Biomedical Engineering and Bioengineering Commons^™

Utilization Of Finite Element Analysis Techniques For Adolescent Idiopathic Scoliosis Surgical Planning, Michael A. Polanco

Mechanical & Aerospace Engineering Theses & Dissertations

Adolescent Idiopathic Scoliosis, a three-dimensional deformity of the thoracolumbar spine, affects approximately 1-3% of patients ages 10-18. Surgical correction and treatment of the spinal column is a costly and high-risk task that is consistently complicated by factors such as patient-specific spinal deformities, curve flexibility, and surgeon experience. The following dissertation utilizes finite element analysis to develop a cost-effective, building-block approach by which surgical procedures and kinematic evaluations may be investigated. All studies conducted are based off a volumetric, thoracolumbar finite element (FE) model developed from computer-aided design (CAD) anatomy whose components are kinematically validated with in-vitro data. Spinal ligament stiffness …

Biomechanical Investigation Of Complete And Partial Medial Collateral Ligament Injuries, Callahan Doughty

Electronic Thesis and Dissertation Repository

The medial collateral ligament (MCL) is composed of two major components: the deep MCL (dMCL) and superficial MCL (sMCL). Recent indications have raised questions as to the validity of previous descriptions of the MCL’s role in knee stability. Despite the relative likelihood of partial injuries to the sMCL, as opposed to complete tears, the impact of these injuries remains largely misunderstood. This thesis set out to (1) interpret the roles of the sMCL and dMCL; and (2) investigate the effect of partial sMCL injuries on knee stability.

A joint motion simulator was used to determine the role of the dMCL …

Biomechanical Analysis Of Ligament Modelling Techniques And Femoral Component Malrotation Following Tka, Liam A. Montgomery

Electronic Thesis and Dissertation Repository

Previous studies have demonstrated that satisfaction and revision rates following total knee arthroplasty (TKA) are lower than those of comparable surgeries such as total hip replacements. A leading cause for these revisions is joint instability which may be due to improper ligament balancing or poorly aligned surgical implants. One of the methods used to investigate biomechanical forces and kinematics is computational modelling of the post-operative TKA knee.

A unique knee model was used to investigate the biomechanical and kinematic effects of ligament model complexity, as well as the effects of simulating ligament wrapping versus ignoring ligament wrapping. We then used …

Knee Joint Internal Forces During Squat Jump Exercise, Ricardo Moreno

Theses and Dissertations

The purpose of this research is to investigate muscular ligament and joint contact forces produced during squat jump exercise. An inverse dynamics, two dimensional, leg model is used to describe the motion in the sagittal plane. The lower extremity model includes two bones, tibia and femur, tibio-femoral ligaments, and muscles such as quadriceps, hamstrings, and gastrocnemius. The ligaments are anatomically modeled as nonlinear strings, but the femoral condyle is modeled as a circle and the tibial plateau as a straight line. Experimental squat jump exercises are conducted to obtain the ground reaction forces, the angular accelerations, and centroid linear acceleration …

The Design And Validation Of A Computational Model Of The Human Wrist Joint, Afsarul Mir

Theses and Dissertations

Advancements in computational capabilities have allowed researchers to turn towards modeling as an efficient tool to replicate and predict outcomes of complex systems. Computational models of the musculoskeletal system have gone through various iterations with early versions employing dramatic simplifications. In this work, a three-dimensional computational model of the wrist joint was developed. It accurately recreated the skeletal structures of the hand and wrist and represented the constraints imposed by soft tissue structures like ligaments, tendons, and other surrounding tissues. It was developed to function as a tool to investigate the biomechanical contributions of structures and the kinematic response of …

Development Of A Rigid Body Computational Model For Investigation Of Wrist Biomechanics, Benjamin Majors

Theses and Dissertations

The wrist is one of the most complex joints in the human body. As such, the wrist joint is difficult to model due to the number of bones involved and its intricate soft tissue interactions. Many studies have attempted modeling the wrist previously; however, the majority of these studies simplify the joint into two-dimensions or idealized mechanical joints to reduce the complexity of the simulation. While these approaches still yield valuable information, the omission of a third-dimension or geometry defined movements limits the models’ usefulness in predicting joint function under non-idealized conditions. Therefore, the goal of this study was to …

Mechanical Structures Resisting Anterior Instability In A Computational Glenohumeral Joint Model, Kevin Elmore

Theses and Dissertations

The glenohumeral joint is the most dislocated joint in the body due to the lack of bony constraints and dependence on soft tissue, primarily muscles and ligaments, to stabilize the joint. The goal of this study was to develop a computational model of the glenohumeral joint whereby joint behavior was dictated by articular contact, ligamentous constraints, muscle loading, and external perturbations. Validation of this computational model was achieved by comparing predicted results from the model to the results of a cadaveric experiment in which the relative contribution of muscles and ligaments to anterior joint stability was examined. The results showed …

Development And Validation Of A Computational Musculoskeletal Model Of The Elbow Joint, Justin Paul Fisk

Theses and Dissertations

Musculoskeletal computational modeling is a versatile and effective tool which may be used to study joint mechanics, examine muscle and ligament function, and simulate surgical reconstructive procedures. While injury to the elbow joint can be significantly debilitating, questions still remain regarding its normal, pathologic, and repaired behavior. Biomechanical models of the elbow have been developed, but all have assumed fixed joint axes of rotation and ignored the effects of ligaments. Therefore, the objective of this thesis was to develop and validate a computational model of the elbow joint whereby joint kinematics are dictated by three-dimensional bony geometry contact, ligamentous constraints, …