3D model assembly, which parts present a high degree of stress when a kinematic simulation is developed. The entire 3D model of the orthosis starts based on the result obtained from a 3D scanning of the knee joint of a patient, providing a precise fixation, and allowing for direct personalization. Based on the results and identification of the critical parts, there will be used different materials and a combination of 3D printing strategies to validate the physical model of the entire orthosis. For the manufacturing process, the researchers use two types of low-cost fused filament fabrication (FFF), which are easy to find on the worldwide market. The motivation for manufacturing the entire assembly using 3D printing techniques is the short time in which complex shapes can be obtained, which is relevant for the present study. The main purpose of the present research is to advance orthotic technology by developing an innovative knee brace made of 3D-printed polymers that are designed to be lightweight, easy-to-use, and provide comfort and functionality to patients during the rehabilitation process.

Foot offloading associated with carbon fiber orthosis use: A pilot study

BackgroundTraumatic lower limb injuries can result in chronic pain. Orthotic interventions are a leading conservative approach to reduce pain, manage loading, and protect the foot. Robust carbon fiber custom dynamic orthoses (CDOs) designed for military service members have been shown to reduce foot loading. However, the effect of carbon fiber orthosis design, including designs widely used in the civilian sector, on foot loading is unknown. Research questionDetermine if carbon fiber orthoses alter foot loading during gait. MethodsLoadsol insoles were used to measure peak forces and force impulse acting on the forefoot, midfoot, hindfoot, and total foot. Nine healthy, able-bodied individuals participated. Force impulse was quantified as cumulative loading throughout stance phase. Participants walked without an orthosis and with three carbon fiber orthoses of differing designs: a Firm stiffness CDO, a Moderate stiffness CDO, and a medial and lateral strut orthosis (MLSO). ResultsThere were significant main effects of orthosis condition on peak forefoot forces as well as forefoot and hindfoot force impulse. Peak forefoot forces were significantly lower in the Moderate and Firm CDOs compared to no orthosis and MLSO. Compared to walking without an orthosis, forefoot force impulse was significantly lower and hindfoot force impulse was significantly greater in all carbon fiber orthoses. Additionally, hindfoot force impulse in the Firm CDO was significantly higher than in the MLSO and Moderate CDO. SignificanceThe three carbon fiber orthosis designs differed regarding foot loading, with more robust orthoses providing greater forefoot offloading. Orthosis-related changes in forefoot loading suggest that carbon fiber orthoses could reduce loading-associated pain during gait. However, increased hindfoot force impulse suggests caution should be used when considering carbon fiber orthoses for individuals at risk of skin breakdown with repetitive loading.

Development of elbow rehabilitation device with iterative learning control and internet of things

In this study, we present a novel approach for rehabilitation devices through the design of an active elbow joint orthosis, inspired by the fundamental principles of robotic exoskeletons. The device not only enables home-based usage but also facilitates the transmission of exercise data from patients to physiotherapists via the Internet of Things (IoT) device. This approach offers the possibility of increased therapy sessions for each patient while allowing physiotherapists access to data for real-time or subsequent analyses, thereby establishing a database. This permits a single physiotherapist to manage multiple patients more effectively. The developed mobile application within this research incorporates a distinct entry interface for both patients and physiotherapists. Maximum force and position values generated during each exercise period are displayed within the application. The device enables active exercise with a single degree of freedom at the elbow joint and is equipped with force sensors to ensure safety against potential high-shear forces. Furthermore, it can be worn on the upper extremity using adjustable Velcro straps to accommodate users with varying arm circumferences. Specifically, this system amalgamates two primary components: a microcontroller operating control algorithms and IoT technology, and a smartphone application containing interfaces for physiotherapists and users undergoing therapy. The control design of the device employs a P-Type Iterative Learning Control (ILC) due to periodic exercise movements, reducing the error norm by approximately 20% during each exercise period (excluding the initial period). The controller consistently diminishes error values with each iteration, ultimately converging to zero. Throughout an exercise lasting around 3 minutes, the average error norm is recorded as 0.229⁰. In essence, this study presents a pioneering approach that sets itself apart from other research by minimizing shear forces and errors through a specialized controller, all while enabling remote, home-based rehabilitation under expert supervision.

Design and analysis of solid ankle foot orthosis by employing mechanical characterization and a low-cost scanning approach for additive manufacturing

PurposeThis study aims to investigate the fabrication of solid ankle foot orthoses (SAFOs) using fused deposition modeling (FDM) printing technology. It emphasizes cost-effective 3D scanning with the Kinect sensor and conducts a comparative analysis of SAFO durability with varying thicknesses and materials, including polylactic acid (PLA) and carbon fiber-reinforced (PLA-C), to address research gaps from prior studies.Design/methodology/approachIn this study, the methodology comprises key components: data capture using a cost-effective Microsoft Kinect® Xbox 360 scanner to obtain precise leg dimensions for SAFOs. SAFOs are designed using CAD tools with varying thicknesses (3, 4, and 5 mm) while maintaining consistent geometry, allowing controlled thickness impact investigation. Fabrication uses PLA and PLA-C materials via FDM 3D printing, providing insights into material suitability. Mechanical analysis uses dual finite element analysis to assess force–displacement curves and fracture behavior, which were validated through experimental testing.FindingsThe results indicate that the precision of the scanned leg dimensions, compared to actual anthropometric data, exhibits a deviation of less than 5%, confirming the accuracy of the cost-effective scanning approach. Additionally, the research identifies optimal thicknesses for SAFOs, recommending a 4 and 5 mm thickness for PLA-C-based SAFOs and an only 5 mm thickness for PLA-based SAFOs. This optimization enhances the overall performance and effectiveness of these orthotic solutions.Originality/valueThis study’s innovation lies in its holistic approach, combining low-cost 3D scanning, 3D printing and computational simulations to optimize SAFO materials and thickness. These findings advance the creation of cost-effective and efficient orthotic solutions.

775 A Unique Semirigid Silicone Neck Collar for Management of Hypertrophic Scars

Abstract Introduction In the realm of burn injuries, the use of rigid hard neck collars, or soft collars, is indispensable for optimizing neck positioning and scar management. However, when injuries encompass the head and neck, a critical challenge arises only one rigid orthosis can typically be worn one at a time. We are introducing a novel solution: a semirigid neck collar crafted from flexible silicone. This collar combines the benefits of semirigid support with the freedom of natural neck and allows jaw movement and may be worn with a rigid facemask. Furthermore, it can be customized to effectively manage hypertrophic scarring, making it a promising advancement in burn injury care. Methods Our semirigid neck collar is crafted with High Consistency Rubber (HCR) silicone. The HCR can be fabricated as a solid sheet or perforated. This HCR applies a gentle, consistent minimum pressure of 20mmHg as displayed by the Kikuhime pressure monitoring device while remaining pliable enough to accommodate natural neck movements and TMJ mobility. The material is mixed, pigment tinted, and rolled to achieve the desired thickness. Following this, the HCR silicone is heated and molded based on a 3D scan of the patient's neck and fit to the patient. A successful trial was conducted in a patient with severe facial and neck burns, resulting in improved neck ROM and hypertrophic scar progression. The resulting scar displayed improvement on the Vancouver Scar Scale yielded as reported on the Likert scale and the patient reporting increased compliance of the semirigid collar. Results In the trial involving a patient with severe neck and facial burns: 1. Improved Neck ROM, Eating, and Mandibular Movement: While using the semirigid silicone neck collar, the patient experienced improvements in neck ROM, eating comfort, and mandibular movement. The average Likert scale rating for these improvements was five out of five. 2. Decreased Scarring upon Vancouver Scar Scale displaying the difference between the initial and final VSS scores, indicating how much the scar improved. 3. Patient Preference: A preference for the semirigid silicone neck collar, upon rating it a perfect five on the Likert scale. The patient was able to wear it in combination with a hard TFO facial orthotic. Conclusions The semirigid silicone neck collar represents a move forward in the field of neck orthosis design, particularly concerning scar management. Its innovative blend of design elements, including flexibility, adaptability, and customizable features, holds great promise for individuals dealing with burn-related neck scarring. Applicability of Research to Practice This semirigid appliance offers increased comfort compared to traditional rigid collars and an option in the management of neck positioning and scar hypertrophy. Its flexible nature, including color-tinting, and cost-effective modification options make it a valuable tool for improving scar management outcomes neck for patients with neck and combined facial/neck scarring.

Design and Evaluation of Dynamic Movement Orthosis on Functional Parameters in a Child With Spastic Diplegia Cerebral Palsy

Design and Evaluation of Dynamic Movement Orthosis on Functional Parameters in a Child With Spastic Diplegia Cerebral Palsy

Active Ankle–Foot Orthosis Design and Computer Simulation with Multi-Objective Parameter Optimization

There are many current active orthosis designs to assist with disabilities related to foot-drop, with most of them intervening during the whole gait cycle. We propose that, for the treatment of foot-drop, it is possible to design an ankle–foot device that will assist a walking user only during the dorsiflexion stages of the gait, avoiding interference with other stages, by using a single actuator with a simple transmission and a suspension block. This design can be improved by the use of multi-objective optimization to obtain a static set of parameters that are applicable to varying initial conditions. We present a computer simulation study of an active ankle–foot orthosis design, based on the interaction of a cam and lever with a suspension block, with the objective of assisting only with dorsiflexion during the gait cycle, leaving the rest of the movements unimpeded while reducing the complexity and weight of the device. This design is validated using a full simulation environment that includes the movements of the lower leg and foot, as they interact with our device and a ground element. As part of the design and validation, we found sets of mechanical and control parameters that provoke adequate output behavior of the orthosis to help the wearer perform a moderate-speed, normal gait. To optimize the design, we proposed three objectives to warrant ankle angle accuracy, minimal oscillations, and low energy consumption. A set of solutions was obtained with multi-objective optimization algorithms NSGA-II and RVEA to tune the parameters of the active orthosis. The solutions set from RVEA resulted in lower mean and standard deviation values for the oscillations and energy objectives in comparison to the solutions from NSGA-II, while for the MSE objective, NSGA-II obtained lower mean and standard deviation; for the energy consumption objective, the mean score using RVEA is 17% less than with NSGA-II. The orthosis is shown to be robust to differences in initial ankle angles. We observed that it is possible to obtain a broad set of solutions with a good performance during the gait cycle in controlled spaces and that in this application, the RVEA algorithm results in a better option for optimization to balance the objectives.

Additive In-Time Manufacturing of Customised Orthoses

Additive manufacturing of plastic components in medical technology enables greater freedom of design when designing patient-specific products, in particular, in production of customised medical products, such as orthoses. In the present contribution, the advantages of a digital process chain are combined, from the 3D scan of the patient to CAD-supported modelling of the corrective form and the orthosis design until the path planning of a printable geometry. The main disadvantages of current additive printing techniques, such as the fused filament fabrication (FFF) process, are high printing times (>12 h) for larger components as well as the low degree of freedom in the 2.5D printing technique that prevent the subsequent application of geometry features to the product. The fast SEAMHex (Screw Extrusion Additive Manufacturing) printing technology with a hexapod kinematic printing bed provides a solution to the mentioned difficulties. Consequently, the high-performance printer has been prepared for the individual requirements of medical technology in terms of materials and geometries. An effective additive manufacturing process has been realised and tested in combination with a digital process chain for orthosis modelling.

Design and Development of a Flexible Active Ankle Joint Orthosis for Locomotion Assistance

Design and Development of a Flexible Active Ankle Joint Orthosis for Locomotion Assistance

Design and Optimization of an Adaptive Knee Joint Orthosis for Biomimetic Motion Rehabilitation Assistance.

In this paper, an adaptive knee joint orthosis with a variable rotation center for biomimetic motion rehabilitation assistance suitable for patients with knee joint movement dysfunction is designed. Based on the kinematic information of knee joint motion obtained by a motion capture system, a Revolute-Prismatic-Revolute (RPR) model is established to simulate the biomimetic motion of the knee joint, then a corresponding implementation for repetitively driving the flexion-extension motion of the knee joint, mainly assembled by a double-cam meshing mechanism, is designed. The pitch curve of each cam is calculated based on the screw theory. During the design process, size optimization is used to reduce the weight of the equipment, resulting in a reduction from 1.96 kg to 1.16 kg, achieving the goal of lightweight equipment. Finally, a prototype of the designed orthosis with the desired biomimetic rotation function is prepared and verified. The result shows that the rotation center of the prototype can achieve biomimetic motion coincident with the rotation center of an active knee joint, which can successfully provide rehabilitation assistance for the knee joint flexion-extension motion.