Papers by Keyword: Biomechanical Analysis

Abstract: The thickness of the residual limb’s soft tissue plays a crucial role in determining the mechanical behavior and stress distribution at the stump–prosthesis interface. Using finite element analysis (FEA), this study investigates the biomechanical effects of different soft tissue thicknesses (30 mm, 50 mm, and 70 mm) on stress distribution. A patient-specific finite element model of the residual limb was developed to simulate realistic anatomical and mechanical conditions. To replicate physiological loading, a static vertical load of 350 N was applied, and the interface between the residual limb and the prosthetic liner was modeled using appropriate contact mechanics. The results revealed that reducing the soft tissue thickness to 3 cm produced higher Von Mises stress concentrations (0.115 MPa) and contact pressure (0.0697 MPa), which may increase discomfort and the risk of tissue damage. Conversely, increasing the thickness to 70 mm reduced stress values (0.016 MPa) and contact pressure (0.0312 MPa) but led to excessive deformations (6.277 mm) that could compromise prosthetic stability. An optimal soft tissue thickness of 5 cm was identified, where Von Mises stress and contact pressure remained at moderate levels, offering a balance between stress distribution and mechanical stability. These findings provide valuable guidance for optimizing prosthetic socket design, as maintaining appropriate soft tissue thickness can enhance comfort, reduce pressure-related injuries, and improve the overall functionality of lower-limb prostheses.

Abstract: Despite the increasing degree of automation many tasks are still performed manually, especially in production of individualized, sensitive or quality critical products. These tasks, e.g. tasks in or above head level, are often non ergonomic. Thus musculoskeletal diseases can occur. This paper presents a novel concept for a modular and wearable technical support system for reducing musculoskeletal stress. The support system which is based on the approach of Human Hybrid Robot (HHR) can be adapted easily to different users and activities. The system emphasizes on modularity and the use of soft materials for kinematic elements and interfaces in order to gain higher flexibility and increased human safety. The basic idea can be applied to various applications. The focus lies on a functional support system prototype for upper extremities. It comprises a Human-Machine-Interface using a vest equipped with soft kinematic elements as well as a control unit. Moreover, results from a biomechanical case study will be illustrated in order to confirm the ergonomic improvements, especially the comparison of the range of motion and the musculoskeletal stress during tasks.

Abstract: Wheelchair is an important equipment to assist people with lower body disability to move from one place to another. The aim of this research is to redesigning manual wheelchair for disabled children using anthropometry data and biomechanical analysis. Anthropometry data is used to determine the dimensions of the wheelchair, while the biomechanical analysis is used to compare the performance of the existing and proposed design. This research resulted a new design which gives more comfort to the users and used a lever mechanism to move the wheelchair. The results of biomechanical analysis show that the force to move the proposed wheelchair is larger than the existing one. It makes more loads are given to the elbow and shoulder of the users. Better performance is shown by the proposed design in the reaction force in neck and lumbar which will reduce the complaining pain of the users in their back.

Abstract: Mandible defect and the lack of dentition may result in facial deformity and chewing organ defects. It happens after the surgery of oral and maxillofacial tumors. This study aims at this problem. In this study, Finite Element Analysis (FEA) was employed to reconstruct the implanted mandible for customized patient. The 3D FEA model has great importance for biomechanical analysis. Though the analysis of the biomechanical situation with different numbers of dental implants, we can optimize the location and quantity of the implants. In this way, we can improve the quality of the implants, reduce the pain of patients, reduce the operation cost and avoid secondary surgery.

Abstract: Aiming at the implanted mandible titanium plate in chewing movement under the action of repeated load is prone to fracture, leading to problems such as secondary surgery. This study makes fatigue simulation analysis for customized implanted titanium plate of fatigue damage. It also analyzes the minimum service life position and low service life area on different loading. Simulation analysis of deformation is done. The analysis contains the deformation area and the maximum deformation degree with a variety of bite condition. This study also analyzes and forecasts the fatigue failure area, which provides basis for preventing fatigue failure for implanted titanium plate. It has important significance to improve titanium plate service life and strength. It also could alleviate patients’ sufferings.

Abstract: The finite element method is often used in the field of biomechanical analysis. It can study the mechanical response of the internal organization without any experiments on the human body. The paper studies the biomechanics of the cervical spine by the method of finite element analysis. Firstly, the finite element model of the cervical spine including cervical vertebrae and soft tissue is constructed. Secondly, biomechanical analysis of cervical finite element model which is validated to be reasonable and reliable is completed. The results of the control group, the anterior cervical decompression and fusion surgery group, and the artificial cervical disc replacement surgery group are obtained to study the motion degree and ligament force of cervical spine. Thirdly, the summary of the biomechanical analysis of cervical finite element model is concluded.

Abstract: The necessary theoretical and methodological foundation is provided by means of which the human mastication process could be studied and reproduced in a digital dynamic way. This paper reviews previous publications and elaborates further mathematical analysis and mechanical analysis of biomechanical functions, explaining the characteristics of human mandible, Temporomandibular joints (TMJs), muscles based on clinical anatomy, and analysing the inter-relationship and inter-reflection between each component of this multi-body assembled organism.

Abstract: Aiming to improve the defect mandible reconstruction operation success rate, the original mandible and fibular 3D model were modeling separately. According to the patient’s virtual reconstruction mandible 3D model, the mandible customized virtual ti-plate was designed and modeling. Through comparing the deformation simulation analysis of reconstructive mandible, the maximum deformation occurred near the mandible midline. There was little deformation at bilateral mandible ramus posterior. As the loading on the reconstructive mandible increasing, the maximum deformation near the mandible midline was increasing. According to the customized titanium plate virtual design and deformation simulation analysis of human lateral mandible defect before operation, the simulation could predict the mandible maximum deformation position after the surgery. The doctors could improve the operation precision of mandible reconstruction and probability of success significantly.

Abstract: A computer-graphics based biomechanical model was constructed to investigate the kinematics of foot joints during the stance-phase of walking. In the model, all joints were assumed to act as monocentric, single degree of freedom hinge joints. To obtain the inputs to the model, the motion of foot segments was captured during the gait by a four-camera video system. The model fitted in an individual subject was simulated with these motion data. The ranges of motion of the first tarsometatarsal joint and the first metatarsophanlangeal joint were 8
∼13
and -13
∼ 48
respectively. The kinematic data of joints were similar to those of the previous studies. Our method based on the graphical computer model is considered useful for kinematic analysis of small joints including foot joints. Also, the results of this study will provide important information to the biomechanical studies which deal with human gait.

Abstract: Anterior cruciate ligament(ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric positions of the substitute during flexion/extension. A threedimensional knee model was constructed from CT images and was used to simulate length change during knee flexion/extension. The results showed that minimum length changes were 1.9~5.8 mm(average 3.6±1.4 mm). The proposed method can be utilized and applied to optimal reconstruction for ACL deficient knee.