The neutral posture of the cervical spine is not unique in human subjects
Cervical spine injuries often happen in dynamic environments (e.g., sports and motor vehicle crashes) where individuals may be moving their head and neck immediately prior to impact. This motion may reposition the cervical vertebrae in a way that is dissimilar to the upright resting posture that is often used as the initial position in cadaveric studies of catastrophic neck injury. Therefore our aim was to compare the “neutral” cervical alignment measured using fluoroscopy of 11 human subjects while resting in a neutral posture and as their neck passed through neutral during the four combinations of active flexion and ...
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: Robyn S. Newell, Jean-S ébastien Blouin, John Street, Peter A. Cripton, Gunter P. Siegmund Source Type: research
Effect of chronic idiopathic low back pain on the kinetic gait characteristics in different foot masks
Identification of kinetic variables in different masks of foot is important for the evaluation and treatment of chronic low back pain. The aim of this study was to investigate the effect of chronic idiopathic low back pain on kinetic variables of gait in different foot masks. 11 idiopathic chronic low back pain patients and 13 healthy matched controls participated in this study. Using Emed foot-scanner system, the ground reaction force and impulse were measured during barefoot normal walking. Then, the average footprints were divided into 10 masks using the Automask program and the data were extracted using Multimask Evalu...
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: Shirin Yazdani, Elnaz Dizji, Farzaneh Alizadeh, Hamidollah Hassanlouei Tags: Short communication Source Type: research
Estimation of Vertical Walking Ground Reaction Force in Real –life Environments using Single IMU Sensor
Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Walking ground reaction forces are among the key parameters necessary for gait analysis. However, these parameters are commonly measured using force plates or instrumented treadmills which are expensive and bulky and can only be used in a controlled laboratory environment. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: E. Shahabpoor, A. Pavic Source Type: research
Functional deficits may be explained by Plantarflexor Remodeling Following Achilles Tendon Rupture Repair: Preliminary Findings
Achilles tendon ruptures are common injuries that often lead to long-term functional deficits. Despite the prevalence of these injuries, the mechanism responsible for limited function has not yet been established. Therefore, the purpose of this study was to present preliminary findings that support a hypothesis that skeletal muscle remodeling is the driving factor of poor outcomes in some patients. Biomechanical and ultrasonography assessments were performed on a patient that presented with poor functional outcomes 2.5 years after a surgically-repaired acute Achilles tendon rupture. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: Josh R. Baxter, Todd J. Hullfish, Wen Chao Tags: Short communication Source Type: research
Assessment of Vertebral Wedge Strength Using Cancellous Textural Properties Derived from DTS and Density Properties from DXA and HRCT
The purpose of this study was to examine the potential of digital tomosynthesis (DTS) derived cancellous bone textural measures to predict vertebral strength under conditions simulating a wedge fracture. 40 vertebral bodies (T6, T8, T11, and L3 levels) from 5 male and 5 female cadaveric donors were utilized. The specimens were scanned using dual energy x-ray absorptiometry (DXA) and high resolution computed tomography (HRCT) to obtain measures of bone mineral density (BMD) and content (BMC), and DTS to obtain measures of bone texture. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: Yener N. Yeni, Woong Kim, Daniel Oravec, Mary Nixon, George W. Divine, Michael J. Flynn Source Type: research
Micropipette aspiration method for characterizing biological materials with surface energy
Many soft biological tissues possess a considerable surface stress, which plays a significant role in their biophysical functions, but most previous methods for characterizing their mechanical properties have neglected the effects of surface stress. In this work, we investigate the micropipette aspiration method to measure the mechanical properties of soft tissues and cells with surface effects. The neo-Hookean constitutive model is adopted to describe the hyperelasticity of the measured biological material, and the surface effect is taken into account by the finite element method. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 22, 2018 Category: Biomedical Science Authors: Yue Ding, Gang-Feng Wang, Xi-Qiao Feng, Shou-Wen Yu Source Type: research
Normal force distribution and posture of a hand pressing on a flat surface
This study aims to analyze the effect of hand posture and surface orientation on hand force while pressing a flat surface. Twelve participants, 6 females and 6 males ages 19 –25, performed three exertions (100%, 30% and 10% MVC- Maximum Voluntary Contraction) perpendicular to a plate in 4 angles (−45°, 0°, 45° and 90° with respect to the horizontal plane) at elbow height. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: R. Figueroa-Jacinto, T.J. Armstrong, W. Zhou Source Type: research
Gait variability and symmetry remain consistent during high-intensity 10,000 m treadmill running
The aim of this study was to analyze changes in gait variability and symmetry in distance runners. Fourteen competitive athletes ran on an instrumented treadmill for 10,000 m at speeds equivalent to 103% of their season’s best time. Spatiotemporal and ground reaction force data were recorded at 1500, 3000, 5000, 7500 and 9500 m. Gait variability and inter-leg symmetry were measured using median absolute deviation (MAD) and the symmetry angle, respectively. There were no overall changes during the running bout for absolute values, symmetry angles or variability, and there were only moderate changes in variability bet...
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: Brian Hanley, Catherine B. Tucker Source Type: research
Validation of Gait Event Detection by Centre of Pressure During Target Stepping in Healthy and Paretic Gait
Target-stepping paradigms are increasingly used to assess and train gait adaptability. Accurate gait-event detection (GED) is key to locating targets relative to the ongoing step cycle as well as measuring foot-placement error. In the current literature GED is either based on kinematics or centre of pressure (CoP), and both have been previously validated with young healthy individuals. However, CoP based GED has not been validated for stroke survivors who demonstrate altered CoP pattern. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: Susanne M. van der Veen, Ulrike Hammerbeck, Richard J. Baker, Kristen L. Hollands Tags: Short communication Source Type: research
An Investigation on Normal Force Distribution and Posture of a Hand Pressing on a Flat Surface
This study aims to analyze the effect of hand posture and surface orientation on hand force while pressing a flat surface. Twelve participants, 6 females and 6 males ages 19-25, performed three exertions (100%, 30% and 10% MVC- Maximum Voluntary Contraction) perpendicular to a plate in 4 angles (-45 ˚, 0˚, 45˚ and 90˚ with respect to horizontal plane) at elbow height. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: R. Figueroa-Jacinto, T. Armstrong, W. Zhou Source Type: research
The effect of football helmet facemasks on impact behavior during linear drop tests
Football helmet certification tests are performed without a facemask attached to the helmet; however, the facemask is expected to contribute substantially to the structure and dynamics of the helmet through the effects of added mass and added stiffness. Facemasks may increase the peak acceleration and severity index; therefore, as-used helmets may not mitigate head impacts as effectively as certification tests indicate. Furthermore, the effect is expected to depend on the helmet design as well as the orientation and speed of the impact. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: Katherine M. Breedlove, Evan L. Breedlove, Thomas G. Bowman, Ellen Arruda, Eric A. Nauman Tags: Short communication Source Type: research
Gait variability and symmetry remain consistent during high-intensity 10000 m treadmill running
The aim of this study was to analyze changes in gait variability and symmetry in distance runners. Fourteen competitive athletes ran on an instrumented treadmill for 10000 m at speeds equivalent to 103% of their season ’s best time. Spatiotemporal and ground reaction force data were recorded at 1500, 3000, 5000, 7500 and 9500 m. Gait variability and inter-leg symmetry were measured using median absolute deviation (MAD) and the symmetry angle, respectively. There were no overall changes during the running bout fo r absolute values, symmetry angles or variability, and there were only moderate changes in variability between...
Source: Journal of Biomechanics - August 14, 2018 Category: Biomedical Science Authors: Brian Hanley, Catherine B. Tucker Source Type: research
Linear and nonlinear analyses of femoral fractures: Computational/experimental study
This paper describes two new methods for computational fracture analysis of human femur using Quantitative Computed Tomography (QCT) voxel-based finite element (FE) simulation. The paper also reports comprehensive mechanical testing for validation of the methods and evaluation of the required material properties. The analyses and tests were carried out on 15 human femurs under 11 different stance-type loading orientations. Several classical forms of subcapital, transcervical, basicervical, and intertrochanteric fractures plus a specific type of subtrochanteric fracture were created and analyzed. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 13, 2018 Category: Biomedical Science Authors: Majid Mirzaei, Fatemeh Alavi, Farzaneh Allaveisi, Vahid Naeini, Pegah Amiri Source Type: research
Flow rates in perfusion bioreactors to maximise mineralisation in bone tissue engineering in vitro
In bone tissue engineering experiments, fluid-induced shear stress is able to stimulate cells to produce mineralised extracellular matrix (ECM). The application of shear stress on seeded cells can for example be achieved through bioreactors that perfuse medium through porous scaffolds. The generated mechanical environment (i.e. wall shear stress: WSS) within the scaffolds is complex due to the complexity of scaffold geometry. This complexity has so far prevented setting an optimal loading (i.e. flow rate) of the bioreactor to achieve an optimal distribution of WSS for stimulating cells to produce mineralised ECM. (Source: ...
Source: Journal of Biomechanics - August 13, 2018 Category: Biomedical Science Authors: Feihu Zhao, Bert van Rietbergen, Keita Ito, Sandra Hofmann Tags: Short communication Source Type: research
The effect of glenohumeral plane of elevation on supraspinatus subacromial proximity
Shoulder pain is a common clinical problem affecting most individuals in their lifetime. Despite the high prevalence of rotator cuff pathology in these individuals, the pathogenesis of rotator cuff disease remains unclear. Position and motion related mechanisms of rotator cuff disease are often proposed, but poorly understood. The purpose of this study was to determine the impact of systematically altering glenohumeral plane on subacromial proximities across arm elevation as measures of tendon compression risk. (Source: Journal of Biomechanics)
Source: Journal of Biomechanics - August 13, 2018 Category: Biomedical Science Authors: Rebekah L. Lawrence, William C. Sessions, Megan C. Jensen, Justin L. Staker, Aya Eid, Ryan Breighner, Nathaniel E. Helwig, Jonathan P. Braman, Paula M. Ludewig Source Type: research
