Biomechanical Engineering Commons^™

Pre-Impact Lower Extremity Posture And Brake Pedal Force Predict Foot And Ankle Forces During An Automobile Collision, Elizabeth C. Hardin, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background: The purpose of this study was to determine how a driver’s foot and ankle forces during a frontal vehicle collision depend on initial lower extremity posture and brake pedal force. Method of Approach: A 2D musculoskeletal model with seven segments and six right-side muscle groups was used. A simulation of a three-second braking task found 3647 sets of muscle activation levels that resulted in stable braking postures with realistic pedal force. These activation patterns were then used in impact simulations where vehicle deceleration was applied and driver movements and foot and ankle forces were simulated. Peak rearfoot ground reaction …

Sagittal Plane Biomechanics Cannot Injure The Acl During Sidestep Cutting, Scott G. Mclean, Xuemei Huang, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background. Knee joint sagittal plane forces are a proposed mechanism of anterior cruciate ligament injury during sport movements such as sidestep cutting. Ligament force magnitudes for these movements however, remain unknown. The need to examine injury-causing events suggests elucidation via model-based investigations is possible. Using this approach, the current study determined whether sagittal plane knee loading during sidestep cutting could in isolation injure the anterior cruciate ligament.

Methods. Experiments were performed on subject-specific forward dynamic musculoskeletal models, generated from data obtained from 10 male and 10 female athletes. Models were optimized to simulate subject-specific cutting movements. Random perturbations …

Distal Placement Of An End-To-Side Bypass Graft Anastomosis A 3-D Computational Study, John Robert Di Cicco

Mechanical & Aerospace Engineering Theses & Dissertations

A three-dimensional computational fluid dynamics study of blood flow through stenotic arteries has been conducted. Flow phenomena, such as separation regions and turbulence, can be found distal to an arterial stenosis. Frequently, a bypass graft using an end-to-side technique is attached to a stenotic artery to restore adequate blood flow. However, a significant percentage of these grafts fail after thirty postoperative days due to intimal hyperplasia development around the distal anastomosis. Moreover, aberrant wall shear rates have been implicated as a factor in the development of intimal hyperplasia. Thus, the present study examines whether placement of the distal end of …

Effect Of Gender And Defensive Opponent On The Biomechanics Of Sidestep Cutting, Scott G. Mclean, Susanne W. Lipfert, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Purpose: Anterior cruciate ligament (ACL) injuries often occur in women during cutting maneuvers to evade a defensive player. Gender differences in knee kinematics have been observed, but it is not known to what extent these are linked to abnormal neuromuscular control elsewhere in the kinetic chain. Responses to defense players, which may be gender-dependent, have not been included in previous studies. This study determined the effects of gender and defense player on entire lower extremity biomechanics during sidestepping.

Methods: Eight male and eight female subjects performed sidestep cuts with and without a static defensive opponent while 3D motion and ground …

Foot And Ankle Forces During An Automobile Collision: The Influence Of Muscles, Elizabeth C. Hardin, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Muscles have a potentially important effect on lower extremity injuries during an automobile collision. Computational modeling can be a powerful tool to predict these effects and develop protective interventions. Our purpose was to determine how muscles influence peak foot and ankle forces during an automobile collision. A 2-D bilateral musculoskeletal model was constructed with seven segments. Six muscle groups were included in the right lower extremity, each represented by a Hill muscle model. Vehicle deceleration data were applied as input and the resulting movements were simulated. Three models were evaluated: no muscles (NM), minimal muscle activation at a brake pedal …

Development And Validation Of A 3-D Model To Predict Knee Joint Loading During Dynamic Movement, Scott G. Mclean, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The purpose of this study was to develop a subject-specific 3-D model of the lower
extremity to predict neuromuscular control effects on 3-D knee joint loading during movements that can potentially cause injury to the anterior cruciate ligament (ACL) in the knee. The simulation consisted of a forward dynamic 3-D musculoskeletal model of the lower extremity, scaled to represent a specific subject. Inputs of the model were the initial position and velocity of the skeletal elements, and the muscle stimulation patterns. Outputs of the model were movement and ground reaction forces, as well as resultant 3-D forces and moments acting …

Exotendons For Assistance Of Human Locomotion, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background: Powered robotic exoskeletons for assistance of human locomotion are currently
under development for military and medical applications. The energy requirements for such devices are excessive, and this has become a major obstacle for practical applications. Legged locomotion in many animals, however, is very energy efficient. We propose that poly-articular elastic mechanisms are a major contributor to the economy of locomotion in such specialized animals. Consequently, it should be possible to design unpowered assistive devices that make effective use of similar mechanisms.

Methods: A passive assistive technology is presented, based on long elastic cords attached to an
exoskeleton and guided …

A Growth Mixture Theory For Cartilage With Application To Growth-Related Experiments On Cartilage Explants, Stephen M. Klisch, Silvia S. Chen, Robert L. Sah, Anne Hoger

Mechanical Engineering

In this paper, we present a growth mixture model for cartilage. The main features of this model are illustrated in a simple equilibrium boundary-value problem that is chosen to illustrate how a mechanical theory of cartilage growth may be applied to growth-related experiments on cartilage explants. The cartilage growth mixture model describes the independent growth of the proteoglycan and collagen constituents due to volumetric mass deposition, which leads to the remodeling of the composition and the mechanical properties of the solid matrix. The model developed here also describes how the material constants of the collagen constituent depend on a scalar …

Entrainment Of Electrical Activation By Spatio-Temporal Distributed Pacing During Ventricular Fibrillation, Yiping Gu

University of Kentucky Master's Theses

Spatio-temporal variation in action intervals during ventricular fibrillation (VF) suggestthat the excitable gap may also be distributed spatio-temporally. The observation leadus to hypothesize that distributed pacing can be used to modify and entrain electricalactivation during VF. We tested this hypothesis using simulated VF and animal studies.

We simulated VF in a 400 by 400 cell matrix. Simulation results showed that activationpattern could be entrained using spatially distributed stimulation. Up to a certain limit,increasing stimulus strength and density led to improved entrainment. Best entrainmentwas obtained by pacing at a cycle length similar to the intrinsic cycle length.

In order to verify …

Comment On "Quadriceps Protects The Anterior Cruciate Ligament", Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

No abstract provided.

Response Time Is More Important Than Walking Speed For The Ability Of Older Adults To Avoid A Fall After A Trip, Antonie J. Van Den Bogert, M. J. Pavol, M. D. Grabiner

Mechanical Engineering Faculty Publications

We previously reported that the probability of an older adult recovering from a forward trip and using a “lowering” strategy increases with decreased walking velocity and faster response time. To determine the within-subject interaction of these variables we asked three questions: (1) Is the body orientation at the time that the recovery foot is lowered to the ground (“tilt angle”) critical for successful recovery? (2) Can a simple inverted pendulum model, using subject-specific walking velocity and response time as input variables, predict this body orientation, and thus success of recovery? (3) Is slower walking velocity or faster response time more …

Horses Damp The Spring In Their Step, Alan M. Wilson, M. Polly Mcguigan, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle–tendon units^{1, 2}.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints^{3, 4}. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle^{5 …}

A Growth Mixture Theory For Cartilage, Stephen M. Klisch, Robert L. Sah, Anne Hoger

Mechanical Engineering

In this paper we present a model of growth for cartilaginous tissues in which there exists a saturated solid matrix composed of multiple constituents that may grow and remodel independently of each other. Klisch and Hoger recently developed a general theory of volumetric growth for a mixture of ν-1 growing elastic materials and an inviscid fluid, which included a treatment of two special types of internal constraints that are relevant to cartilage. Here, that theory is specialized to construct a cartilage growth model. This theory allows the constituents of the solid matrix to grow independently of each other, and can …

Tibiocalcaneal Kinematics Of Barefoot Versus Shod Running, Alex Stacoff, Benno M. Nigg, Christoph Reinschmidt, Antonie J. Van Den Bogert, Arne Lundberg

Mechanical Engineering Faculty Publications

Barefoot running kinematics has been described to vary considerably from shod running. However, previous investigations were typically based on externally mounted shoe and/or skin markers, which have been shown to overestimate skeletal movements. Thus, the purpose of this study was to compare calcaneal and tibial movements of barefoot versus shod running using skeletal markers. Intracortical bone pins with reflective marker triads were inserted under standard local anesthetic into the calcaneus and tibia of five healthy male subjects. The subjects ran barefoot, with a normal shoe, with three shoe soles and two orthotic modifications. The three-dimensional tibiocalcaneal rotations were determined using …

Contributions Of Proximal And Distal Moments To Axial Tibial Rotation During Walking And Running, T. L. Bellchamber, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The purpose of this study was to determine the cause and effect relationship between tibial internal rotation and pronation of the foot during walking and heel–toe running. This would allow predictions of orthotic effectiveness in reducing knee pain related to excessive internal tibial rotation. Kinematic and force plate data were collected from twenty subjects performing ten running and ten walking trials across a force plate. Using a least-squares algorithm, attitude matrices for each segment in each frame were obtained and the angular velocity vector of the tibia was calculated. The intersegmental moment at the ankle was calculated from ground reaction …

The Influence Of Orthotic Devices And Vastus Medialis Strength And Timing On Patellofemoral Loads During Running, R. R. Neptune, I. C. Wright, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Objective. To use a musculoskeletal model and simulation of running to examine: (1) the influence of two commonly prescribed treatments for patellofemoral pain (vastus medialis oblique strengthening and orthoses) and (2) the functional significance of timing differences between vastus medialis oblique and vastus lateralis on lateral patellofemoral joint loads.

Design. A three-dimensional musculoskeletal model of the lower extremity was used to simulate running at 4 m/s.

Background. Repetitive and excessive joint loading is often associated with overuse injuries that require clinical treatments to reduce pain and restore function. Affecting one in four runners, patellofemoral pain is one …

The Influence Of Foot Positioning On Ankle Sprains, I. C. Wright, R. R. Neptune, Antonie J. Van Den Bogert, B. M. Nigg

Mechanical Engineering Faculty Publications

The goal of this study was to examine the influence of changes in foot positioning at touch-down on ankle sprain occurrence. Muscle model driven computer simulations of 10 subjects performing the landing phase of a side-shuffle movement were performed. The relative subtalar joint and talocural joint angles at touchdown were varied, and each subject-specific simulation was exposed to a set of perturbed floor conditions. The touchdown subtalar joint angle was not found to have a considerable influence on sprain occurrence, while increased touchdown plantar flexion caused increased ankle sprain occurrences. Increased touchdown plantar flexion may be the mechanism which causes …

Quantification Of In Vivo Acl Elongation During Dynamic Joint Movements: A New Methodology, Scott G. Mclean, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Anterior cruciate ligament (ACL) injuries are common in movement tasks incorporating sudden changes in velocity, such as sidtestepping. Current techniques adopted to quantify ACL strain are invasive as well as limited to slow, quasi-static move- ments. This paper presents a method for non-invasive measurement of ACL elongation during dynamic movement tasks, validation of the method, and demonstrates its applicability to the analysis of sidestep movements

A Special Theory Of Biphasic Mixtures And Experimental Results For Human Annulus Fibrosus Tested In Confined Compression, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

A finite deformation mixture theory is used to quantify the mechanical properties of the annulus fibrosus using experimental data obtained from a confined compression protocol. Certain constitutive assumptions are introduced to derive a special mixture of an elastic solid and an inviscid fluid, and the constraint of intrinsic incompressibility is introduced in a manner that is consistent with results obtained for the special theory. Thirty-two annulus fibrosus specimens oriented in axial (n = 16) and radial (n = 16) directions were obtained from the middle-lateral portion of intact intervertebral discs from human lumbar spines and tested in a stress-relaxation protocol. …

Movement Coupling At The Ankle During The Stance Phase Of Running, Alex Stacoff, Benno M. Nigg, Christoph Reinschmidt, Antonie J. Van Den Bogert, Arne Lundberg, Edgar Stüssi, Jachen Denoth

Mechanical Engineering Faculty Publications

The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between …

Effects Of Foot Orthoses On Skeletal Motion During Running, A. Stacoff, C. Reinschmidt, B. M. Nigg, Antonie J. Van Den Bogert, A. Lundberg, J. Denoth, E. Stüssi

Mechanical Engineering Faculty Publications

Objective. To quantify the effects of medial foot orthoses on skeletal movements of the calcaneus and tibia during the stance phase in running.

Design. Kinematic effects of medial foot orthoses (anterior, posterior, no support) were tested using skeletal (and shoe) markers at the calcaneus and tibia.

Background. Previous studies using shoe and skin markers concluded that medially placed orthoses control/reduce foot eversion and tibial rotation. However, it is currently unknown if such orthoses also affect skeletal motion at the lower extremities.

Methods. Intracortical Hofman pins with reflective marker triads were inserted under standard local anesthetic into the calcaneus …

Computer-Assisted Gait Analysis In Equine Orthopaedic Practice: The Case For Inverse Dynamic Analysis, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

No abstract provided.

Mechanical Properties Of The Tendinous Equine Interosseus Muscle Are Affected By In Vivo Transducer Implantation, M. O. Jansen, H. C. Schamhardt, Antonie J. Van Den Bogert, W. Hartman

Mechanical Engineering Faculty Publications

Liquid metal strain gauges (LMSGs) were implanted in the tendinous interosseous muscle, also called suspensory ligament (SL), in the forelimbs of 6 ponies in order to quantify in vivo strains and forces. Kinematics and ground reaction forces were recorded simultaneously with LMSG signals at the walk and the trot prior to implantation, and 3 and 4 days thereafter. The ponies were euthanised and tensile and failure tests were performed on the instrumented tendons and on the tendons of the contra lateral limb, which were instrumented post mortem. The origo–insertional (OI) strain of the SL was computed from pre- and post-operative …

Robotic Arm Design For Compressor Handling, Eve Blair

Honors Capstone Projects and Theses

No abstract provided.

An Experimental Study Of An Advanced Polymeric Material For Use In Total Knee Replacements Including Gait Analysis Of Mobile Knee Bearings, Lisa Ann Scott

Mechanical & Aerospace Engineering Theses & Dissertations

The primary objectives of this research were to clinically examine the New Jersey Low Contact Stress (LCS)™ Rotating Platform and Meniscal knee bearing systems and to investigate the tribological properties of a new polymer for potential application in total joint replacement. Thus, clinical studies were performed on subjects having the LCSTM Rotating Platform knee bearing and subjects having the LCS™ meniscal knee bearing. The results indicated that there was a statistically significant difference in the braking force for both implant groups when compared to a control group. There was also a statistically significant difference noted for the LCS™ Rotating Platform …

Optimization Of The Seating Position In A Human-Powered Vehicle, Y. Lei, Mohamed Trabia, D. Too

Mechanical Engineering Faculty Research

Until recently, most of the human-powered vehicles (HPV) were designed focusing solely on its aerodynamics characteristic. In many of these HPV designs, the rider seating position was arbitrarily chosen without consideration of its effect on the rider's comfort and cycling effectiveness. Also, there is no guarantee that the seating position is related to maximum power output. Too (1991) used an experimental approach to determine that the rider will produce the maximum anaerobic power when the seat tube angle of a bicycle is at 75° whereas Hull and Gonzalez (1990) used an engineering approach to optimize the cycling biomechanics. However several …

Synthesis Of An Efficient Band Mechanism For Robots And Prosthetic Devices, Run Chen Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

A noncircular pulley has been applied to improve the system efficiency of an electrical-powered elbow prosthesis. The dynamics of the motor and the prosthetic arm have been incorporated into the kinematic synthesis relationships for determining the pulley profile that maximizes the efficiency of the elbow prosthesis.

The nonlinear dynamic equations have been solved by the code Differential Equation (DE) while determining the motor power and efficiency which are the criteria in the nonlinear programming problem. The optimal design variables for determining the pulley profile along with some simulation results have been obtained from an optimization program (based on the Generalized …

Determination Of Systemic Blood Pressure Via Autospectral Analysis Of Oscillometric Data, Eugene Elie Warner

Dissertations and Theses

The currently accepted methods for measuring systemic blood pressure are either highly accurate but invasive in nature or clinically convenient but prone to observer-related errors. A new oscillometric method uses sensitive signal conditioning and sensing equipment with a non-invasive arm cuff to record arterial pulsations. The goal of this study is to establish more reliable criteria for the identification of systolic and diastolic pressures from oscillometric data.

Investigation Of Blood Pressure Measurement Using A Hydraulic Occlusive Cuff, Kusha R. Bhattarai

Dissertations and Theses

This thesis presents an improved oscillotonometric system for the measurement of human blood pressure. The study included:

1. The design of a hydraulic occlusive cuff,

2. The investigation of the wave forms taken from the blood pressure measurements, and

3. The design of a mechanism for the simulation of human blood pressure pulse.

In this study, an experimental system consisting of a rigid shell occlusive cuff, a constant volume displacement pump, a transducer, and a chart recorder was designed and used for data collection.

Designing Yards For Sheep, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

This article has been adapted from a report of the 1976 Sheep and Wool Refresher Course.

The officers attending the Course inspected W. A. farms, and then met in groups to discuss what they had seen, and to pool their experience in compiling a report. This article has been adapted from the report of the group working on the topic "Sheep yards and facilities".

The W. A. representative in the group working on sheep yard design was Mr John Wise of the Department's Katanning office.

The principals discussed here should help farmers either design new sheep yards, or improve the …