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Search Results: 1 - 10 of 2667 matches for " Saeed Talebian Moghadam "
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Effect of Aging on Anticipatory Postural Adjustment and Reaction Times in the Pre-Crossing Phase of Obstacle Negotiation  [PDF]
Maryam Hayati, Saeed Talebian, Hassan Ashayeri, Behrouz Attarbashi Moghadam
Advances in Aging Research (AAR) , 2015, DOI: 10.4236/aar.2015.45017
Abstract: Background: Obstacle crossing is the common reason of falling in older adults. Anticipatory postural adjustments phase (APAP) and reaction time phase (RTP) are two important factors in falling prediction. According to previous studies, these parameters increase in older adults at high risk falling. This study explored the effect of aging on APAP and RTP in obstacle negotiation. Method: Nineteen older adults (mean age: 66.73 ± 3.38 years) and twelve young adults (mean age: 26.5 ± 4.37 years), participated in this study. Participants take part in gait initiation task from a starting position on a force platform under two conditions, unobstructed and obstructed (obstacle placed at 1 m from the initial position). RTP and APAP were measured and Timed “Up” & “Go” test (TUG) as a functional test, recorded for all participants. Results: There was no significant difference between healthy young and older adults in RTP and APAP in the unobstructed and obstructed conditions. TUG test was the most sensitive indicator of falling between two groups. Conclusion: Information processing capacity for motor planning and proper strategy selection in pre crossing phase of obstacle negotiation did not have significant difference in healthy old and young groups. Maybe in respect to select healthy older adults without any neurological disorders and cognitive impairments, low attention demand of well learned walking and obstacle negotiation tasks, lead to perform both postural task more automatically and without any significant difference detection.
Surface Electrical Stimulation for Treating Swallowing Disorders after Stroke: A Review of the Stimulation Intensity Levels and the Electrode Placements
Marziyeh Poorjavad,Saeed Talebian Moghadam,Noureddin Nakhostin Ansari,Mostafa Daemi
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/918057
Abstract: Neuromuscular electrical stimulation (NMES) for treating dysphagia is a relatively new therapeutic method. There is a paucity of evidence about the use of NMES in patients with dysphagia caused by stroke. The present review aimed to introduce and discuss studies that have evaluated the efficacy of this method amongst dysphagic patients following stroke with emphasis on the intensity of stimulation (sensory or motor level) and the method of electrode placement on the neck. The majority of the reviewed studies describe some positive effects of the NMES on the neck musculature in the swallowing performance of poststroke dysphagic patients, especially when the intensity of the stimulus is adjusted at the sensory level or when the motor electrical stimulation is applied on the infrahyoid muscles during swallowing. 1. Introduction Diverse paramedical treatments for swallowing disorders usually carried out by speech and language pathologists (SLPs) are introduced in the literature. It is expected that these treatment methods help to recover the swallowing functions, improve nutritional status, and prevent from developing the dysphagia consequences [1]. But, when these treatments are evaluated by scientific methods according to standards of evidence-based practice, lots of unanswered questions emerge [2] about the efficacy of them, dose-response effects, and certain populations who respond to each method well. So as mentioned by Speyer and colleagues, although some positive significant results have been published regarding the effects of different kinds of treatments in oropharyngeal dysphagia, further carefully controlled researches are needed [2]. Neuromuscular electrical stimulation (NMES) of the swallowing muscles is a relatively new therapeutic modality that is of great interest to the SLPs recently [3, 4]. Several studies were performed to evaluate the efficacy of this method. But, in spite of this increasing interest, there are important methodological issues about many of these existing publications that cause concerns regarding their therapeutic outcomes [3, 5]. A variety of protocols and techniques were used in these studies. Therefore reaching a firm conclusion about this approach and its effects will be hard. The only existing meta-analysis regarding the NMES for swallowing disorders [4] had reported just a small statistically significant improvement in clinical swallowing performance following the application of this technique. Moreover some reviews and systematic reviews [3, 5–7] emphasize the necessity for performing more carefully controlled
Changes of Flexion Relaxation Pattern Following Rhythmic Motion and Fatigue During Neck Flexion
Saeed Talebian,Gholam Reza Olyaie
Modern Rehabilitation , 2011,
Abstract: Background and aim: Cognition of fatigue effects on motion response can improve treatment approaches. Determination of mechanism (maximal voluntary contraction and repetition of movement) that cause change of central responses and neuromuscular transmission have specific emphasis in evaluation and treatment of patients. Following fatigue it is arguable which is more important, neural or osteo-ligamental components. Behavior of para spinal muscles due to their roles in control of posture and spinal alignments are more importance. Gesture and motion pattern of neck and lumbar column following fatigue is due to accession of disorder in neuromuscular junction (NMJ) or limitation in reflex response at this system. Reflex influence is not just for muscle fatigue but also it appeared in synergic muscles. It is clear that stimuli and inhibitory ways have important role in this process.Materials and Methods: Twenty normal subjects (10 female and 10 male) contributed in this study. Tests were including: 1- Training and warm up 2- Placement of recording electrodes on neck extensor muscles at second and forth spinal vertebra of dominant side. 3- Five motion of neck flexion and extension in sitting position at full range without external load. 4- Fatigue test, contain; A- Maximal isometric contraction at middle range about 3 minute, which were controlled by a dynamometer until onset of fatigue. B- Fifty dynamic and cyclic motions of neck flexion and extension in full range of it. 5- Perform five motions similar stage 3 immediately after muscle fatigue. Three middle cycles were chosen for evaluation. Degree of off activities in flexion, degree of onset of activities in extension, silent period and mean of muscles activities (RMS), before and after fatigue selected for analysis.Results: Comparison of two type of fatigue indicated that there are significant differences between them. Range of motion and eccentric activity were similar for two conditions. Isometric fatigue showed more effect than cyclic condition.Conclusion: In neck motions flexion relaxation occurred. Dynamic motion and isometric activities caused muscle fatigue and changed silent period. This period reduced and it means that onset of extensor muscle activities occurred very soon and moved to middle and outer ranges. In this manner, naught privilege mechanical of non contractile elements in neck region is cause of this reduction. On the other hand extensor muscles have more responsibility for control and preservation of posture. Comparison of two approaches indicated that isometric activity produce more
Neurophysiological changes following muscle fatigue in healthy subjects and patients with anterior knee pain syndrome
Saeed Khatamsaz,Malihe Moosavi,Saeed Talebian
Modern Rehabilitation , 2012,
Abstract: Background and Aim: Muscle fatigue is a factor that caused muscle injuries. Ability to perform movement without error and controllability has important role in reduction of injuries. Reproduce ability of motion is reduced after muscle fatigue. Evaluation of motor control can produce suitable conditions for assessment of these changes and help us treatment guide lines for prevention of injuries. The aim of this study was to evaluate motor control changes following onset of fatigue in patients with anterior knee pain as a physiological aspect. Materials and Methods: Fifteen voluntary female (10 healthy, 5 patients with bilateral syndromes) participated in this study. During dynamic fatigue test (open and closed chain movements), muscle activities were recorded from bilateral vastus medialis, vastus lateralis and rectus femoris (20 healthy and 10 patients quadriceps muscles) by surface electromyography (sEMG). Five dynamic cycles of motions were selected before and immediately after fatigue and then average of three middle cycles were compared for Symmetry Index (SI) as motor control assessment. Also Median Frequency (MDF) were computed as an indicator for onset of fatigue. Results: MDF reduced significantly in both groups. This reduction was markedly showed in patients group. Reduction of SI was significant after fatigue test. Comparison of SI between groups indicated that before fatigue there was significant difference but after fatigue test was not significant. Conclusion: Dynamic motions can produce muscle fatigue and reduction of MDF. High central control system used different synergies following pain and functional impairment. Synergy patterns change after dynamic motions fatigue and cause reduction of SI. This change is dependent to pain and functional impairment and has not a stable pattern. Key Words: Muscle fatigue, Motor control, Symmetry index, Surface electromyography, Anterior knee pain syndrome.
Employing Orphan Nodes to Avoid Energy Holes in Wireless Sensor Networks  [PDF]
Sepideh Zareei, Elham Babaee, Rosli Salleh, Saeed Moghadam
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2112
Abstract:

When energy consumption by wireless sensor nodes gets off balance, partitions in the network appear because several of the nodes stop functioning. The respective network’s lifetime also diminishes. This problem is commonly known as the “hot spot” or “energy hole” phenomenon. To resolve this issue, a Multi-Hop Decentralized Cluster-Based Routing (MDCR) protocol is proposed. This algorithm uses orphan nodes as intermediate nodes to form inter-cluster multi-hop routing and balance the energy consumption among sensor nodes. Simulation experiments have shown that MDCR is significantly better at prolonging network lifetime compared to the Adaptive Decentralized Re-Clustering Protocol.

 

Assessment of Motor Units Recruitment at the Knee Extensor Muscles
Marzieh Najafi,Sobhan Najafi,Saeed Talebian
Modern Rehabilitation , 2011,
Abstract: Background and Aim: Biomechanical conditions of limbs can affect on motor unit recruitment (MUR) markedly. Surface Electromyography (SEMG) is an approach for evaluation of muscle activities and onset time during different functions. The purpose of this study is to use SEMG for detection of central motor control in different functions of knee extensor muscles. Materials and Methods: Ten healthy subjects contributed in this study. They were done five repetitions of knee flexion/extension in open and close chain separately during recording of SEMG simultaneously. Integrated EMG (iEMG) of three middle repeated cycles were detected according to chain (open- close) and kind of contraction (concentric- eccentric).then the Average of three slope of iEMG compared to each other. Results: There were not significant differences in MUR of three extensor muscles for concentric and eccentric contractions in open chain but vastus medialis and lateralis muscles showed significant changes in close chain (P<0.05). Result showed that there were significant differences of MUR for two kind of muscle contractions between open and close chains (P<0.05 .Conclusion: Recruitment of motor units has not shown difference in open chain between concentric and eccentric contractions. This process indicates representative similarity of control pattern in two kind of contraction in open chain. Concentric contraction at close chain cycle has more MUR in comparison with eccentric contraction. It is equal to more interference of contractible compartment in concentric to eccentric contraction. This happens due to the nature of two kind of contraction particularly in close chain cycle. Comparison between two chains indicated that more motor units contribute in close chain (concentric and eccentric). It means that motor unit recruitment increased&due to effect of increase of load in close chain.
Design of Combined Sliding Mode Controller Back Stepping Using Genetic Algorithm
Atefeh Marvi Moghadam,Saeed Balochian
Journal of Engineering , 2013, DOI: 10.1155/2013/614803
Abstract: This research has tried to achieve a new robust controller with back stepping control and sliding mode control method. Also as we know, in all analytical controllers there are constant coefficients like the back stepping and sliding mode controllers, redesigning the Lyapunov and the feedback linearization, - and so forth. There are two major problems in their set: firstly, the adjustment is cumbersome and time-consuming. Secondly, assuming that these parameters can be adjusted to workability, a designer can never tell exactly what are the parameters chosen to be optimal. To resolve this problem, the numerical algorithm which is a genetic algorithm is used here and we have the optimal parameters of the proposed controller. That genetic algorithm (GA) has been used to solve difficult engineering problems that are complex and difficult to solve by conventional optimization methods, and at the end of this section, we apply a new robust controller on ball and beam system. Simulation results are expressed. 1. Introduction The ball and beam system is one of the most popular and important bench systems for studying control systems. Many classical and modern control methods have been used to stabilize the ball and beam system [1, 2]. However, some of the dynamic properties were neglected in most research work regarding the ball and beam mechanism in order to simplify the dynamic equation of the system [1–7]. Yu [1] and Oh et al. [3] modeled the ball and beam system and neglected the coupling effect of the dynamic equations for two DOFs. They controlled the system considering only one DOF to define the motion of the ball on the beam and suggested two separate control algorithms for motor and ball positions. The angular velocity of the beam during the slow motion of the ball has a small value. Therefore, this parameter was neglected in modeling the ball and beam system in [3, 4, 6]. Also, due to the nonlinearity and complexity of the governing dynamics, some researchers used non-model-based control strategies such as neural network [7], fuzzy logic [3], and PID [4] to control the ball position and beam angle. In [8] is designed a tracking control strategy for the ball and beam system using a pair of decoupled fuzzy sliding mode controllers (DFSMCs). Decoupling adaptive fuzzy sliding mode control with rule reduction for nonlinear system is presented in [9]. Also, in [5], modeling and control of ball and beam system using model-based and non-model-based control approaches is presented. Pareto design of decoupled sliding mode controllers for nonlinear systems (ball
The Effect of Soft Cervical Collar on Movement Response and Anticipatory Postural Adjustment of Postural Muscle of Neck Following Arm Flexion During Standing
M Nasirpour,S Talebian Moghadam,GR Olyaei,G Aminian
Modern Rehabilitation , 2012,
Abstract: Backgroung and aim: Neck pain is one of three common complains of neuromuscular system. There are three subsystem to maintain stability of spine: passive subsystem, active (muscles) subsystem and control subsystem. Detection of postural muscle response during postural perturbation like fast arm movement can be utilized to analyse of postural control. Wearing cervical collars is a way to prevent or cure cervical pain. The aim of the present study was to investigate the effect of soft cervical collar on movement response and duration of activity and recruitment pattern of cervical muscles. Materials and methods: Twenty healthy young women participated in this study. They flex right shoulder in response to sound stimulus with and without wearing soft cervical collar. Surface Electromyography (EMG) used to assess postural muscle activity in following muscles: Deltoid , Trapezius , Cervical Erector spinae and Sternocleidomastoid. The effect of soft cervical collar on reaction time, onset and duration of activity of cervical muscles was calculated.Results: Wearing soft cervical collar increased reaction time of arm flexion (P< 0.05) and decreased duration of activity of cervical extensor, trapezius and erector spinae (P< 0.05). During shoulder flexion with additional load, onset activity of trapezius muscle was significantly earlier than other neck muscles but cervical erector spinae and sternocleidomastoid exhibit coactivation pattern in response to perturbation .Conclusion: During fast arm movement that leads to postural perturbation, soft cervical collar alleviates the response and reduce activity of muscles. The strategy of motor control centers in response to perturbation in cervical spine is coactivation of flexor and extensor muscles to maintain stability.
Effects of wearing a lumbosacral support on velocity and torque of lumbar spine during three-dimensional trunk motion
Vahid Samadi,Saeed Talebian,Gholam Reza Olyaei,Mehdi Sadeghi
Koomesh , 2011,
Abstract: Introduction: The use of back support is one of the common methods aimed to prevent low back pain. The purpose of the present study was to investigate the effect of wearing a lumbosacral support on lumbar spine velocity and torque in six directions during combined trunk motion. Materials and Methods : In this interventional study, 30 young healthy men were selected simply from convenient samples. They were asked to stand in Isostation B200 system and perform three-dimensional trunk motion against a resistance of 50% of maximal voluntary contraction torque while wearing or not wearing a lumbosacral support. Under each condition of test, five successive motions of trunk were performed in downward direction (as flexion, right lateral flexion, and right rotation) and upward direction (as extension, left lateral flexion, and left rotation), and the variables of average velocity and average torque were recorded during motion. Results : With the use of a lumbosacral support, average velocity was significantly increased in flexion (P=0.015) and extension (P=0.005), but no significant changes were found in other directions (P>0/05). Back support decreased average torque of right rotation significantly (P=0.006), but did not significantly changed this variable in other directions (P>0/05). Conclusion : Wearing a lumbosacral support can increase velocity in sagittal plane. Decreased rotation torque of trunk, as a result of using a back support, may reduce the twisting forces on lumbar spine joints.
Cerebral Sinovenous Thrombosis (CSVT) in a Neonate with Different Manifestations
Saeed Shoar,Nasrin Shoar,Nima Rezaei,Ahmad Talebian
Acta Medica Iranica , 2012,
Abstract: Cerebral sinovenous thrombosis (CSVT) is increasingly diagnosed in neonates. Despite many studies which have addressed diagnosis and management of pediatric CSVT, diagnosis of CVSD in neonates is difficult. A female neonate born by natural vaginal delivery was diagnosed with CSVT after initiation of seizure. The seizure was stabilized and after performing diagnostic tests, the diagnosis of CSVT was made. This report describes diagnosis of this rare condition in a newborn baby in order to make awareness about this serious condition in neonates.
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