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Background and aim: Asymmetric motions of trunk, external forces and other occupational factors such as frequent bending and twisting, lifting and forceful movement contribute to low back disorders. However, the dynamic and three-Dimensional motions of trunk at varying exertion levels were not addressed in literature. Hence, the aim of this study was to investigate the movement pattern and motor output during resisted trunk three-dimensional motion. 

Materials and Methods: Thirty healthy male subjects randomly performed dynamic asymmetric trunk motion at four resistance levels (nominal resistance, 25%, 50%, and 75% maximal voluntary contraction (MVC) torque) while positioned in standing with the L5-S1 interspinous space aligned with the flexion / extension axis of isostation B200. Under each resistance condition, movement patterns (range of motion), motor output (maximum torque) of the trunk were measured.

Results: In general, with increasing resistance from nominal to 75% MVC torque, the maximum torque of trunk in different directions of motion (flexion, extension, right & left lateral flexion, right & left rotation) increased significantly (p= 0.000). With increasing resistance from nominal to 50%  MVC torque, the range of motion of the trunk decreased significant (p<0.0083), but no significant change was found in this variable between resistance conditions of 50% and 75% MVC torque (p>0.0083).

Conclusion: When the resistance level is increased , the created external forces  must be balanced by internal forces generated by trunk muscles. Because the muscles have short lever arms compared with the external forces, they must generate large amounts of forces, placing compressive and shear loads on the structures of the spine. Under these conditions, spine injuries may be enhanced.

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Background and aim: Belts and back supports are frequently used to prevent low back pain. Despite many studies, there are not sufficient evidence and conclusive consensus about the effects of these supports. The purpose of the present study was to determine the effect of lumbosacral supports on motor control pattern during combined trunk motion.

Materials and Methods: 30 healthy young men were selected for the study. Temporal parameters of motor control and activity level of three pairs of trunk muscles were measured during combined trunk motion against minimum resistance and resistance equal to 50% of maximal isometric strength, under with and without back support conditions.

Results: By application of a lumbosacral support, movement response time was significantly decreased under minimum resistance (P=0/004). Application of support decreased reaction time and motor time under two resistance conditions significantly (P<0/05). No significant changes were found in trunk muscle activity levels following wearing a back support (P>0/05).

 Conclusion: By application of a lumbosacral support, individual reaction time was decreased. Although back support did not change the trunk muscle activity level, but the erector spinae muscle efficiency was increased to initiate desired movement.

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  Background and Aim: Hearing impairment in critical period of speech and language development is caused defects in oral and written language. The aim of this study is to use a test for comparing the reading skills of elementary fifth grade hearing and moderately severe hearing loss students in public schools.
Materials and Methods: In this cross sectional study, 10 hearing impaired children selected from the total number of fifth grade moderately severe hearing loss students' community (public schools) based on the inclusion criteria and compared with 10 hearing children that were matched according to grade, as a control group. In order to gather the data, reading and writing tests for school students was used. Data analysis was done through SPSS-16.
Results: The findings indicated that hearing impaired children on auditory discrimination skills (P=0.001), word auditory memory (P=0.034) sentence auditory memory (P<0.001), phonological blending (P=0.034), phonological segmentation (P=0.012) and text reading comprehension (P=0.044) were significantly weaker than the control group, but they had similar function in other skills.
Conclusion: Children with hearing impairment have the same function in tasks based on visual processing to normal children, whereas, in tasks based on auditory and phonological processing are weaker than them. Keywords: Reading skills, Hearing loss children, Public schools

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Background and Aim: With regard to importance of the role of balance in performance of daily activity especially in exercise activity and necessary to identify the factors that influence the balance, the purpose of this study was to survey the effect of lower limb muscle fatigue on balance in elite young athletes.
Materials and Methods: For this purpose, 15 young elite swimmers with a mean age and body mass index 17±0.7 and 21.62±0.5 during the two test phase, were studied. All participants performed the postural Stability and limit of stability tests in six for each test (three repetitions before and three repetitions after fatigue protocol by Wingate test)on the balance Biodex system. Values obtained by the system of the total , anterior - posterior, medial - lateral, anterior, anterior - right, anterior- left, posterior, posterior - right and posterior left index, were analyzed using paired sample t-test(P0.05).
Results: Results showed that fatigue caused a significantly influence the anterior - posterior, medial - lateral, posterior, left and posterior –left index.
Conclusion: With considering the specificity of training principle, the results can be helpful in the design of exercises involving the lower limb muscles in the specific direction. Keyword: Balance, Limit of stability, Fatigue, Athlete.

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Background and Aim: Stuttering is a multifaceted disorder that affects motor control, language performance and communication attitude. It seems that investigating the relationship between overt (stuttering severity) and cover (communication attitude) features of stuttering is necessary. The aim of this study is to investigate the relationship between stuttering severity and the communication attitude of adults who stutter.

Materials and Methods: Fifty-six adults who stutter participated in this study. The SSI-3 (Stuttering Severity Instrument-3) in the 200 words read text and communication attitude by Overall Assessment of the Speaker's Experience of Stuttering (OASES-A) were used. Spearman's correlation coefficient and Non-parametric Mann-Whitney test were used to determine relationship between severity of stuttering, communication attitude, age and history of treatment.

Results: This study showed that there was not significant correlation between the severity of stuttering assessment and communication attitude (P >0.14). As well as, age with communication attitude (P&ge; 0.050) and history of treatment with the stuttering severity (P <0.001) were correlated. The relationship between stuttering severity with age (P >0.13) and communication attitude with history of treatment (P >0.7) were not correlated.

Conclusion: There was no relationship between the severity of stuttering and communication attitude. Since, in people who have had a history of treatment, severity of stuttering was reduced but communication attitude did not reduce, therefore, communication attitude should be considered in treatment.

Keywords: Stuttering, Stuttering severity inventory, Communication attitude, Overall assessment of the Speaker's Experience of Stuttering.

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Background and Aim: Proverb comprehension can be used to assess cognitive function. Since tests of proverb comprehension impressed by language and culture, designing proverb comprehension test in Persian is necessary in order to evaluate cognitive and executive function. The purpose of the present study was to design a proverb comprehension test and to determine its validity and reliability.

Material and Methods: The present, Proverb Comprehension Test includes two subscales of out context and in context. The statistical population of the study were students of elementary and high schools in 1393-1394. The sample included 234 student with age range 10 to 18 years old that selected by Convenience Sampling scheme. Two halves method and Cronbach's alpha test were used in order to evaluate internal consistency. Discriminative validity was achieved from comparing average scores of age groups. For investigation of concurrent validity, Pearson test was used between results of proverb comprehension test and verbal fluency test.

Results: Subscales of out context  Proverb Comprehension Test with verbal fluency test had positive significant relationship. Cronbach's alpha coefficient of subscales of out context, in context and the total test was respectively 0.76, 0.72 and 0.88 and the reliability coefficient of two halves method was 0.82. Comparing between groups indicated the discriminative validity of the test.

Conclusion: Proverb Comprehension Test is a valid and reliable test for measuring executive and verbal functions.

Keywords: Proverb Comprehension, Reliability, Verbal fluency, Validity