Displaying publications 21 - 40 of 154 in total

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  1. Amiri-Khorasani M, Abu Osman NA, Yusof A
    J Strength Cond Res, 2011 Apr;25(4):1177-81.
    PMID: 20838249 DOI: 10.1519/JSC.0b013e3181d6508c
    This study investigated the number of trials necessary to obtain optimal biomechanical responses in 10 consecutive soccer instep kicks. The kicking motions of dominant legs were captured from 5 experienced and skilled adult male soccer players (height: 184.60 ± 4.49 cm; mass: 80 ± 4.24 kg; and age: 25.60 ± 1.14 years) using a 3D infrared high-speed camera at 200 Hz. Some of the important kinematics and kinetics parameters are maximum thigh angular velocity, maximum lower leg angular velocity, maximum of thigh moment, maximum lower leg moment at forward and impact phases, and finally maximum ball velocity after impact selected to be analyzed. There was a significant decrease of ball velocity between the first and the fifth kick and the subsequent kicks. Similarly, the lower leg angular velocity showed a significant decrease after the fifth kick and thereafter. Compared with the first kick, the thigh angular velocity has been shown to decrease after the sixth kick and thereafter, and the thigh moment result of the sixth kick was significantly lower when compared with the first kick. Moreover, the lower leg moment result of the fourth kick was significantly lower in comparison with the first kick. In conclusion, it seems that 5 consecutive kicks are adequate to achieve high kinematics and kinetics responses and selecting more than 5 kicks does not result in any high biomechanical responses for analysis.
  2. Abd Razak NA, Abu Osman NA, Gholizadeh H, Ali S
    Biomed Eng Online, 2014;13:134.
    PMID: 25208636 DOI: 10.1186/1475-925X-13-134
    Understanding of kinematics force applied at the elbow is important in many fields, including biomechanics, biomedical engineering and rehabilitation. This paper provides a comparison of a mathematical model of elbow joint using three different types of prosthetics for transhumeral user, and characterizes the forces required to overcome the passive mechanical of the prosthetics at the residual limb.
  3. Asadi-Eydivand M, Ebadzadeh MM, Solati-Hashjin M, Darlot C, Abu Osman NA
    Biol Cybern, 2015 Dec;109(6):561-74.
    PMID: 26438095 DOI: 10.1007/s00422-015-0661-7
    The demand today for more complex robots that have manipulators with higher degrees of freedom is increasing because of technological advances. Obtaining the precise movement for a desired trajectory or a sequence of arm and positions requires the computation of the inverse kinematic (IK) function, which is a major problem in robotics. The solution of the IK problem leads robots to the precise position and orientation of their end-effector. We developed a bioinspired solution comparable with the cerebellar anatomy and function to solve the said problem. The proposed model is stable under all conditions merely by parameter determination, in contrast to recursive model-based solutions, which remain stable only under certain conditions. We modified the proposed model for the simple two-segmented arm to prove the feasibility of the model under a basic condition. A fuzzy neural network through its learning method was used to compute the parameters of the system. Simulation results show the practical feasibility and efficiency of the proposed model in robotics. The main advantage of the proposed model is its generalizability and potential use in any robot.
  4. Abu Osman NA, Gholizadeh H, Eshraghi A, Wan Abas WAB
    Prosthet Orthot Int, 2017 Oct;41(5):476-483.
    PMID: 28946824 DOI: 10.1177/0309364616670396
    OBJECTIVES: This study aimed to evaluate and compare a newly designed suspension system with a common suspension in the market.

    STUDY DESIGN: Prospective study.

    METHODS: Looped liners with hook fastener and Iceross Dermo Liner with pin/lock system were mechanically tested using a tensile testing machine in terms of system safety. A total of 10 transtibial amputees participated in this study and were asked to use these two different suspension systems. The pistoning was measured between the liner and socket through a photographic method. Three static axial loading conditions were implemented, namely, 30, 60, and 90 N. Furthermore, subjective feedback was obtained.

    RESULTS: Tensile test results showed that both systems could safely tolerate the load applied to the prosthesis during ambulation. Clinical evaluation confirmed extremely low pistoning in both systems (i.e. less than 0.4 cm after adding 90 N traction load to the prosthesis). Subjective feedback also showed satisfaction with both systems. However, less traction at the end of the residual limb was reported while looped liner was used.

    CONCLUSION: The looped liner with hook fastener is safe and a good alternative for individuals with transtibial amputation as this system could solve some problems with the current systems. Clinical relevance The looped liner and hook fastener were shown to be good alternative suspension for people with lower limb amputation especially those who have difficulty to use and align the pin/lock systems. This system could safely tolerate centrifugal forces applied to the prosthesis during normal and fast walking.

  5. Gholizadeh H, Abu Osman NA, Kamyab M, Eshraghi A, Lúvíksdóttir AG, Wan Abas WA
    Am J Phys Med Rehabil, 2012 Oct;91(10):894-8.
    PMID: 22173083
    The effects of Seal-In X5 and Dermo liner (Össur) on suspension and patient's comfort in lower limb amputees are unclear. In this report, we consider the case of a 51-yr-old woman with bilateral transtibial amputation whose lower limbs were amputated because of peripheral vascular disease. The subject had bony and painful residual limbs, especially at the distal ends. Two prostheses that used Seal-In X5 liners and a pair of prostheses with Dermo liners were fabricated, and the subject wore each for a period of 2 wks. Once the 2 wks had passed, the pistoning within the socket was assessed and the patient was questioned as to her satisfaction with both liners. This study revealed that Seal-In X5 liner decreased the residual limb pain experienced by the patient and that 1-2 mm less pistoning occurred within the socket compared with the Dermo liner. However, the patient needed to put in extra effort for donning and doffing the prosthesis. Despite this, it is clear that the Seal-In X5 liner offers a viable alternative for individuals with transtibial amputations who do not have enough soft tissue around the bone, especially at the end of the residual limb.
  6. Gholizadeh H, Osman NA, Eshraghi A, Abd Razak NA
    Biomed Eng Online, 2014;13:89.
    PMID: 24981801 DOI: 10.1186/1475-925X-13-89
    Prosthesis suspension systems can alter the distribution of pressure within the prosthetic socket. This study evaluates a new suspension system for lower limb prostheses, and aims to compare the interface pressure and amputees' satisfaction with the new system compared with a common prosthetic suspension system (pin/lock).
  7. Ali S, Osman NA, Mortaza N, Eshraghi A, Gholizadeh H, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2012 Nov;27(9):943-8.
    PMID: 22795863 DOI: 10.1016/j.clinbiomech.2012.06.004
    The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. Liners provide a comfortable interface by adding a soft cushion between the residual limb and the socket. The Dermo and the Seal-In X5 liner are two new interface systems and, due to their relative infancy, very little are known about their effect on patient satisfaction. The aim of this study was to compare the interface pressure with these two liners and their effect on patient satisfaction.
  8. Khan SJ, Khan SS, Usman J, Mokhtar AH, Abu Osman NA
    Gait Posture, 2018 03;61:243-249.
    PMID: 29413792 DOI: 10.1016/j.gaitpost.2018.01.024
    OBJECTIVE: To test the hypothesis that toe-in gait (TI) will further reduce first peak (Knee Adduction Moment) KAM and decrease balance when combined with a knee brace (KB) and laterally wedged insoles (LWI) in medial knee osteoarthritis (kOA) patients.
    PARTICIPANTS: Twenty patients with bilateral symptomatic medial kOA.
    INTERVENTIONS: 4-point leverage-based KB, full-length LWI with 5° inclination and toe-in gait (TI).
    MAIN OUTCOME MEASURES: First and second peak knee adduction moment (fKAM and sKAM respectively), balance and pain.
    METHODS: The fKAM and sKAM were determined from 3-dimensional gait analysis with six randomized conditions: (1) N (without any intervention), (2) KB, (3) KB + TI, (4) LWI, (5) LWI + TI, (6) KB + LWI + TI. Balance was assessed by Biodex Balance System using three stability settings, (i) Static (ii) Moderate dynamic setting for fall risk (FR12) and (iii) High dynamic setting for fall risk (FR8).
    RESULTS: The reduction in fKAM and sKAM was greatest (19.75% and 12%) when TI was combined with KB and LWI respectively. No change in balance was observed when TI combined with KB, and LWI and when used concurrently with both the orthosis at static and FR12 conditions. Significant balance reduction was found at FR8 for KB + TI (22.22%), and KB + LWI + TI (35.71%). Pain increased significantly for KB (258%), KB + TI (305%), LWI + TI (210%) and KB + LWI + TI (316%). LWI showed no effect on pain.
    CONCLUSIONS: There is a synergistic effect of TI when combined with KB and LWI concurrently in sKAM reduction. However, the concurrent use of TI, KB and LWI decreases balance and pain as assessed on a highly dynamic platform.
    Study site: Department of Sports Medicine, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
  9. Khan SJ, Khan SS, Usman J, Mokhtar AH, Abu Osman NA
    Prosthet Orthot Int, 2019 Apr;43(2):148-157.
    PMID: 30192706 DOI: 10.1177/0309364618796849
    BACKGROUND:: Knee osteoarthritis is a major contributor to the global burden of disease. There is a need of reducing knee joint load and to improve balance and physical function among knee osteoarthritis patients.

    OBJECTIVES:: To test the hypothesis that toe-out gait will reduce second peak knee adduction moment further and increase fall risk when combined with knee brace and laterally wedged insole in knee osteoarthritis patients.

    STUDY DESIGN:: Single visit study with repeated measures.

    METHODS:: First and second peak knee adduction moments, fall risk and comfort level. First and second peak knee adduction moments were determined from three-dimensional gait analysis, completed under six randomized conditions: (1) natural, (2) knee brace, (3) knee brace + toe-out gait, (4) laterally wedged insole, (5) laterally wedged insole + toe-out gait, and (6) knee brace + laterally wedged insole + toe-out gait. Fall risk was assessed by Biodex Balance System using three randomized stability settings: (1) static, (2) moderate dynamic setting (FR12), and (3) high dynamic setting (FR8).

    RESULTS:: The reduction in first peak knee adduction moment and second peak knee adduction moment was greatest (7.16% and 25.55%, respectively) when toe-out gait combine with knee brace and laterally wedged insole. Significant increase in fall risk was observed with knee brace + laterally wedged insole + toe-out gait (42.85%) at FR12. Similar significant balance reductions were found at FR8 condition for knee brace + toe-out gait (35.71%), laterally wedged insole + toe-out gait (28.57%), and knee brace + laterally wedged insole + toe-out gait (50%) as compared to natural. However, knee brace decreased fall risk at FR12 by 28.57%.

    CONCLUSION:: There is a synergistic effect of toe-out when combined with knee brace and laterally wedged insole concurrently in second peak knee adduction moment reduction but with a greater degree of fall risk. Simultaneous use of conservative treatments also decreases comfort level.

    CLINICAL RELEVANCE: Patients with mild and moderate knee osteoarthritis are usually prescribed conservative treatment techniques. This study will provide an insight whether or not a combination of these techniques have a synergistic effect in reducing knee joint load.

  10. Ali S, Abu Osman NA, Arifin N, Gholizadeh H, Abd Razak NA, Abas WA
    ScientificWorldJournal, 2014;2014:769810.
    PMID: 25184154 DOI: 10.1155/2014/769810
    This study aimed to compare the effect of satisfaction and perceived problems between Pelite, Dermo with shuttle lock, and Seal-In X5 liners on the transtibial amputees.
  11. Mehmood W, Abd Razak NA, Lau MS, Chung TY, Gholizadeh H, Abu Osman NA
    Proc Inst Mech Eng H, 2019 Feb;233(2):181-192.
    PMID: 30518308 DOI: 10.1177/0954411918816124
    Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve using plaster of Paris bandages for casting. This will include modifications through hand, scanning and digital imaging of software. The aim of this study is to determine the circumferential profiles and conduct a volumetric analysis of a conventional socket that has fabrication using biosculptor technology. In doing this, a male transtibial amputee, age 28 years old with stable health condition was studied, where circumferential measurements were taken at intervals of 1 cm from the distal end of the residual limb to the medial tibial plateau level. Furthermore, the interior volume of both sockets and residuum were determined directly using water displacement method. A comparative value for the calculation of volume was also carried out using engineering mathematical equations. From these measurements, a total surface bearing transtibial sockets was fabricated to compare the changes of circumferential values of both sockets. The finding shows a percentage of the difference between the volume of the residual limb and conventional sockets to be 6.09%, whereas the biosculptor fabrication socket was 7.84% using the water displacement method. A comparison of circumferential profiles and volumetric analysis findings on the contrary showed that socket fabricated using the biosculptor technology is interchangeable with the conventional socket with more advantages, where biosculptor technology produces cheaper sockets and faster process with digital function in the procedure, unlike the conventional manual technique.
  12. Oshkour AA, Talebi H, Shirazi SF, Bayat M, Yau YH, Tarlochan F, et al.
    ScientificWorldJournal, 2014;2014:807621.
    PMID: 25302331 DOI: 10.1155/2014/807621
    This study is focused on finite element analysis of a model comprising femur into which a femoral component of a total hip replacement was implanted. The considered prosthesis is fabricated from a functionally graded material (FGM) comprising a layer of a titanium alloy bonded to a layer of hydroxyapatite. The elastic modulus of the FGM was adjusted in the radial, longitudinal, and longitudinal-radial directions by altering the volume fraction gradient exponent. Four cases were studied, involving two different methods of anchoring the prosthesis to the spongy bone and two cases of applied loading. The results revealed that the FG prostheses provoked more SED to the bone. The FG prostheses carried less stress, while more stress was induced to the bone and cement. Meanwhile, less shear interface stress was stimulated to the prosthesis-bone interface in the noncemented FG prostheses. The cement-bone interface carried more stress compared to the prosthesis-cement interface. Stair climbing induced more harmful effects to the implanted femur components compared to the normal walking by causing more stress. Therefore, stress shielding, developed stresses, and interface stresses in the THR components could be adjusted through the controlling stiffness of the FG prosthesis by managing volume fraction gradient exponent.
  13. Ibrahim N, Abu Osman NA, Mokhtar AH, Arifin N, Usman J, Shasmin HN
    Sports Biomech, 2020 Mar 06.
    PMID: 32138608 DOI: 10.1080/14763141.2020.1726995
    Service is assumed important in table tennis because an effective service may allow the serving player to control over the game; hence, the aim of this study was to determine the contribution of arm segment rotations towards ball impact during forehand service. Sixteen shake-hand grip collegiate table tennis athletes had participated in the study. It was revealed that by increasing the radial deviation angular velocity will increase the ball and racket velocities during drop shot service. Furthermore, it was revealed that increasing the wrist palmar flexion and radial deviation will enhance the racket velocity at impact during long shot service. However, it was recommended to the players not to concern on racket speed and arm segment rotations during contact phase as it could not accelerate the ball at impact during long shot service. Although it was the same forehand service, different length of flight ball lead to different contributions of arm segment rotations towards ball impact. The present findings highlight several better postures to increase racket and ball speed at impact during forehand long shot and drop shot services among advanced and intermediate players. Other ranked players may find this study useful as a fundamental understanding on kinematics serving arm.
  14. Ting CY, Adruce SAZ, Hassali MA, Ting H, Lim CJ, Ting RS, et al.
    Trials, 2019 05 10;20(1):267.
    PMID: 31077233 DOI: 10.1186/s13063-019-3348-x
    After publication of the original article [1], the authors have notified us that there are changes to the primary outcome of the study, instrument, subject's inclusion criteria, the funding and acknowledgements. These changes were made during the recruitment of participants and after approved by the Medical Research and Ethics Committee (MREC), National Institutes of Health Malaysia, on 16th November 2018.
  15. Mehrali M, Shirazi FS, Mehrali M, Metselaar HS, Kadri NA, Osman NA
    J Biomed Mater Res A, 2013 Oct;101(10):3046-57.
    PMID: 23754641 DOI: 10.1002/jbm.a.34588
    Functionally graded material (FGM) is a heterogeneous composite material including a number of constituents that exhibit a compositional gradient from one surface of the material to the other subsequently, resulting in a material with continuously varying properties in the thickness direction. FGMs are gaining attention for biomedical applications, especially for implants, owing to their reported superior composition. Dental implants can be functionally graded to create an optimized mechanical behavior and achieve the intended biocompatibility and osseointegration improvement. This review presents a comprehensive summary of biomaterials and manufacturing techniques researchers employ throughout the world. Generally, FGM and FGM porous biomaterials are more difficult to fabricate than uniform or homogenous biomaterials. Therefore, our discussion is intended to give the readers about successful and obstacles fabrication of FGM and porous FGM in dental implants that will bring state-of-the-art technology to the bedside and develop quality of life and present standards of care.
  16. Tripathy A, Pramanik S, Manna A, Bhuyan S, Azrin Shah NF, Radzi Z, et al.
    Sensors (Basel), 2016 Jul 21;16(7).
    PMID: 27455263 DOI: 10.3390/s16071135
    Despite the many attractive potential uses of ceramic materials as humidity sensors, some unavoidable drawbacks, including toxicity, poor biocompatibility, long response and recovery times, low sensitivity and high hysteresis have stymied the use of these materials in advanced applications. Therefore, in present investigation, we developed a capacitive humidity sensor using lead-free Ca,Mg,Fe,Ti-Oxide (CMFTO)-based electro-ceramics with perovskite structures synthesized by solid-state step-sintering. This technique helps maintain the submicron size porous morphology of the developed lead-free CMFTO electro-ceramics while providing enhanced water physisorption behaviour. In comparison with conventional capacitive humidity sensors, the presented CMFTO-based humidity sensor shows a high sensitivity of up to 3000% compared to other materials, even at lower signal frequency. The best also shows a rapid response (14.5 s) and recovery (34.27 s), and very low hysteresis (3.2%) in a 33%-95% relative humidity range which are much lower values than those of existing conventional sensors. Therefore, CMFTO nano-electro-ceramics appear to be very promising materials for fabricating high-performance capacitive humidity sensors.
  17. Pramanik S, Pingguan-Murphy B, Cho J, Abu Osman NA
    Sci Rep, 2014 Jul 28;4:5843.
    PMID: 25068570 DOI: 10.1038/srep05843
    The complex architecture of the cortical part of the bovine-femur was examined to develop potential tissue engineering (TE) scaffolds. Weight-change and X-ray diffraction (XRD) results show that significant phase transformation and morphology conversion of the bone occur at 500-750°C and 750-900°C, respectively. Another breakthrough finding was achieved by determining a sintering condition for the nucleation of hydroxyapatite crystal from bovine bone via XRD technique. Scanning electron microscopy results of morphological growth suggests that the concentration of polymer fibrils increases (or decreases, in case of apatite crystals) from the distal to proximal end of the femur. Energy-dispersive analysis of X-ray, Fourier transform infrared, micro-computer tomography, and mechanical studies of the actual composition also strongly support our microscopic results and firmly indicate the functionally graded material properties of bovine-femur. Bones sintered at 900 and 1000°C show potential properties for soft and hard TE applications, respectively.
  18. Yusoff N, Abu Osman NA, Pingguan-Murphy B
    Med Eng Phys, 2011 Jul;33(6):782-8.
    PMID: 21356602 DOI: 10.1016/j.medengphy.2011.01.013
    A mechanical-conditioning bioreactor has been developed to provide bi-axial loading to three-dimensional (3D) tissue constructs within a highly controlled environment. The computer-controlled bioreactor is capable of applying axial compressive and shear deformations, individually or simultaneously at various regimes of strain and frequency. The reliability and reproducibility of the system were verified through validation of the spatial and temporal accuracy of platen movement, which was maintained over the operating length of the system. In the presence of actual specimens, the system was verified to be able to deliver precise bi-axial load to the specimens, in which the deformation of every specimen was observed to be relatively homogeneous. The primary use of the bioreactor is in the culture of chondrocytes seeded within an agarose hydrogel while subjected to physiological compressive and shear deformation. The system has been designed specifically to permit the repeatable quantification and characterisation of the biosynthetic activity of cells in response to a wide range of short and long term multi-dimensional loading regimes.
  19. Oshkour AA, Abu Osman NA, Yau YH, Tarlochan F, Abas WA
    Proc Inst Mech Eng H, 2013 Jan;227(1):3-17.
    PMID: 23516951
    This study aimed to develop a three-dimensional finite element model of a functionally graded femoral prosthesis. The model consisted of a femoral prosthesis created from functionally graded materials (FGMs), cement, and femur. The hip prosthesis was composed of FGMs made of titanium alloy, chrome-cobalt, and hydroxyapatite at volume fraction gradient exponents of 0, 1, and 5, respectively. The stress was measured on the femoral prosthesis, cement, and femur. Stress on the neck of the femoral prosthesis was not sensitive to the properties of the constituent material. However, stress on the stem and cement decreased proportionally as the volume fraction gradient exponent of the FGM increased. Meanwhile, stress became uniform on the cement mantle layer. In addition, stress on the femur in the proximal part increased and a high surface area of the femoral part was involved in absorbing the stress. As such, the stress-shielding area decreased. The results obtained in this study are significant in the design and longevity of new prosthetic devices because FGMs offer the potential to achieve stress distribution that more closely resembles that of the natural bone in the femur.
  20. El-Sayed AM, Hamzaid NA, Tan KY, Abu Osman NA
    ScientificWorldJournal, 2015;2015:923286.
    PMID: 25945365 DOI: 10.1155/2015/923286
    This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket's wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket's wall. A second setup was established by attaching three piezoelectric sensors at the anterior distal, anterior proximal, and posterior sites. Gait cycle and locomotion movements such as stair ascent and sit to stand were adopted to characterize the validity of the technique. FSR and piezoelectric outputs were measured with reference to the knee angle during each phase. Piezoelectric sensors could identify the movement of midswing and terminal swing, pre-full standing, pull-up at gait, sit to stand, and stair ascent. In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand. FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states. The study highlighted the capacity of using in-socket sensors for knee movement identification. In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.
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