bluuebunny/crossref_metadata_2025_split huggingface dataset:
Passive Knee Joint Mechanics in A-P Forces: Role of Boundary Conditions, Cruciates, and Menisci
Authors: Bendjaballah M. Z. , Shirazi-Adl A. , Zukor D. J. 
Published: March 2022

Abstract
The ligaments and menisci are the principal stabilizers of the knee joint under various loadings such as anterior-posterior (A-P) horizontal forces. When either of these structures is torn, damaged, or removed, the joint’s stability is compromised resulting in the overload of remaining intact ligaments, menisci, and articular cartilage. The deleterious effects of altered mechanical environment of the joint associated with the ACL deficiency and meniscectomy in generating or accelerating the joint osteoarthritis have been well documented by many clinical studies. Following our earlier investigations [1,2], the purpose of this work is to study the passive biomechanics of the tibiofemoral joint at full extension in A-P loads. Attention is given to the identification of the role of boundary conditions, cruciate ligaments, and menisci on the joint detailed response.
Microindentation of the Individual Layers of Articular Cartilage
Authors: Shin Daehwan , Lin Jian-Hua , Athanasiou Kyriacos 
Published: March 2022

Abstract
Articular cartilage is known to have three distinct layers (superficial, middle, and deep) along its depth. Each layer has different biochemical, structural, and cellular characteristics. In the superficial layer, collagen fibrils are densely arranged along a tangential direction to the articular surface. Collagen fibrils are randomly oriented in the middle layer and vertically toward the subchondral bone in the deep layer. The superficial layer has a relatively low concentration of proteoglycans while the matrix in the middle and deep zones contains higher concentrations. The chondrocytes are flattened and most densely populated in the superficial layer, are rounded in the middle zone, and are larger, elongated, and arranged vertically between extracellular matrix in the deep layer [1, 2]. Based on the depth-related differences in the structural, biochemical, and cellular compositions, it is reasonable to assume that intrinsic mechanical properties of articular cartilage vary with depth. However, little information is available on the variation of the biomechanical properties in different layers of articular cartilage. The objectives of this study were 1) to test the applicability of the microindenter for testing cartilage at the microscopic level and 2) to obtain the intrinsic biomechanical properties of rabbit articular cartilage as a function of depth.
Compression-Induced Intervertebral Disc Degeneration in a Mouse Model
Authors: Colliou Olivier K. , Liebenberg Ellen , Duncan Neil A. , Lotz Jeffrey C. 
Published: March 2022

Abstract
While the cause of low-back pain is unknown in many patients, a significant percentage is thought to be due to degeneration of the intervertebral disc1. Because of the severe structural demands placed on the spine, and the epidemiological association between physical activity and disc degeneration, mechanical forces are thought to be a central etiologic factor. Therefore, precise knowledge of the cascade of biologic events associated with disc degeneration, and the means by which they are coupled to physical loading, would be invaluable for developing improved guidelines for maintaining disc health and for directing tissue repair. The aim of this study was to develop an in vivo mouse model in which disc degeneration is induced through the application of a precisely controlled and quantified mechanical load.
Formulation of a Continuum Anisotropic Model for the Anulus Fibrosus in Tension
Authors: Elliott Dawn M. , LeRoux Michelle A. , Laursen Tod A. , Setton Lori A. 
Published: March 2022

Abstract
The anulus fibrosus (AF) of the intervertebral disc is a highly structured material made up of alternating tissue layers (lamella) with collagen fibers oriented +30° and −30° to the circumferential axis (Figure 1). Collagen confers a high tensile stiffness to the AF which contributes to the load-bearing function of the intervertebral disc in vivo. In addition, the specialized organization of the AF gives rise to strongly anisotropic behaviors which may contribute to its mechanical function. Numerous models have been proposed for the material behavior of the AF including a fiber-reinforced composite or membrane, a layered transversely isotropic material, an orthotropic material, and a poroelastic isotropic material [6,8,9,12]. Fiber-reinforced models are complicated by the need to quantify the collagen content, the collagen and ground substance material properties, and associated fiber-matrix interactions. Continuum models of the AF are complicated by the need to determine a unique set of material properties which can require as many as 9 independent constants for a linear orthotropic material.
The Role of Mechanical Stimulation on Ligament Fibroblast Gene Expression of Extracellular Matrix and Adhesion Proteins
Authors: Hsieh Adam H. , Shi Yan , Sung K.-L. Paul 
Published: March 2022

Abstract
This study investigates mechanical stretch induced gene expression of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) fibroblasts, in particular the gene expression of extracellular matrix (ECM) proteins. While the ACL does not exhibit a functional healing response after injury, the MCL does heal post-traumatically [1]. Intrinsic differences between ACL and MCL fibroblasts are hypothesized to be partially responsible for the healing differential. The objective of this study is to examine the effects of stretch on gene expression in ACL and MCL fibroblasts to understand how physical forces can influence tissue healing and remodeling.
Dissociation of Individual Molecular Bonds Under Force
Authors: Zhu Cheng , Chesla Scott E. 
Published: March 2022

Abstract
Specific interactions between receptors on cell surfaces are essential for living organisms to sense and adapt to their environment. For example, CD16A (Feγ receptor IIIA) signals a variety of immune functions upon binding of immunoglobulin (Ig) G. While receptor-ligand binding has been extensively studied in chemical terms, only until very recently has direct measurement of individual bond forces become possible. Evans et al. [1] pioneered the use of the micropipet technique to measure detachment forces between two red blood cells (RBC) crosslinked by antibodies. While these authors achieved the sensitivity necessary to detect individual bonds (in piconewton range), the forces they measured appeared to be those of uprooting the molecules from the cell membrane (cohesive detachment mode) instead of dissociating the antibody-antigen bonds (adhesive detachment mode).
A Finite Deformation Theory and Finite Element Formulation for Coupled Electrokinetic and Fluid Flow in Soft Tissues: Application to Electroosmotic Flow
Authors: Levenston Marc E. , Frank Eliot H. , Grodzinsky Alan J. 
Published: March 2022

Abstract
Due to the fixed charge density (FCD) in the solid matrix and the ionic nature of the interstitial fluid, cartilage and other soft tissues exhibit coupling between mechanical (deformation, fluid flow, fluid pressurization) and electrical (current, streaming potential) phenomena (Maroudas et al., 1969; Frank and Grodzinsky, 1987). Similar behavior has long been recognized in soil mechanics, and linear finite element formulations have been developed (Lewis and Garner, 1972). Soft tissues, however, typically undergo large deformations and have material properties that strongly vary with deformation. To date, no finite element formulations have been introduced that are capable of representing the nonlinear, electromechanically coupled behavior of soft tissues.
Analysis of Transient Swelling and Electrical Responses of an Isolated Cell to Sudden Osmotic Loading
Authors: Gu W. Y. , Lai W. M. , Hung C. T. , Liu Z. P. , Mow V. C. 
Published: March 2022

Abstract
The cell volume changes in response to changes in the osmolality of an extracellular medium. When the medium osmolality decreases, extracellular water will move into the cell so that the cell volume increases (swelling). The rate of change in cell volume depends on the material properties of the cell, such as the tensile stiffness and hydraulic permeability. During cell swelling, the cell membrane is stretched, possibly affecting membrane permeability to various ions (i.e., stretch-activated ion-channels). The transport of ions and water will result in a change in membrane potential [e.g., 1] as well as a change in intracellular ion concentrations. Therefore, mechanical, chemical and electrical events are coupled within a cell. It is important to understand these coupled events in order to separate mechanical and chemical signals and to begin to elucidate the biophysical signal transduction pathways. As a first step to model a cell, we have begun to study mechanical, chemical and electrical phenomena across a cell membrane using recently developed theories [1–3]. In this study, we report our analysis of transient swelling and electrical responses of an isolated cell to an osmotic load, which has been studied experimentally [e.g., 4]. The objective of this study was to relate the changes in cell volume, intracellular ion concentration and electrical potential (which can be readily measured) to the cell material properties (e.g., stiffness, hydraulic permeability and ion-channels).
A Material Characterization of Human Medial Collateral Ligament
Authors: Quapp Krista M. , Weiss Jeffrey A. 
Published: March 2022

Abstract
Despite the vast amount of research on mechanical properties of the knee ligaments, the material properties of human medial collateral ligament (MCL) have never been characterized. The material properties of knee ligaments have only been determined in the longitudinal direction of the ligament. The transverse properties are also necessary for development of 3-d constitutive models. This study determined the longitudinal and transverse material properties of the MCL and evaluated the ability of three material models to describe the material behavior.
Finite Element Study of the Human Cervical Spine
Authors: Kumaresan Srirangam , Yoganandan Narayan , Pintar Frank A. 
Published: March 2022

Abstract
Finite element studies have proliferated in the lumbar spine. Similar modeling efforts to understand the biomechanical behavior of the cervical spine are lacking [3]. The purpose of this study is to report the advancements made in the finite element analysis of the human cervical spine by our group. Details specific to this presentation include the validation studies and the stress analysis of the intervertebral components under complex loading.
Facet Joint Local Component Kinetics in Whiplash Trauma
Authors: Yoganandan Narayan , Pintar Frank A. 
Published: March 2022

Abstract
The term whiplash was introduced in 1928. Since its introduction, it has been primarily dedicated to refer to the sequela of events stemming from vehicular rear-end crashes wherein the human body is initially accelerated from back to front through dynamic impact. Other terminologies have included cantilever injury, hyperextension injuries, cervical sprain/strain, and acceleration-deceleration syndrome. It is estimated that 86% of all clinically seen neck injuries result from motor vehicle crashes and that 85% of these injuries occur due to rear-end impact. Precise estimates for the actual incidence and the associated economics of the injury are not easily available. This is primarily due to the multitude of variables involved in the production and assessment of trauma. Vehicular factors, occupant demographics and positioning at the time of crash, and collision variables together with the human tolerance constitute a significant body of parameters responsible for the injury sequela; symptoms may be acute or chronic. A generally reported incidence rate of whiplash injury is about one in 1000 in Western countries and approximately 25% of the patients become chronic with 10% suffering serious pain [1].
Loads on Neck and Head Joints due to G-Y Acceleration
Authors: Sadegh Ali M. , Perry Chris , Knox Francis 
Published: March 2022

Abstract
During an emergency ejection from aircraft, pilots are subjected to a high acceleration that could cause injuries. To determine the forces and torques at the head, neck and upper-torso joints, an ATB model was developed. The model was validated with test results for G-y accelerations of human subjects. The sled test results of human subjects were used and the loads and torques were determined. The results indicated that the maximum forces and torques increas with the increase in the amplitude and duration of the input acceleration; however, the maximum compressive force at the head pin has a minimum value of 150 lb at 5.5 G.
Biodynamics of Cervical Spine Hyperflexion Injuries
Authors: Voo Liming M. , Pintar Frank A. , Yoganandan Narayan , Maiman Dennis J. 
Published: March 2022

Abstract
Hyperflexion injuries of the human cervical spine occur in the vehicular crash environment, contact sports, and accidental falls. Hyperflexion of the head-neck is a violent movement when head-neck is forced to bend forward into extremely position. It often causes injuries to the posterior ligamentous tissues and instability of the lower cervical spine. Cervical spine injuries are frequently associated with head impact. Our previous experimental studies have demonstrated that alignment variation of the head-neck complex with respect to a similar external load vector significantly alters the injury mechanisms and biomechanical response variables (3, 4). Determining the correlation among the alignment condition, spinal column configuration, biomechanical responses, and injury mechanisms can assist the evaluation of injury risks and preventive measures. The present in vitro experimental study was conducted to delineate the biodynamic parameters associated with hyperflexion injury of the cervical spine.
Use of Calf Lumbar Spine Models for the Test of Spinal Instrumentation
Authors: Lim Tae-Hong , Eck Jason C. , Riley Lee H. , Yoshida Hyroyuki 
Published: March 2022

Abstract
Calf lumbar spines have been widely used for the biomechanical tests of various spinal fixation devices as a substitute for human cadaveric lumber spines. While similar size, loss cost, and less inter-specimen variations are positive attributes, little effort has been made to determine if the use of calf spines is biomechanically justifiable. Wilke et al.[1] investigated the range of motion, neutral zone, and stiffness of thoracolumbar calf spines. It was determined that these values were similar to those previously reported for the human spine. In this study, however, the test was limited to the intact calf spine, and no statistical analysis was made since the results were compared to the results of various studies reported in the literature. Direct comparison of biomechanical testing results of calf and human models has not been presented yet. The purpose of this study was to perform flexibility tests on calf and human lumbar spines using identical methods in order to determine if the anatomical and mechanical differences in the two models affect the results of flexibility tests.
Determining Inertial Properties of Female Adolescents
Authors: Todd Beth A. , Buckner Tina K. , Owens Jonathan M. , Horne Stephanie M. , Bennett M. Virginia 
Published: March 2022

Abstract
There are many instances where inertial properties of the human body or its segments are needed for analysis of human motion. Some of the most critical of these are the design of safety devices to protect a seated person during a vehicular collision, such as an automotive seat belt system or a pilot ejection system. [1] Since many studies have dealt with military combat situations, they have primarily dealt with young adult males. [2] However, a few studies have included adult females and individuals of other ages. [3]-[6] Automotive restraints, for instance, have been designed using this data under the assumption that a system able to restrain a 50% male could restrain the 95% female and all children. However, as automotive safety systems have become more complex than passive restraints, this assumption may no longer be adequate. Therefore, it is more critical than ever before to determine the inertial properties of children.
Biomechanical Comparison of a New Soft Composite Functional ACL Knee Brace vs. Hard Shell Designs
Authors: Han Gayle , Mazza Steven B. , Holt Lisa J. , Billotti Joseph , Langrana Noshir A. , Zimmerman Mark C. 
Published: March 2022

Abstract
The anterior cruciate ligament is the most commonly injured ligament in the knee [1]. Functional knee braces have been widely used to protect the ACL deficient patient. Research suggests that the hard shell design, although cumbersome, is the most resistant to anterior tibial displacement in the ACL deficient knee [1]. The purpose of this study is to compare the mechanical test performance of an off-the-shelf soft composite brace to custom-fit hard shell braces using a clinically relevant testing protocol.
Small Punch Testing for Characterization of Ultra-High Molecular Weight Polyethylene Used in Total Joint Replacements
Authors: Kurtz Steven M. , Jewett Charles W. , Foulds Jude R. , Srivastav Sanjeev , Edidin Avram A. 
Published: March 2022

Abstract
Gamma sterilization results in temporally and spatially inhomogeneous density distributions through the thickness of ultra-high molecular weight polyethylene (UHMWPE) components for total joint replacement [1]. Conventional approaches to estimate the through-thickness distribution of mechanical properties in total joint replacement components have relied on empirical correlations between local measurements of density and these properties [2].
A Fracture Toughness Test of Bone-Biomaterial Interfaces Under Mixed Mode Loading Conditions
Authors: Wang X. D. , Agrawal C. M. 
Published: March 2022

Abstract
Bone-biomaterial interfaces in orthopaedic and dental prosthetic systems are often exposed to a complex loading environment1–4. However, current testing of interfacial strength of orthopaedic and dental material systems is mainly performed under isolated tensile or shear mode and there are no effective methodologies for assessing the interfacial bonding strength under mixed-mode loading conditions. To address this issue, the present study was performed to develop a fracture mechanics based technique for estimating the mixed-mode fracture toughness of bone-biomaterial interfaces. A sandwich specimen comprising the bone-biomaterial interface was used in this study, and both analytical and numerical analyses were performed in conjunction with an empirical validation using bone to bone and dental cement interfaces.
Fatigue Properties of Acrylic Bone Cement as Improved by Processing Technique: A Review of Concepts
Authors: Furman Benjamin R. , Saha Subrata 
Published: March 2022

Abstract
The fatigue properties of bone cement are a critical factor in the long-term aseptic loosening of total hip arthroplasties. The objective of this paper is to provide a condensed review of recent findings related to the effect of porosity reduction and fiber reinforcement on the fatigue properties of bone cement. Individual treatments are discussed.
Material Tissue Interfaces of New Biostable Polymers
Authors: Greenbaum S. R. , Zambo S. J. 
Published: March 2022

Abstract
Polymers have been used in the human body for the last 25 years for things such as vascular grafts, pacemaker leads and joint replacement. Until recently, these polymers have been polyesters or polyethers. The newest polymers, developed by Corvita Corporation, are polycarbonates. These polymers have shown better resistance to biodegredation than their predecessors1. These newer polyurethanes are now being used in applications, such as stent grafts, where they were not before. The new polymer structure, method of manufacture and characteristics allow the material to be used in arterial vascular graft applications.
A Survey of Multibody Dynamics for Virtual Environments
Authors: Gillespie R. Brent , Colgate J. Edward 
Published: March 2022

Abstract
The field of computational dynamics is surveyed, focusing on issues relevant to the construction of a general purpose simulator with haptic display. The various formalisms available for generating dynamical models will be examined with regard to the form of the equations of motion which they produce. To render the effects of intermittent contact and other transient phenomena as driven by a human haptic explorer, a model is needed which is computationally efficient yet can handle changing kinematic constraints neatly. Models in dependent and independent coordinates produced with the Newton-Euler, Lagrangian and Kane formalisms will each be examined in order to provide a vantage point from which an informed selection may be made from among the many tools now available in computational dynamics.
Passive Implementation of Multibody Simulations for Haptic Display
Authors: Brown J. Michael , Colgate J. Edward 
Published: March 2022

Abstract
This paper addresses the issue of providing stability guarantees during the implementation of multibody simulations for haptic display. It introduces the concept of a virtual coupling between the multibody simulation and haptic display hardware. This coupling separates the simulation design process from the sampled-data stability issues that arise during its implementation with a haptic display. Necessary conditions for passivity of a 1-DOF haptic display with a discrete-time passive simulation and an arbitrary virtual coupling are given. The implications of discrete-time passivity on numerical integration and collision response algorithms are also addressed.
Temporal Bandwidth Requirements for Tactile Shape Displays
Authors: Peine William J. , Wellman Parris S. , Howe Robert D. 
Published: March 2022

Abstract
Haptic interfaces that include tactile shape displays must correlate small-scale shape information with finger position. High temporal bandwidth of the display actuators is required to provide realistic sensation during rapid finger motions. To characterize finger speeds during surgical palpation, we performed an experiment where subjects used the tip of the index finger to search for 4 mm lumps embedded in flat rubber models. The models were 15 to 25 mm thick soft silicone rubber with mechanical characteristics approximating lung or breast tissue. Average fingertip speed while in contact with the rubber was approximately 38±16 mm/s (mean ± standard deviation), and average maximum speed was 90±31 mm/s. While moving between contact intervals, the average finger tip speed was approximately 76±18mm/s, and average maximum speed was 146±37 mm/s. There were no significant speed differences between experienced surgeons and subjects who had no medical training. The results indicate that a 30 Hz bandwidth is necessary for shape displays used in haptic interfaces for lump localization in surgery. A shape display design meeting this specification is also presented.
Achieving a Massless Haptic Interface
Authors: Stoianovici Dan , Richer Edmond , Ephanov Anton , Hurmuzlu Yildirim 
Published: March 2022

Abstract
Transparency is an important characteristic that has to be achieved in a haptic interface. In an exoskeletal device, this requirement translates into an active compensation scheme that renders a massless mechanism. Specifically, one has to balance gravitational, Coriolis, and inertia forces/torques of the mechanical structure. The success of such compensation methods strictly relies on an effective identification of the system parameters that appear in the dynamic equations of the interface. In this paper we apply a novel parameter identification method that achieves this task. We conduct a set of experiments to evaluate the transparency of the Pneumatic Haptic Interface (Φ) developed in the Systems Laboratory at Southern Methodist University.