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Background and aim: Knee osteoarthritis is one of the most common musculoskeletal problems, can affect on patient's daily activity and produce dependency in their daily activity and functional disability The aim of present study is to compare static balance in patients with knee osteoarthritis and healthy subjects using force plate. 

Materials & Methods: Postural stability in knee OA patients and healthy subjects (each group 20 subjects) were measured by force plate. Two positions were selected double stance with closed or opened eyes. Range of fore/aft (Rfa) and Range of side ways (Rsw), were measured as static postural stability.

Results: Rsw increased significantly in the double stance position in patients group (P<0.05). Also in both groups, Rsw and Rfa in the double stance with closed eyes were more than of open eyes position (P<0.05).

Conclusion: Postural control deficits and increase of center of pressure's sway were identified in participants with knee osteoarthritis. Therefore, one of the most important goals of rehabilitation is to improve balance control in knee OA patients.

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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. 

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Background and aim: Spinal injury especially during occupational lifting is one of the most common neuromuscular disorders in the general population of the world. Asymmetric motions of trunk frequent bending and twisting, lifting and forceful activities contribute to spine disorders. Sport as a comprehensive activity might be able to cause less force to the spine and decrease spinal injuries. The purpose of present study was to determine the effect of lifting on motor control pattern during combined symmetric and asymmetric trunk motions on athlete and non-athlete subjects.
Materials and Methods: Seventeen non-athlete female subjects and seventeen athlete female subjects performed to lift four loads ( 5,7,9 ,12 kilogram ) at symmetric and asymmetric conditions. Under each condition temporal parameters of motor control were measured on flexor and extensor of trunk muscles.
Result: In two groups of athletes and non-athletes with increasing load , muscles begin their activity faster ( P<0.05 ). No significant change was found at asymmetric condition. Also, in athletes premotor time of muscles during lifting was less than non-athletes.
Conclusion: With increasing load, according to the feed forward control mechanism and awareness of subjects from amount of loads, muscles quickly prepared to contract for starting the movement. It seems that the response of movement on the neuromotor system of athletes is preprogrammed and automatic due to sport experience. Actually muscles have anticipation activity.

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Background and Aim: Cerebral palsy (CP) is the most common motor impairment in childhood and affects 2 in 1000 live births, in which postural and motor control involved. In hemiplegic type, two sides of the body have differences in postural tone that cause weight shift to the intact side. In these children postural disorders appear as postural stability disorder. The aim of this study is to assess the effect of lateral wedge insole on postural control in cerebral palsy children.
Materials and Methods:  Sixteen hemiplegic children attended in this program and stood in two conditions on the force plate with and without lateral wedge on the hard plate. Center of pressure displacement measured for medio-lateral and antro-posterio directions. Every test took 20 seconds. It was repeated 3 times.
Results: Range of sideways decreased significantly with use of 5º wedge. Also a shoe wedge of 5º provided symmetrical weight distribution.
Conclusion: The results represent that a 5º lateral wedge applied to the unaffected limb, can improve factors of postural control and gain the symmetry in hemiplegic children

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Background and Aim: Few studies have assessed the reliability of postural balance measures during dynamic balance performance that introduce additional challenging to postural control system. In addition sometimes in the static conditions some deficiencies of the postural control system may not be revealed obviously therefore the aim of this study was to assess the reliability of postural control parameters during functional performance on force plate in healthy subjects.
Materials and Methods:  Ten healthy male subjects (mean age: 25.4 years, weight: 68.2 kg height:176.9cm) participated  in this study. None of the subjects were involved in sport activities. Every subject performed three 15seconds trials of eyes open single leg stance on a force plate during dynamic balance task. Participants grasped object with hand at their waist level and release it at above shoulder level.  The reproducibility of the center of pressure (COP) deviations (average speed &length of path) was assessed. All participants were tested on 2 sessions with an inter-measurement interval of 7 days. COP data was collected for each trial. The intraclass correlation coefficient (ICC) was used as parameter of intra-session and inter-session (Test-Retest) reliability.
Results: The ICCs for intra-session reliability of average speed and length of COP path were  0.89 and 0.91  respectively. The ICCs for inter-session reliability were 0.95 and 0.96 respectively.
Conclusion: The study showed high and very high reliability for center of pressure measures during dynamic balance task. Therefore this dynamic performance can be used as a balance pattern in postural control assessment. These can be used as reliable parameters in dynamic postural control assessment due to high reliability of average speed and length of COP path

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Background and aim: The importance of cognitive resources was shown in dual task studies of postural control. However, there was no definite evidence on how verbal instructions influence the allocation of attention to postural control. Therefore, the objective of this study is to explore the effect of verbal instructions on postural performance.
Materials and Methods: this Cross-sectional study was performed in 20 young adults (23.95 ± 3.31). Parallel standing/ hard surface, parallel standing/ foam surface, tandem standing/ hard surface were used as postural tasks and the choice reaction time task were conducted as cognitive task. Dual- task performance was measured under three different instructions including to pay attention to cognitive task, to postural task, and equal attention to both tasks.
Results: Comparing the performance of postural tasks under three different instructions were conducted by One-way ANOVA and showed in parallel standing on hard surface (p=0.831), parallel standing on foam (p=0.433), tandem standing on hard surface (p=0.912) for path length of COP and instructions in parallel standing on hard surface (p=0.308), parallel standing on foam (p=0.414), tandem standing on hard surface (p=0.867) for mean velocity were not significant. Postural performance in single and dual task conditions was significant only in parallel standing/ foam surface (p=0.046).
Conclusion: various instructions could not influence the amount of attention allocated to automatic postural tasks.

 

 

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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. 

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Background and Aim: Forces which applied to ankle joint for control of stability can cause damage to joint if it does not have suitable control. Chronic ankle instability (CAI) is a current disability that can affect on activity daily living of the patients. The aim of this study is to evaluate forces which contribute to control of posture in difficult conditions.

Material and Methods: Postural control was measured by force plate in two groups of CAI and healthy subjects. Eight positions were selected , including of double stances with closed or opened eyes, and single stances with opened eyes (right/ left) with and without a cognitive task. Force changes in two direction medial/lateral and anterior/posterior were evaluated with fractal time series analysis.

Results: Fractal dimension of force in two groups, following dual task in all of conditions reduced significantly (P<0.05). There was not significant different between two groups in double stance with or without dual task. Single stance in patients indicated significant increase of fractal dimension in affected ankle joint (P<0.05) but comparison of two side in healthy subjects did not have difference. Also there was significant increase of fractal in affected ankle joint of patients in comparison with similar side of healthy subjects (P<0.05).

Conclusion: Patients with (CAI) have a problem in regulation of force for control of posture. This difficulty increased and clearly indicated by dual task condition, which can cause susceptible qualifications for recurrent injuries. Fractal dimension is a suitable factor for analysis of control of posture in difficult situations.

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Background and Aim: Knee osteoarthritis is one of the most common musculoskeletal problems that can affect activity daily living of patients. Many studies have indicated postural control deficits in these patients but the effect of dual tasking on postural control has not been examined yet. The aim of this study is to investigat the effect of cognitive task on postural control in the female patients with knee osteoarthritis.
Materials and Methods: Postural stability in knee OA patients and healthy subjects (20 subjects in each group ) in four positions was measured using the Force plate. Positions included double leg stance with closed or opened eyes with and without cognitive task. Area of COP and mean velocity (Vm) were measured for as static postural stability.
Results: Area under the curve increased in the double leg stance position in the patients significantly (P<0.05). While mean velocity decreased by performing a dual task (P<0.05). The response to dual-tasking was not significant between the 2 groups(P>0.05).
Conclusion: Postural control deficits and increased of center of pressure’s sway were identified in participants with Knee osteoarthritis. Also performance of a cognitive task resulted in decrease of postural sway, but the dual- tasking did not change the postural performance of knee OA patients compared to healthy subjects.

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Background and Aim: Accurate control of movement is one of the multiple components in skillful motor performance that can be impaired by disease. Trackingtests quantify the effects oftreatments designed toimprovecontrol of movement and they are considered as anideal protocol forimproving motor control. The purpose of the present study was to examine reliability of the control error during target tracking tasks in trunk region in sagittal transverse torque plane in healthy subjects.

Materials and Methods: Nine healthy subjects (4 females and 5 males) randomly performed target tracking tasks at levels of 0% to 80% Maximum Voluntary Exertions (MVE) and twelve different directions (0 ̊, 30 ̊, 60 ̊, …, 330 ̊) twice in upright standing posture. In this study, the tracking system included a moving target circle, which moved on a straight line in specific direction from 0 to 80% of individual MVE with speed of 6% MVE/S.The direction of isometric trunk exertion was presented to participants in the online visual feedback by a computer monitor positioned in front of them. Trunk controllability was determined by computing the control errors (Absolute Value Error from the Target [AVET], Error from the Target Path [ETP] and Error from the Target in the Target Path [ETTP]) during each performance. Relative reliability (Intra-class Correlation Coefficient [ICC]) of the control error in each direction was determined. Also absolute reliability (Standard Error of Measurement [SEM]) and Minimal Detected Change (MDC95) were computed.

Results:The results have shown that ICC for AVET, ETP and ETTP ranged from 0.81 to 0.99, 0.71 to 0.98 and 0.7 to 0.99, respectively. Also SEM for these variables ranged between 0.003- 0.013, 0.001- 0.009 and 0.003- 0.011, respectively and finally MDC95 ranged between 0.008 to 0.036 for AVET, 0.003 to 0.025 for ETP and 0.008 to 0.03 for ETTP.

Conclusion: The study showed high and very high reliability for control error measures during target tracking tasks in sagittal transverse torque plane in asymptomatic subjects. Therefore this performance may be used as a test in trunk controllability assessment.

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Abstract

 Background and Aim: Regard with the importance of balance in daily activities especially in sport activities and understanding the important factor affecting it, the purpose of this study was to compare the role of vision system on dynamic postural stability of young women with men elite athletes.

Materials and Methods: Twenty six young women and men elite swimmer were chosen from the available society. They were divided in two groups according to body mass index. Each subject performed postural stability tests for 6 trials with open and close eyes (3 trials with open and 3 trial with close eyes) that each trial was taken for 30 seconds and with 10 seconds rest between each of them. Balance index in anterior- posterior and medial- lateral directions were calculated and independent t test was used to compare between groups.

Result: Results show that men swimmer are more depended to vision than women swimmer in maintaining retrieval postural stability (p= 0.001), while most impairment in maintaining postural stability in both groups occur in lack of vision status in anterior- posterior direction (p= 0.001).

 Conclusion: The findings of this study can be used to design training programs to prepare athletes.

Key words: balance, vision, athlete, control

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Background and Aim: The target tracking tests is a known method to quantify the performance of the neuromuscular system. It has been used in several studies for evaluation of neuromuscular control strategies. The purpose of the present study was to examine the effect of direction and speed of isometric trunk exertion on the trunk controllability during the target tracking tests in sagittal versus axial rotation torque plane.

  

Materials and Methods: Twenty- two healthy subjects (13 female and 9 male) randomly performed target tracking tasks at levels of 0% to 80% Maximum Voluntary Exertions (MVE) and seven different directions (0 ̊ , 30 ̊ , 60 ̊ , …, 180 ̊ ) in upright standing posture. In this study, the tracking system included a moving target circle, which moved on a straight line in specific direction from 0 to 80% of individual MVE with speed of 5, 6 and 7% MVE/s . The d irection of isometric trunk exertion was presented to participants in the real time visual feedback by a computer monitor positioned in front of them. Trunk controllability was determined by computing the control errors (Absolute Value Error from the Target [AVET], Error from the Target Path [ETP] and Error from the Target in the Target Path [ETTP]) during each performance. Analysis of variance was used to test the effect of speed and direction of isometric trunk exertion on trunk controllability.

  

Results: The results have shown that the direction of isometric trunk exertion had significant effect on the AVET and ETTP (p= 0.000) while the effect of speed and interaction between direction and speed were not significant. The error decomposition in to two independent parts showed that the only direction of exertion on ETTP was significant (p= 0.000) and speed of exertion on any of them ( ETP and ETTP ) was not significant. On the other hand, Borg scale (a simple method of rating perceived exertion) significantly affected by direction (p= 0.000) and speed (p= 0.000) of exertion during the target tracking tests.

  

Conclusion: According to the findings of the current study, the effect of d irection of isometric trunk exertion on the controllability was significant. Trunk controllability was significantly decreased during rotational exertions which may impair trunk neuromuscular coordination, increasing the risk of developing low back pain.

  

Keywords: Target t racking t ests , T runk controllability , Speed and d irectio n of isometric trunk exertion

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Background and Aim: Postural control is the ability of maintaining of the body posture in space. Peripheral and central factors have important role in muscle fatigue. Repetitive muscle contraction leads to muscle fatigue. If strength is educed up to 30% of maximum contraction can be disturbed stance control of subjects. The objective of the present study was to compare the effect of lumbar muscle fatigue on postural control in athlete and non-athlete subjects.

  

Materials and Methods: Fifteen men as athlete subjects and other fifteen matched men as non- athlete subjects participated in this study. Trunk extensor muscle fatigue was produced by dynamometer. Stance postural sways were evaluated by force platform device in bipedal stance with open eye.

  

Results: In pre-fatigue state there is no significant difference between two groups. Fatigue had significantly effect on postural sways in both group after Lumbar muscle fatigue specially in non-athlete group (P ≥ 0.05) .

  

Conclusion: The postural control of athletes after muscle fatigue was better than non athlete subjects probably due to better proprioception in athlete subjects.

  

Keywords: Muscle fatigue, Postural control, Force plattform.

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Backgrouna and Aim : Children with cerebral palsy have often movement and postural disorders. The purpose of this study is to evaluate the effect of new neoprene dynamic orthosis on balance in children with cerebral palsy.

  

Materials and Methods : This study is quazi experimental. Five children with cerebral palsy (spastic diplegia) with mean age of 9/6± 3.78 years old participated in this study. The degree of knee extension was measured using electrogoniometer. Center of Pressure(COP) displacement in anterior/posterior and medial/lateral planes and functional balance were also measured using kistler forceplate (BA, Kistler- Switzerland 9286) and berg test in two occasions, before and after wearing neoprene orthosis in a period of six weeks. Wilcoxon test was used for comparing data before and after 6 weeks.

  

Results : There was statistically significant difference in right knee extension before and after wearing orthosis (p<0/05). The result of this study show no statistically significant in COP parameters. However, functional balance of children with CP shows significant improvement using neoprene orthosis.

  

Conclusion : New neoprene orthosis can be effective in knee biomechanical alignment as well as functional balance

  

Keywords : Cerebral palsy, Lycra dynamic orthosis, Postural control

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Background and Aim: Patellofemoral pain syndrome (PFPS) is the most common overuse injury occurring at the knee. Reduction of proprioception, pain, changes in muscle activity patterns are seen in PFPS. Therefore these patients may demonstrate less balance. Thus the main objective of this study was to determine the postural control in patients with patellofemoral syndrome and compare it with healthy subjects.

Materials and Methods: Ten subjects (age 31.1 ± 5.31, weight 59.6 ± 8.95, height 1.62 ± 0.05) presenting with PFPS were compared with 10 matched control subjects (age 27.2 ± 1.81, weight 60.6 ± 2.36, height 1.67 ± 0.01).

Pain was measured with VAS scale and patella position was assessed using the method first described by McConnell. Force Plate was used to measures COP paths in sagittal and frontal plane with open and close eyes.

Results: The data showed that COP paths were different between PFPS and healthy subjects with open eyes in sagittal and frontal plane (P< 0.05). Means of COP paths increase in patients with PFPS. No differences were detected between PFPS and healthy subjects with closed eyes in sagittal and frontal plane.

Conclusion: Body sways increase in patients with PFPS with open eyes due to pain, lateral tracking patella and reduction of proprioception in knee.

Keyword:  Postural control, Patellofemoral syndrome, Open & close eye

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Background and Aim: Different aspects of the motor control parameters of dominant and non-dominant legs are investigated but the effect of dominancy on motor control strategy is still unclear. The aim of the present study is to compare the pre- motor time, motor time and reaction time in dominant and non- dominant leg muscles of the non- professional healthy athletes in response to visual stimulus during forward jumping.

Methods and Materials: Eleven non- professional healthy athletes participated in this cross-sectional study determined by convenience non probability sampling. Surface electromyography were performed in the dominant and non-dominant leg muscles including  gastrosoleous , peroneus longus, peroneus brevis, and tibialis anterior in response to visual stimulus during forward jumping.

Results: There was no significant difference (P > 0.05) between the dominant and no-dominant legs with respect to the pre-motor time, motor time and reaction time of the gastrosoleus, peroneus longus, peroneus brevis and tibialis anterior.

Conclusion: Our findings suggest that limb dominancy is not an important parameter in the motor control studies.

Keywords: Motor control strategy, Visual stimulus, Forward jumping

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Background and Aim: ACL injury is one of the most common sport injuries which undergo reconstructive surgery. Electromyography or recording of muscles’ electrical activity is a suitable means to assess changes in motor control system output. The goal of this study is to compare the lower limb muscles EMG activity during drop landing in individuals after ACL reconstruction and healthy subjects.

Materials and Methods: Eleven men who had undergone ACL reconstruction 6 to 24 months ago (Age 29±6 years old) and 11 healthy men (Age 28±2 years old) participated in the study. Amount of electrical activity for tibialis anterior, vastus medialis, vastus lateralis, semitendinosus and biceps femoris muscles was recorded using surface electrodes during drop landing and calculated for two time intervals. The amount of activity was measured in -150 to +50 and +50 to +180 intervals in relation to the landing moment. Subjective IKDC questionnaire and cross-over hop functional test were used to determine the subjective and objective functional level.  Independent t test was used to determine between-group statistical differences.

Results: Feed forward activity of semitendinosus (P=.041) and biceps femoris (P=.008) muscles were significantly higher in ACLR group and feedback activity of vastus medialis (P=.03) muscles was significantly lower in ACLR group. Healthy individuals showed higher score on both the functional test and IKDC questionnaire. (P<.0005)

Conclusion: Individuals who had undergone reconstructive surgery of ACL showed different muscular activity compared to healthy subjects and closer to ACL deficient individuals 6 months after surgery and routine rehabilitation.

Keywords: Anterior cruciate ligament reconstruction, Electromyography, Neuromuscular control

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Background and Aim: The structure and function of the hamstring and quadriceps can contribute to the development and process of patellofemoral pain syndrome. As open and closed kinetic chain exercises have different effects on the knee joint, the aim of the current study was to investigate motor control of knee joint in both kinetic chains according to voluntary response index aspect.

 

Materials and Methods: 12 healthy knees and 12 injured knees (6 females in each group) were examined. Surface electromyography were performed in knee muscles including vastus medialis oblique, rectus femoris, vastus lateralis and biceps femoris while the subjects were doing flexion-extension of knee joint by isokinetic dynamometer system and one leg semi-squat movement. Then voluntary response index was calculated.

 

Results: There were no significant difference between the patients and healthy groups (p>0.05). In the patient group, correlation between similarity index and magnitude was seen.

 

Conclusion: Probably in the low intensity patellofemoral syndromes, voluntary response index could not differentiate between healthy and the patient groups. In the patients with patellofemoral syndrome group, correlation between similarity index and magnitude may represent co-contraction in their muscles.

 

Keywords: Patellofemoral pain syndrome, Motor control, Voluntary response index, Surface electromyography

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Background and Aim: This study was conducted dueto the limited results of past studies in relation to postural control in children with developmental coordination disorders and the importance of postural control with the ability to integrate the vestibular, visual and somatosensory inputs. In this study the postural control of the children with Developmental Coordination Disorder (DCD) and their normal peers was compared under the reduced or the conflicted sensory input conditions.

Materials and Methods: Twenty two children with Developmental Coordination Disorder (16 males, 6 females with mean age of 7 years old and 9 months, SD 1 year and 5 months) and 19 children with normal motor development (13 males, 6 females, with mean age of 6 years and 11 months, SD 1 year and 1 month) were evaluated. Standing balance, sensory organization and motor control strategy were evaluated using the sensory organization test (SOT).

Result: The results showed that the children with DCD had poorer function than the normal children in the composite equilibrium (p&le; 0.001), visual ratios (p=0.005) and vestibular ration (p=0.002). There were no meaningful differences between groups in their average somatosensory ratio. Additionally, children with Developmental Coordination Disorder had lower motor strategy scores than the normal children when they were forced to depend on vestibular cues alone (p < 0.05). The children with Developmental Coordination Disorder had deficits in standing balance control in conditions that included reduced or conflicting sensory signals. The visual and vestibular systems tended to be more involved in contributing to the balance deficits than the somatosensory system. Moreover, children with Developmental Coordination Disorder were tended to use hip strategy excessively when forced to rely primarily on vestibular signals to maintain postural stability.

Conclusion: In order to improve the postural control in the patients, the rehabilitation protocols should focus on the sensory-motor deficits.

Keywords: Postural control, Postural stability, Developmental Coordination Disorder

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Background and Aim: The concept of locus of control refers to the degree in which a person perceives daily occurrences to be a consequence of his or her own behavior. Some people accept responsibility of their own continued well-being and maintained improvement, but the others, particularly those who do not accept this responsibility, may be at risk of relapse. It recommends a kind of measurement in order to identify such persons so that further steps can be taken to inhibit the relapse before occurs. One of this measurement is Locus of Control of Behavior. The purpose of the present study is to translate the Locus of Control of Behavior (LCB) into Persian and investigation of validity and reliability of the scale.

Materials and Methods: In this research, 35 adults with stuttering and 35 non-stuttering were evaluated. After the translation of the test according to Protocol IQOLA and its equalization to Persian Language, content validity and face validity of it were determined by the opinions of experts. Then, for concurrent validity determination 35 adults with stuttering were examined by LCB and Rotters locus of control .In order to test reliability, test –retest and Cronbach,s alpha were used.

Results: Entirely relevant items had simple translation. The translation items had content and face validity. Correlation between the marks of LCB and Rotters locus of control was (p=0.000, r= %53). LCB has high Test-retest (p=0.000, ICC= %87) and internal reliability (p=0.000, &alpha;=%85).

Conclusion: The present research showed that the Persian version of the LCB is a reliable and valid tool for locus of control from the perspective of a person who is stutter.

Key Words: Stuttering, Reliability, Validity, Locus of Control of Behavior