Finite Element Analysis of a Transtibial prosthetic during Gait Cycle (original) (raw)
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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8915 To cite this version : Xavier BONNET, Helene PILLET, Pascale FODE, Francois LAVASTE, Wafa SKALLI -Finite element modelling of an energy-storing prosthetic foot during the stance phase of transtibial amputee Abstract
UT Electronic Theses and Dissertations, 2010
Over one million amputees are living in the United States with major lower limb loss (Ziegler-Graham et al. 2008). Lower limb amputation leads to the functional loss of the ankle plantar flexor muscles, which are important contributors to body support, forward propulsion, and leg swing initiation during walking (Neptune et al. 2001; Liu et al. 2006). Effective prosthetic component design is essential for successful rehabilitation of amputees to return to an active lifestyle by partially replacing the functional role of the ankle muscles. The series of experimental and computer simulation studies presented in this research showed that design characteristics of energy storage and return prosthetic ankles, specifically the elastic stiffness, significantly influence residual and intact leg ground reaction forces, knee joint moments, and muscle activity, thus affecting muscle output. These findings highlight the importance of proper prosthetic foot stiffness prescription for amputees to assure effective rehabilitation outcomes. The research also showed that the ankle muscles serve to stabilize the body during turning the center of mass. When amputees turn while supported by their prosthetic components, they rely more on gravity to redirect the center of mass than active muscle generation. This mechanism increases the risks of falling and identifies a need for prosthetic components and rehabilitation focused on increasing amputee stability during turning. A proper understanding of the effects of prosthetic components on amputee walking mechanics is critical to decreasing complications and risks that are prevalent among lower-limb amputees. The presented research is an important step towards reaching this goal.
Biomechanical Analysis of a prosthetic foot Bioc-dm2
2019 International Conference on Wireless Technologies, Embedded and Intelligent Systems (WITS), 2019
Walking is one of the aspects directly compromising human wellbeing, as it has a physical and emotional impact in daily life. For this study, we delve into the challenge of improving some walking conditions in a patient suffering lower limb loss, specifically at transtibial or transfemoral levels. Given that our purpose was the analysis, design and manufacture of a lower-limb prosthetic component, which fills the needs for functionality, it became necessary to build a foot with all the quality standards associated to each and all movements required to form the complex fundamental pattern of walking. Besides, this foot should also easily endure weight, daily use and physical characteristics of the patient object of this study. When performing physical validation and during human walk, a proper response is observed in terms of mechanics, materials and dynamics of the component, thus making evident proper construction and assembly. On the other hand, it is feasible that design and verification of the component provided a competitive element, as compared to existing elements currently in the market. The previous situation generated the need for verification from the National Institute for Medications and Food (INVIMA), as well as the revision of the use replying device, for component verification, in accordance with ISO 10328.
Biomechanical Design and Prototyping of a Powered Ankle-Foot Prosthesis
Materials, 2020
Powered ankle-foot prostheses for walking often have limitations in the range of motion and in push-off power, if compared to a lower limb of a healthy person. A new design of a powered ankle-foot prosthesis is proposed to obtain a wide range of motion and an adequate power for a push-off step. The design methodology for this prosthesis has three points. In the first one, a dimensionless kinematic model of the lower limb in the sagittal plane is built, through an experimental campaign with healthy subjects, to calculate the angles of lower limb during the gait. In the second point a multibody inverse dynamic model of the lower limb is constructed to calculate the foot-ground contact force, its point of application and the ankle torque too, entering as input data the calculated angles of the lower limb in the previous point. The third point requires, as input of the inverse dynamic model, the first dimensioning data of the ankle-foot prosthesis to obtain the load acting on the compon...
Design & Development of Prosthetic Leg
IRJET, 2022
This article aims to design a prosthetic leg prototype that can be used by above knee amputees especially the people who cannot afford to invest in costly and expensive high-end prosthetics. This product can be used to sit, stand and walk comfortably without any backlash or jerk to the user. The size of the product is carefully designed to be an approximate replication of knee joint and has a relatively light weight as compared to its high-end counterparts. The knee mechanism is cast entirely from aluminum & the conical spring used is manufactured using spring steel. The knee joint mechanism has a cap and belt to be tied to the leg of the amputee using a belt and lower end of the knee is connected to the rod which connects the knee end to the ankle. The product is successfully tested and is modelled using Creo 4.0 and analyzed in Ansys Structural. Prosthetics manufacturing has reached great heights in technology and have achieved perfect muscular movement like a biological leg. But maximum people having leg disability cannot afford such high-tech technology for their leg. Our attempt is to achieve a similar movement of a leg at minimum cost and based on this attempt we are considering the manufacturing. The lower middle-class people of the society find it difficult to purchase such prosthetic from private orthopedic centers so we have aimed to make it easier for those people to buy the product. Our low-cost project can also influence other producers to make such low-cost prosthesis and make them believe that it can be possible. This is not just beneficial for the producers but also to the consumers as it lowers the overall cost of such prosthesis due to aggressive competition
Modeling and stress analyses of a normal foot-ankle and a prosthetic foot-ankle complex
Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in prosthetic ankle-foot complex compared to normal one. The predicted plantar pressures and von Misses stress distributions for a normal foot were consistent with other FE models given in the literature. The present study is aimed to open new approaches for the development of ankle prosthesis.
DESIGN AND ANALYSIS OF A NEW PROSTHETIC FOOT FOR PEOPLE OF SPECIAL NEEDS
Loss of the lower limb can cause loss of mobility .At all places and at all times, efforts have always been made to make up for such a loss. The basis of this investigation is to research current prosthetic in order to design and build a more human like prosthesis. Also this investigation aims at combining these characteristics in order to achieve a more multi functional prosthesis. In undertaking such a design, the new prosthesis will be exhibit a broader range of characteristics than those displayed in current prosthetic feet. In doing so, the new prosthesis will enable a closer representation of the functions inherent of a normal human foot. The characteristics involved in normal walking include dorsiflexion, impact absorption and fatigue foot test. The characteristics displayed in the manufactured new foot tested were compared to those of SACH foot. The characteristics exhibited by prostheses which compared favorably to those of a human foot were investigated further. A new prosthetic foot is designed and manufactured from polyethylene and a comparison study with SACH foot was used to determine if there are differences in the gait pattern while wearing the NEW foot and whether these differences would be problematic. The basis of the new prosthetic design combines current prosthetic design elements, such as materials and components. The analytical part presents the results of the static and fatigue analysis by methods; numerical methods (Finite Element method FEM) and experimental methods. The new foot was designed and the number of cycle, dorsiflexion and impact were measured. The new prosthetic foot has a good characteristic when compared with the SACH foot, such as good dorsiflexion (7.8-6.4o), force transmitted at impact heel (9.82N-9.50N) and life of foot (2,103,445-896,213) cycles respectively.
Journal of Biomechanics, 2006
Most trans-tibial amputation (TTA) patients use a prosthesis to retain upright mobility capabilities. Unfortunately, interaction between the residual limb and the prosthetic socket causes elevated internal strains and stresses in the muscle and fat tissues in the residual limb, which may lead to deep tissue injury (DTI) and other complications. Presently, there is paucity of information on the mechanical conditions in the TTA residual limb during load-bearing. Accordingly, our aim was to characterize the mechanical conditions in the muscle flap of the residual limb of a TTA patient after donning the prosthetic socket and during load-bearing. Knowledge of internal mechanical conditions in the muscle flap can be used to identify the risk for DTI and improve the fitting of the prosthesis. We used a patient-specific modelling approach which involved an MRI scan, interface pressure measurements between the residual limb and the socket of the prosthesis and three-dimensional non-linear large-deformation finite-element (FE) modelling to quantify internal soft tissue strains and stresses in a female TTA patient during static load-bearing. Movement of the truncated tibia and fibula during loadbearing was measured by means of MRI and used as displacement boundary conditions for the FE model. Subsequently, we calculated the internal strains, strain energy density (SED) and stresses in the muscle flap under the truncated bones. Internal strains under the tibia peaked at 85%, 129% and 106% for compression, tension and shear strains, respectively. Internal strains under the fibula peaked at substantially lower values, that is, 19%, 22% and 19% for compression, tension and shear strains, respectively. Strain energy density peaked at the tibial end (104 kJ/m 3 ). The von Mises stresses peaked at 215 kPa around the distal end of the tibia. Stresses under the fibula were at least one order of magnitude lower than the stresses under the tibia. We surmise that our present patient-specific modelling method is an important tool in understanding the etiology of DTI in the residual limbs of TTA patients. r
Contributions to the Dynamic Regime Behavior of a Bionic Leg Prosthesis
Biomimetics
The purpose of prosthetic devices is to reproduce the angular-torque profile of a healthy human during locomotion. A lightweight and energy-efficient joint is capable of decreasing the peak actuator power and/or power consumption per gait cycle, while adequately meeting profile-matching constraints. The aim of this study was to highlight the dynamic characteristics of a bionic leg with electric actuators with rotational movement. Three-dimensional (3D)-printing technology was used to create the leg, and servomotors were used for the joints. A stepper motor was used for horizontal movement. For better numerical simulation of the printed model, three mechanical tests were carried out (tension, compression, and bending), based on which the main mechanical characteristics necessary for the numerical simulation were obtained. For the experimental model made, the dynamic stresses could be determined, which highlights the fact that, under the conditions given for the experimental model, th...
Comprehensive Design and Analysis of a Prosthetic Leg: Material Selection and Performance Evaluation
IJRAME PUBLICATIONS, 2024
Prosthetic limbs serve as indispensable tools in restoring mobility and enhancing the quality of life for individuals with limb loss. This project focuses on the modeling and analysis of prosthetic legs, aiming to optimize their design for improved functionality and comfort. The study begins with an exploration of the significance of prostheses in enhancing the mobility and independence of amputees. Utilizing Solid Works for modeling and ANSYS for analysis, the project investigates the performance of prosthetic legs constructed from four distinct materials: Aluminum Alloy, Titanium Alloy, Carbon Fibre, and Structural Steel. These materials are selected based on their mechanical properties and suitability for prosthetic applications. The design and analysis stages involve simulating various activities that mimic the typical movements and stresses encountered during daily l ife, including walking and engaging in other essential tasks. By subjecting the prosthetic leg models to rigorous testing, the project evaluates their durability, strength, and overall performance under realistic conditions. The outcomes of this research provide valuable insights into the comparative advantages and limitations of different materials in prosthetic leg design. Additional ly, it offers recommendations for optimizing prosthetic limb design to better meet the diverse needs and preferences of users. Ultimately, this work contributes to advancing the field of prosthetic engineering, paving the way for the development of mor e efficient and user-friendly prosthetic solutions.