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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: Multifidus muscle is one of the short and deep posterior Paraspinal muscles, which gives stability to the spine during various activities. Studies have shown that in people with neck pain, weakness and atrophy of neck muscles are major factors in the incidence of neck pain. Measurement of muscle's dimensions by ultrasonography provides an opportunity to be able to objectively assess muscle atrophy or hypertrophy. This study aimed to assess symmetry of cervical multifidus muscle size in females with chronic non-specific neck pain and healthy by ultrasonography apparatus.

Materials & Methods: Twenty five women with unilateral chronic nonspecific neck pain and 25 healthy women were participated in this study. All subjects were employed and more than 4 hours working with computers or paying office in a day. Imaging of the cervical multifidus muscles were done bilaterally in the level of the fourth vertebra. Anterior-Posterior Dimension(APD), Lateral Dimension(LD), Cross-Sectional Area (multiplied of two diameters(APD&LD)) and the Shape ratio (Lateral diameter divided by the Anterior-Posterior diameter(LD/APD)) of the muscle were measured and recorded. 

Results: Multifidus muscle size in patients group was smaller than the healthy group. In patients group, size of multifidus muscle in the painful side was smaller than the opposite side. Asymmetry of muscle size between the two sides, in the patient group was higher than the control group (P < 0.05). The ratio of smaller size to the larger size of the muscle, in the healthy group was higher than the ratio in the patient group (P < 0.05).

Conclusion: In patients group, asymmetry of the muscle size between two sides, also smaller size of the muscle in the painful side, showed that muscle atrophy has happened in the involved side.

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Abstract

Background and Aim: The Action Observation stimulates mirror neurons. It is the effective acquisition of skills, motor learning and memory formation and this feature can be used to treat injuries such as stroke. The aim of this study was to investigate the effect of action observation on the symmetry of weight distribution in lower limbs and stability indices in semi-dynamic stability.

Materials and Methods: This study was conducted in 91 healthy male and female non-athletes aged 20 to 45 years. Data were collected through questionnaires and clinical examinations. Subjects were randomly assigned to men and women with and without film observation. A 3-minute short film was preapared to stimulate mirror neurons in the standing position on the symmetry weight measurement system and Biodex platform system. In film observation group, before and after viewing the film, distribution of weigh bearing on the right and left sides, and dynamic stability indices in two stability levels of 5 and 8 were measured and calculated indices of total, anterior - posterior and medio- lateral indices were obtained. In without film observation group, measurements were performed at the similar time as a film observation group.

Results: Percentage weight distribution showed no significant difference between the two groups. The comparison of percentage changes between two groups showed that observation of the film improved significantly total index (p <0.002) and anterior – posterior index (p <0.018) in the stability level of 5. Analysis of the results in the separately men and women groups, showed the significant improvement of these parameters only in women group after film observation regardless of film observation, the percentage changes of stability indices showed no significant differences in men groups.

Conclusion: Action Observation (by activating the mirror neurons) can be effective methods to improve the balance standing of healthy people on the stable and unstable surfaces. Significant improvement stability indices in women after viewing the film, may suggest the greater sensitivity of women's mirror neurons related to men.

Keywords: Mirror Neurons, Action Observation, Symmetry of Weight Distribution, Dynamic Stability, Stability

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Background and Aim: Autism-Spectrum Disorders (ASD) are neural connectivity abnormalities at global and local of brain levels. A one-dimensional non-invasive technique that allows a highly accurate measurement of brain function and connectivity is Quantitative electroencephalography (QEEG). This is a systemic review that encompasses the key finding of QEEG application in subjects with ASD, in order to assess the relevance of this approach in characterizing brain function and clustering phenotypes.

Materials and Methods: QEEG studies evaluating both the spontaneous brain activity and brain signals under controlled experimental stimuli were examined. In despite of conflicting results, literature analysis suggests that QEEG features are sensitive to modification in neuronal regulation dysfunctions which characterizes autistic brain but features types are very important.

Results: Therefore QEEG may help in detecting regions of altered brain function and connectivity abnormalities, in linking behavior with brain activity, and subgrouping affected individuals within the wide heterogeneity of ASD. The use of advanced techniques for the increase of the specificity and of spatial localization could allow finding distinctive patterns of QEEG abnormalities in ASD subjects, paving the way for the development of tailored intervention strategies.

Conclusion: Autism is a disorder in which multiple aspects of behavior, emotion, language and cognition are disrupted, among which, autistic individuals appear to have a range of perceptual processing abnormalities, expressed especially entirely by a high level of sensitivity to auditory and tactile stimuli. It seems Autism Spectrum Disorder (ASD) is potentially caused by unbalanced portion of excitation/inhibition, in other words a disproportionate high level of excitation (or disproportionately weak inhibition) in neural circuits that mediate language and social behaviors. Holistic approaches could help us to have better detections

Keywords: Diagnosis autism-spectrum disorder, Quantitative electroencephalography, Coherence, asymmetry, Non-linear techniques