Displaying publications 21 - 40 of 155 in total

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  1. Fulltext The effect on human balance of standing with toe-extension
    Ku PX, Abu Osman NA, Yusof A, Wan Abas WA
    PLoS One, 2012;7(7):e41539.
    PMID: 22848523 DOI: 10.1371/journal.pone.0041539
    Postural balance is vital for safely carrying out many daily activities, such as locomotion. The purpose of this study was to determine how changes in normal standing (NS) and standing with toe-extension (SWT) impact postural control during quiet standing. Furthermore, the research aimed to examine the extent to which the effect of these factors differed between genders.
  2. Clinical investigation of the interface pressure in the trans-tibial socket with Dermo and Seal-In X5 liner during walking and their effect on patient satisfaction
    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.
  3. Kinematic comparison of the wrist movements that are possible with a biomechatronics wrist prosthesis and a body-powered prosthesis: a preliminary study
    Abd Razak NA, Abu Osman NA, Wan Abas WA
    Disabil Rehabil Assist Technol, 2013 May;8(3):255-60.
    PMID: 22830946 DOI: 10.3109/17483107.2012.704654
    This study examined the kinematic differences between a body-powered prosthesis and a biomechatronics prosthesis as a transradial amputee performed activities that involve flexion/extension and supination/pronation of the wrist.
  4. 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.
  5. Clinical evaluation of two prosthetic suspension systems in a bilateral transtibial amputee
    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. Quantitative and qualitative comparison of a new prosthetic suspension system with two existing suspension systems for lower limb amputees
    Eshraghi A, Abu Osman NA, Karimi MT, Gholizadeh H, Ali S, Wan Abas WA
    Am J Phys Med Rehabil, 2012 Dec;91(12):1028-38.
    PMID: 23168378 DOI: 10.1097/PHM.0b013e318269d82a
    The objectives of this study were to compare the effects of a newly designed magnetic suspension system with that of two existing suspension methods on pistoning inside the prosthetic socket and to compare satisfaction and perceived problems among transtibial amputees.
  7. An experimental study of the interface pressure profile during level walking of a new suspension system for lower limb amputees
    Eshraghi A, Abu Osman NA, Gholizadeh H, Ali S, Sævarsson SK, Wan Abas WA
    Clin Biomech (Bristol, Avon), 2013 Jan;28(1):55-60.
    PMID: 23157843 DOI: 10.1016/j.clinbiomech.2012.10.002
    Different suspension systems that are used within prosthetic devices may alter the distribution of pressure inside the prosthetic socket in lower limb amputees. This study aimed to compare the interface pressure of a new magnetic suspension system with the pin/lock and Seal-In suspension systems.
  8. Evaluation of postural steadiness in below-knee amputees when wearing different prosthetic feet during various sensory conditions using the Biodex® Stability System
    Arifin N, Abu Osman NA, Ali S, Gholizadeh H, Wan Abas WA
    Proc Inst Mech Eng H, 2015 Jul;229(7):491-8.
    PMID: 26019139 DOI: 10.1177/0954411915587595
    In recent years, computerized posturography has become an essential tool in quantitative assessment of postural steadiness in the clinical settings. The purpose of this study was to explore the ability of the Biodex(®) Stability System (BSS) to quantify postural steadiness in below-knee amputees. A convenience sample of 10 below-knee amputees participated in the study. The overall (OSI), anterior-posterior (APSI) and medial-lateral (MLSI) stability indexes as well as the percentage of time spent in left and right quadrants and four concentric zones were measured under altered sensory conditions while standing with solid ankle cushion heel (SACH), single-axis (SA) and energy storage and release (ESAR) feet. Significant difference was found between sensory conditions in SACH and ESAR feet for OSI (SACH, p = 0.002; ESAR, p = 0.005), APSI (SACH, p = 0.036; ESAR, p = 0.003) and MLSI (SACH, p = 0.008; ESAR, p = 0.05) stability indexes. The percentage of time spent in Zone A (0°-5°) was significantly greater than the other three concentric zones (p < 0.01). The loading time percentage on their intact limb (80%-94%) was significantly longer than the amputated limb (20%-6%) in all conditions for all three prosthetic feet. Below-knee amputees showed compromised postural steadiness when visual, proprioceptive or vestibular sensory input was altered. The findings highlight that the characteristics of postural stability in amputees can be clinically assessed by utilizing the outcomes produced by the BSS.
  9. Re: Re: "Quantitative and Qualitative Comparison of a New Prosthetic Suspension System with Two Existing Suspension Systems for Lower Limb Amputees"
    Eshraghi A, Osman NA, Karimi MT, Gholizadeh H, Ali S, Wan Abas WA
    Am J Phys Med Rehabil, 2015 Jul;94(7):e60.
    PMID: 25888670 DOI: 10.1097/PHM.0000000000000304
  10. 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.
  11. Contribution of the arm segment rotations towards the horizontal ball and racket head velocities during forehand long shot and drop shot services in table tennis
    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.
  12. A case study on interface pressure pattern of two garment orthoses on a child with cerebral palsy
    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.
  13. Fulltext 100 top-cited scientific papers in limb prosthetics
    Eshraghi A, Osman NA, Gholizadeh H, Ali S, Shadgan B
    Biomed Eng Online, 2013;12:119.
    PMID: 24237942 DOI: 10.1186/1475-925X-12-119
    Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett's initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case-control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies.
  14. Fulltext Influence of functional knee bracing on the isokinetic and functional tests of anterior cruciate ligament deficient patients
    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.
  15. Transtibial prosthesis suspension systems: systematic review of literature
    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.
  16. Transtibial prosthetic suspension: less pistoning versus easy donning and doffing
    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.
  17. Design and validation of a bi-axial loading bioreactor for mechanical stimulation of engineered cartilage
    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.
  18. The metabolic dynamics of cartilage explants over a long-term culture period
    Moo EK, Osman NA, Pingguan-Murphy B
    Clinics (Sao Paulo), 2011;66(8):1431-6.
    PMID: 21915496
    INTRODUCTION: Although previous studies have been performed on cartilage explant cultures, the generalized dynamics of cartilage metabolism after extraction from the host are still poorly understood due to differences in the experimental setups across studies, which in turn prevent building a complete picture.

    METHODS: In this study, we investigated the response of cartilage to the trauma sustained during extraction and determined the time needed for the cartilage to stabilize. Explants were extracted aseptically from bovine metacarpal-phalangeal joints and cultured for up to 17 days.

    RESULTS: The cell viability, cell number, proteoglycan content, and collagen content of the harvested explants were analyzed at 0, 2, 10, and 17 days after explantation. A high percentage of the cartilage explants were found to be viable. The cell density initially increased significantly but stabilized after two days. The proteoglycan content decreased gradually over time, but it did not decrease to a significant level due to leakage through the distorted peripheral collagen network and into the bathing medium. The collagen content remained stable for most of the culture period until it dropped abruptly on day 17.

    CONCLUSION: Overall, the tested cartilage explants were sustainable over long-term culture. They were most stable from day 2 to day 10. The degradation of the collagen on day 17 did not reach diseased levels, but it indicated the potential of the cultures to develop into degenerated cartilage. These findings have implications for the application of cartilage explants in pathophysiological fields.

  19. Fulltext Role of morphological structure, doping, and coating of different materials in the sensing characteristics of humidity sensors
    Tripathy A, Pramanik S, Cho J, Santhosh J, Osman NA
    Sensors (Basel), 2014;14(9):16343-422.
    PMID: 25256110 DOI: 10.3390/s140916343
    The humidity sensing characteristics of different sensing materials are important properties in order to monitor different products or events in a wide range of industrial sectors, research and development laboratories as well as daily life. The primary aim of this study is to compare the sensing characteristics, including impedance or resistance, capacitance, hysteresis, recovery and response times, and stability with respect to relative humidity, frequency, and temperature, of different materials. Various materials, including ceramics, semiconductors, and polymers, used for sensing relative humidity have been reviewed. Correlations of the different electrical characteristics of different doped sensor materials as the most unique feature of a material have been noted. The electrical properties of different sensor materials are found to change significantly with the morphological changes, doping concentration of different materials and film thickness of the substrate. Various applications and scopes are pointed out in the review article. We extensively reviewed almost all main kinds of relative humidity sensors and how their electrical characteristics vary with different doping concentrations, film thickness and basic sensing materials. Based on statistical tests, the zinc oxide-based sensing material is best for humidity sensor design since it shows extremely low hysteresis loss, minimum response and recovery times and excellent stability.
  20. Fulltext Mechanical and in vitro biological performance of graphene nanoplatelets reinforced calcium silicate composite
    Mehrali M, Moghaddam E, Seyed Shirazi SF, Baradaran S, Mehrali M, Latibari ST, et al.
    PLoS One, 2014;9(9):e106802.
    PMID: 25229540 DOI: 10.1371/journal.pone.0106802
    Calcium silicate (CaSiO3, CS) ceramic composites reinforced with graphene nanoplatelets (GNP) were prepared using hot isostatic pressing (HIP) at 1150°C. Quantitative microstructural analysis suggests that GNP play a role in grain size and is responsible for the improved densification. Raman spectroscopy and scanning electron microscopy showed that GNP survived the harsh processing conditions of the selected HIP processing parameters. The uniform distribution of 1 wt.% GNP in the CS matrix, high densification and fine CS grain size help to improve the fracture toughness by ∼130%, hardness by ∼30% and brittleness index by ∼40% as compared to the CS matrix without GNP. The toughening mechanisms, such as crack bridging, pull-out, branching and deflection induced by GNP are observed and discussed. The GNP/CS composites exhibit good apatite-forming ability in the simulated body fluid (SBF). Our results indicate that the addition of GNP decreased pH value in SBF. Effect of addition of GNP on early adhesion and proliferation of human osteoblast cells (hFOB) was measured in vitro. The GNP/CS composites showed good biocompatibility and promoted cell viability and cell proliferation. The results indicated that the cell viability and proliferation are affected by time and concentration of GNP in the CS matrix.
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