Displaying publications 1 - 20 of 248 in total

  1. Doewes RI, Elumalai G, Azmi SH
    J Popul Ther Clin Pharmacol, 2022;29(4):e116-e125.
    PMID: 36441049 DOI: 10.47750/jptcp.2022.989
    The force in the pencak silat jejag kick is called the moment of force or torque. The force moment is a measure of the force that can cause an object to rotate around the axis where the axis of rotation is located at the knee joint with the length of the calf as the length of the arm (the radius of the rotation axis). This research was conducted using laboratory biomechanical analysis. The research sample consisted of three male athletes of pencak silat. Previously, anthropometric measurements were carried out in the form of measuring calf length and calf muscle mass, then taking videos of athletes doing jejag kick movements in a static state with targets, which were then analyzed by kinovea. Research results showed that the technique of the jejag kick pencak silat produces a force called the moment of force or torque. Sample 1 produces a force moment of -12.00 Nm, sample 2 produces -5.53 Nm, and sample 3 produces -8.73 (negative sign means the direction of the pencak silat jejag kick is counterclockwise). The magnitude of the force moment is influenced by the angle of knee extension and the radius of the rotation axis. The amount of force moment affects the kick speed. In the speed of a movement, there is a tendency to keep moving, which is called the moment of inertia. The fasterthe movement, the greater the moment of inertia. The result is a force moment, influenced by the rotational kinetic energy that is owned and requires effort. Every effort is made to produce a force moment; it takes power to drive the effort. This means that the greater the angle of extension and the longer the calf, the greater the force moment, the faster the kick speed, and the greater the moment of inertia. This requires a large amount of rotational kinetic energy, effort, and power.
    Matched MeSH terms: Biomechanical Phenomena*
  2. Teo SH, Ng WM, Abd Rahim MR, Al-Fayyadh MZM, Ali MRM
    Indian J Orthop, 2020 Apr;54(2):168-173.
    PMID: 32257034 DOI: 10.1007/s43465-019-00024-2
    Introduction: This study aims to compare the biomechanical properties and ease of learning and tying of our novel knot (UM Knot) with other commonly used arthroscopic sliding knots.

    Materials and methods: The Duncan, HU, SMC, Pretzel, Nicky's and square knots were selected for comparisons with UM knot. All knots were prepared with size 2 HiFi® suture by a single experienced surgeon and tested with cyclic loading and load to failure tests. The ease of learning was assessed objectively by recording the time to learn the first correct knot and the total number of knots completed in 5 min by surgeons and trainees.

    Results: The UM knot average failure load is significantly superior to the HU knot (p 

    Matched MeSH terms: Biomechanical Phenomena
  3. El-Sayed AM, Hamzaid NA, Abu Osman NA
    ScientificWorldJournal, 2014;2014:297431.
    PMID: 25110727 DOI: 10.1155/2014/297431
    Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees' gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system's efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on the percentage of amputees' gait deviation from normal gait profile points. The results identified particular components that contributed closest to normal gait parameters. However, the conclusion is limitedly extendable due to the small number of studies. Thus, more clinical validation of the active prosthetic knee technology is needed to better understand the extent of contribution of each component to the most functional development.
    Matched MeSH terms: Biomechanical Phenomena
  4. Eshraghi A, Osman NA, Gholizadeh H, Ahmadian J, Rahmati B, Abas WA
    Sci Rep, 2013;3:2270.
    PMID: 23881340 DOI: 10.1038/srep02270
    Individuals with lower limb amputation need a secure suspension system for their prosthetic devices. A new coupling system was developed that is capable of suspending the prosthesis. The system's safety is ensured through an acoustic alarm system. This article explains how the system works and provides an in vivo evaluation of the device with regard to pistoning during walking. The system was designed to be used with silicone liners and is based on the requirements of prosthetic suspension systems. Mechanical testing was performed using a universal testing machine. The pistoning during walking was measured using a motion analysis system. The new coupling device produced significantly less pistoning compared to a common suspension system (pin/lock). The safety alarm system would buzz if the suspension was going to fail. The new coupling system could securely suspend the prostheses in transtibial amputees and produced less vertical movement than the pin/lock system.
    Matched MeSH terms: Biomechanical Phenomena
  5. Mohd Firdaus Abdul Razak, Mohd Saiful Aizat Mohd Shafie, Muhamad Sharafee Shamsudin, Muhamad Faris Che Aminudin
    The main objective of this study is to compare the execution times produced by fending off techniques of Seni Silat Cekak Malaysia (SSCM), Kaedah A for different movement trajectories. Three kind of movement trajectories for Kaedah A were carried out, which were Trajectory A (normal path), Trajectory B (curve path) and Trajectory C (starting by pulling the hand to the back and continue as Trajectory A). The experiments were conducted using a motion capture system. The movement position of the left hand during the execution of Kaedah A were recorded by a Kinect sensor, prior to storing and processing via Virtual Sensei (VS) Lite software. A total of four (4) experienced practitioners from SSCM were selected to perform Kaedah A techniques. The data acquired were further analyzed to determine their kinematic characteristics. The results showed that the execution of Kaedah A using Trajectory A produced the shortest time and highest velocity with averages of 0.071±0.007s and 6.438±0.863ms-1 respectively, compared to Trajectory B (0.087±0.011s, 5.230±0.578 ms-1) and Trajectory C (0.149±0.015s, 2.903±0.273ms-1). Therefore, Trajectory A is considered to be more efficient than Trajectory B and Trajectory C in terms of execution times and maximum velocity produced by Kaedah A.
    Matched MeSH terms: Biomechanical Phenomena
  6. Yi C, Jiang F, Yang C, Chen Z, Ding Z, Liu J
    Sensors (Basel), 2021 Mar 05;21(5).
    PMID: 33807746 DOI: 10.3390/s21051813
    Inertial measurement unit (IMU)-based joint angle estimation is an increasingly mature technique that has a broad range of applications in clinics, biomechanics and robotics. However, the deviations of different IMUs' reference frames, referring to IMUs' individual orientations estimating errors, is still a challenge for improving the angle estimation accuracy due to conceptual confusion, relatively simple metrics and the lack of systematical investigation. In this paper, we clarify the determination of reference frame unification, experimentally study the time-varying characteristics of reference frames' deviations and accordingly propose a novel method with a comprehensive metric to unify reference frames. To be specific, we firstly define the reference frame unification (RFU) and distinguish it with drift correction that has always been confused with the term RFU. Secondly, we design a mechanical gimbal-based experiment to study the deviations, where sensor-to-body alignment and rotation-caused differences of orientations are excluded. Thirdly, based on the findings of the experiment, we propose a novel method to utilize the consistency of the joint axis under the hinge-joint constraint, gravity acceleration and local magnetic field to comprehensively unify reference frames, which meets the nonlinear time-varying characteristics of the deviations. The results on ten human subjects reveal the feasibility of our proposed method and the improvement from previous methods. This work contributes to a relatively new perspective of considering and improving the accuracy of IMU-based joint angle estimation.
    Matched MeSH terms: Biomechanical Phenomena
  7. Ramlee MH, Seng GH, Ros Felip A, Abdul Kadir MR
    Injury, 2021 Aug;52(8):2131-2141.
    PMID: 33745700 DOI: 10.1016/j.injury.2021.03.017
    An external fixator is a promising medical device that could provide optimum stability and reduce the rate of complications in treating bone fracture during intervention period. It is noted that the biomechanics behaviour of device can be altered by introducing more features such as material suitability and additional components. Therefore, this study was conducted via finite element method to investigate the effects of additional hollow cylinder coated with external fixator screws in treating Type III pilon fracture. Finite element models which have been validated with experimental data were used to simulate stresses at the pin-bone interface and relative micromovement at interfragmentary fractures during swing (70 N load) and stance phases (350 N load). All bones and external fixators were assigned with isotropic material properties while the cartilages were simulated with hyper-elastic. For the hollow cylinder, polyethylene was assigned due to its properties which are equivalent to the bone. From the results, it is found that stresses at the pin-bone interface for the coated screws were reduced to 54% as compared to the conventional fixator. For the micromovement, there was no difference between both models, whereby the value was 0.03 mm. The results supported previously published literature, in which high stresses are unavoidable at the interface, fortunately, those stresses did not exceed the ultimate strength of bone, which is safe for treating patients. In conclusion, if patients are allowed to bear weight bearing, the external fixator with coated screws is a more favourable option to be fixed into the bone to avoid complications at the interface.
    Matched MeSH terms: Biomechanical Phenomena
  8. Abdul Wahab AH, Wui NB, Abdul Kadir MR, Ramlee MH
    Comput Biol Med, 2020 12;127:104062.
    PMID: 33096298 DOI: 10.1016/j.compbiomed.2020.104062
    External fixators have been widely used in treating open fractures and have produced excellent outcomes, as they could successfully heal bones. The stability of external fixators lies greatly in their construction. Factors that associated with the stability of the external fixators includes stress, displacement, and relative micromotion. Three-dimensional (3D) models of bone and external fixators were constructed by using 3D modelling software, namely Materialise and SolidWorks, respectively. Three different configurations of external fixators namely Model 1, Model 2, and Model 3 were analysed. Three load cases were simulated to assess the abovementioned factors at the bone, specifically at the fracture site and at the external fixator. Findings showed that the double-cross configuration (Model 3) was the most promising in axial, bending, and torsion load cases as compared to the other two configurations. The no-cross configuration (Model 1) had the highest risk of complication due to high stress, relative micromotion, and displacement in the bending and torsion load cases. On the other hand, the single-cross configuration (Model 2) had the highest risk of complication when applied with axial load. In conclusion, the double-cross locking construct (Model 3) showed the biggest potential to be a new option for medical surgeons in treating patients associated with bone fracture. This new double-cross locking construct showed superior biomechanical stability as compared to single-cross and no-cross configurations in the axial, bending, and torsion load cases.
    Matched MeSH terms: Biomechanical Phenomena
  9. Soleimani Amiri M, Ramli R
    Sensors (Basel), 2021 May 03;21(9).
    PMID: 34063574 DOI: 10.3390/s21093171
    It is necessary to control the movement of a complex multi-joint structure such as a robotic arm in order to reach a target position accurately in various applications. In this paper, a hybrid optimal Genetic-Swarm solution for the Inverse Kinematic (IK) solution of a robotic arm is presented. Each joint is controlled by Proportional-Integral-Derivative (PID) controller optimized with the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), called Genetic-Swarm Optimization (GSO). GSO solves the IK of each joint while the dynamic model is determined by the Lagrangian. The tuning of the PID is defined as an optimization problem and is solved by PSO for the simulated model in a virtual environment. A Graphical User Interface has been developed as a front-end application. Based on the combination of hybrid optimal GSO and PID control, it is ascertained that the system works efficiently. Finally, we compare the hybrid optimal GSO with conventional optimization methods by statistic analysis.
    Matched MeSH terms: Biomechanical Phenomena
  10. Yunus MNH, Jaafar MH, Mohamed ASA, Azraai NZ, Hossain MS
    PMID: 34444087 DOI: 10.3390/ijerph18168342
    Work-related musculoskeletal disorders (WMSDs) are among the most common disorders in any work sector and industry. Ergonomic risk assessment can reduce the risk of WMSDs. Motion capture that can provide accurate and real-time quantitative data has been widely used as a tool for ergonomic risk assessment. However, most ergonomic risk assessments that use motion capture still depend on the traditional ergonomic risk assessment method, focusing on qualitative data. Therefore, this article aims to provide a view on the ergonomic risk assessment and apply current motion capture technology to understand classical mechanics of physics that include velocity, acceleration, force, and momentum in ergonomic risk assessment. This review suggests that using motion capture technologies with kinetic and kinematic variables, such as velocity, acceleration, and force, can help avoid inconsistency and develop more reliable results in ergonomic risk assessment. Most studies related to the physical measurement conducted with motion capture prefer to use non-optical motion capture because it is a low-cost system and simple experimental setup. However, the present review reveals that optical motion capture can provide more accurate data.
    Matched MeSH terms: Biomechanical Phenomena
  11. Rosli Darmawan
    The study on the possibility of using DMU Kinematics module in CAE tools for dose exposure work planning was carried out. A case scenario was created using 3D CAD software and transferred to DMU Kinematics module in a CAE software. The work plan created using DMU Kinematics module was animated to simulate a real time scenario. Data on the phantom position against the radioactive source was collected by activating positioning sensors in the module. The data collected was used to calculate the estimated dose rate exposure for the phantom. The results can be used to plan the safest and optimum procedures in carrying out the radiation related task.
    Matched MeSH terms: Biomechanical Phenomena
  12. Mehdizadeh S, Glazier PS
    J Biomech, 2018 05 17;73:243-248.
    PMID: 29628131 DOI: 10.1016/j.jbiomech.2018.03.032
    The aims of this study were to demonstrate "order error" in the calculation of continuous relative phase (CRP) and to suggest two alternative methods-(i) constructing phase-plane portraits by plotting position over velocity; and (ii), the Hilbert transform-to rectify it. Order error is the change of CRP order between two degrees of freedom (e.g., body segments) when using the conventional method of constructing phase-plane portraits (i.e., velocity over position). Both sinusoidal and non-sinusoidal simulated signals as well as signals from human movement kinematics were used to investigate order error and the performance of the two alternative methods. Both methods have been shown to lead to correct results for simulated sinusoidal and non-sinusoidal signals. For human movement data, however, the Hilbert transform is superior for calculating CRP.
    Matched MeSH terms: Biomechanical Phenomena
  13. Ainul Mardhiyah Mohd Razib, Goh TL, Nur Amanina Mazlan, Muhammad Fahmi Abdul Ghani, Tuan Rusli Tuan Mohamed, Abdul Ghani Rafek, et al.
    Sains Malaysiana, 2018;47:1413-1421.
    The stability of the limestone cliff at Gunung Kandu, Gopeng, Perak, Malaysia was assessed based on the Slope Mass
    Rating (SMR) system on 53 cross sections of the Gunung Kandu hill slopes. The slopes of Gunung Kandu were identified
    as class I (very good) to IV (poor). The kinematic analysis showed that 12 out of 53 hill slopes of Gunung Kandu were
    identified as having potential wedge, planar and toppling failures. The assessment showed that the stability of the western
    flanks can be classified as stable to unstable with the probability of failure from 0.2 to 0.6. The stability of the eastern and
    southern flanks range from very stable to partially stable with the probability of failure from 0.0 to 0.4. While the stability
    of northern flanks are from very stable to stable with the probability of failure of 0.0 - 0.2. This systematic approach
    offers a practical method especially for large area of rock slope stability assessment and the results from probability of
    failure values will help engineers to design adequate mitigation measures.
    Matched MeSH terms: Biomechanical Phenomena
  14. Shokravi H, Shokravi H, Bakhary N, Heidarrezaei M, Rahimian Koloor SS, Petrů M
    Sensors (Basel), 2020 Jun 08;20(11).
    PMID: 32521806 DOI: 10.3390/s20113274
    Vehicle classification (VC) is an underlying approach in an intelligent transportation system and is widely used in various applications like the monitoring of traffic flow, automated parking systems, and security enforcement. The existing VC methods generally have a local nature and can classify the vehicles if the target vehicle passes through fixed sensors, passes through the short-range coverage monitoring area, or a hybrid of these methods. Using global positioning system (GPS) can provide reliable global information regarding kinematic characteristics; however, the methods lack information about the physical parameter of vehicles. Furthermore, in the available studies, smartphone or portable GPS apparatuses are used as the source of the extraction vehicle's kinematic characteristics, which are not dependable for the tracking and classification of vehicles in real time. To deal with the limitation of the available VC methods, potential global methods to identify physical and kinematic characteristics in real time states are investigated. Vehicular Ad Hoc Networks (VANETs) are networks of intelligent interconnected vehicles that can provide traffic parameters such as type, velocity, direction, and position of each vehicle in a real time manner. In this study, VANETs are introduced for VC and their capabilities, which can be used for the above purpose, are presented from the available literature. To the best of the authors' knowledge, this is the first study that introduces VANETs for VC purposes. Finally, a comparison is conducted that shows that VANETs outperform the conventional techniques.
    Matched MeSH terms: Biomechanical Phenomena
  15. Mehdizadeh S, Glazier PS
    Comput Methods Biomech Biomed Engin, 2021 Aug;24(10):1097-1103.
    PMID: 33426927 DOI: 10.1080/10255842.2020.1867852
    Whether higher variability in older adults' walking is an indication of increased instability has been challenged recently. We performed a computer simulation to investigate the effect of sensorimotor noise on the kinematic variability and stability in a biped walking model. Stochastic differential equations of the system with additive Gaussian white noise was constructed and solved. Sensorimotor noise mainly resulted in higher kinematic variability but its influence on gait stability is minimal. This implies that kinematic variability evident in walking gaits of older adults could be the result of internal sensorimotor noise and not an indication of instability.
    Matched MeSH terms: Biomechanical Phenomena
  16. Ahamed NU, Sundaraj K, Ahmad B, Rahman M, Ali MA, Islam MA
    Australas Phys Eng Sci Med, 2014 Mar;37(1):83-95.
    PMID: 24477560 DOI: 10.1007/s13246-014-0245-1
    Cricket bowling generates forces with torques on the upper limb muscles and makes the biceps brachii (BB) muscle vulnerable to overuse injury. The aim of this study was to investigate whether there are differences in the amplitude of the EMG signal of the BB muscle during fast and spin delivery, during the seven phases of both types of bowling and the kinesiological interpretation of the bowling arm for muscle contraction mechanisms during bowling. A group of 16 male amateur bowlers participated in this study, among them 8 fast bowlers (FB) and 8 spin bowlers (SB). The root mean square (EMGRMS), the average sEMG (EMGAVG), the maximum peak amplitude (EMGpeak), and the variability of the signal were calculated using the coefficient of variance (EMGCV) from the BB muscle of each bowler (FB and SB) during each bowling phase. The results demonstrate that, (i) the BB muscle is more active during FB than during SB, (ii) the point of ball release and follow-through generated higher signals than the other five movements during both bowling categories, (iii) the BB muscle variability is higher during SB compared with FB, (iv) four statistically significant differences (p<0.05) found between the bowling phases in fast bowling and three in spin bowling, and (v) several arm mechanics occurred for muscle contraction. There are possible clinical significances from the outcomes; like, recurring dynamic contractions on BB muscle can facilitate to clarify the maximum occurrence of shoulder pain as well as biceps tendonitis those are medically observed in professional cricket bowlers, and treatment methods with specific injury prevention programmes should focus on the different bowling phases with the maximum muscle effect. Finally, these considerations will be of particular importance in assessing different physical therapy on bowler's muscle which can improve the ball delivery performance and stability of cricket bowlers.
    Matched MeSH terms: Biomechanical Phenomena/physiology
  17. Glazier PS, Mehdizadeh S
    J Biomech, 2019 Sep 20;94:1-4.
    PMID: 31427095 DOI: 10.1016/j.jbiomech.2019.07.044
    The development of methods that can identify athlete-specific optimum sports techniques-arguably the holy grail of sports biomechanics-is one of the greatest challenges for researchers in the field. This 'perspectives article' critically examines, from a dynamical systems theoretical standpoint, the claim that athlete-specific optimum sports techniques can be identified through biomechanical optimisation modelling. To identify athlete-specific optimum sports techniques, dynamical systems theory suggests that a representative set of organismic constraints, along with their non-linear characteristics, needs to be identified and incorporated into the mathematical model of the athlete. However, whether the athlete will be able to adopt, and reliably reproduce, his/her predicted optimum technique will largely be dependent on his/her intrinsic dynamics. If the attractor valley corresponding to the existing technique is deep, or if the attractor valleys corresponding to the existing technique and the predicted optimum technique are in different topographical regions of the dynamic landscape, technical modifications may be challenging or impossible to reliably implement even after extended practice. The attractor layout defining the intrinsic dynamics of the athlete, therefore, needs to be determined to establish the likelihood of the predicted optimum technique being reliably attainable by the athlete. Given the limited set of organismic constraints typically used in mathematical models of athletes, combined with the methodological challenges associated with mapping the attractor layout of an athlete, it seems unlikely that athlete-specific optimum sports techniques will be identifiable through biomechanical optimisation modelling for the majority of sports skills in the near future.
    Matched MeSH terms: Biomechanical Phenomena*
  18. Talib I, Sundaraj K, Lam CK, Sundaraj S
    J Musculoskelet Neuronal Interact, 2018 12 01;18(4):446-462.
    PMID: 30511949
    This systematic review aims to categorically analyses the literature on the assessment of biceps brachii (BB) muscle activity through mechanomyography (MMG). The application of our search criteria to five different databases identified 319 studies. A critical review of the 48 finally selected records, revealed the diversity of protocols and parameters that are employed in MMG-based assessments of BB muscle activity. The observations were categorized into the following: muscle torque, fatigue, strength and physiology. The available information on the muscle contraction protocol, sensor(s), MMG signal parameters and obtained results were then tabulated based on these categories for further analysis. The review affirms that - 1) MMG is suitable for skeletal muscle activity assessment and can be employed potentially for further investigation of the BB muscle activity and condition (e.g., force, torque, fatigue, and contractile properties), 2) a majority of the records focused on static contractions of the BB, and the analysis of dynamic muscle contractions using MMG is thus a research gap, and 3) very few studies have focused on the analysis of BB muscle activity under externally stimulated contractions. Taken together, the findings of this review on BB activity assessment using MMG affirm the potential of MMG as an alternative tool.
    Matched MeSH terms: Biomechanical Phenomena/physiology
  19. Marconi G, Gopalai AA, Chauhan S
    Med Biol Eng Comput, 2023 May;61(5):1167-1182.
    PMID: 36689083 DOI: 10.1007/s11517-023-02778-2
    This simulation study aimed to explore the effects of mass and mass distribution of powered ankle-foot orthoses, on net joint moments and individual muscle forces throughout the lower limb. Using OpenSim inverse kinematics, dynamics, and static optimization tools, the gait cycles of ten subjects were analyzed. The biomechanical models of these subjects were appended with ideal powered ankle-foot orthoses of different masses and actuator positions, as to determine the effect that these design factors had on the subject's kinetics during normal walking. It was found that when the mass of the device was distributed more distally and posteriorly on the leg, both the net joint moments and overall lower limb muscle forces were more negatively impacted. However, individual muscle forces were found to have varying results which were attributed to the flow-on effect of the orthosis, the antagonistic pairing of muscles, and how the activity of individual muscles affect each other. It was found that mass and mass distribution of powered ankle-foot orthoses could be optimized as to more accurately mimic natural kinetics, reducing net joint moments and overall muscle forces of the lower limb, and must consider individual muscles as to reduce potentially detrimental muscle fatigue or muscular disuse. OpenSim modelling method to explore the effect of mass and mass distribution on muscle forces and joint moments, showing potential mass positioning and the effects of these positions, mass, and actuation on the muscle force integral.
    Matched MeSH terms: Biomechanical Phenomena/physiology
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