International Journal of Experimental and Computational Biomechanics http://www.inderscience.com/browse/index.php?journalID=290&year=2011&vol=1&issue=4 Inderscience Publishers Ltd en-uk International Journal of Experimental and Computational Biomechanics 1755-8735 1755-8743 © 2011 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijecb_scoverijecb.jpg http://www.inderscience.com/browse/index.php?journalID=290&year=2011&vol=1&issue=4 http://www.inderscience.com/link.php?id=39945 The aim of this study was to quantify the importance of biarticular muscles on vertical squat jump. In order to do that, we used a neuromusculoskeletal model and a forward dynamics computer simulation. In separate trials biarticular muscles were removed from the neuromusculoskeletal model, firstly only one muscle was removed each trial, and then all three biarticular muscles were removed together in one more trial. Investigated were three main groups of biarticular muscles of lower extremities: m. rectus femoris, hamstrings and m. gastrocemius. The results demonstrated that monoarticular muscles are primary producers of the force used to accelerate the body's centre of gravity vertically. While the function of biarticular muscles is twofold: 1) for the force of biarticular muscles to contribute to vertical acceleration of the body's centre of gravity, like the force of monoarticular muscles; 2) for biarticular muscles to fine-tune coordination of monoarticular muscles, by optimising the exertion pattern of the muscle and by transferring energy among all joints. Therefore, we conclude that the most important function of biarticular muscles in a vertical jump is to help to coordinate jump movement and increase the effectiveness of the usage of muscle force to accelerate vertically the body's centre of gravity. Simulation study of the importance of biarticular muscles on human vertical jump performance
Przemyslaw Prokopow, Krzysztof Pomorski
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 333 - 342
The aim of this study was to quantify the importance of biarticular muscles on vertical squat jump. In order to do that, we used a neuromusculoskeletal model and a forward dynamics computer simulation. In separate trials biarticular muscles were removed from the neuromusculoskeletal model, firstly only one muscle was removed each trial, and then all three biarticular muscles were removed together in one more trial. Investigated were three main groups of biarticular muscles of lower extremities: m. rectus femoris, hamstrings and m. gastrocemius. The results demonstrated that monoarticular muscles are primary producers of the force used to accelerate the body's centre of gravity vertically. While the function of biarticular muscles is twofold: 1) for the force of biarticular muscles to contribute to vertical acceleration of the body's centre of gravity, like the force of monoarticular muscles; 2) for biarticular muscles to fine-tune coordination of monoarticular muscles, by optimising the exertion pattern of the muscle and by transferring energy among all joints. Therefore, we conclude that the most important function of biarticular muscles in a vertical jump is to help to coordinate jump movement and increase the effectiveness of the usage of muscle force to accelerate vertically the body's centre of gravity.

]]> 10.1504/IJECB.2011.039945 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 333 - 342 Przemyslaw Prokopow Krzysztof Pomorski Computational Biomechanics Unit, The Institute of Physical and Chemical Research, RIKEN, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan. ' Institute of Physics, Jagiellonian University, ul. Reymonta 4 30-059, Krakow, Poland biarticular muscles squat jumps simulation human vertical jumps jump performance neuromusculoskeletal models forward dynamics hamstrings muscle force vertical acceleration coordination. 2011-05-08T23:20:50-05:00 1 4 333 342 2011-05-08T23:20:50-05:00 http://www.inderscience.com/link.php?id=39946 A key factor in press fit hip implant fixation is the amount of interfacial motion between implant stem and the femur. A finite element analysis of hip implant stem designs was performed to determine the effect on stem interfacial motion. Implants of distinct cross section and stem profile were analysed. Implant material property effects were studied by analysing cobalt chromium (CoCr), stainless steel (SS316L), and titanium alloy (Ti 6Al-4V) implants. Each implant was subjected to a static loading simulating the weight of an average US male (189 lb) taking a step forward. Study results showed that implant cross section played a role in interfacial motion amounts. Ti 6Al-4V showed the greatest difference in implant interfacial motion as compared to SS316L and CoCr. Continued design and development of implant stems resistant to interfacial motion is needed. Hip implant stem interfacial motion, a finite element analysis
Mbulelo T. Makola, Tarun Goswami
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 343 - 358
A key factor in press fit hip implant fixation is the amount of interfacial motion between implant stem and the femur. A finite element analysis of hip implant stem designs was performed to determine the effect on stem interfacial motion. Implants of distinct cross section and stem profile were analysed. Implant material property effects were studied by analysing cobalt chromium (CoCr), stainless steel (SS316L), and titanium alloy (Ti 6Al-4V) implants. Each implant was subjected to a static loading simulating the weight of an average US male (189 lb) taking a step forward. Study results showed that implant cross section played a role in interfacial motion amounts. Ti 6Al-4V showed the greatest difference in implant interfacial motion as compared to SS316L and CoCr. Continued design and development of implant stems resistant to interfacial motion is needed.

]]> 10.1504/IJECB.2011.039946 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 343 - 358 Mbulelo T. Makola Tarun Goswami Department of Biomedical Engineering, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435-0001, USA. ' Department of Biomedical Engineering, Department Orthopedic Surgery and Sports Medic, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435-0001, USA hip arthroplasty hip implant implant stems total hip replacement cement less interfacial motion micromotion implant fixation implant loosening finite element analysis FEA press fit implants femur cobalt chromium implants stainless steel implants titanium alloy implants titanium alloys. 2011-05-08T23:20:50-05:00 1 4 343 358 2011-05-08T23:20:50-05:00 http://www.inderscience.com/link.php?id=39947 Non-invasive ultrasound imaging of carotid plaques is used in routine clinical evaluation of atherosclerosis and stroke. Strain imaging of the atherosclerotic plaques represents a very promising, emerging application of ultrasound imaging because it can assess plaque vulnerability without the risks of intervention. The promise of strain imaging includes the development of advanced diagnostic tools that can be used to predict plaque rupture. This review paper presents the fundamental assumptions and methods that can be used to extract motion estimates from ultrasound images. In terms of assumptions, both the constant and non-constant brightness models are presented. The most commonly used energy functionals are presented, along with both local and global solutions. Motion and strain imaging examples are also provided to demonstrate the methods. Our goal is that this review will facilitate the development of new, reliable strain imaging methods that can be used to assess the risk of plaque rupture. A review of motion estimation methods for non-invasive ultrasound motion and emerging strain imaging methods of carotid artery plaques
Sergio Murillo, Marios S. Pattichis, E. Simon Barriga
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 359 - 380
Non-invasive ultrasound imaging of carotid plaques is used in routine clinical evaluation of atherosclerosis and stroke. Strain imaging of the atherosclerotic plaques represents a very promising, emerging application of ultrasound imaging because it can assess plaque vulnerability without the risks of intervention. The promise of strain imaging includes the development of advanced diagnostic tools that can be used to predict plaque rupture. This review paper presents the fundamental assumptions and methods that can be used to extract motion estimates from ultrasound images. In terms of assumptions, both the constant and non-constant brightness models are presented. The most commonly used energy functionals are presented, along with both local and global solutions. Motion and strain imaging examples are also provided to demonstrate the methods. Our goal is that this review will facilitate the development of new, reliable strain imaging methods that can be used to assess the risk of plaque rupture.

]]> 10.1504/IJECB.2011.039947 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 359 - 380 Sergio Murillo Marios S. Pattichis E. Simon Barriga Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, 87131, USA. ' Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, 87131, USA. ' VisionQuest Biomedical, Albuquerque, NM 87106, USA motion estimation image processing carotid artery plaques strain imaging elastography atherosclerosis, ultrasound images carotid plaques strokes plaque rupture brightness models. 2011-05-08T23:20:50-05:00 1 4 359 380 2011-05-08T23:20:50-05:00 http://www.inderscience.com/link.php?id=39948 The effect of vacuum mixer brand is studied on six commercial bone cements, three with prophylactic doses of antibiotics and three without. The modulus of elasticity, ultimate tensile strength, maximum strain, and 0.2% yield strength was analysed. Bone cement specimens were manufactured and tested in accordance with ASTM D638 specifications using three different types of vacuum mixers in an operating room. The specimens were tested in a universal testing machine. Statistical analysis revealed that a proprietary mixer did not generally outperform the other two mixers for its own cement. It was found that the mixer had a significant effect on the results and that the Stryker/Simplex mixer generally outperformed Biomet and Zimmer. However, for the Simplex bone cement, the mixer type did not have a significant effect for most of the data analysed. The overall conclusion is that the proprietary mixer does not perform the best with its own cement. Effect of vacuum mixer brand on tensile properties of acrylic bone cement
Alexandra Schonning, Carmen Masnita Iusan, Mark Rawls, Michael Straatsma, Peter Wludyka, Michael Patney, J. Ryan Cotton
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 381 - 396
The effect of vacuum mixer brand is studied on six commercial bone cements, three with prophylactic doses of antibiotics and three without. The modulus of elasticity, ultimate tensile strength, maximum strain, and 0.2% yield strength was analysed. Bone cement specimens were manufactured and tested in accordance with ASTM D638 specifications using three different types of vacuum mixers in an operating room. The specimens were tested in a universal testing machine. Statistical analysis revealed that a proprietary mixer did not generally outperform the other two mixers for its own cement. It was found that the mixer had a significant effect on the results and that the Stryker/Simplex mixer generally outperformed Biomet and Zimmer. However, for the Simplex bone cement, the mixer type did not have a significant effect for most of the data analysed. The overall conclusion is that the proprietary mixer does not perform the best with its own cement.

]]> 10.1504/IJECB.2011.039948 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 381 - 396 Alexandra Schonning Carmen Masnita Iusan Mark Rawls Michael Straatsma Peter Wludyka Michael Patney J. Ryan Cotton Department of Mechanical Engineering, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA. ' Department of Mathematics and Statistics, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA. ' Department of Mechanical Engineering, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA. ' Department of Mechanical Engineering, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA. ' Department of Mathematics and Statistics, University of North Florida, 1 UNF Dr., Jacksonville, FL 32224, USA. ' Department of Orthopaedics, University of Florida Shands Jacksonville, 655 West 8th St., ACC bldg. 2nd fl., Jacksonville, FL 32209, USA. ' Department of Orthopaedics, University of Florida Shands Jacksonville, 655 West 8th St., ACC bldg. 2nd fl., Jacksonville, FL 32209, USA acrylic bone cement tensile strength modulus of elasticity antibiotics vacuum mixer brand tensile tests maximum strain yield strength. 2011-05-08T23:20:50-05:00 1 4 381 396 2011-05-08T23:20:50-05:00 http://www.inderscience.com/link.php?id=39949 Mechanobiological growth is the biological process whereby bone growth is modulated by mechanical loading. The goal of this study is to develop an energy-based mechanobiological bone growth model. Mechanobiological procedures basically include mechanosensing and mechanoregulation. This study represented the mechanosensing as a mathematical model combining energy and mechanical-triggered deformation. The mechanoregulation was modelled as a mathematical form integrated distortion and dilatation energy. Mechanobiological growth model was developed from those two procedures and represented as a function of distortion and dilatation stresses. The model was tested by using finite element model of a thoracic vertebra (T7) for simulating one-year growth procedure under multi-axial loads. The simulation results presented the retarded and stimulated growth under compression and tension. Shear stress increased the growth rate with 20%-40%. This model agreed with experimental study of growth and published numerical growth simulation of human vertebrae as well as mechanobiology theory. This model allows simulating vertebral growth under multi-direction loads. An energy-based technique for the development of a mechanobiological growth model of vertebrae
Hui Lin, Meiqing Wang
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 397 - 416
Mechanobiological growth is the biological process whereby bone growth is modulated by mechanical loading. The goal of this study is to develop an energy-based mechanobiological bone growth model. Mechanobiological procedures basically include mechanosensing and mechanoregulation. This study represented the mechanosensing as a mathematical model combining energy and mechanical-triggered deformation. The mechanoregulation was modelled as a mathematical form integrated distortion and dilatation energy. Mechanobiological growth model was developed from those two procedures and represented as a function of distortion and dilatation stresses. The model was tested by using finite element model of a thoracic vertebra (T7) for simulating one-year growth procedure under multi-axial loads. The simulation results presented the retarded and stimulated growth under compression and tension. Shear stress increased the growth rate with 20%-40%. This model agreed with experimental study of growth and published numerical growth simulation of human vertebrae as well as mechanobiology theory. This model allows simulating vertebral growth under multi-direction loads.

]]> 10.1504/IJECB.2011.039949 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 397 - 416 Hui Lin Meiqing Wang Department of Mechanical Engineering, Ecole Polytechnique de Montreal, P.O. Box 6079, Station 'Centre-Ville', Montreal, Quebec, H3C 3A7, Canada; Sainte-Justine University Hospital Center, 3175 Cote-Ste-Catherine Rd., Montreal, Quebec, H3T 1C5, Canada. ' Department Oral Anatomy and Physiology and TMD, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, Xi-an, China mechanobiological growth mechanosensing mechanoregulation finite element method FEM multi-direction loads human vertebrae energy modelling bone growth mechanical loading mathematical modelling deformation distortion dilatation stress compression tension shear stress. 2011-05-08T23:20:50-05:00 1 4 397 416 2011-05-08T23:20:50-05:00 http://www.inderscience.com/link.php?id=39950 An automated anatomical torsion monitor (A-ATM) is developed to evaluate the stiffness and visco-elasticity of the low back as a static load is applied and removed from the pelvis. The resulting hysteresis loop area (HLA) is used to evaluate the mechanical properties of the low back. Also a technique for improving the low back dysfunction by imparting oscillations to the low back is presented. The before and after HLAs are compared for objective evaluation. It is observed that providing oscillations to the low back for five minutes at a frequency of 20 cycles per minute results in improved elasticity of the low back for those subjects whose BMI is 25 or less and an insignificant change in stiffness for all the subjects. However the correct displacement amplitude, frequency, and duration of treatment will depend upon individual medical and physical conditions. Evaluation of the rotational stiffness and visco-elasticity of the low back and improving the low back visco-elasticity
Hans Chaudhry, Nadi Atalla, Vishal K. Singh, Max Roman, Thomas Findley
International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 417 - 429
An automated anatomical torsion monitor (A-ATM) is developed to evaluate the stiffness and visco-elasticity of the low back as a static load is applied and removed from the pelvis. The resulting hysteresis loop area (HLA) is used to evaluate the mechanical properties of the low back. Also a technique for improving the low back dysfunction by imparting oscillations to the low back is presented. The before and after HLAs are compared for objective evaluation. It is observed that providing oscillations to the low back for five minutes at a frequency of 20 cycles per minute results in improved elasticity of the low back for those subjects whose BMI is 25 or less and an insignificant change in stiffness for all the subjects. However the correct displacement amplitude, frequency, and duration of treatment will depend upon individual medical and physical conditions.

]]> 10.1504/IJECB.2011.039950 International Journal of Experimental and Computational Biomechanics, Vol. 1, No. 4 (2011) pp. 417 - 429 Hans Chaudhry Nadi Atalla Vishal K. Singh Max Roman Thomas Findley Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, NJ 07102, USA. ' Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, NJ 07102, USA. ' Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, NJ 07102, USA. ' Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, NJ 07102, USA. ' War-related Illness and Injury Study Center, VA Medical Center, East Orange, NJ 07018, USA rotational stiffness viscoelasticity low back dysfunction anatomic torsion monitor ATM automated anatomical torsional monitor A-ATM oscillations hysteresis loop area low back elasticity. 2011-05-08T23:20:50-05:00 1 4 417 429 2011-05-08T23:20:50-05:00