Introduction & Objective: It is known that postural control performance in upright standing position could be affected by abnormal posture alignment. Despite the fact that kyphosis is one of the most common spine abnormality, the effect of thoracic curve abnormality at sagittal plane on postural stability has received little attention to date. Therefore, the purpose of our study was to investigate the dynamic and static postural control among individuals with kyphosis in comparison with a control matched group.Materials & Methods: Nineteen males with increased normal thoracic kyphosis (> 40 degrees) were randomly selected as kyphotic group. Eighteen controls matched for age, weight and height were selected to participate in the study. We measured the amount of kyphosis using flexible ruler as a noninvasive and reliable method. Dynamic and static postural stability were assessed using the biodex stability system and the balance error scoring system respectively. ANOVA with repeated measures followed by Tukey HSD test and independent t-test were employed for statistical analyses (p<0.05).Results: For dynamic postural assessment, the means of all stability indices were significantly higher in the kyphotic individuals than controls in the eyes-closed condition. With the platform in the most unstable position, kyphotic group were detected to have significantly poorer balance performance than controls in both eyes-open and eyes-closed conditions. For static balance evaluation, no difference was noted between both groups in stability performance during double and tandem stances. During the single-limb stance trials, the kyphotic group had poorer performance than controls while standing on the firm surface and foam surface (firm surface: p=0.044; foam surface: p=0.000).Conclusion: The findings suggest that postural control especially dynamic postural stability may be altered in individuals with increased thoracic kyphosis.

Purpose: Postural control and balance take place through the central nervous system based on the system inputs involved in balance (visual, vestibular and sensory-motor). The aim of this study was to compare the postural control strategy in hearing elite with deaf elite wrestlers. Methods: This study was causal-comparative research, and samples were selected from elite hearing (10 subjects) and deaf (10 subjects) wrestlers present in the national’ s team. A computer dynamic Posturography device was used to measure the variables of the research including trunk sway and changes the center of gravity in the horizontal (X) and vertical (Y) axis using sensory organization test (SOT). To check the normality of the data, the Shaipro-wilk test was used and independent t-test was used for comparison of variables between groups at a significant level (p≤ 0. 05). Results: findings show that of the six positions related to the postural control, only variable of stability in the fourth condition was significantly different between hearing and deaf elite wrestlers (p≤ 0/05) in proprioception manipulation while visual and vestibular sensory signals were available between the groups difference. However, for the variables of the center of gravity in the horizontal axis (X) and vertical (Y) no significant differences were noted in any situations related to postural control between hearing and deaf elite wrestlers (p≥ 0. 05). Conclusion: According to the results of this study, it can be stated that a defect in one sense can be largely offset by other sensory inputs and other systems involved in postural control. In the fourth condition, while the visual and vestibular sensory signals are available and proprioception is manipulated, a significant difference is observed between the groups. So that it can be concluded deaf elite wrestlers are more dependent on the proprioception sense of hearing and deaf elite wrestlers.

Background and Aim: Reaching is one of the common daily life tasks. Most of daily life activities, such as reaching, are performed simultaneously by cognitive tasks, and thus result in decline in performance of the main tasks. The aim of the present study was to investigate the effect of constant (simple reaction time) and random variable (choice reaction time) trainings on anticipatory postural adjustment under dual task conditions. Materials and Methods: A total of 16 right handed young girls with an average age of (27. 18 3. 18) participated in the current pre-test, post-test randomized group design research. To evaluate magnitude of anticipatory postural adjustment, center of pressure displacement and center of pressure mean velocity were measured using force plate before reaching movement initiation under dual task conditions. Data was analyzed using Matlab and SPSSS softwares. Results: The results of independent t-test of pre-test and post-test scores showed that, in constant training, mean velocity of center of pressure was greater than that of random variable training. Also, 2×2 combine variance analysis in the center of pressure displacement did not show significant differences between the two groups Conclusion: According to the results, after constant training, anticipatory postural adjustment is improved under dual task conditions. This type of training leads to improvement of anticipatory postural adjustment after internal perturbation. Findings of the present study support Task-specific practice hypothesis evidence.

Introduction: Postural control is the body's innate capacity to maintain the center of gravity in the support limits. About the effects of spinal curvature on postural stability (balance), there are conflicting results and often have been considered change a special curvature only. The purpose of this study was to study postural control in individuals with sway back abnormalities. Methods: To conduct the present study, 35 subjects with sway back posture with the average of age 20.65±1.52 years, Weight 67.39±12.31 kg and height 171.93±6.84 cm and 35 normal people with the average of age 20.6±1.23 years, Weight 67.07±11.31 kg and height 171.81±7.77 cm were selected. Side view photography and calculate the sway angle was used to select subjects with sway back posture (>10). Other tools used in this study were as follows: photography and craniovertebral angle calculating for measuring the forward head displacement, dual inclinometer for measurement of kyphosis and lordosis. COP parameters were also measured by foot pressure distribution software. Pearson correlation coefficient and independent t-test in the significant level of P≤0.05 was used to analyze the collected data.Findings: No significant differences were observed between natural subject and subjects with sway back on the forward head angle (p=0.02), thoracic kyphosis (p=0.023), lumbar lordosis (p=0.017) and sway angle (p=0.001). There was significant difference between COP variables of the normal and sway back subjects (p=0.02). A significant relationship was observed between anterior - posterior COP displacement and forward head angle (r=0.2), thoracic kyphosis (r=0.29), lumbar lordosis (r=0.41) and lordosis, kyphosis ratio (r=0.53) (p≤0.05). Conclusion: As a result, it appears that the spinal abnormalities in the subjects with sway back posture can cause poor postural control.

Background and Aims: Postural control of the kinetic variable of motion plays an essential role in maintaining stability in daily activities. Dual tasks for studying balance or postural control are accompanied by cognitive tasks. The aim of the present study was to investigate the effect of listening task complexity and offline learning on postural control. Methods: Twenty-eight employees with an age range of 30-40 years from Alzahra University of Tehran (PBUH) were selected by available sampling and based on inclusion criteria and divided into three groups with different training distributions of 2 minutes, 15 minutes, and 24 hours with three levels of difficulty (easy, medium, and difficult). Each group performed three blocks of six attempts with each attempt time of 35 seconds, the interval between attempts of 20 seconds, and the time interval between blocks depending on the division of the group: 2 minutes, 15 minutes, and 24 hours with three difficulty levels. Findings were analyzed using a combined factor analysis of variance with repeated measures of three groups (mass, 15 minutes, and 24 hours) and three task levels (easy, moderate, and difficult) and the Bonferroni post hoc test. Results: Findings showed that the main effect of homework difficulty level and practice distribution was significant (P=0. 001) and in the retention stage, there was a significant difference between the mean frequency power in the anterior-posterior direction in the low difficulty listening group and the high difficulty listening group. In the listening task, the interactive effect of task difficulty level in the distribution of practice was not significant. In the memorization stage, regarding the COP components (average frequency power in the anterior-posterior direction), the training group (24 hours), and in the listening task with an easy complexity level, the best condition was posture control, and in the training group (2 minutes) and in the listening task with difficult complexity level, the weakest condition was control posture. In the listening task with a high level of difficulty, the 24 hour training group had better average COP components than the mass training group and the 15 minute training group. Conclusion: It seems that distance training over mass training along with the parameters of strengthening motor memory increases cognitive effort and motivation. According to Hacken, Kelso, and Bondes hypothesis (progress-regression), educators should include homework in teaching instruction and from simple to difficult in the curriculum.

Postural control and dynamic balance are essential in activities of daily living and for optimal performance in sport activity. The purpose of this study was to determine if excessive and normal knee Q angle influence measure of dynamic balance in female athletes. Twenty females athlete with right dominant side participated in this study. 10 subjects with excessive knee Q angle (Q>18), (age= 21.20±1.4 years, height= 163.5±4.5 cm, mass= 61±8.02 kg, Q angle= 19.85±1.2 degree) and 10 subjects with normal knee Q angle (13<Q<18), (age= 22.10±1.1 years, height= 165.5±6.02 cm, mass= 59.9±10.1kg, Q angle= 15.35±1.4 degree) volunteered. The subject’s demography, medical and athletic backgrounds, exercise programs and their injury reputation were collected by special forms. The subjects reported no history of fracture in lower extremity or history of neurological or vestibular impairments. The rest of the information was measured through quantitative measuring and examinations so that measuring of Q angle by standard drawing method and universal goniometry. The star excursion balance test was used to measure dynamic balance, which was reported as the reach distance (cm) in each of the 8 directions tested. The average of 3 trials of each measure was calculated and normalized to the subject’s leg length. The mean of reach distance in 8 directions in females with abnormal Q angle (Q>18) were less than females with normal Q angle. We found significant differences in anteromedial, poster lateral and anterior directions between two groups. Our results suggest that postural stability is affected by knee alignment under dynamic conditions.

Background and Aims: Improvement of motion skills in children is facilitated by improved posture control. However, there is no comprehensive study on how to organize posture control sensing systems in children. Therefore, the present study was conducted to provide a comprehensive review on organizing sensory systems visual, proprioception, and vestibular in children’ s posture control. Materials and Methods: A comprehensive review was performed on the organization of sensory systems in postural control of children by searching the following English databases: Science Direct, PubMed, Web of Science, EBSCO, Springer, COCHRANCE REVIEW, Pedro, EMBASE, CINAHL, and Google Scholar, using the following keywords: visual system, proprioception system, somatosensory, vestibular system, computerized dynamic posturography, postural control, postural stability, children, child, postural balance, quiet stance, postural sway, stabilography, body sway, sensory organization, human development, and child development. In addition, Persian databases, such as MAGIRAN, IRANDOC, IranMedex, MedLib, Sid, and Google Scholar were searched for the following keywords: balance in children, postural control in children, postural control, balance, visual system, vestibular system, proprioception system, somatosensory, and sensory systems, from among papers published from 1985 to January 2020. Moreover, unable to find articles online, manual search and full review of resources of the articles were carried out to find the respective articles. Inclusion criteria included: study on the reweighting of sensory system, given the target population (children), study on healthy children, and use of computer devices that accurately measure the reweighting of sensory systems. Results: A total number of 16 studies were chosen based on our measures and objectives. In five studies, it was concluded that proprioception is organized much faster than visual system. However, three studies reported that visual system in children was organized faster than proprioception, similar to that in adults. It was agreed that vestibular system developed later compared with the other two systems to adult form. Conclusion: In conclusion, the growth of postural control occurs by age non-linearly, and there are changes in some ages. It can be inferred that children are dependent on the visual system at first, but as time goes, by walking and standing time, they become more dependent on the proprioception system than on the visual system. Also, it seems that the organization of the proprioception system occurs sooner than the visual system. It can also be reported that the progression of the visual system does not occur linearly and is critical in some age groups. In addition, the vestibular system matures compared with than other systems.