Displaying publications 141 - 160 of 251 in total

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  1. Finite element analysis of Puddu and Tomofix plate fixation for open wedge high tibial osteotomy
    Raja Izaham RM, Abdul Kadir MR, Abdul Rashid AH, Hossain MG, Kamarul T
    Injury, 2012 Jun;43(6):898-902.
    PMID: 22204773 DOI: 10.1016/j.injury.2011.12.006
    The use of open wedge high tibial osteotomy (HTO) to correct varus deformity of the knee is well established. However, the stability of the various implants used in this procedure has not been previously demonstrated. In this study, the two most common types of plates were analysed (1) the Puddu plates that use the dynamic compression plate (DCP) concept, and (2) the Tomofix plate that uses the locking compression plate (LCP) concept. Three dimensional model of the tibia was reconstructed from computed tomography images obtained from the Medical Implant Technology Group datasets. Osteotomy and fixation models were simulated through computational processing. Simulated loading was applied at 60:40 ratios on the medial:lateral aspect during single limb stance. The model was fixed distally in all degrees of freedom. Simulated data generated from the micromotions, displacement and, implant stress were captured. At the prescribed loads, a higher displacement of 3.25 mm was observed for the Puddu plate model (p<0.001). Coincidentally the amount of stresses subjected to this plate, 24.7 MPa, was also significantly lower (p<0.001). There was significant negative correlation (p<0.001) between implant stresses to that of the amount of fracture displacement which signifies a less stable fixation using Puddu plates. In conclusion, this study demonstrates that the Tomofix plate produces superior stability for bony fixation in HTO procedures.
    Matched MeSH terms: Biomechanical Phenomena
  2. A new approach for the pistoning measurement in transtibial prosthesis
    Gholizadeh H, Abu Osman NA, Lúvíksdóttir Á, Eshraghi A, Kamyab M, Wan Abas WA
    Prosthet Orthot Int, 2011 Dec;35(4):360-4.
    PMID: 21975850 DOI: 10.1177/0309364611423130
    Good suspension lessens the pistoning (vertical displacement) of the residual limb inside the prosthetic socket. Several methods are used for measuring the pistoning.
    Matched MeSH terms: Biomechanical Phenomena
  3. A biomechanical study comparing plate fixation using unicortical and bicortical screws in transverse metacarpal fracture models subjected to cyclic loading
    Afshar R, Fong TS, Latifi MH, Kanthan SR, Kamarul T
    J Hand Surg Eur Vol, 2012 Jun;37(5):396-401.
    PMID: 22019989 DOI: 10.1177/1753193411424557
    The use of bicortical screws to fix metacarpal fractures has been suggested to provide no added biomechanical advantage over unicortical screw fixation. However, this was only demonstrated in static loading regimes, which may not be representative of biological conditions. The present study was done to determine whether similar outcomes are obtained when cyclic loading is applied. Transverse midshaft osteotomies were created in 20 metacarpals harvested from three cadavers. Fractures were stabilised using 2.0 mm mini fragment plates fixed with either bicortical or unicortical screw fixation. These fixations were tested to failure with a three-point bending cyclic loading protocol using an electromechanical microtester and a 1 kN load cell. The mean load to failure was 370 N (SD 116) for unicortical fixation and 450 N (SD 135) for bicortical fixation. Significant differences between these two constructs were observed. A biomechanical advantage was found when using bicortical screws in metacarpal fracture plating.
    Matched MeSH terms: Biomechanical Phenomena
  4. Ageing modifies the fibre angle and biomechanical function of the lumbar extensor muscles
    Singh DK, Bailey M, Lee RY
    Clin Biomech (Bristol, Avon), 2011 Jul;26(6):543-7.
    PMID: 21392870 DOI: 10.1016/j.clinbiomech.2011.02.002
    Ageing is associated with geometrical changes in muscle fascicles that may lead to deteriorations in physical functions. The purpose of this study was to study the effects of ageing on fibre orientation and strength of the lumbar extensor muscles.
    Matched MeSH terms: Biomechanical Phenomena
  5. Fulltext Which is the best method of sterilization of tumour bone for reimplantation? A biomechanical and histopathological study
    Singh VA, Nagalingam J, Saad M, Pailoor J
    Biomed Eng Online, 2010;9:48.
    PMID: 20831801 DOI: 10.1186/1475-925X-9-48
    Sterilization and re-usage of tumour bone for reconstruction after tumour resection is now gaining popularity in the East. This recycle tumour bone needs to be sterilized in order to eradicate the tumour cells before re-implantation for limb salvage procedures. The effect of some of these treatments on the integrity and sterility of the bone after treatment has been published but there has yet been a direct comparison between the various methods of sterilization to determine the one method that gives the best tumour kill without compromising the bone's structural integrity.
    Matched MeSH terms: Biomechanical Phenomena
  6. The use of graphic rules in grade one to help identify children at risk of handwriting difficulties
    Khalid PI, Yunus J, Adnan R, Harun M, Sudirman R, Mahmood NH
    Res Dev Disabil, 2010 Nov-Dec;31(6):1685-93.
    PMID: 20554150 DOI: 10.1016/j.ridd.2010.04.005
    Previous researches on elementary grade handwriting revealed that pupils employ certain strategy when writing or drawing. The relationship between this strategy and the use of graphic rules has been documented but very little research has been devoted to the connection between the use of graphic rules and handwriting proficiency. Thus, this study was conducted to investigate the relative contribution of the use of graphic rules to the writing ability. A sample of 105 first graders who were average printers and 65 first graders who might experience handwriting difficulty, as judged by their teachers, of a normal primary school were individually tested on their use of graphic rules. It has been found that pupils who are below average printers use more non-analytic strategy than average printers to reproduce the figures. The results also reveal that below average printers do not acquire the graphic principles that foster an analytic approach to production skills. Although the findings are not sufficient to allow definitive conclusions about handwriting ability, it can be considered as one of the screening measures in identifying pupils who are at risk of handwriting difficulties.
    Matched MeSH terms: Biomechanical Phenomena
  7. Extraction of dynamic features from hand drawn data for the identification of children with handwriting difficulty
    Khalid PI, Yunus J, Adnan R
    Res Dev Disabil, 2010 Jan-Feb;31(1):256-62.
    PMID: 19854613 DOI: 10.1016/j.ridd.2009.09.009
    Studies have shown that differences between children with and without handwriting difficulties lie not only in the written product (static data) but also in dynamic data of handwriting process. Since writing system varies among countries and individuals, this study was conducted to determine the feasibility of using quantitative outcome measures of children's drawing to identify children who are at risk of handwriting difficulties. A sample of 143 first graders of a normal primary school was investigated regarding their handwriting ability. The children were divided into two groups: test and control. Ten children from test group and 40 children from control group were individually tested for their Visual Motor Integration skills. Analysis on dynamic data indicated significant differences between the two groups in temporal and spatial measures of the drawing task performance. Thus, kinematic analysis of children's drawing is feasible to provide performance characteristic of handwriting ability, supporting its use in screening for handwriting difficulty.
    Matched MeSH terms: Biomechanical Phenomena
  8. Interface pressure profile analysis for patellar tendon-bearing socket and hydrostatic socket
    Moo EK, Osman NA, Pingguan-Murphy B, Abas WA, Spence WD, Solomonidis SE
    Acta Bioeng Biomech, 2009;11(4):37-43.
    PMID: 20405814
    Conventionally, patellar tendon-bearing (PTB) sockets, which need high dexterity of prosthetist, are widely used. Lack of chartered and experienced prosthetist has often led to painful experience of wearing prosthesis and this will in turn deter the patients to wear the prosthesis, which will further aggravate stump shrinkage. Thus, the hydrostatic socket which demands relatively lower level of fabricating skill is proposed to replace the PTB socket in order to produce the equivalent, if not better, quality of support to the amputee patients. Both sockets' pressure profiles are studied and compared using finite element analysis (FEA) software. Three-dimensional models of both sockets were developed using MIMICS software. The analysis results showed that hydrostatic socket did exhibit more uniform pressure profiles than that of PTB socket. PTB socket showed pressure concentration near the proximal brim of the socket and also at the distal fibula. It was also found that the pressure magnitude in hydrostatic socket is relatively lower than that of PTB socket.
    Matched MeSH terms: Biomechanical Phenomena
  9. Investigating data entry task performance on a laptop under the impact of vibration: the effect of color
    Mallick Z
    Int J Occup Saf Ergon, 2007;13(3):291-303.
    PMID: 17888238
    The last 20 years have seen a tremendous growth in mobile computing and wireless communications and services. An experimental study was conducted to explore the effect of text/background color on a laptop computing system along with variable environmental vibration on operators' data entry task performance in moving automobiles. The operators' performance was measured in terms of the number of characters entered per minute without spaces (NCEPMWS) on a laptop computing system. The subjects were divided into 3 categories, namely, Novices, Intermediates and Experts. Findings suggest a re-evaluation of existing laptop designs taking ergonomics into consideration. It appears that proper selection of text/background color on the laptop coupled with controlled vehicular speed could result in a better quality of interaction between human and laptops and it could also resolve the problem of poor data entry task performance.
    Matched MeSH terms: Biomechanical Phenomena
  10. The influence of different plasticizers on some physical and mechanical properties of hydroxypropyl methylcellulose free films
    Saringat HB, Alfadol KI, Khan GM
    Pak J Pharm Sci, 2005 Jul;18(3):25-38.
    PMID: 16380341
    Coating has been widely used in pharmaceutical manufacture either as non-functional or a functional entity. The objectives of the present study were to investigate the effect of plasticizers such as PEG400, PEG1000 and triacetin on mechanical properties, glass transition temperature and water vapor transmission of free films prepared from HPMC and/or HPMC:PVA blends, to develop suitable coating system for tablets, and to determine the release profiles of the coated tablets. The tensile strength of plasticized HPMC films was generally lower than that of control HPMC film and could be attributed to increased crystallinity and segmental chain mobility of HPMC. This effect increased as the concentration of plasticizer increased. Generally the addition of both grades of polyethylene glycol (PEG400 & PEG1000) increased the moisture permeability of HPMC films but the films containing triacetin provided a more rigid barrier to moisture compared to unplasticized HPMC films. The dissolution profiles of paracetamol tablets coated with 7% w/v HPMC coating-solutions containing PEG400, PEG1000 and triacetin, and those containing PEG400 & PVA together showed that HPMC had weak water resistance. The presence of PEG400 and 1000 in HPMC films further weakened its resistance to solubility while the presence of triacetin caused a little increase in HPMC water resistance. From the results it was concluded that HPMC at 7%w/w concentration was suitable for film-coating intended for non-functional coating. Presence of the PEG 400, PEG1000 and triacetin as well as the presence of PVA and PEG400 together improved the coating properties of HPMC films and made it more suitable as a non-functional coating material.
    Matched MeSH terms: Biomechanical Phenomena
  11. Patellar thickness and lateral retinacular release affects patellofemoral kinematics in total knee arthroplasty
    Merican AM, Ghosh KM, Baena FR, Deehan DJ, Amis AA
    Knee Surg Sports Traumatol Arthrosc, 2014 Mar;22(3):526-33.
    PMID: 23271038 DOI: 10.1007/s00167-012-2312-z
    PURPOSE: To study the effect of increasing patellar thickness (overstuffing) on patellofemoral kinematics in total knee arthroplasty and whether subsequent lateral retinacular release would restore the change in kinematics.

    METHODS: The quadriceps of eight fresh-frozen knees were loaded on a custom-made jig. Kinematic data were recorded using an optical tracking device for the native knee, following total knee arthroplasty (TKA), then with patellar thicknesses from -2 to +4 mm, during knee extension motion. Staged lateral retinacular releases were performed to examine the restoration of normal patellar kinematics.

    RESULTS: Compared to the native knee, TKA led to significant changes in patellofemoral kinematics, with significant increases in lateral shift, tilt and rotation. When patellar composite thickness was increased, the patella tilted further laterally. Lateral release partly corrected this lateral tilt but caused abnormal tibial external rotation. With complete release of the lateral retinaculum and capsule, the patella with an increased thickness of 4 mm remained more laterally tilted compared to the TKA with normal patellar thickness between 45° and 55° knee flexion and from 75° onwards. This was on average by 2.4° ± 2.9° (p 

    Matched MeSH terms: Biomechanical Phenomena
  12. The use of freeze-dry bovine pericardium (FDBP) in diaphragmatic herniorrhaphy in dogs
    Loqman MY, Wong CM, Hair-Bejo M, Zuki AB, Hafeez YM
    Med J Malaysia, 2004 May;59 Suppl B:113-4.
    PMID: 15468844
    A study was conducted to investigate the effectiveness of freeze-dried bovine pericardium (FDBP) as a biomaterial in diaphragmatic herniorrhapy in dogs. Eight adult dogs were randomly selected and divided into two equal groups. In FDBP group, a diaphragmatic defect was induced and repaired with an identical size of FDBP. In the control group, a diaphragmatic wall was incised at three-side border creating a flap and sutured. Grossly, only mild intrathoracic adhesion was observed for most of the animals, and no herniation occured. Microscopically, the biomaterial incorporated into the host's tissue by ingrowth of young muscle fiber and massive new blood vessel formation in between the fibrous tissue.
    Matched MeSH terms: Biomechanical Phenomena
  13. Mechanical properties of HDPE/UHMWPE blends: effect of filler loading and filler treatment
    Lai KL, Roziyanna A, Ogunniyi DS, Zainal AM, Azlan AA
    Med J Malaysia, 2004 May;59 Suppl B:61-2.
    PMID: 15468819
    Various blend ratios of high-density polyethylene (HDPE) and ultra high molecular weight polyethylene (UHMWPE) were prepared with the objective of determining their suitability as biomaterials. In the unfilled state, a blend of 50/50 (HDPE/UHMWPE) ratio by weight was found to yield optimum properties in terms of processability and mechanical properties. Hydroxyapatite (HA) was compounded with the optimum blend ratio. The effects of HA loading, varied from 0 to 50wt% for both filled and unfilled blends were tested for mechanical properties. It was found that the inclusion of HA in the blend led to a remarkable improvement of mechanical properties compared to the unfilled blend. In order to improve the bonding between the polymer blend and the filler, the HA used was chemically treated with a coupling agent known as 3-(trimethoxysiyl) propyl methacrylate and the treated HA was mixed into the blend. The effect of mixing the blend with silane-treated HA also led to an overall improvement of mechanical properties.
    Matched MeSH terms: Biomechanical Phenomena
  14. Scaffolds in bone tissue engineering
    Nather A
    Med J Malaysia, 2004 May;59 Suppl B:37-8.
    PMID: 15468807
    Matched MeSH terms: Biomechanical Phenomena
  15. In vitro development of autologous tissue engineered human articular neocartilage for orthopaedic surgery
    Samsudin OC, Aminuddin BS, Munirah S, Chua KH, Fuzina NH, Isa MR, et al.
    Med J Malaysia, 2004 May;59 Suppl B:15-6.
    PMID: 15468796
    Treatment of articular cartilage lesions remains a clinical challenge. The uses of prosthetic joint replace allograft and/or autograft transplant carry a risk of complications due to infection, loosening of its component, immunological rejection and morbidity at the donor site. There has been an increasing interest in the management of cartilage damages, owing to the introduction of new therapeutic options. Tissue engineering as a method for tissue restoration begins to provide a potential alternative therapy for autologous grafts transplantations. We aimed to evaluate how well a tissue engineered neocartilage implant, consist of human articular chondrocytes cultured with the presence of autologous serum and mixed in a fresh fibrin derived from patient, would perform in subcutaneous implantation in athymic mice.
    Matched MeSH terms: Biomechanical Phenomena
  16. Numerical simulations of flow through the aorta using both ideal and realistic geometrical models
    Wan Ab Naim WN, Ganesan P, Al Abed A, Lim E
    Annu Int Conf IEEE Eng Med Biol Soc, 2012;2012:653-6.
    PMID: 23365977 DOI: 10.1109/EMBC.2012.6346016
    The effects of curvature and tapering on the flow progression in the aorta were studied using numerical simulations on a realistic geometrical model of the aorta and three different versions of the ideal aorta models. The results showed that tapering increases velocity magnitude and wall shear stress while local curvatures affect the skewness of the velocity profile, the thickness of the boundary layer as well as the recirculation regions. Wall shear stress distribution in the aorta serves as an important determinant in the progression of arterial disease.
    Matched MeSH terms: Biomechanical Phenomena
  17. Compression and texture in socks enhance football kicking performance
    Hasan H, Davids K, Chow JY, Kerr G
    Hum Mov Sci, 2016 Aug;48:102-11.
    PMID: 27155962 DOI: 10.1016/j.humov.2016.04.008
    The purpose of this study was to observe effects of wearing textured insoles and clinical compression socks on organisation of lower limb interceptive actions in developing athletes of different skill levels in association football. Six advanced learners and six completely novice football players (15.4±0.9years) performed 20 instep kicks with maximum velocity, in four randomly organised insoles and socks conditions, (a) Smooth Socks with Smooth Insoles (SSSI); (b) Smooth Socks with Textured Insoles (SSTI); (c) Compression Socks with Smooth Insoles (CSSI) and (d), Compression Socks with Textured Insoles (CSTI). Reflective markers were placed on key anatomical locations and the ball to facilitate three-dimensional (3D) movement recording and analysis. Data on 3D kinematic variables and initial ball velocity were analysed using one-way mixed model ANOVAs. Results revealed that wearing textured and compression materials enhanced performance in key variables, such as the maximum velocity of the instep kick and increased initial ball velocity, among advanced learners compared to the use of non-textured and compression materials. Adding texture to football boot insoles appeared to interact with compression materials to improve kicking performance, captured by these important measures. This improvement in kicking performance is likely to have occurred through enhanced somatosensory system feedback utilised for foot placement and movement organisation of the lower limbs. Data suggested that advanced learners were better at harnessing the augmented feedback information from compression and texture to regulate emerging movement patterns compared to novices.
    Matched MeSH terms: Biomechanical Phenomena
  18. Mechanical properties and biocompatibility of co-axially electrospun polyvinyl alcohol/maghemite
    Ngadiman NH, Mohd Yusof N, Idris A, Kurniawan D
    Proc Inst Mech Eng H, 2016 Aug;230(8):739-49.
    PMID: 27194535 DOI: 10.1177/0954411916649632
    Electrospinning is a simple and efficient process in producing nanofibers. To fabricate nanofibers made of a blend of two constituent materials, co-axial electrospinning method is an option. In this method, the constituent materials contained in separate barrels are simultaneously injected using two syringe nozzles arranged co-axially and the materials mix during the spraying process forming core and shell of the nanofibers. In this study, co-axial electrospinning method is used to fabricate nanofibers made of polyvinyl alcohol and maghemite (γ-Fe2O3). The concentration of polyvinyl alcohol and amount of maghemite nanoparticle loading were varied, at 5 and 10 w/v% and at 1-10 v/v%, respectively. The mechanical properties (strength and Young's modulus), porosity, and biocompatibility properties (contact angle and cell viability) of the electrospun mats were evaluated, with the same mats fabricated by regular single-nozzle electrospinning method as the control. The co-axial electrospinning method is able to fabricate the expected polyvinyl alcohol/maghemite nanofiber mats. It was noticed that the polyvinyl alcohol/maghemite electrospun mats have lower mechanical properties (i.e. strength and stiffness) and porosity, more hydrophilicity (i.e. lower contact angle), and similar cell viability compared to the mats fabricated by single-nozzle electrospinning method.
    Matched MeSH terms: Biomechanical Phenomena
  19. Fulltext Dexterous robotic manipulation of alert adult Drosophila for high-content experimentation
    Savall J, Ho ET, Huang C, Maxey JR, Schnitzer MJ
    Nat. Methods, 2015 Jul;12(7):657-60.
    PMID: 26005812 DOI: 10.1038/nmeth.3410
    We present a robot that enables high-content studies of alert adult Drosophila by combining operations including gentle picking; translations and rotations; characterizations of fly phenotypes and behaviors; microdissection; or release. To illustrate, we assessed fly morphology, tracked odor-evoked locomotion, sorted flies by sex, and dissected the cuticle to image neural activity. The robot's tireless capacity for precise manipulations enables a scalable platform for screening flies' complex attributes and behavioral patterns.
    Matched MeSH terms: Biomechanical Phenomena
  20. Angular stable lateral plating is a valid alternative to conventional plate fixation in the proximal phalanx. A biomechanical study
    Shanmugam R, Ernst M, Stoffel K, Fischer MF, Wahl D, Richards RG, et al.
    Clin Biomech (Bristol, Avon), 2015 Jun;30(5):405-10.
    PMID: 25846324 DOI: 10.1016/j.clinbiomech.2015.03.019
    Dorsal plating is commonly used in proximal phalanx fractures but it bears the risk of interfering with the extensor apparatus. In this study, dorsal and lateral plating fixation methods are compared to assess biomechanical differences using conventional 1.5mm non-locking plates and novel 1.3mm lateral locking plates.
    Matched MeSH terms: Biomechanical Phenomena
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