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Obesity and spinal loads; a combined MR imaging and subject-specific modeling investigation
, Article Journal of Biomechanics ; 2017 ; 00219290 (ISSN) ; Kazemi, H ; Eskandari, A. H ; Arjmand, N ; Sharif University of Technology
Abstract
Epidemiological studies have identified obesity asa possible risk factor for low back disorders. Biomechanical models can help test such hypothesis and shed light on the mechanism involved. A novel subject-specific musculoskeletal-modelling approach is introduced to estimate spinal loads during static activities in five healthy obese (BMI>30kg/m2) and five normal-weight (20
Obesity and spinal loads; a combined MR imaging and subject-specific modeling investigation
, Article Journal of Biomechanics ; Volume 70 , March , 2018 , Pages 102-112 ; 00219290 (ISSN) ; Kazemi, H ; Eskandari, A. H ; Arjmand, N ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Epidemiological studies have identified obesity as a possible risk factor for low back disorders. Biomechanical models can help test such hypothesis and shed light on the mechanism involved. A novel subject-specific musculoskeletal-modelling approach is introduced to estimate spinal loads during static activities in five healthy obese (BMI > 30 kg/m2) and five normal-weight (20 < BMI < 25 kg/m2) individuals. Subjects underwent T1 through S1 MR imaging thereby measuring cross-sectional-area (CSA) and moment arms of trunk muscles together with mass and center of mass (CoM) of T1-L5 segments. MR-based subject-specific models estimated spinal loads using a kinematics/optimization-driven...
Prediction of Surgical Procedures Effect on Mal-tracking Correction of Patello-femoral Joint Using Patient-specific Musculo-skeletal Modeling
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Zohoor, Hassan (Supervisor)
Abstract
According to the statistical studies, knee pain is the most common and costliest disorder after low back pain. One of its types is the patello-femoral disorder and instability. Patellar instability can be affected by different factors, such as: low depth of the trochlear groove, low height of the lateral femoral condyle, high length of the patellar tendon, abnormal lateral rotation of the tibia, unusual tibial attachment of the patellar tendon, small patellar size, general loosening of ligaments, etc. So, the mechanical properties of knee joint including patello-femoral joint, surrounding soft tissues, and incoming forces must be examined carefully, in order to find out suitable and...
Subject-Specific Musculoskeletal Modeling of Gait for a Patient with Torsional Misalignment of Lower Extremity
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Narimani, Roya (Supervisor)
Abstract
Torsional misalignment of lower extremities is a bone deformity of femur, tibia, knee twist or a complex of all these factors. These deformities affect the patient's gait kinematics. These patients are usually treated with osteotomy surgery with the aim of correction of anatomy. But it doesn't necessarily lead to the modification of gait. Therefor development and application of subject-specific musculoskeletal models to analyze patient's specific condition and predict corrective surgery results are considered. Accordingly, the aim of this project is to create a subject-specific musculoskeletal model for a patient with femoral anteversion in order to predict result of anatomical correction...
A Subject-Specific Simulation of Tibial Osteotomy Surgery Using Finite Element Method
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Hoviat Talab, Maryam (Supervisor)
Abstract
Varus-Valgus deformity increases local stress in cartilage and the other soft tissues of knee. This phenomenon may adversely influence patient’s walking pattern and also lead to worsen its existing impairments. In this situation, osteotomy is used to modify the alignment of the lower limb. Using CT-scan, radiography data, and their experiences, surgeons quantify the amount of modification. However, in many cases, the surgery does not result in desired output. It seems that the effects of soft tissues, which play an important role in this respect, should be taken into account. In order to design effectively for the osteotomy surgery, it is necessary to develop a patient-specific...
A Subject-Specific Simulation of Tibial Osteotomy Surgery Using Finite Element Method
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Hoviat Talab, Maryam (Supervisor)
Abstract
Varus-Valgus deformity increases local stress in cartilage and the other soft tissues of knee. This phenomenon may adversely influence patient’s walking pattern and also lead to worsen its existing impairments. In this situation, osteotomy is used to modify the alignment of the lower limb. Using CT-scan, radiography data, and their experiences, surgeons quantify the amount of modification. However, in many cases, the surgery does not result in desired output. It seems that the effects of soft tissues, which play an important role in this respect, should be taken into account. In order to design effectively for the osteotomy surgery, it is necessary to develop a patient-specific...
Modeling and Analysis of Angular Mis-alignments of Lower Extremity and Prediction of the Results of Osteotomy Surgery
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Hoviattalab, Maryam (Supervisor)
Abstract
Varus-valgus deformity is the improper alignment of lower extremities, which results in the increment of the local stress within the cartilage and the consequent alteration of the performance mechanism of the soft tissues around the knee joint. This accounts for changes within the movement pattern and thus further deformities, which, when continued, can lead to more serious damage in the form of osteoarthritis. The aforementioned cycle can be prevented through the conduction ofosteotomy; a surgical procedure in which the addition or removal of a bone wedge can correct the improper alignment. The correct design and conduction of osteotomy in terms of the location, angle, and size of the...
Subject-specific loads on the lumbar spine in detailed finite element models scaled geometrically and kinematic-driven by radiography images
, Article International Journal for Numerical Methods in Biomedical Engineering ; Volume 35, Issue 4 , 2019 ; 20407939 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Sharif University of Technology
Wiley-Blackwell
2019
Abstract
Traditional load-control musculoskeletal and finite element (FE) models of the spine fail to accurately predict in vivo intervertebral joint loads due mainly to the simplifications and assumptions when estimating redundant trunk muscle forces. An alternative powerful protocol that bypasses the calculation of muscle forces is to drive the detailed FE models by image-based in vivo displacements. Development of subject-specific models, however, both involves the risk of extensive radiation exposures while imaging in supine and upright postures and is time consuming in terms of the reconstruction of the vertebrae, discs, ligaments, and facets geometries. This study therefore aimed to introduce a...