Displaying publications 81 - 100 of 116 in total

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  1. Al-Fakih E, Abu Osman NA, Mahamd Adikan FR
    Sensors (Basel), 2012 Sep 25;12(10):12890-926.
    PMID: 23201977 DOI: 10.3390/s121012890
    In recent years, fiber Bragg gratings (FBGs) are becoming increasingly attractive for sensing applications in biomechanics and rehabilitation engineering due to their advantageous properties like small size, light weight, biocompatibility, chemical inertness, multiplexing capability and immunity to electromagnetic interference (EMI). They also offer a high-performance alternative to conventional technologies, either for measuring a variety of physical parameters or for performing high-sensitivity biochemical analysis. FBG-based sensors demonstrated their feasibility for specific sensing applications in aeronautic, automotive, civil engineering structure monitoring and undersea oil exploration; however, their use in the field of biomechanics and rehabilitation applications is very recent and its practicality for full-scale implementation has not yet been fully established. They could be used for detecting strain in bones, pressure mapping in orthopaedic joints, stresses in intervertebral discs, chest wall deformation, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments, angles between body segments during gait, and many others in dental biomechanics. This article aims to provide a comprehensive overview of all the possible applications of FBG sensing technology in biomechanics and rehabilitation and the status of ongoing researches up-to-date all over the world, demonstrating the FBG advances over other existing technologies.
  2. Al-Fakih EA, Abu Osman NA, Mahmad Adikan FR
    Sensors (Basel), 2016 Jul 20;16(7).
    PMID: 27447646 DOI: 10.3390/s16071119
    The distribution of interface stresses between the residual limb and prosthetic socket of a transtibial amputee has been considered as a direct indicator of the socket quality fit and comfort. Therefore, researchers have been very interested in quantifying these interface stresses in order to evaluate the extent of any potential damage caused by the socket to the residual limb tissues. During the past 50 years a variety of measurement techniques have been employed in an effort to identify sites of excessive stresses which may lead to skin breakdown, compare stress distributions in various socket designs, and evaluate interface cushioning and suspension systems, among others. The outcomes of such measurement techniques have contributed to improving the design and fitting of transtibial sockets. This article aims to review the operating principles, advantages, and disadvantages of conventional and emerging techniques used for interface stress measurements inside transtibial sockets. It also reviews and discusses the evolution of different socket concepts and interface stress investigations conducted in the past five decades, providing valuable insights into the latest trends in socket designs and the crucial considerations for effective stress measurement tools that lead to a functional prosthetic socket.
  3. Mortaza N, Abu Osman NA, Mehdikhani N
    Eur J Phys Rehabil Med, 2014 Dec;50(6):677-91.
    PMID: 24831570
    Fall is a common and a major cause of injuries. It is important to find elderlies who are prone to falls. The majority of serious falls occur during walking among the older adults. Analyzing the spatio-temporal parameters of walking is an easy way of assessment in the clinical setting, but is it capable of distinguishing a faller from a non-faller elderly? Through a systematic review of the literature, the objective of this systematic review was to identify and summarize the differences in the spatio-temporal parameters of walking in elderly fallers and non-fallers and to find out if these parameters are capable of distinguishing a faller from a non-faller. All original research articles which compared any special or temporal walking parameters in faller and non-faller elderlies were systematically searched within the Scopus and Embase databases. Effect size analysis was also done to standardize findings and compare the gait parameters of fallers and non-fallers across the selected studies. The electronic search led to 5381 articles. After title and abstract screening 30 articles were chosen; further assessment of the full texts led to 17 eligible articles for inclusion in the review. It seems that temporal measurements are more sensitive to the detection of risk of fall in elderly people. The results of the 17 selected studies showed that fallers have a tendency toward a slower walking speed and cadence, longer stride time, and double support duration. Also, fallers showed shorter stride and step length, wider step width and more variability in spatio-temporal parameters of gait. According to the effect size analysis, step length, gait speed, stride length and stance time variability were respectively more capable of differentiating faller from non-faller elderlies. However, because of the difference of methodology and number of studies which investigated each parameter, these results are prone to imprecision. Spatio-temporal analysis of level walking is not sufficient and cannot act as a reliable predictor of falls in elderly individuals.
  4. Aboodarda SJ, Yusof A, Abu Osman NA, Thompson MW, Mokhtar AH
    Int J Sports Physiol Perform, 2013 Mar;8(2):181-7.
    PMID: 23428490
    To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs).
  5. Touri M, Moztarzadeh F, Abu Osman NA, Dehghan MM, Brouki Milan P, Farzad-Mohajeri S, et al.
    ACS Biomater Sci Eng, 2020 05 11;6(5):2985-2994.
    PMID: 33463293 DOI: 10.1021/acsbiomaterials.9b01789
    Hypoxia, the result of disrupted vasculature, can be categorized in the main limiting factors for fracture healing. A lack of oxygen can cause cell apoptosis, tissue necrosis, and late tissue healing. Remedying hypoxia by supplying additional oxygen will majorly accelerate bone healing. In this study, biphasic calcium phosphate (BCP) scaffolds were fabricated by robocasting, an additive manufacturing technique. Then, calcium peroxide (CPO) particles, as an oxygen-releasing agent, were coated on the BCP scaffolds. Segmental radial defects with the size of 15 mm were created in rabbits. Uncoated and CPO-coated BCP scaffolds were implanted in the defects. The empty (control) group received no implantation. Repairing of the bone was investigated via X-ray, histological analysis, and biomechanical tests at 3 and 6 months postoperatively, with immunohistochemical examinations at 6 months after operation. According to the radiological observations, formation of new bone was augmented at the interface between the implant and host bone and internal pores of CPO-coated BCP scaffolds compared to uncoated scaffolds. Histomorphometry analysis represented that the amount of newly formed bone in the CPO-coated scaffold was nearly two times higher than the uncoated one. Immunofluorescence staining revealed that osteogenic markers, osteonectin and octeocalcin, were overexpressed in the defects treated with the coated scaffolds at 6 months of postsurgery, demonstrating higher osteogenic differentiation and bone mineralization compared to the uncoated scaffold group. Furthermore, the coated scaffolds had superior biomechanical properties as in the case of 3 months after surgery, the maximal flexural force of the coated scaffolds reached to 134 N, while it was 92 N for uncoated scaffolds. The results could assure a boosted ability of bone repair for CPO-coated BCP scaffolds implanted in the segmental defect of rabbit radius because of oxygen-releasing coating, and this system of oxygen-generating coating/scaffold might be a potential for accelerated repairing of bone defects.
  6. 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.
  7. Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Sævarsson SK, Wan Abas WA, et al.
    J Rehabil Res Dev, 2012;49(9):1321-30.
    PMID: 23408214
    Poor suspension increases slippage of the residual limb inside the socket during ambulation. The main purpose of this article is to evaluate the pistoning at the prosthetic liner-socket interface during gait and assess patients' satisfaction with two different liners. Two prostheses with seal-in and locking liners were fabricated for each of the 10 subjects with transtibial amputation. The Vicon motion system was used to measure the pistoning during gait. The subjects were also asked to complete a Prosthesis Evaluation Questionnaire. The results revealed higher pistoning inside the socket during gait with the locking liner than with the seal-in liner (p < 0.05). The overall satisfaction with the locking liner was higher (p < 0.05) because of the relative ease with which the patients could don and doff the device. As such, pistoning may not be the main factor that determines patients' overall satisfaction with the prosthesis and other factors may also contribute to comfort and satisfaction with prostheses. The article also verifies the feasibility of the Vicon motion system for measuring pistoning during gait.
  8. Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Razak NA
    Clin Biomech (Bristol, Avon), 2014 Jan;29(1):87-97.
    PMID: 24315710 DOI: 10.1016/j.clinbiomech.2013.10.013
    Today a number of prosthetic suspension systems are available for transtibial amputees. Consideration of an appropriate suspension system can ensure that amputee's functional needs are satisfied. The higher the insight to suspension systems, the easier would be the selection for prosthetists. This review attempted to find scientific evidence pertaining to various transtibial suspension systems to provide selection criteria for clinicians.
  9. Mortaza N, Abu Osman NA, Jamshidi AA, Razjouyan J
    PLoS One, 2013;8(5):e64308.
    PMID: 23717593 DOI: 10.1371/journal.pone.0064308
    Use of functional knee braces has been suggested to provide protection and to improve kinetic performance of the knee in Anterior cruciate ligament(ACL)-injured patients. However, many athletes might refrain from wearing the braces because of the fear of performance hindrance in the playing field. The aim of this study was to examine the effect of three functional knee brace/sleeves upon the isokinetic and functional performance of ACL-deficient and healthy subjects. Six anterior cruciate ligament deficient (29.0 ± 5.3 yrs., 175.2 ± 5.4 cm, and 73.0 ± 10.0 kg) and six healthy male subjects (27.2 ± 3.7 yrs., 176.4 ± 6.4 cm, and 70.3 ± 6.9 kg) were selected. The effect of a custom-made functional knee brace, and two neoprene knee sleeves, one with four metal supports and one without support were examined via the use of isokinetic and functional tests in four sets (non-braced,wearing functional knee brace,and wearing the sleeves). Cross-over hop and single leg vertical jump test were performed and jump height, and hop distance were recorded. Peak torque to body weight ratio and average power in two isokinetic velocities(60°.s(-1),180°.s(-1)) were recorded and the brace/sleeves effect was calculated as the changes in peak torque measured in the brace/sleeves conditions, expressed as a percentage of peak torque measured in non-braced condition. Frequency content of the isokinetic torque-time curves was also analyzed. Wilcoxon signed rank test was used to compare the measured values in four test conditions within each control and ACL-deficient group,and Mann-Whitney U test was used for the comparison between the two groups. No significant differences in peak torque, average power, torque-time curve frequency content, vertical-jump and hop measurements were found within the experimental and the non-braced conditions (p>0.05). Although the examined functional knee brace/sleeves had no significant effect on the knee muscle performance, there have been some enhancement regarding the extension peak torques and power generating capacity of the ACL-deficient subjects that could be helpful in reducing the bilateral asymmetry in these patients.
  10. 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.
  11. Shaari IH, Abu Osman NA, Shasmin HN
    Proc Inst Mech Eng H, 2020 Aug;234(8):884-894.
    PMID: 32459140 DOI: 10.1177/0954411920923541
    Many studies have shown that medical compression products produce different levels of interface pressure during the usage of the products. However, limited studies have explored the pattern of interface pressure exerted by orthotic garments. This case study aimed to investigate the pattern of interface pressure exerted by two types of orthotic garments on a child with cerebral palsy. A 13-year-old child diagnosed with ataxic spastic diplegia cerebral palsy has difficulty to perform sit-to-stand motion even with a walking frame due to his truncal ataxia. A TheraTogsTM orthosis and a Dynamic Lycra® Fabric Orthosis (DLFO) were prepared for the child. The child's sit-to-stand ability without and with the usage of orthoses was recorded using five sit-to-stand tests. The garments' interface pressure was measured using F-scan (9811E) and F-scan 6.5.1 version software. The pressure was recorded when the child was in sitting position and performing sit-to-stand-to-sit motion. Overall, the child completed the five sit-to-stand test duration within 2.53 ± 0.04 s and 2.51 ± 0.09 s with the usage of TheraTogsTM orthosis and DLFO, respectively. Higher pressure was exerted by Dynamic Lycra Fabric Orthosis (axillary = 122 mmHg) in contrast to TheraTogsTM orthosis (77 mmHg) when the child was in a sitting position. Lower pressure was exerted by DLFO (7 mmHg), over xiphoid level and for TheraTogsTM orthosis is 1.2 mmHg over axillary level when the child was performing sit-to-stand motion. The largest range of pressure was exerted by TheraTogsTM orthosis with a minimum pressure of 5 mmHg and a maximum pressure of 155 mmHg during sit-to-stand motion. Overall, the DLFO exerted higher mean interface pressure on the child in comparison to TheraTogsTM orthosis when the child's body was in a sitting position wearing both upper garment and pants. Both TheraTogsTM orthosis and DLFO presented a different range of interface pressure over different body segments and activities.
  12. Pirouzi G, Abu Osman NA, Eshraghi A, Ali S, Gholizadeh H, Wan Abas WA
    ScientificWorldJournal, 2014;2014:849073.
    PMID: 25197716 DOI: 10.1155/2014/849073
    Socket is an important part of every prosthetic limb as an interface between the residual limb and prosthetic components. Biomechanics of socket-residual limb interface, especially the pressure and force distribution, have effect on patient satisfaction and function. This paper aimed to review and evaluate studies conducted in the last decades on the design of socket, in-socket interface pressure measurement, and socket biomechanics. Literature was searched to find related keywords with transtibial amputation, socket-residual limb interface, socket measurement, socket design, modeling, computational modeling, and suspension system. In accordance with the selection criteria, 19 articles were selected for further analysis. It was revealed that pressure and stress have been studied in the last decaeds, but quantitative evaluations remain inapplicable in clinical settings. This study also illustrates prevailing systems, which may facilitate improvements in socket design for improved quality of life for individuals ambulating with transtibial prosthesis. It is hoped that the review will better facilitate the understanding and determine the clinical relevance of quantitative evaluations.
  13. Khalaj N, Abu Osman NA, Mokhtar AH, Mehdikhani M, Wan Abas WA
    PLoS One, 2014;9(3):e92270.
    PMID: 24642715 DOI: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC39584
    Balance is essential for mobility and performing activities of daily living. People with knee osteoarthritis display impairment in knee joint proprioception. Thus, the aim of this study was to evaluate balance and risk of fall in individuals with bilateral mild and moderate knee osteoarthritis. Sixty subjects aged between 50 and 70 years volunteered in this study. They were categorized into three groups which were healthy (n = 20), mild (n = 20) and moderate (n = 20) bilateral knee osteoarthritis groups. Dynamic and static balance and risk of fall were assessed using Biodex Stability System. In addition, Timed Up and Go test was used as a clinical test for balance. Results of this study illustrated that there were significant differences in balance (dynamic and static) and risk of fall between three groups. In addition, the main (most significant) difference was found to be between healthy group and moderate group. Furthermore, on clinical scoring of balance, the "Timed Up and Go" test, all three groups showed significant difference. In conclusion, bilateral knee osteoarthritis impaired the balance and increased the risk of fall, particularly in people with moderate knee osteoarthritis.
  14. Eshraghi A, Abu Osman NA, Karimi M, Gholizadeh H, Soodmand E, Wan Abas WA
    PLoS One, 2014;9(5):e96988.
    PMID: 24865351 DOI: 10.1371/journal.pone.0096988
    Prosthetic suspension system is an important component of lower limb prostheses. Suspension efficiency can be best evaluated during one of the vital activities of daily living, i.e. walking. A new magnetic prosthetic suspension system has been developed, but its effects on gait biomechanics have not been studied. This study aimed to explore the effect of suspension type on kinetic and kinematic gait parameters during level walking with the new suspension system as well as two other commonly used systems (the Seal-In and pin/lock). Thirteen persons with transtibial amputation participated in this study. A Vicon motion system (six cameras, two force platforms) was utilized to obtain gait kinetic and kinematic variables, as well as pistoning within the prosthetic socket. The gait deviation index was also calculated based on the kinematic data. The findings indicated significant difference in the pistoning values among the three suspension systems. The Seal-In system resulted in the least pistoning compared with the other two systems. Several kinetic and kinematic variables were also affected by the suspension type. The ground reaction force data showed that lower load was applied to the limb joints with the magnetic suspension system compared with the pin/lock suspension. The gait deviation index showed significant deviation from the normal with all the systems, but the systems did not differ significantly. Main significant effects of the suspension type were seen in the GRF (vertical and fore-aft), knee and ankle angles. The new magnetic suspension system showed comparable effects in the remaining kinetic and kinematic gait parameters to the other studied systems. This study may have implications on the selection of suspension systems for transtibial prostheses. Trial registration: Iranian Registry of Clinical Trials IRCT2013061813706N1.
  15. Arifin N, Abu Osman NA, Ali S, Wan Abas WA
    Biomed Eng Online, 2014;13(1):23.
    PMID: 24597518 DOI: 10.1186/1475-925X-13-23
    Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet.
  16. Khalaj N, Abu Osman NA, Mokhtar AH, Mehdikhani M, Wan Abas WA
    Proc Inst Mech Eng H, 2014 Feb;228(2):190-9.
    PMID: 24458100 DOI: 10.1177/0954411914521155
    The knee adduction moment represents the medial knee joint load, and greater value is associated with higher load. In people with knee osteoarthritis, it is important to apply proper treatment with the least side effects to reduce knee adduction moment and, consequently, reduce medial knee joint load. This reduction may slow the progression of knee osteoarthritis. The research team performed a literature search of electronic databases. The search keywords were as follows: knee osteoarthritis, knee adduction moment, exercise program, exercise therapy, gait retraining, gait modification and knee joint loading. In total, 12 studies were selected, according to the selection criteria. Findings from previous studies illustrated that exercise and gait retraining programs could alter knee adduction moment in people with knee osteoarthritis. These treatments are noninvasive and nonpharmacological which so far have no or few side effects, as well as being low cost. The results of this review revealed that gait retraining programs were helpful in reducing the knee adduction moment. In contrast, not all the exercise programs were beneficial in reducing knee adduction moment. Future studies are needed to indicate best clinical exercise and gait retraining programs, which are most effective in reducing knee adduction moment in people with knee osteoarthritis.
    Study design: systematic review
  17. Gholizadeh H, Abu Osman NA, Eshraghi A, Ali S, Arifin N, Wan Abas WA
    Biomed Eng Online, 2014;13:1.
    PMID: 24410918 DOI: 10.1186/1475-925X-13-1
    Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems).
  18. Chandrasekhar A, Abu Osman NA, Tham LK, Lim KS, Wan Abas WA
    PLoS One, 2013;8(11):e80799.
    PMID: 24260483 DOI: 10.1371/journal.pone.0080799
    BACKGROUND: A clinical parameter commonly used to assess the neurological status of an individual is the tendon reflex response. However, the clinical method of evaluation often leads to subjective conclusions that may differ between examiners. Moreover, attempts to quantify the reflex response, especially in older age groups, have produced inconsistent results. This study aims to examine the influence of age on the magnitude of the patellar tendon reflex response.

    METHODOLOGY/PRINCIPAL FINDINGS: This study was conducted using the motion analysis technique with the reflex responses measured in terms of knee angles. Forty healthy subjects were selected and categorized into three different age groups. Patellar reflexes were elicited from both the left and right patellar tendons of each subject at three different tapping angles and using the Jendrassik maneuver. The findings suggested that age has a significant effect on the magnitude of the reflex response. An angle of 45° may be the ideal tapping angle at which the reflex can be elicited to detect age-related differences in reflex response. The reflex responses were also not influenced by gender and were observed to be fairly symmetrical.

    CONCLUSIONS/SIGNIFICANCE: Neurologically normal individuals will experience an age-dependent decline in patellar reflex response.

  19. Ku PX, Abu Osman NA, Wan Abas WA
    Gait Posture, 2014 Feb;39(2):672-82.
    PMID: 24331296 DOI: 10.1016/j.gaitpost.2013.07.006
    Postural control has been widely evaluated for the normal population and different groups over the past 20 years. Numerous studies have investigated postural control in quiet standing posture among amputees. However, a comprehensive analysis is lacking on the possible contributing factors to balance. The present systematic review highlights the current findings on variables that contribute to balance instability for lower extremity amputees. The search strategy was performed on PubMed, Web of Science, Medline, Scopus, and CINAHL and then followed by additional manual searching via reference lists in the reviewed articles. The quality of the articles was evaluated using a methodological quality assessment tool. This review included and evaluated a total of 23 full-text articles. Despite the inconsistencies in the methodological design of the studies, all articles scored above the acceptable level in terms of quality. A majority of the studies revealed that lower extremity amputees have increased postural sway in the standing posture. Asymmetry in body weight, which is mainly distributed in the non-amputated leg, was described. Aside from the centre of pressure in postural control, sensory inputs may be a related topic for investigation in view of evidence on their contribution, particularly visual input. Other balance-related factors, such as stump length and patients' confidence level, were also neglected. Further research requires examination on the potential factors that affect postural control as the information of standing postural is still limited.
  20. Ali S, Abu Osman NA, Eshraghi A, Gholizadeh H, Abd Razak NA, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2013 Nov-Dec;28(9-10):994-9.
    PMID: 24161521 DOI: 10.1016/j.clinbiomech.2013.09.004
    Transtibial amputees encounter stairs and steps during their daily activities. The excessive pressure between residual limb/socket may reduce the walking capability of transtibial prosthetic users during ascent and descent on stairs. The purposes of the research were to evaluate the interface pressure between Dermo (shuttle lock) and Seal-In X5 (prosthetic valve) interface systems during stair ascent and descent, and to determine their satisfaction effects on users.
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